Publications (14)36.75 Total impact
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Article: Population-based Risk Factors for Elevated Alanine Aminotransferase in a South Texas Mexican-American Population.
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ABSTRACT: Elevated alanine aminotransferase (ALT >40 IU/mL) is a marker of liver injury but provides little insight into etiology. We aimed to identify and stratify risk factors associated with elevated ALT in a randomly selected population with a high prevalence of elevated ALT (39%), obesity (49%) and diabetes (30%). Two machine learning methods, the support vector machine (SVM) and Bayesian logistic regression (BLR), were used to capture risk factors in a community cohort of 1532 adults from the Cameron County Hispanic Cohort (CCHC). A total of 28 predictor variables were used in the prediction models. The recently identified genetic marker rs738409 on the PNPLA3 gene was genotyped using the Sequenom iPLEX assay. The four major risk factors for elevated ALT were fasting plasma insulin level and insulin resistance, increased BMI and total body weight, plasma triglycerides and non-HDL cholesterol, and diastolic hypertension. In spite of the highly significant association of rs738409 in females, the role of rs738409 in the prediction model is minimal, compared to other epidemiological risk factors. Age and drug and alcohol consumption were not independent determinants of elevated ALT in this analysis. The risk factors most strongly associated with elevated ALT in this population are components of the metabolic syndrome and point to nonalcoholic fatty liver disease (NAFLD). This population-based model identifies the likely cause of liver disease without the requirement of individual pathological diagnosis of liver diseases. Use of such a model can greatly contribute to a population-based approach to prevention of liver disease.Archives of medical research 09/2012; 43(6):482-8. · 1.88 Impact Factor -
Article: Current use of hepatitis B immune globulin for prevention of de novo hepatitis B in recipients receiving anti-HBc-positive livers.
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ABSTRACT: Livers from donors positive for antibody against anti-HBc can potentially transmit de novo hepatitis B (DNH) to their recipients. Despite a good outcome, prophylaxis is usually offered to such recipients. There is no consensus on the standard prophylactic regimen and hence prophylaxis varies among different transplant centres. Nonetheless, hepatitis B immune globulin (HBIG) is considered the mainstay of such prophylaxis, either alone or in combination with an oral antiviral treatment. We aim to provide a concise review of the current use of HBIG in prevention of DNH. We also address a few important questions regarding HBIG use.Hepatology International 06/2011; 5(2):635-43. · 2.64 Impact Factor -
Article: Asymptomatic primary biliary cirrhosis is not associated with increased frequency of cardiovascular disease.
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ABSTRACT: To estimate the prevalence of cardiovascular events in Primary biliary cirrhosis (PBC) and to determine whether this risk is higher within specific subgroups of patients with PBC. We included 180 patients with PBC (cases) and 151 patients seen for HCV infection (controls). Medical records were reviewed and statistical analyses were performed as appropriate. When compared to controls, PBC patients were older, leaner and had higher serum levels of total cholesterol, high density lipoprotein and low density cholesterol. There were more females in the PBC group (91.7% vs 43%, P < 0.001). More control subjects had smoked than the PBC patients (63.6% vs 35%, P < 0.001). The prevalence of hypertension, diabetes, coronary artery disease and stroke was similar between the two groups. Seven percent of controls and 10% of cases developed any type of cardiovascular disease (P = 0.3). Only 36.7% were asymptomatic at diagnosis. Three cardiovascular events were documented among asymptomatic patients (4.5%) and fifteen among symptomatic patients (13.2%; P = 0.06). Among PBC patients with fatigue, 10 (13.5%) had a cardiovascular event compared to 7 (6.7%) among patients without fatigue (P = 0.1). Asymptomatic PBC patients do not have a greater frequency of cardiovascular disease; nor do patients suffering with fatigue.World journal of hepatology. 04/2011; 3(4):93-8. -
Article: Prevalence of metabolic syndrome and risks of abnormal serum alanine aminotransferase in Hispanics: a population-based study.
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ABSTRACT: Study the prevalence of metabolic syndrome (MS) and risk factors for and association with elevated alanine aminotransferase (ALT) as markers of hepatic injury in a large Hispanic health disparity cohort with high rates of obesity. Analysis of data from a prospective cross-sectional population based study. From 2004-7, we randomly recruited 2000 community participants to the Cameron County Hispanic Cohort collecting extensive socioeconomic, clinical and laboratory data. We excluded 153 subjects due to critical missing data. Pearson chi-square tests and Student's t-tests were used for categorical and continuous variable analysis, respectively. Logistic regression analysis was performed to determine the risk factors for elevated ALT. The mean age of the cohort was 45 years and 67% were females. The majority of the cohort was either overweight (32.4%) or obese (50.7%). Almost half (43.7%) had MS and nearly one-third diabetes. Elevated ALT level was more prevalent in males than females. Obesity was a strong risk for abnormal ALT in both genders. Hypertriglyceridemia, hypercholesterolemia and young age were risks for elevated ALT in males only, whereas increased fasting plasma glucose was associated with elevated ALT in females only. We identified high prevalence of MS and markers of liver injury in this large Mexican American cohort with gender differences in prevalence and risk factors, with younger males at greatest risk.PLoS ONE 01/2011; 6(6):e21515. · 4.09 Impact Factor -
Article: Low prevalence of HBV DNA in the liver allograft from anti-HBc-positive donors: a single-center experience.
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ABSTRACT: Allografts from donors positive for antibody to hepatitis B core antigen (anti-HBc(+)) can transmit hepatitis B virus (HBV) to the recipients. We aimed to study the prevalence of HBV DNA in liver allografts from anti-HBc(+) donors. Between January 2003 and December 2008, this retrospective study identified 18 patients who received a liver from an anti-HBc(+) donor. Pre- and post-transplantation HBV serology and serum HBV DNA level of the study subjects were reviewed. DNA extracted from liver biopsy tissue was used for PCR assay. Immunohistochemistry was also performed to determine viral protein expression. We observed a low prevalence of HBV DNA in allografts from anti-HBc(+) donors even among patients who did not receive prophylaxis. Only one of 18 patients had detectable HBV DNA in the liver allograft. This recipient was seronegative for HBV before transplantation and did not receive prophylaxis after transplantation, and developed de novo hepatitis B. Of the five patients who were positive for both antibody to hepatitis B surface antigen and anti-HBc before transplantation and did not receive prophylaxis after transplantation, none developed HBV infection. Prophylaxis for HBV is important for seronegative recipients receiving a liver from an anti-HBc(+) donor. Such prophylaxis may not be necessary for recipients who do not have detectable HBV DNA in the liver allograft.Clinical Transplantation 02/2010; 25(1):164-70. · 1.67 Impact Factor -
Article: Prospective randomized blinded comparison of a short-wire endoscopic retrograde cholangiopancreatography system with traditional long-wire devices.
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ABSTRACT: Short-wire endoscopic retrograde cholangiopancreatography (ERCP) systems are perceived to carry advantage over traditional long-wire devices. To date, this potential advantage has not been well documented, and gastroenterologists are confronted in everyday practice with the dilemma of choosing a particular system without the benefit of having objective comparative data. The aim of this study was to compare the performance characteristics of the Fusion ERCP short-wire system with traditional long-wire devices. This is a prospective, blinded, randomized, controlled trial. Patients with a clinical indication for ERCP were randomized to undergo the procedure with the Fusion short-wire system or long-wire devices. All procedures were done by one experienced endoscopist who was blinded to the outcomes of the study. The person recording the outcomes was an independent observer not involved in the procedure and was blinded to the study hypothesis. The main outcome was device exchange time. Secondary outcomes included stent insertion time, total procedure time, fluoroscopy time, cannulation time, successful cannulation of the desired duct, and complications. A total of 71 patients were enrolled. The short-wire system provided for significantly faster mean device exchange time (125 versus 177 s; P = 0.05) and stent insertion time (135 versus 254 s; P < 0.001) as compared with the long-wire system. A trend towards shorter total procedure time, fluoroscopy time, and cannulation time was noted with the short-wire system but did not reach statistical significance. Successful cannulation of the desired duct was achieved in all patients. Post-ERCP pancreatitis occurred in one patient in the short-wire and in two patients in the long-wire group. This short-wire system provides for significantly shorter device exchange and stent insertion times compared with traditional long-wire devices.Digestive Diseases and Sciences 12/2009; 55(2):510-5. · 2.12 Impact Factor -
Article: Adverse reactions to iodinated contrast media administered at the time of endoscopic retrograde cholangiopancreatography (ERCP).
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ABSTRACT: Adverse reactions after intravascular administration of iodine contrast media are common and prophylactic regiments consisting of the use of steroids and low osmolality contrast media are highly effective in significantly decreasing the adverse reactions rate. The same type of contrast media are also used for opacification of the biliary tree and the pancreatic duct at the time of endoscopic retrograde cholangiopancreatography (ERCP). Systemic absorption of contrast media after ERCP routinely occurs. Although the adverse reaction rate appears to be very low the exact incidence remains unknown due to the retrospective nature of all reports. Despite the lack of formal recommendations, numerous prophylactic regiments are routinely used prior to ERCP in patients with history of prior reaction to intravascular contrast media. Moreover, the use of prophylaxis has even expanded to patients with no prior reaction to intravascular contrast media who are somehow perceived to be at increase risk (e.g. shellfish allergy). Recently, the first large scale prospective study reported exceedingly low incidence of adverse reaction to high oslmolality iodine-containing contrast media administered at the time of ERCP done without prophylactic premedication even in patients considered to be at the highest risk (prior severe reaction to intravascular contrast media administration). These data suggest that the use of prophylactic regiments prior to ERCP appears to be unnecessary.Inflammation & allergy drug targets. 04/2009; 8(1):17-20. -
Article: Bone marrow-derived progenitor cells could modulate pancreatic cancer tumorigenesis via peritumoral microenvironment in a rat model.
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ABSTRACT: Metaplastic tubular complexes (MTC) have been proposed as precursor lesions for pancreatic adenocarcinoma (PDAC). In this study, we investigated the potential role of bone marrow-derived progenitor cells (BMPC) in the formation of MTC and PDAC in a rat model. F344 rats defective for CD26 (dipeptidyl peptidase IV, DPPIV) expression were sublethally irradiated and received rescue bone marrow cells from wild-type F344 rats that express CD26. After confirming engraftment, recipient animals received dimethylbenzanthracene (DMBA) implantation in their pancreas. Animals were sacrificed monthly from 3 to 7 months. We observed both MTC and tumors in animals that received DMBA. These MTC were ductal complexes because they stained positive for cytokeratin but were negative for chymotrypsin and chromogranin A. Cells that expressed both CD26 and cytokeratin were rarely observed in the MTC. Cells expressing either both CD26 and CD45 or CD26 and smooth muscle actin were also found near the MTC. However, no CD26 signal was detected in the tumors. Within this model, there appeared to be no evidence supporting that BMPC turned into tumor cells directly. BMPC could modulate pancreatic cancer growth through tumor microenvironment.Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics 02/2009; 17(8):339-45. · 1.30 Impact Factor -
Article: Using an immune functional assay to differentiate acute cellular rejection from recurrent hepatitis C in liver transplant patients.
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ABSTRACT: In transplant recipients transplanted for hepatitis C, presentation of abnormal transaminases can herald the presentation of recurrent hepatitis C, cellular rejection, or both. Given the sometimes ambiguous histology with these 2 entities, the ability to distinguish them is of great importance because misinterpretation can potentially affect graft survival. We used an immune functional assay to help assess the etiology of abnormal liver function test results in liver transplant recipients. Blood samples for the immune functional assay were taken from 42 recipients prospectively at various times post-transplant and compared with clinical and histologic findings. In patients whose liver biopsy showed evidence of cellular rejection, the immune response was noted to be very high, whereas in those with active recurrence of hepatitis C, the immune response was found to be very low. This finding was found to be statistically significant (P < 0.0001). In those patients in whom there was no predominant histologic features suggesting 1 entity over the other, the immune response was higher than in those with aggressive hepatitis C but lower than in those with cellular rejection. In conclusion, these data show the potential utility of the ImmuKnow assay as a means of distinguishing hepatitis C from cellular rejection and its potential usefulness as a marker for outlining the progression of hepatitis C.Liver Transplantation 01/2009; 15(2):216-22. · 3.39 Impact Factor -
Article: Factors predicting survival after transjugular intrahepatic portosystemic shunt creation: 15 years' experience from a single tertiary medical center.
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ABSTRACT: This retrospective analysis was conducted to identify factors predictive of survival after transjugular intrahepatic portosystemic shunt (TIPS) creation. Patients who underwent TIPS creation between January 1991 and December 2005 at a tertiary-care center were identified. Log-rank tests were used to compare the cumulative survival functions among groups of patients who underwent TIPS creation for various indications. Thirty-day mortality after TIPS creation was examined by logistic regression. Cox proportional-hazards analyses were performed to analyze the cumulative 90-day and 1-year survival. Selected variables such as creatinine, bilirubin, and International Normalized Ratio (INR) were assessed with respect to survival. The study included 352 patients, of whom 229 (65.1%) were male. The mean age at the time of TIPS creation was 53.6 years (range, 21-82 y). A Model for End-stage Liver Disease (MELD) score greater than 15 was significantly associated with poor survival (P < .05) at 30 days, 90 days, and 1 year after TIPS creation. Independently, a serum total bilirubin level greater than 2.5 mg/dL, an INR greater than 1.4 (P < .05), and a serum creatinine level greater than 1.2 mg/dL were predictive of poor survival. Finally, age greater than 70 years was associated with poor survival at 90 days and 1 year after TIPS creation (P < .05). The choice to create a TIPS in individuals whose MELD score is greater than 15 and/or whose age is greater than 70 years should involve a careful consideration of risk/benefit ratio, taking into account the finding that such patients have significantly poorer survival after TIPS creation.Journal of vascular and interventional radiology: JVIR 10/2008; 19(11):1576-81. · 1.81 Impact Factor -
Article: Rapid-sequence endoscopic management of posttransplant anastomotic biliary strictures.
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ABSTRACT: Post-liver-transplant anastomotic biliary strictures generally have been managed through ERCP with gradual balloon dilation and placement of multiple stents over an extended period of time. Our purpose was to evaluate the long-term outcome of rapid sequence dilation and to shorten the duration of stenting as a therapy for anastomotic biliary strictures. Prospective case series. Academic tertiary referral center. ERCP with rapid-sequence balloon dilation of post-liver-transplant anastomotic biliary strictures followed by stenting with multiple stents over a short time period. Long-term anastomotic stricture resolution. Thirty-eight patients were prospectively enrolled into a standardized ERCP treatment protocol. The mean number of ERCPs per patient was 3.4 (range 2-6), the mean number of maximum stents inserted was 2.5 (range 1-6), and the mean total stenting period was 107 days (range 20-198 days); the mean follow-up time from completion of the endoscopic therapy was 360 days (range 140-1347 days). Long-term stricture resolution was achieved in 33 of the 38 (87%) patients. Lack of control group, relatively small patient population. Accelerated dilation and shorter total length of stenting leads to long-term success in the majority of patients with post-liver-transplant anastomotic biliary strictures.Gastrointestinal Endoscopy 06/2008; 67(6):879-85. · 4.88 Impact Factor -
Article: Connective tissue growth factor with a novel fibronectin binding site promotes cell adhesion and migration during rat oval cell activation.
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ABSTRACT: Oval cell activation, as part of the regenerative process after liver injury, involves considerable cell-matrix interaction. The matricellular protein, connective tissue growth factor (CTGF), has been shown to be critical for oval cell activation during liver regeneration following N-2-acetylaminofluorene/partial hepatectomy. To understand the mode of action of CTGF during this process, N-terminal CTGF was used as bait to screen a yeast two-hybrid complementary DNA library specific for regenerating livers with massive oval cell presence. Fibronectin (FN), a prominent component of hepatic extracellular matrix (ECM), was found to specifically bind to a new site on CTGF. In addition to module IV, this study showed that module I of CTGF was sufficient for binding to FN in both solid-phase in vitro binding assays and immunoprecipitation. Immunofluorescent staining revealed a dynamic ECM remodeling characterized by an FN-concentrated provisional matrix during oval cell-aided liver regeneration. Abundant CTGF protein was colocalized with FN in the provisional matrix. When expressed as recombinant proteins and immobilized on plastic surfaces, modules I and IV of CTGF were selectively adhesive to thymus cell antigen 1-positive (Thy1(+)) oval cells, stellate cells, and sinusoidal endothelial cells but not to hepatocytes. The adhesion of these two modules on Thy1(+) oval cells required heparan sulfate proteoglycan and integrin alpha(5)beta(1). Recombinant CTGF promoted an integrin alpha(5)beta(1)-dependent migration but not proliferation on Thy1(+) oval cells. CONCLUSION: Modules I and IV enabled the linkage of CTGF to FN and activated hepatic cells. Through these bindings, CTGF on the FN-concentrated provisional matrix promoted cell adhesion and migration, thereby facilitating oval cell activation.Hepatology 04/2008; 47(3):996-1004. · 11.66 Impact Factor -
Article: The clinical experience of Chinese patients with Wilson's disease.
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ABSTRACT: Wilson's disease has protean presentations. Most patients manifested as either hepatic or neurologic symptoms and signs initially. No study has investigated the predictor of presentation and differences in laboratory tests and survival between patients presented with hepatic or neurological disease so far. Forty-one patients with Wilson's disease were diagnosed between 1981 and 2002 at our hospital. Their clinical features at presentation and laboratory findings were retrospectively collected. Survival was calculated using the Kaplan-Meier analysis. Twelve patients initially presented with hepatic symptoms including chronic hepatitis, complications of cirrhosis, and fulminant hepatic failure. Twenty-nine patients presented with neurological symptoms including tremor, dysarthria, ataxia, and psychiatric diseases. No specific factor identified could predict the initial presentations. Compared to patients with neurological symptoms, patients with hepatic disease had significantly higher serum levels of aminotransferase, ceruloplasmin, copper, and 24-hour urine copper excretion. There was no significant difference in survival between these two groups. Among the patients who died, the most common causes of death were fulminant hepatic failure and complications of cirrhosis. Our results suggested that the overall survival did not differ significantly according to the initial presentations. There was no predictor found that could foretell the clinical course of Wilson's disease.Hepato-gastroenterology 52(61):166-9. · 0.66 Impact Factor -
Article: Prediction of liver fibrosis in patients with chronic hepatitis B by serum markers.
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ABSTRACT: Liver biopsy has been considered as the gold standard for assessing fibrosis in patients with chronic hepatitis. The objective of this study was to explore the feasibility of using serum tests to predict the presence of fibrosis in patients with chronic hepatitis B. Fibrosis scores for 153 patients were established by examining liver biopsy specimens. Serum was obtained from each patient around the time of the biopsy and analyzed by standard laboratory techniques. Student's t test, univariate analysis, and multivariate logistic regression were employed to test the presence of statistical significance. Only platelet count was an independent factor that could predict the presence of significant fibrosis. Platelet count was lower (p = 0.04) in the group with moderate/severe fibrosis. When platelet count was above 150 x 10(9)/L, the negative prediction value and specificity for the presence of significant fibrosis was 0.78 and 0.87 (AUC under ROC curve was 0.68). In this study, AST/ALT ratio was not associated with either activity or fibrosis. This study suggests that platelet count is an independent noninvasive marker for prediction of the presence of significant liver fibrosis in patients with chronic hepatitis B.Hepato-gastroenterology 54(77):1503-6. · 0.66 Impact Factor
Top co-authors
Top Journals
Institutions
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2011
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University of Texas Medical School
- Department of Internal Medicine
Houston, TX, USA -
University of Texas Health Science Center at Houston
Houston, TX, USA
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2010
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University of Florida
- Division of Gastroenterology, Hepatology & Nutrition
Gainesville, FL, USA
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