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236 citation(s) found for "O'Byrne, J".

First quantification of alpha‐Gal epitope in current glutaraldehyde‐fixed heart valve bioprosthesis (by Naso et al.)
Byrne, Guerard W. , McGregor, Christopher G.A.

Xenotransplantation | November 5, 2013 | Volume: 21 | Issue: 1 | Pages: 11-12

10.1111/xen.12072 | PMID 24188452 Get It

New Onset Diabetes Mellitus in Living Donor versus Deceased Donor Liver Transplant Recipients: Analysis of the UNOS/OPTN Database
Yadav, Anitha, Chang, Yu‐Hui , Aqel, Bashar , Byrne, Thomas , Chakkera, Harini A. , Douglas, David D., Rakela, Jorge , Vargas, Hugo E. , Carey, Elizabeth J. , Yadav, Anitha D, Aqel, Bashar A. , Mulligan, David C. , Vargas, Hugo E , Chakkera, Harini A , Chang, Yu-Hui

Journal of Transplantation | September 24, 2013 | Volume: 2013 | Issue: No issue available | Pages: 1-7

10.1155/2013/269096 | PMID 24205434 Get It

New onset diabetes after transplantation (NODAT) occurs less frequently in living donor liver transplant (LDLT) recipients than in deceased donor liver transplant (DDLT) recipients. The aim of this study was to compare the incidence and predictive factors for NODAT in LDLT versus DDLT recipients. The Organ Procurement and Transplant Network/United Network for Organ Sharing database was reviewed from 2004 to 2010, and 902 LDLT and 19,582 DDLT nondiabetic recipients were included. The overall incidence of NODAT was 12.2% at 1 year after liver transplantation. At 1, 3, and 5 years after transplant, the incidence of NODAT in LDLT recipients was 7.4, 2.1, and 2.6%, respectively, compared to 12.5, 3.4, and 1.9%, respectively, in DDLT recipients. LDLT recipients have a lower risk of NODAT compared to DDLT recipients (hazard ratio = 0.63 (0.52–0.75),P<0.001). Predictors for NODAT in LDLT recipients were hepatitis C (HCV) and treated acute cellular rejection (ACR). Risk factors in DDLT recipients were recipient male gender, recipient age, body mass index, donor age, donor diabetes, HCV, and treated ACR. LDLT recipients have a lower incidence and fewer risk factors for NODAT compared to DDLT recipients. Early identification of risk factors will assist timely clinical interventions to prevent NODAT complications.
A Clinical Deterioration Prediction Tool for Internal Medicine Patients
Kirkland, Lisa L., Malinchoc, Michael, O’Byrne, Megan M., Benson, Joanne T., Kashiwagi, Deanne T. , Burton, M. Caroline , Varkey, Prathibha, Morgenthaler, Timothy I. , Morgenthaler, Timothy I

American Journal of Medical Quality | July 21, 2012 | Volume: 28 | Issue: 2 | Pages: 135-142

10.1177/1062860612450459 | PMID 22822159 Get It

Immunological Effects of [alpha]Gal-positive and [alpha]Gal Knockout Biological Heart Valves
McGregor, Christopher G.A. , Kogelberg, Heide, Byrne, Guerard W.

QScience Proceedings | July 5, 2012 | Volume: 2012 | Issue: 4 | Pages: No page available

10.5339/qproc.2012.heartvalve.4.61 Get It

Abstract As immune responses likely contribute to degeneration of bioprosthetic heart valves (BHVs), this nonhuman primate study compares the anti-Gal antibody response to BHVs from wild type (WT) pigs (current BHVs) and those from α-galactosyltransferase knockout (GTKO) pigs. Stented glutaraldehyde fixed BHVs from WT (n=4) and GTKO (n=3) pigs were commercially manufactured and implanted in the mitral position in nonhuman primates using standard surgical techniques. Recipients were treated with Lovenox (1mg/kg BID) for 5 weeks reducing to 1mg/kg daily for one week and then discontinued. Recipients were sensitized to the αGal antigen by immunization to match IgG levels found in humans. Serum antibody responses were monitored by ELISA. WT BHVs were explanted at 3 hours, 1 year, 2 years and the fourth is currently ongoing at 3 years. One GTKO BHV was explanted at 218 days. The remaining two GTKO BHVs are currently ongoing at 3 years. After immunization, circulating anti-Gal IgG levels were comparable in both groups at the time of implantation and were equal or greater than human levels. Anti-Gal antibody levels decreased in both WT and GTKO recipients after implantation. WT recipients, however, retained elevated levels (greater than 20% preimplant values) of anti-Gal IgG for at least the first year post implant. Conversely anti-Gal IgG levels in all GTKO recipients fell within one month and remained at less than 20% preimplant values. Analysis of the area under the curve showed a significant increase of anti-Gal IgG in the WT BHV group compared to GTKO BHV recipients (p<0.01). In this nonhuman primate model, the persistently and significantly (p<0.01) elevated levels of anti-Gal IgG antibody observed in WT but not GTKO BHV recipients, indicate continuing immune stimulation to the αGal antigen. Current commercially available BHVs are similarly known to contain αGal antigen. Anti-Gal antibody has been shown to increase calcification of processed pericardium in the rat implant model. These data support the hypothesis that preformed and induced anti-Gal antibody in BHV recipients may initiate an early immune response, which promotes subsequent calcification. BHVs made from GTKO pigs would eliminate this major xenoreactive antigen and provide a prosthesis with reduced immunogenicity. Such BHVs made from GTKO pigs may have greater durability and be potentially used in younger patients with more active immune systems.
Pretransplant Fasting Glucose Predicts New-Onset Diabetes after Liver Transplantation
Carey, Elizabeth J. , Aqel, Bashar , Byrne, Thomas , Douglas, David D., Rakela, Jorge , Vargas, Hugo E. , Moss, Adyr A. , Reddy, Kunam S. , Chakkera, Harini A. , Aqel, Bashar A. , Mulligan, David C. , Vargas, Hugo E , Chakkera, Harini A

Journal of Transplantation | January 29, 2012 | Volume: 2012 | Issue: No issue available | Pages: 1-6

10.1155/2012/614781 | PMID 22461975 Get It

New-onset diabetes after transplantation (NODAT) is common after liver transplant and associated with poorer outcomes. The aim of this study was to identify risk factors for NODAT in liver transplant recipients off corticosteroids. In 225 adult nondiabetic liver transplant recipients, the mean age was 51.7 years, the majority were men (71%), and half had HCV (49%). The mean calculated MELD score at transplantation was 18.7, and 19% underwent living-donor transplant (LDLT). One year after transplantation, 17% developed NODAT, and an additional 16% had impaired fasting glucose. The incidence of NODAT in patients with HCV was 26%. In multivariate analysis, HCV, pretransplant FPG, and LDLT were significant. Each 10 mg/dL increase in pretransplant FPG was associated with a twofold increase in future development of NODAT. The incidence of NODAT after liver transplant in patients off corticosteroids is 17%. Risk factors for developing NODAT include HCV and pretransplant FPG; LDLT is protective.
CD28 Expressed on Malignant Plasma Cells Induces a Prosurvival and Immunosuppressive Microenvironment
Carlson, Louise, Koorella, Chandana, Rozanski, Cheryl H, Byrne, Gerald E., Bergsagel, P. Leif , Shaughnessy, John P., Boise, Lawrence , Chanan‐Khan, Asher , Lee, Kelvin P. , Nair, Jayakumar R. , Rozanski, Cheryl H, Bergsagel, P. Leif , Boise, Lawrence H

The Journal of Immunology | June 30, 2011 | Volume: 187 | Issue: 3 | Pages: 1243-1253

10.4049/jimmunol.1100016 | PMID 21715687 Get It

Abstract Interactions between the malignant plasma cells of multiple myeloma and stromal cells within the bone marrow microenvironment are essential for myeloma cell survival, mirroring the same dependence of normal bone marrow-resident long-lived plasma cells on specific marrow niches. These interactions directly transduce prosurvival signals to the myeloma cells and also induce niche production of supportive soluble factors. However, despite their central importance, the specific molecular and cellular components involved remain poorly characterized. We now report that the prototypic T cell costimulatory receptor CD28 is overexpressed on myeloma cells during disease progression and in the poor-prognosis subgroups and plays a previously unrecognized role as a two-way molecular bridge to support myeloid stromal cells in the microenvironment. Engagement by CD28 to its ligand CD80/CD86 on stromal dendritic cell directly transduces a prosurvival signal to myeloma cell, protecting it against chemotherapy and growth factor withdrawal-induced death. Simultaneously, CD28-mediated ligation of CD80/CD86 induces the stromal dendritic cell to produce the prosurvival cytokine IL-6 (involving novel cross-talk with the Notch pathway) and the immunosuppressive enzyme IDO. These findings identify CD28 and CD80/CD86 as important molecular components of the interaction between myeloma cells and the bone marrow microenvironment, point to similar interaction for normal plasma cells, and suggest novel therapeutic strategies to target malignant and pathogenic (e.g., in allergy and autoimmunity) plasma cells.
Cost-Effectiveness of Contralateral Prophylactic Mastectomy Versus Routine Surveillance in Patients With Unilateral Breast Cancer
Zendejas, Benjamin , Moriarty, James P. , O’Byrne, Jamie, Farley, David R. , Degnim, Amy C. , Boughey, Judy C.

Journal of Clinical Oncology | June 21, 2011 | Volume: 29 | Issue: 22 | Pages: 2993-3000

10.1200/jco.2011.35.6956 | PMID 21690472 Get It

Purpose Contralateral prophylactic mastectomy (CPM) rates in women with unilateral breast cancer are increasing despite controversy regarding survival advantage. Current scrutiny of the medical costs led us to evaluate the cost-effectiveness of CPM versus routine surveillance as an alternative contralateral breast cancer (CBC) risk management strategy. Methods Using a Markov model, we simulated patients with breast cancer from mastectomy to death. Model parameters were gathered from published literature or national databases. Base-case analysis focused on patients with average-risk breast cancer, 45 years of age at treatment. Outcomes were valued in quality-adjusted life-years (QALYs). Patients' age, risk level of breast cancer, and quality of life (QOL) were varied to assess their impact on results. Results Mean costs of treatment for women age 45 years are comparable: $36,594 for the CPM and $35,182 for surveillance. CPM provides 21.22 mean QALYs compared with 20.93 for surveillance, resulting in an incremental cost-effectiveness ratio (ICER) of $4,869/QALY gained for CPM. To prevent one CBC, six CPMs would be needed. CPM is no longer cost-effective for patients older than 70 years (ICER $62,750/QALY). For BRCA-positive patients, CPM is clearly cost-effective, providing more QALYs while being less costly. In non-BRCA patients, cost-effectiveness of CPM is highly dependent on assumptions regarding QOL for CPM versus surveillance strategy. Conclusion CPM is cost-effective compared with surveillance for patients with breast cancer who are younger than 70 years. Results are sensitive to BRCA-positive status and assumptions of QOL differences between CPM and surveillance patients. This highlights the importance of tailoring treatment for individual patients.
Risk Factors for Splenic Injury During Colectomy: A Matched Case–Control Study
Wang, Jeffrey K., Holubar, Stefan D. , Wolff, Bruce G., Follestad, Barbara, O’Byrne, Megan M., Qin, Rui , Holubar, Stefan D

World Journal of Surgery | February 15, 2011 | Volume: 35 | Issue: 5 | Pages: 1123-1129

10.1007/s00268-011-0994-x | PMID 21327837 Get It

AbstractPurposeWe assessed risk factors for splenic injury during colectomy and associated outcomes for a 15‐year period at a single institution.MethodsAll adult general surgery patients who sustained a splenic injury during colectomy at our institution from 1992 to 2007 were retrospectively identified and matched 1:1 to controls without splenic injury. Putative risk factors were assessed using paired univariate analysis and conditional logistic regression. Differences in short‐ and long‐term mortality were assessed using the log‐rank test. Results are reported as a proportion, median, or odds ratio [OR (95% confidence intervals)].ResultsA total of 118 patients were included: 59 patients with splenic injury and 59 control patients. Statistically significant risk factors for splenic injury during colectomy found on univariate analysis included: splenic flexure mobilization, OR 21.00 (2.82–156.12); Charlson comorbidity index ≥5, OR 3.17 (1.26–7.93); ASA class ≥3, OR 5.33 (1.55–18.3); and nonelective surgery, OR 5.00 (1.1–22.82). On multivariate analysis, only splenic flexure mobilization was independently associated with increased risk of splenic injury (OR 18.4 (2.1–161); p = 0.0085). Splenic injured patients trended toward decrease survival both at 30 days (98 vs. 88%; p = 0.06) and at 5 years (58 vs. 55%), with a hazard ratio of 1.6 (1.0, 2.6; p = 0.05).ConclusionsSplenic flexure mobilization is the primary risk factor for splenic injury during colectomy, independent of other factors, such as higher ASA class, Charlson score, and nonelective surgery. Splenic injury during colectomy has an increased risk of death in both the short‐ and long‐term.
Abstract B25: Mammographic density and risk of breast cancer by body weight: A combined analysis of four case-control studies
Koga, Karin, Nagata, Chisato , Vachon, Celine M. , Yaffe, Martin J. , Conroy, Shannon M. , Woolcott, Christy , Pagano, Ian , Byrne, Celia , Ursin, Giske , Vachon, Celine M. , Maskarinec, Gertraud

Cancer Prevention Research | January 10, 2011 | Volume: 3 | Issue: 12_Supplement | Pages: B25-B25

10.1158/1940-6207.prev-10-b25 Get It

Abstract Background. Breast density assessed from mammography is a strong predictor of breast cancer risk, but the strength of the association may vary with adiposity. To examine effect modification by adiposity, we combined data from four case-control studies on breast density that represented an ethnically diverse population with a wide variation in level of adiposity as measured by body mass index (BMI, kg/m2). Methods. We combined data from four case-control studies representing different locations: California, Hawaii and Minnesota in the United States, and Gifu in Japan. All studies included incident breast cancer cases diagnosed between 1994 and 2002 and matched controls representing the underlying case population. One mammographic image per subject was selected, specifically the mammogram at diagnosis for the studies from California, Minnesota, and Japan and the closest prediagnostic mammogram for Hawaii. Percent density was measured by one reader, who was blinded to case status, using a computer-assisted method. Self-reported anthropometric measures were used to classify women as normal, overweight, and obese according to ethnic-specific BMI cut points (&lt;23, 23-27.4, and ≥27.5 for Asian women and &lt;25, 25-29.9, and ≥30 for other ethnic groups). Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) and to evaluate interactions using the likelihood ratio while adjusting for potential confounders, including age and ethnicity. Heterogeneity across studies was marginally significant as assessed by examining density-by-study interaction (P = 0.09) and, therefore, we also adjusted for study-site. Results. The study included 1,699 cases and 2,422 controls of diverse ethnicity: 45% Caucasian, 40% Asian, 9% African-American, and 7% Other. Of these women, we classified 34% as overweight and19% as obese. Age-adjusted mean percent density was significantly greater for cases than for controls: 31.7% versus 28.9%, respectively (P &lt; 0.001). BMI was inversely associated with breast density; the estimated age-adjusted mean percent density was 36.5%, 26.8%, and 19.3% for normal, overweight, and obese, respectively (Ptrend &lt; 0.001). The overall OR for a 10% higher percent density was 1.15 (95% CI: 1.05, 1.18) with higher estimates in overweight (OR: 1.19, 95% CI: 1.09, 1.29) and obese (OR: 1.25, 95% CI: 1.11, 1.41) than normal BMI (OR: 1.11, 95% CI: 1.05, 1.18). The effect modification by BMI was statistically significant (Pinteraction = 0.01). Conclusions. Our findings confirm that the elevated risk of breast cancer associated with breast density differs by level of adiposity, with a higher risk for overweight and obese than normal BMI. Further research is needed to understand the underlying biological reasons for these noted differences in association by adiposity. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B25.
A Qualitative and Quantitative Comparison of Two Rubella Virus-Specific IgG Antibody Immunoassays
Greenwood, Nicholas P., Ovsyannikova, Inna G. , Vierkant, Robert A. , O’Byrne, Megan M., Poland, Gregory A. , Vierkant, Robert A

Viral Immunology | August 16, 2010 | Volume: 23 | Issue: 4 | Pages: 353-357

10.1089/vim.2010.0026 | PMID 20712479 Get It