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Featured researches published by Mark Bonnen.


Translational Medicine | 2016

Vascular Aging: Implications for Cardiovascular Disease and Therapy

Yohannes T. Ghebre; Eduard Yakubov; Wing Tak Wong; Prasanna Krishnamurthy; Nazish Sayed; Andrew G. Sikora; Mark Bonnen

The incidence and prevalence of cardiovascular disease is highest among the elderly, in part, due to deleterious effects of advancing age on the heart and blood vessels. Aging, a known cardiovascular risk factor, is progressively associated with structural and functional changes to the vasculature including hemodynamic disturbance due to increased oxidative stress, premature cellular senescence and impairments in synthesis and/or secretion of endothelium-derived vasoactive molecules. These molecular and physiological changes lead to vessel wall stiffening and thickening, as well as other vascular complications that culminate to loss of vascular tone regulation and endothelial function. Intriguingly, the vessel wall, a biochemically active structure composed of collagen, connective tissue, smooth muscle and endothelial cells, is adversely affected by processes involved in premature or normal aging. Notably, the inner most layer of the vessel wall, the endothelium, becomes senescent and dysfunctional with advancing age. As a result, its ability to release vasoactive molecules such as acetylcholine (ACh), prostacyclin (PGI2), endothelium-derived hyperpolarizing factor (EDHF), and nitric oxide (NO) is reduced and the cellular response to these molecules is also impaired. By contrast, the vascular endothelium increases its generation and release of reactive oxygen (ROS) and nitrogen (RNS) species, vasoconstrictors such as endothelin (ET) and angiotensin (AT), and endogenous inhibitors of NO synthases (NOSs) to block NO. This skews the balance of the endothelium in favor of the release of highly tissue reactive and harmful molecules that promote DNA damage, telomere erosion, senescence, as well as stiffened and hardened vessel wall that is prone to the development of hypertension, diabetes, atherosclerosis and other cardiovascular risk factors. This Review discusses the impact of advancing age on cardiovascular health, and highlights the cellular and molecular mechanisms that underlie age-associated vascular changes. In addition, the role of pharmacological interventions in preventing or delaying age-related cardiovascular disease is discussed.


International Journal of Gynecological Cancer | 2015

Treatment Compliance and Outcomes for Women With Locoregionally Advanced Cervical Cancer Treated in a Safety Net Health System.

Gillian L. Hsieh; Sarah Linesch; Ahmar Sajjad; Andrew Macdonald; Mark Bonnen; Matthew L. Anderson; Michelle S. Ludwig

Objective This study aims to assess treatment compliance among women undergoing definitive chemoradiation with weekly cisplatin for cervical cancer within a safety net health system and to quantify the impact of chemotherapy compliance on outcomes. Materials and Methods All women who were treated for International Federation of Gynecology and Obstetrics stage IB2 to stage IVA cervical cancer between April 2008 and May 2014 were identified. Treatment delays were attributed to toxicity, comorbid conditions, or system issues, or categorized as patient-initiated. Disease-free survival and overall survival of women who received fewer than 6 versus 6 or more doses of weekly cisplatin 40 mg/m2 were compared using Kaplan-Meier analyses. Results One hundred nineteen women (mean [SD] age, 48.5 [11.8] years) were identified. Most women (n = 112; 94.1%) completed definitive radiotherapy, requiring a mean (SD) of 56.5 (20.1) days. Sixty-four women (57.1%) completed definitive radiotherapy in 56 days or less. Only 44 women (36.4%) received 6 or more cycles of cisplatin. Of 122 delayed cycles, reasons for delay were as follows: grade 2 or higher toxicity (n = 70; 57.4%), medical comorbidity (n = 12; 9.8%), system issues (n = 9; 7.4%), and patient-initiated (n = 14; 11.5%). Multiple issues complicated treatment for 3 doses (2.5%). Reasons for delay were not documented in 14 doses (11.5%). Among patients who received 6 or more cycles, disease-free survival improved by 17.4 months (mean [SD], 61.1 [3.7] vs 43.7 [4.3] months, P = 0.002) and overall survival improved by 8.6 months (mean [SD], 68.7 [2.3] vs 60.1 [3.7] months, P = 0.011). Conclusions Higher rates of toxicity and psychosocial barriers to chemotherapy compliance adversely impact survival among women who seek care in low-resource settings. In our population, administration of all 6 cycles of cisplatin was necessary for optimal survival benefit. Future efforts to improve cervical cancer outcomes should address preventable reasons for treatment delays among underinsured or uninsured individuals.


Frontiers in Pharmacology | 2017

Therapeutic Efficacy of Esomeprazole in Cotton Smoke-Induced Lung Injury Model

Christina Nelson; Jameisha Lee; Kang Ko; Andrew G. Sikora; Mark Bonnen; Perenlei Enkhbaatar; Yohannes T. Ghebre

Proton pump inhibitors (PPIs) are well-known antacid drugs developed to treat gastric disorders. Emerging studies demonstrate that PPIs possess biological activities that extend beyond inhibition of H+/K+ ATPase (proton pumps) expressed in parietal cells of the stomach. Some of the extra-gastric activities of PPIs include modulation of epithelial, endothelial, and immune cell functions. Recently, we reported that PPIs suppress the expression of several proinflammatory and profibrotic molecules, as well as enhance antioxidant mechanisms in order to favorably regulate lung inflammation and fibrosis in an animal model of bleomycin-induced lung injury. In addition, several retrospective clinical studies report that the use of PPIs is associated with beneficial outcomes in chronic lung diseases including idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD). Based on these preclinical and clinical observations, we hypothesized that PPIs ameliorate smoke-induced lung injury. Accordingly, we evaluated the pharmacological efficacy of the PPI esomeprazole in a mouse model of cotton smoke-induced lung injury. The animals were exposed to cotton smoke for 3-weeks in the presence or absence of esomeprazole treatment. We found that therapeutic administration of esomeprazole significantly inhibited the progression of fibrosis throughout the lungs of the animals in this group compared to controls. In addition, esomeprazole also reduced circulating markers of inflammation and fibrosis. Overall, our work extends the emerging anti-inflammatory and antifibrotic potential of PPIs and their role in modulation of chronic lung diseases.


Frontiers in Psychology | 2018

Dyadic Coping In Patients Undergoing Radiotherapy for Head and Neck Cancer and Their Spouses

Hoda Badr; Krista Herbert; Mark Bonnen; Joshua Asper; Timothy Wagner

Background: Head and neck cancer (HNC) adversely affects the psychological (i.e., depression, anxiety) and marital adjustment of patients and their spouses. Dyadic coping refers to how couples cope with stress. It includes positive actions like sharing practical or emotional concerns (i.e., problem- and emotion-focused stress communication; PFSC, EFSC), and engaging in problem- or emotion-focused actions to support each other (problem- and emotion-focused dyadic coping; PFDC, EFDC). It also includes negative actions like avoidance (negative dyadic coping; NEGDC). In this secondary analysis of a randomized pilot trial of a couple-based intervention called SHARE (Spouses coping with the Head And neck Radiation Experience), we first examined associations between patients’ and spouses’ dyadic coping (and satisfaction with dyadic coping; SATDC) and their own/each other’s psychological and marital adjustment. Next, we examined the effects of SHARE relative to usual medical care (UMC) on patients’ and spouses’ dyadic coping. Finally, we examined whether changes in dyadic coping were associated with changes in patients’ and spouses’ psychological and marital adjustment. Methods and Measures: Thirty HNC patients (80% men) and their spouses (N = 60) completed baseline surveys prior to initiating radiotherapy (RT) and were randomized to SHARE or UMC. One month after RT, they completed follow-up surveys. Results: Baseline multilevel Actor-Partner Interdependence Models revealed significant actor effects of PFSC (effect size r = −0.32) and PFDC (r = −0.29) on depression. For marital adjustment, significant actor effects were found for PFSC, PFDC, EFDC, and SATDC (p < 0.05, r = 0.23 to 0.38). Actor (r = −0.35) and partner effects (r = −0.27) for NEGDC were also significant. Moderate to large effect sizes were found in favor of SHARE on PFSC (Cohen’s d = 1.14), PFDC (d = 0.64), NEGDC (d = −0.68), and SATDC (d = 1.03). Improvements in PFDC were associated with reductions in depression and anxiety (p < 0.05); and, improvements in SATDC were associated with improvements in anxiety and marital adjustment (p < 0.05). Conclusion: The SHARE intervention improved positive and decreased negative dyadic coping for patients and spouses. Increases in positive dyadic coping were also associated with improvements in psychological and marital adjustment. Although findings are preliminary, more research on ways to integrate dyadic coping into oncology supportive care interventions appears warranted.


Expert Review of Anticancer Therapy | 2018

Anticancer therapy and lung injury: molecular mechanisms

Li Li; Henry Mok; Pavan M. Jhaveri; Mark Bonnen; Andrew G. Sikora; N. Tony Eissa; Ritsuko U Komaki; Yohannes T. Ghebre

ABSTRACT Introduction: Chemotherapy and radiation therapy are two mainstream strategies applied in the treatment of cancer that is not operable. Patients with hematological or solid tumor malignancies substantially benefit from chemotherapeutic drugs and/or ionizing radiation delivered to the site of malignancy. However, considerable adverse effects, including lung inflammation and fibrosis, are associated with the use of these treatment modalities. Areas covered: As we move toward the era of precision health, we are compelled to understand the molecular basis of chemoradiation-induced pathological lung remodeling and to develop effective treatment strategies that mitigate the development of chronic lung disease (i.e. fibrosis) in cancer patients. The review discusses chemotherapeutic agents that are reported to induce or associate with acute and/or chronic lung injury. Expert commentary: There is a need to molecularly understand how chemotherapeutic drugs induce or associate with respiratory toxicities and whether such characteristics are inherently related to their antitumor effect or are collateral. Once such mechanisms have been identified and/or fully characterized, they may be able to guide disease-management decisions including effective intervention strategies for the adverse effects. In the meantime, radiation oncologists should be judicious on the dose of radiation delivered to the lungs, the volume of lung irradiated, and concurrent use of chemotherapeutic drugs.


Journal of Radiation Oncology | 2018

Pre-treatment peer-review: enhancing value through increased efficiency and effectiveness of radiation oncology peer review

Ngoc Pham; Joshua Asper; Mark Bonnen; Henry Mok; Timothy Wagner; Michelle S. Ludwig; Larry Steven Carpenter; Pavan M. Jhaveri


International Journal of Gynecological Cancer | 2018

Stereotactic Body Radiation Therapy, Intensity-Modulated Radiation Therapy, and Brachytherapy Boost Modalities in Invasive Cervical Cancer: A Study of the National Cancer Data Base

Barrett OʼDonnell; Jay C. Shiao; Todd A. Pezzi; Nabila Waheed; Shelly Sharma; Mark Bonnen; Michelle S. Ludwig


Brachytherapy | 2018

A Single Institution Experience of Image-Guided High-Dose Rate Interstitial Brachytherapy in the Definitive Setting for Locally Advanced Cervical Cancer

Alexander Hanania; Alison Yoder; Pamela Myers; Zhiqian Henry Yu; Ahmet Bulut; Salman Eraj; Alfredo Echeverria; Mark Bonnen; Michelle S. Ludwig


American Journal of Case Reports | 2018

Silent Neoplastic Cardiac Invasion in Small Cell Lung Cancer: A Case Report and Review of the Literature

Ngoc Pham; Mark Bonnen; Yohannes T. Ghebre


Journal of Radiation Oncology | 2017

Effectiveness of intensity-modulated radiation therapy with simultaneous integrated boost in cervical cancer patients with PET positive lymph nodes

John W Shumway; Alfredo Echeverria; Umang Patel; Joshua Asper; Mark Bonnen; Michelle S. Ludwig

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Joshua Asper

Baylor College of Medicine

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Andrew G. Sikora

Baylor College of Medicine

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Ngoc Pham

Baylor College of Medicine

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Pavan M. Jhaveri

Baylor College of Medicine

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B.P. O'Donnell

University of Texas Health Science Center at Houston

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H.J. Manley

Southern Methodist University

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Henry Mok

Baylor College of Medicine

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