Carlos E. Marroquin
Duke University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Carlos E. Marroquin.
Annals of Surgery | 2006
Rebecca A. Schroeder; Carlos E. Marroquin; Barbara Phillips Bute; Shukri F. Khuri; William G. Henderson; Paul C. Kuo
Objective:To determine if use of Model for End-Stage Liver Disease (MELD) scores to elective resections accurately predicts short-term morbidity or mortality. Summary Background Data:MELD scores have been validated in the setting of end-stage liver disease for patients awaiting transplantation or undergoing transvenous intrahepatic portosystemic shunt procedures. Its use in predicting outcomes after elective hepatic resection has not been evaluated. Methods:Records of 587 patients who underwent elective hepatic resection and were included in the National Surgical Quality Improvement Program Database were reviewed. MELD score, CTP score, Charlson Index of Comorbidity, American Society of Anesthesiology classification, and age were evaluated for their ability to predict short-term morbidity and mortality. Morbidity was defined as the development of one or more of the following complications: pulmonary edema or embolism, myocardial infarction, stroke, renal failure or insufficiency, pneumonia, deep venous thrombosis, bleeding, deep wound infection, reoperation, or hyperbilirubinemia. The analysis was repeated with patients divided according to their procedure and their primary diagnosis. Parametric or nonparametric analyses were performed as appropriate. Also, a new index was developed by dividing the patients into a development and a validation cohort, to predict morbidity and mortality in patients undergoing elective hepatic resection. ROC curves were also constructed for each of the primary indices. Results:CTP and ASA scores were superior in predicting outcome. Also, patients undergoing resection of primary malignancies had a higher rate of mortality but no difference in morbidity. Conclusion:MELD scores should not be used to predict outcomes in the setting of elective hepatic resection.
Journal of Biological Chemistry | 2006
Philip Y. Wai; Zhiyong Mi; Chengjiang Gao; Hongtao Guo; Carlos E. Marroquin; Paul C. Kuo
Osteopontin (OPN) is a sialic acid-rich phosphoprotein secreted by a wide variety of cancers. We have shown previously that OPN is necessary for mediating hepatic metastasis in CT26 colorectal cancer cells. Although a variety of stimuli can induce OPN, the molecular mechanisms that regulate OPN gene transcription in colorectal cancer are unknown. We hypothesized that cis- and trans-regulatory elements determine OPN transcription in CT26 cells. OPN transcription was analyzed in CT26 cancer cells and compared with YAMC (young adult mouse colon) epithelial cells. Clonal deletion analysis of OPN promoter-luciferase constructs identified cis-regulatory regions. A specific promoter region, nucleotide (nt) –107 to –174, demonstrated a >8.0-fold increase in luciferase activity in CT26 compared with YAMC. Gel-shift assays sublocalized two cis-regulatory regions, nt –101 to –123 and nt –121 to –145, which specifically bind CT26 nuclear proteins. Competition with unlabeled mutant oligonucleotides revealed that the regions nt –115 to –118 and nt –129 to –134 were essential for protein binding. Subsequent supershift and chromatin immunoprecipitation assays confirmed the corresponding nuclear proteins to be Ets-1 and Runx2. Functional relevance was demonstrated through mutations in the Ets-1 and Runx2 consensus binding sites resulting in >60% decrease in OPN transcription. Ets-1 and Runx2 protein expression in CT26 was ablated using antisense oligonucleotides and resulted in a >7-fold decrease in OPN protein expression. Ets-1 and Runx2 are critical transcriptional regulators of OPN expression in CT26 colorectal cancer cells. Suppression of these transcription factors results in significant down-regulation of the OPN metastasis protein.
American Journal of Transplantation | 2010
Barbara D. Alexander; Wiley A. Schell; A. M. Siston; C. Y. Rao; W. A. Bower; S. A. Balajee; David N. Howell; Z. S. Moore; J. Noble-Wang; J. A. Rhyne; A. T. Fleischauer; J. M. Maillard; M. Kuehnert; Deepak Vikraman; Bradley H. Collins; Carlos E. Marroquin; Benjamin Park
Two patients developed renal mucormycosis following transplantation of kidneys from the same donor, a near‐drowning victim in a motor vehicle crash. Genotypically, indistinguishable strains of Apophysomyces elegans were recovered from both recipients. We investigated the source of the infection including review of medical records, environmental sampling at possible locations of contamination and query for additional cases at other centers. Histopathology of the explanted kidneys revealed extensive vascular invasion by aseptate, fungal hyphae with relative sparing of the renal capsules suggesting a vascular route of contamination. Disseminated infection in the donor could not be definitively established. A. elegans was not recovered from the same lots of reagents used for organ recovery or environmental samples and no other organ transplant‐related cases were identified. This investigation suggests either isolated contamination of the organs during recovery or undiagnosed disseminated donor infection following a near‐drowning event. Although no changes to current organ recovery or transplant procedures are recommended, public health officials and transplant physicians should consider the possibility of mucormycosis transmitted via organs in the future, particularly for near‐drowning events. Attention to aseptic technique during organ recovery and processing is re‐emphasized.
Journal of Gastrointestinal Surgery | 2008
John E. Scarborough; Ricardo Pietrobon; Janet E. Tuttle-Newhall; Carlos E. Marroquin; Bradley H. Collins; Dev M. Desai; Paul C. Kuo; Theodore N. Pappas
IntroductionRecent data suggests that the previously demonstrable relationship between hospital volume and outcomes for liver transplant procedures may no longer exist. Furthermore, to our knowledge, no study has been published examining whether individual surgeon volume is associated with outcomes in liver transplantation.Materials and methodsThe Nationwide Inpatient Sample database was used to obtain early clinical outcome and resource utilization data for liver transplant procedures performed in the USA from 1988 through 2003. The relationship between surgeon and hospital volume and early clinical outcomes was analyzed with and without adjustment for certain confounding variables such as patient age and presence of co-morbid disease.ResultsThe in-hospital mortality rate, major postoperative complication rate, and length of hospital stay after liver transplantation did not differ significantly based on hospital procedural volume. These outcome variables did, however, exhibit a statistically significant inverse relationship with individual surgeon volume of liver transplant procedures. A significant relationship between procedure volume and outcomes for liver transplantation cannot be demonstrated at the level of transplant center, but does appear to exist at the level of the individual transplant center.ConclusionMinimal volume requirements for individual liver transplant surgeons may be justified, pending validation of this volume–outcomes relationship using a clinical data source.
Transplantation | 2005
Carlos E. Marroquin; Erick B. Edwards; Bradley H. Collins; Dev M. Desai; Janet E. Tuttle-Newhall; Paul C. Kuo
Although graft and patient survival data are available for pancreas and kidney transplants, they are rarely reported in terms of half-life. Our aim was to determine whether a more relevant measure of outcome is patient and allograft half-life. Using the data from the Organ Procurement and Transplantation Network Registry on kidney and pancreas transplants from January 1988 to December 1996, patient and graft half-life and 95% confidence intervals were calculated and demographic variables compared. No significant differences were found between demographic variables. Kidneys transplanted in diabetics as a simultaneous kidney-pancreas (SPK) fared better than diabetics receiving a kidney alone (9.6 vs. 6.3 years). Pancreatic graft survival in an SPK pair was better than pancreas after kidney transplant or pancreas transplant alone (11.2 vs. 2.5 years). Because kidney and pancreatic grafts have a longer half-life when transplanted with their mate grafts, we should consider the relative benefits of SPKs over pancreas after kidney transplant or pancreas transplant alone to limit the loss of precious resources.
Clinical Transplantation | 2005
Alastair D. Smith; Diane Bai; Carlos E. Marroquin; Janet E. Tuttle-Newhall; Dev M. Desai; Bradley H. Collins; Andrew J. Muir; Paul C. Kuo; John G. McHutchison; Don C. Rockey
Abstract: Sirolimus is emerging as a popular immunosuppressive agent for patients undergoing solid organ and pancreatic cell transplantation. Here, we report the clinical courses of three patients receiving sirolimus who developed aggressive gastroduodenal ulcer disease. One patient died from massive gastrointestinal bleeding, and ulcers in the other two patients healed only after discontinuation of sirolimus. We propose that the mechanism underlying this severe ulcer diathesis, and poor ulcer healing, was linked to the well‐known inhibitory effects of sirolimus on wound healing. We propose that sirolimus should be used carefully (or even withheld) in patients with known or previous ulcer disease, and further that it should be used prudently and/or in conjunction with aggressive prophylaxis therapy in those at risk for ulcer disease.
Journal of Gastrointestinal Surgery | 2007
John E. Scarborough; Ricardo Pietrobon; Carlos E. Marroquin; Janet E. Tuttle-Newhall; Paul C. Kuo; Bradley H. Collins; Dev M. Desai; Theodore N. Pappas
IntroductionProcedures such as liver transplantation, which entail large costs while benefiting only a small percentage of the population, are being increasingly scrutinized by third-party payors. The purpose of our study was to conduct a longitudinal analysis of the early clinical outcomes and health care resource utilization for liver transplantation in the United States.MethodsThe Nationwide Inpatient Sample database was used to conduct a longitudinal analysis of the clinical outcome and resource utilization data for liver transplantation procedures in adult recipients performed in the United States over three time periods (Period I: 1988–1993; Period II: 1994–1998: Period III: 1999–2003).ResultsCompared to Period I, adult liver transplant recipients were more likely to be male, older, and non-White in Period III. Recipients were more likely to have at least one major comorbidity preoperatively than in Period I. The in-hospital mortality rate after liver transplantation decreased significantly from Period I to Period III, but the major intraoperative and postoperative complication rates increased over the same time period. Mean length of hospital stay decreased over the 15-year period, but the percentage of patients with a non-routine discharge status increased.ConclusionOur findings indicate that the rate of postoperative complications and non-routine discharges after liver transplantation is increasing. However, these negative changes in the cost–outcomes relationship for liver transplantation are balanced by improving postoperative survival rates and reductions in the length of hospital stay.
Digestive Diseases and Sciences | 2005
Hongtao Guo; Carlos E. Marroquin; Philip Y. Wai; Paul C. Kuo
Our objective was to delineate the role of nitric oxide (NO) in osteopontin (OPN)-associated metastatic properties in HepG2 cells. OPN is the major phosphoprotein secreted by malignant cells in patients with advanced metastatic cancer, is frequently overexpressed in human tumors, and has been implicated as a key mediator of tumor cell metastasis. OPN is significantly overexpressed in hepatocellular cancer (HCC) and correlates with capsular infiltration and behavior. In addition, significantly increased inducible nitric oxide synthase (iNOS) and NO expression are found in HCC. In archived human samples of normal, cirrhotic, and HCC livers, we demonstrate that iNOS and OPN protein are strongly coexpressed in hepatoma cells. In the setting of cirrhosis, hepatocytes express iNOS, but not OPN. Further in vitro studies performed with HepG2 hepatocellular cancer cells demonstrate that exogenous NO transcriptionally upregulates OPN expression. Enhanced expression of OPN in this setting is associated with increased in vitro cell adhesion and invasion. These data suggest that NO enhances HCC expression of OPN and, as a result, conveys a metastatic phenotype.
Hpb | 2008
John E. Scarborough; Janet E. Tuttle-Newhall; Ricardo Pietrobon; Carlos E. Marroquin; Bradley H. Collins; Dev M. Desai; Paul C. Kuo; Theodore N. Pappas
The purpose of our study is to determine whether the current level of transplant fellow training is sufficient to meet the future demand for liver transplantation in the United States. Historical data from the Nationwide Inpatient Samples (NIS) for the years 1998 through 2003 were used to construct an estimate of the annual number of liver transplant procedures currently being performed in the United States, and the number projected for each year through 2020. Estimates for the current and future number of surgeons performing liver transplant procedures were also constructed using the same database. The NIS database was used because current national transplant registries do not include information on the number of surgeons performing liver transplant procedures. Using historical data derived from the NIS database, we project that the estimated number of liver transplant procedures per surgeon will remain relatively stable through 2020, with each surgeon performing an average of 12.9 procedures in 2020 compared to 12.9 currently. We conclude that the relationship between demand for liver transplantation in the United States and the supply of liver transplant surgeons will remain stable over the next 15 years.
Hpb | 2009
Elisabeth T. Tracy; Kyla M. Bennett; Emeline M. Aviki; Theodore N. Pappas; Bradley H. Collins; Janet E. Tuttle-Newhall; Carlos E. Marroquin; Paul C. Kuo; John E. Scarborough
BACKGROUND Although prior studies have suggested an inverse association between liver transplant centre volume and postoperative patient mortality, more recent analyses have failed to confirm this association. To date, all studies of the relationship between centre volume and outcomes in liver transplantation have been cross-sectional in design. OBJECTIVE The objective of our study was to examine temporal trends in the volume-outcomes relationship for liver transplantation. METHODS We used information obtained from the Scientific Registry of Transplant Recipients (SRTR) programme-specific data reports to examine the outcomes of adult liver transplant recipients stratified by annual centre volume. This relationship between centre volume and patient outcomes was assessed over three consecutive time periods from 2000 through 2007. RESULTS The overall 25% increase in adult liver transplant volume in the USA from 2000 to 2007 appeared to be distributed fairly equally among existing transplant centres. In the earliest time period of our analysis, high-volume centres achieved superior risk-adjusted 1-year patient outcomes compared with low-volume centres. By the third and most recent time period of the analysis, this discrepancy between the outcomes of high- and low-volume centres was no longer statistically apparent. CONCLUSIONS The relationship between centre volume and patient outcomes for liver transplantation in the USA has become less pronounced over time, suggesting that the use of procedure volume as a marker of liver transplant centre quality cannot be justified. The performance-based review process currently utilized in the USA may have contributed to this diminishing influence of centre volume on liver transplant recipient outcomes. This type of review process should be considered as a potential alternative to the volume-based referral initiatives that have been developed for other non-transplant, complex surgical procedures.