65 results on '"Joseph A. Awad"'
Search Results
2. Adherence to the evidence-based guidelines in the management of acute biliary pancreatitis: A case series
- Author
-
Ahmed Osama Hassan, Yasmine Hany Hegab, Joseph Ri Awad, Yasser A. Orban, and Abd-Elrahman M. Metwalli
- Subjects
CECT, contrast-enhanced computed tomography ,Pediatrics ,medicine.medical_specialty ,Evidence-based practice ,Japanese guidelines of acute pancreatitis, 2015 ,Disease ,030230 surgery ,03 medical and health sciences ,0302 clinical medicine ,AP, acute pancreatitis ,medicine ,Case Series ,Biliary pancreatitis ,MRCP, magnetic resonant cholangiopancreatography ,US, ultrasound ,Systemic complication ,business.industry ,Incidence (epidemiology) ,Epidemiology of acute biliary pancreatitis ,Gallstones ,medicine.disease ,CT, computed tomography ,Acute pancreatitis ,030220 oncology & carcinogenesis ,Step up approach in acute pancreatitis ,Surgery ,Management of acute biliary pancreatitis ,Early phase ,business ,EUS, endoscopic ultrasound ,ERCP, endoscopic retrograde cholangiopancreatography - Abstract
Highlights • The diagnosis and management of cases with acute biliary pancreatitis. • Minimally invasive techniques gave encouraging results with minimal complications. • Cholecystectomy is recommended to prevent the recurrence of acute gallstone induced pancreatitis., Background Acute pancreatitis (AP) is considered one of the most common gastrointestinal disorders; the annual worldwide incidence for AP is 4.9–73.4 cases / 100,000 people and the total mortality rate is 4–8%, increasing to 33% in patients with infected necrosis. This study aims to assess the outcome of providing standardized evidence-based care to patients with acute biliary pancreatitis. Methods Thirty patients diagnosed with acute biliary pancreatitis, were enrolled in this study and managed according to the Japanese guidelines, 2015 with a complementary scope on other recent guidelines. Results Out of 30 patients in the study, 60% were females. Twenty-five cases were presented in the early phase of the disease while the rest presented in the late phase. Gallstones were the commonest cause (80%). The complications encountered were a systemic complication in one case, organ failure in three cases, and the local complications in the form of fluid collections in (43.3%) of cases.Out of 30 patients, 6 patients had an intervention. The main approach was minimally invasive techniques (4 cases), Open approach was performed in 2 cases. The total mortality rate was 10%. Most mild cases were discharged within one week from admission. Cases readmitted with recurrent attacks of acute pancreatitis were 3 cases, one male and 2 females. Conclusion By applying guidelines in the management of acute biliary pancreatitis, we can reduce disease-related morbidity and mortality. Besides, we can reduce the costs of medical services with the proper investment of healthcare resources.
- Published
- 2020
- Full Text
- View/download PDF
3. Trends in Renal Function Among Heart Transplant Recipients of Donor-Derived Hepatitis C Virus
- Author
-
Jonathan N. Menachem, Ashish S. Shah, Matthew R. Danter, Sandip Zalawadiya, Kelly Schlendorf, JoAnn Lindenfeld, Joseph A. Awad, Roman E. Perri, Suzanne Brown Sacks, H. O'Dell, C. Darragh, L. Punnoose, R. Fowler, D. Marshall Brinkley, Mark Wigger, Keki R. Balsara, H. Ooi, S. Smith, and Shelly Ruzevich-Scholl
- Subjects
Adult ,Male ,medicine.medical_specialty ,Sofosbuvir ,Sustained Virologic Response ,Hepatitis C virus ,medicine.medical_treatment ,Biomedical Engineering ,Biophysics ,Renal function ,Bioengineering ,030204 cardiovascular system & hematology ,medicine.disease_cause ,Gastroenterology ,Antiviral Agents ,Heterocyclic Compounds, 4 or More Rings ,Biomaterials ,03 medical and health sciences ,0302 clinical medicine ,Pharmacotherapy ,Interquartile range ,Internal medicine ,medicine ,Humans ,Heart transplantation ,Fluorenes ,business.industry ,General Medicine ,Hepatitis C ,Middle Aged ,medicine.disease ,Tissue Donors ,Transplant Recipients ,030228 respiratory system ,Cohort ,Heart Transplantation ,Benzimidazoles ,Drug Therapy, Combination ,Female ,Kidney Diseases ,Carbamates ,business ,Uridine Monophosphate ,medicine.drug - Abstract
Donor-derived hepatitis C (dd-HCV) infection may increase the risk of renal impairment (RI) among heart transplantation (HT) recipients. Sofosbuvir, an integral component of HCV direct-acting antivirals (DAAs) has also been linked to RI. To date, no study has examined the trends in renal function for HT recipients of dd-HCV infection and assessed safety and efficacy of Sofosbuvir-based DAAs. Between September 2016 and June 2018, 46 HCV-naive patients and one patient with a history of HCV treated pretransplant, underwent HT from HCV-positive donors (follow-up available through October 10, 2018). Patients were treated with Ledipasvir-Sofosbuvir (genotype 1) or Sofosbuvir-Velpatasvir (genotype 3) for 12 or 24 weeks; no dose adjustments were made for renal function. Data on renal function were available for 23 patients who achieved a sustained virologic response at 12 weeks after the treatment (SVR12; cohort A) and 18 patients who completed 1 year of follow-up (cohort B). Treatment of dd-HCV infection was initiated at a median of 6 weeks post-HT. In both cohorts, a nonsignificant reduction in median estimated glomerular filtration rate (eGFR; ml/min/1.73 m) was noted (cohort A: pretransplant eGFR: 62 [interquartile range {IQR}: 1-84] to SVR12 eGFR: 49 [IQR: 37-82]; p = 0.43; cohort B: pretransplant eGFR: 65 [IQR: 54-84] to 1 year post-HT eGFR: 56 [IQR: 39-75]; p = 0.29). Pretreatment renal function had no significant impact on changes in renal function during treatment. All patients tolerated DAAs well with 100% completion rate to the assigned therapy and duration and 100% success at achieving SVR12. In this first and largest reported case series to date of HT recipients with dd-HCV infection, we observed that neither the dd-HCV infection nor its treatment with Sofosbuvir-based DAAs increased the risk of RI. Sofosbuvir-based DAAs appear safe, tolerable, and effective for HCV treatment even in presence of severe RI.
- Published
- 2019
4. Three-dimensional therapy needle applicator segmentation for ultrasound-guided focal liver ablation
- Author
-
Derek W. Cool, Joseph A. Awad, Jessica R. Rodgers, Derek J. Gillies, Chandima Edirisinghe, Nirmal Kakani, and Aaron Fenster
- Subjects
Ablation Techniques ,Liver tumor ,Percutaneous ,Computer science ,Tissue mimicking phantom ,medicine.medical_treatment ,Local cancer ,computer.software_genre ,Imaging phantom ,Tumor ablation ,Otsu's method ,symbols.namesake ,Voxel ,medicine ,Humans ,Segmentation ,Minimally invasive procedures ,Ultrasonography ,business.industry ,Phantoms, Imaging ,Microwave ablation ,Ultrasound ,General Medicine ,medicine.disease ,Ablation ,Ultrasound guided ,Liver ,Surgery, Computer-Assisted ,Needles ,symbols ,Liver cancer ,business ,computer ,Biomedical engineering - Abstract
Purpose Minimally invasive procedures, such as microwave ablation, are becoming first-line treatment options for early-stage liver cancer due to lower complication rates and shorter recovery times than conventional surgical techniques. Although these procedures are promising, one reason preventing widespread adoption is inadequate local tumor ablation leading to observations of higher local cancer recurrence compared to conventional procedures. Poor ablation coverage has been associated with two-dimensional (2D) ultrasound (US) guidance of the therapy needle applicators and has stimulated investigation into the use of three-dimensional (3D) US imaging for these procedures. We have developed a supervised 3D US needle applicator segmentation algorithm using a single user input to augment the addition of 3D US to the current focal liver tumor ablation workflow with the goals of identifying and improving needle applicator localization efficiency. Methods The algorithm is initialized by creating a spherical search space of line segments around a manually chosen seed point that is selected by a user on the needle applicator visualized in a 3D US image. The most probable trajectory is chosen by maximizing the count and intensity of threshold voxels along a line segment and is filtered using the Otsu method to determine the tip location. Homogeneous tissue mimicking phantom images containing needle applicators were used to optimize the parameters of the algorithm prior to a four-user investigation on retrospective 3D US images of patients who underwent microwave ablation for liver cancer. Trajectory, axis localization, and tip errors were computed based on comparisons to manual segmentations in 3D US images. Results Segmentation of needle applicators in ten phantom 3D US images was optimized to median (Q1, Q3) trajectory, axis, and tip errors of 2.1 (1.1, 3.6)°, 1.3 (0.8, 2.1) mm, and 1.3 (0.7, 2.5) mm, respectively, with a mean ± SD segmentation computation time of 0.246 ± 0.007 s. Use of the segmentation method with a 16 in vivo 3D US patient dataset resulted in median (Q1, Q3) trajectory, axis, and tip errors of 4.5 (2.4, 5.2)°, 1.9 (1.7, 2.1) mm, and 5.1 (2.2, 5.9) mm based on all users. Conclusions Segmentation of needle applicators in 3D US images during minimally invasive liver cancer therapeutic procedures could provide a utility that enables enhanced needle applicator guidance, placement verification, and improved clinical workflow. A semi-automated 3D US needle applicator segmentation algorithm used in vivo demonstrated localization of the visualized trajectory and tip with less than 5° and 5.2 mm errors, respectively, in less than 0.31 s. This offers the ability to assess and adjust needle applicator placements intraoperatively to potentially decrease the observed liver cancer recurrence rates associated with current ablation procedures. Although optimized for deep and oblique angle needle applicator insertions, this proposed workflow has the potential to be altered for a variety of image-guided minimally invasive procedures to improve localization and verification of therapy needle applicators intraoperatively.
- Published
- 2018
5. FRI-388-Hepatitis C ilnfected liver grafts transplanted into non-infected recipients are safe in the era of highly effective direct-acting antiviral therapy
- Author
-
H. O'Dell, J. K. Wright, L. Gorden, Andrew Scanga, S. Karp, A. Rafferty, S. Alexopoulos, S. Geevarghese, L. Matsuoka, Joseph A. Awad, N. Schneider, and R. Perri
- Subjects
Hepatology ,business.industry ,medicine ,Antiviral therapy ,Hepatitis C ,medicine.disease ,business ,Virology ,Direct acting - Published
- 2019
- Full Text
- View/download PDF
6. Expanding Heart Transplant in the Era of Direct-Acting Antiviral Therapy for Hepatitis C
- Author
-
H. Ooi, Sandip Zalawadiya, Joseph A. Awad, Matthew R. Danter, D. Marshall Brinkley, Mark Wigger, Roman E. Perri, S. Ruzevich-Scholl, Ashish S. Shah, Jonathan N. Menachem, JoAnn Lindenfeld, H. O'Dell, Cori Edmonds, Keki R. Balsara, L. Punnoose, Christopher Schwartz, Alicia Carver, Kelly Schlendorf, Emily Sandhaus, and Suzanne Brown Sacks
- Subjects
Male ,medicine.medical_specialty ,Time Factors ,Tissue and Organ Procurement ,Waiting Lists ,Hepatitis C virus ,medicine.medical_treatment ,030204 cardiovascular system & hematology ,medicine.disease_cause ,Antiviral Agents ,Donor Selection ,03 medical and health sciences ,0302 clinical medicine ,Interquartile range ,Internal medicine ,medicine ,Humans ,Prospective Studies ,030212 general & internal medicine ,Original Investigation ,Hepatitis ,Heart transplantation ,Transmission (medicine) ,business.industry ,Hepatitis C ,Middle Aged ,medicine.disease ,Transplantation ,Cohort ,Heart Transplantation ,Female ,Cardiology and Cardiovascular Medicine ,business ,Follow-Up Studies - Abstract
Importance For patients awaiting heart transplant, hepatitis C–positive donors offer an opportunity to expand the donor pool, shorten wait times, and decrease wait-list mortality. While early reported outcomes among few heart transplant recipients have been promising, knowledge of 1-year outcomes in larger cohorts of patients is critical to shared decision-making with patients about this option. Objective To better define the association of hepatitis C–positive donors with heart transplant volumes, wait-list duration, the transmission and cure of donor-derived hepatitis C, and morbidity and mortality at 1 year. Design, Setting, and Participants This was a prospective, single-center observational study of 80 adult (age 18 years or older) patients who underwent heart transplant using hearts from hepatitis C–positive donors between September 2016 and April 2019 at a large academic medical center. Among donors, who were considered hepatitis C–positive if results from hepatitis C antibody and/or nucleic acid testing were positive, 70 had viremia and 10 were seropositive but did not have viremia. Follow-up was available through May 15, 2019. Comparisons were drawn with patients who underwent transplant with hearts from hepatitis C–negative donors during the same period. Exposures In addition to standard posttransplant management, transplant recipients who developed donor-derived hepatitis C infection were treated with direct-acting antivirals. Main Outcomes and Measures The main outcomes included wait-list duration and 1-year survival in all patients, and for those who developed donor-derived hepatitis C, the response to direct-acting antiviral treatment. Results Of 80 patients, 57 (71.3%) were men, 55 (68.7%) were white, and 17 (26.3%) were black; the median age at transplant was 54.5 years (interquartile range, 46-62 years). Following consent to accept hearts from hepatitis C-exposed donors, the median days to heart transplant was 4 (interquartile range, 1-18). No recipients of donors with negative nucleic acid testing results (10 [12.5%]) developed donor-derived hepatitis C. Of 70 patients who were recipients of donors with positive nucleic acid testing results, 67 (95.7%) developed donor-derived hepatitis C over a median follow-up of 301 days (interquartile range, 142-617). Treatment with direct-acting antivirals was well tolerated and yielded sustained virologic responses in all treated patients. Within the cohort with infection, 1-year patient survival was 90.4%, which was not significantly different compared with the cohort without infection or with patients who received transplants from hepatitis C–negative donors during the same period. Conclusions and Relevance In the era of direct-acting antivirals, hepatitis C–positive donors are a viable option to expand the donor pool, potentially reducing wait-list duration and mortality. In heart transplant recipients with donor-derived hepatitis C, infection is well-tolerated and curable, and 1-year survival is equivalent to that in recipients of hepatitis C–negative donors.
- Published
- 2020
- Full Text
- View/download PDF
7. Trends in Renal Function Among Heart Transplant Recipients of Donors With Hepatitis C
- Author
-
Chan Y. Chung, JoAnn Lindenfeld, Roman E. Perri, Mark Wigger, Joseph A. Awad, Matthew R. Danter, Ashish S. Shah, C. Rueda Rios, Jonathan N. Menachem, S. Smith, H. O'Dell, C. Darragh, S. Ruzevich-Scholl, Kelly Schlendorf, H. Ooi, Rachel M. Hayes, M. Brinkley, Sandip Zalawadiya, Mary E. Keebler, and S.B. Sacks
- Subjects
Pulmonary and Respiratory Medicine ,Transplantation ,medicine.medical_specialty ,business.industry ,Internal medicine ,medicine ,Renal function ,Surgery ,Hepatitis C ,Cardiology and Cardiovascular Medicine ,medicine.disease ,business ,Gastroenterology - Published
- 2018
- Full Text
- View/download PDF
8. Successful Transplantation of 58 Hepatitis C-Exposed Donor Hearts in the Era of Direct-Acting Antiviral Therapies
- Author
-
H. Ooi, L. Punnoose, Roman E. Perri, S. Ruzevich-Scholl, Keki R. Balsara, Ashish S. Shah, H. O'Dell, M. Brinkley, S. Brown Sacks, Mark Wigger, Sandip Zalawadiya, R. Fowler, Kelly Schlendorf, JoAnn Lindenfeld, Lynne W. Stevenson, Joseph A. Awad, Jonathan N. Menachem, and Matthew R. Danter
- Subjects
Pulmonary and Respiratory Medicine ,Hepatitis ,Heart transplantation ,Transplantation ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Immunosuppression ,Viremia ,Hepatitis C ,030230 surgery ,medicine.disease ,03 medical and health sciences ,0302 clinical medicine ,Pharmacotherapy ,Ventricular assist device ,Internal medicine ,medicine ,030211 gastroenterology & hepatology ,Surgery ,Cardiology and Cardiovascular Medicine ,business - Abstract
Purpose The shortage of suitable donors for heart transplantation (HT) contributes to wait-list mortality and increased reliance on mechanical circulatory support. Since the advent of direct-acting antivirals (DAA) for treatment of hepatitis C (HCV), utilization of hepatitis C-exposed donors is now a viable strategy to expand the donor pool and potentially reduce waitlist time. Methods Between September 2016 and October 2018, 58 patients underwent HT from HCV-exposed donors. All patients were treated with standard immunosuppression and, for those who developed HCV infection, with a course of DAA. Data collection and analysis were performed after obtaining informed patient consent and IRB approval. Results Baseline characteristics: Mean age of recipients at time of HT was 52 ± 13 years (72% male, 69% Caucasian, 41% on left ventricular assist device support). Mean age of donors was 30 ± 7 years. Among donors, results of HCV antibody (Ab) and nucleic acid testing (NAT) were: 47 Ab+/NAT+, 9 Ab+/NAT-, 2 Ab-/NAT+. Time to transplant: Among all patients, active waitlist time from time of consent to accept HCV-exposed donors was median 4 days (IQR 1, 17). Hepatitis C testing and treatment: No recipients of NAT- donor hearts developed HCV infection. Of the 49 patients who received NAT+ donor hearts, 46 (94%) developed HCV infection, including 27 patients who completed DAA therapy with cure demonstrated by absence of viremia at 12 weeks post-treatment (SVR12), 7 patients in whom treatment is ongoing or recently completed, and 7 patients who have yet to initiate treatment. By the time of ISHLT 2019, we expect to have SVR12 data for all infected patients who have completed treatment, 30 of whom will be at least one year post-HT. To date, there has been no suggestion of increased rates of rejection, graft dysfunction or vasculopathy among infected patients, nor has there been a suggestion of liver injury. Conclusion In the era of highly effective HCV pharmacotherapy, the use of HCV-exposed donors safely allows for expansion of the donor pool.
- Published
- 2019
- Full Text
- View/download PDF
9. Trends in Renal Function among Heart-Transplant Recipients of Donor-Derived Hepatitis C Virus
- Author
-
Mark Wigger, H. Ooi, Matthew R. Danter, S. Smith, S. Ruzevich-Scholl, H. O'Dell, C. Darragh, D.M. Brinkley, Jonathan N. Menachem, Sandip Zalawadiya, Ashish S. Shah, Roman E. Perri, Joseph A. Awad, L. Punnoose, JoAnn Lindenfeld, R. Fowler, Keki R. Balsara, S. Brown Sacks, and Kelly Schlendorf
- Subjects
Pulmonary and Respiratory Medicine ,Transplantation ,medicine.medical_specialty ,Sofosbuvir ,business.industry ,Hepatitis C virus ,Renal function ,Hepatitis C ,medicine.disease ,medicine.disease_cause ,Early initiation ,Gastroenterology ,Internal medicine ,Cohort ,Genotype ,Medicine ,Surgery ,Donor derived ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Abstract
Purpose Donor-derived hepatitis C infection (dd-HCV) infection may increase risk of renal impairment (RI) among heart transplant (HT) recipients. Sofosbuvir, an integral component of anti-HCV direct-acting antivirals (DAAs), has also been linked to RI. To date, no prior study has examined the trends in renal function for HT recipients of dd-HCV infection, and assessed safety and efficacy of sofosbuvir-based DAAs. Methods Between September 2016 and June 2018, 46 HCV-naive patients and 1 with a history of treated-HCV pre-HT underwent HT from HCV-positive donors (follow-up through October 10th, 2018). Patients were treated with ledipasvir-sofosbuvir (genotype 1) or sofosbuvir-velpatasvir (genotype 3) for 12 or 24 weeks; no dose adjustments were made for renal function. Data on renal function were available for 23 patients who achieved a sustained virologic response at 12 weeks after the end of treatment (SVR12; cohort A) and 18 patients who completed 1-year of follow-up (cohort B). Results Treatment of dd-HCV infection was initiated after a median of 6 weeks post-HT. In both cohorts, a non-significant change in median eGFR was noted (Cohort A: pre-transplant eGFR: 62 (IQR 51,84) to SVR12 eGFR: 49 ((IQR: 37, 82), p=0.43); Cohort B: pre-transplant eGFR: 65 (IQR: 54, 84) to 1-year post-HT eGFR: 56 ((IQR: 39, 75); p=0.29). Pre-treatment renal function or early initiation of DAAs post-transplant had no significant impact on changes in renal function during treatment. All patients tolerated DAAs well with 100% completion rate to the assigned therapy and duration, and 100% success at achieving SVR12. Conclusion In this first and largest reported case series to date of HT recipients with dd-HCV infection, we observed that neither the dd-HCV infection nor its treatment with Sofosbuvir-based DAAs increased the risk of RI. Sofosbuvir-based DAAs appear safe, tolerable and effective for HCV treatment even in presence of severe RI.
- Published
- 2019
- Full Text
- View/download PDF
10. Intracoronary Intimal Thickness in Transplant Recipients of Hepatitis C-Positive Donor Hearts
- Author
-
H. Ooi, L. Punnoose, JoAnn Lindenfeld, S. Ruzevich-Scholl, S. Negrotto, D.M. Brinkley, Sandip Zalawadiya, Joseph A. Awad, Mark Wigger, Roman E. Perri, H. O'Dell, C. Darragh, Jonathan N. Menachem, Matthew R. Danter, Keki R. Balsara, Elias V. Haddad, Ashish S. Shah, S. Brown Sacks, Kelly Schlendorf, R. Fowler, and S. Smith
- Subjects
Pulmonary and Respiratory Medicine ,Transplantation ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Percutaneous coronary intervention ,Viremia ,Hepatitis C ,medicine.disease ,medicine.anatomical_structure ,Internal medicine ,Cohort ,Genotype ,medicine ,Surgery ,In patient ,Cardiology and Cardiovascular Medicine ,business ,Donor pool ,Artery - Abstract
Purpose Prior to the advent of direct-acting antivirals (DAAs), donor-derived hepatitis C (dd-HCV) viremia predicted poor post-heart transplant (HT) outcomes, including a higher risk of coronary allograft vasculopathy (CAV) and death. Considering the success of DAAs to treat HCV and the shortage of organs for HT, we institutionalized a clinical protocol of using HCV+ donors. Using intracoronary ultrasound (ICUS) in patients acquiring post-HT HCV infection, we examined the risk of CAV in the current era. Methods Between September 1st 2016 and October 2nd 2018, 54 HCV-naive patients and 1 with a history of treated-HCV pre-transplant, underwent HT from HCV-positive donors (follow-up available through October 10th, 2018). Patients were treated with ledipasvir-sofosbuvir (genotype 1) or sofosbuvir-velpatasvir (genotype 3) for 12 or 24 weeks. ICUS of left anterior descending artery was performed at 6-months and 1-year post-HT for those developing donor-derived HCV (dd-HCV) infection using an automated, mechanical pullback at a rate of 1 mm/ second. Results The ICUS data were available for 20 patients at 6-months (cohort A) and 16 patients at 1-year (cohort B); 14 patients had serial data available at 6-months and 1-year (cohort C). Figures A and B show changes in maximum intima thickness (MIT) for the overall sample and cohort C. For cohort C, absolute change in MIT from 6-months to 1-year was +0.15 (median) (Inter-quartile range: -0.03, 0.42) and only one patient had an increase in MIT by >0.5mm. Two patients in cohort A (10%) and 4 patients in cohort B (25%) had angiographic CAV grade 1; one patient in each cohort had known coronary artery disease in the donor heart. None required percutaneous coronary intervention or re-transplant for CAV at 1-year. Conclusion Utilization of HCV-positive donors may represent a viable strategy to expand the donor pool in era of DAAs. Larger scale data on changes in MIT is required to appropriately assess the effect of dd-HCV infection on incident CAV.
- Published
- 2019
- Full Text
- View/download PDF
11. Three-dimensional lung tumor segmentation from x-ray computed tomography using sparse field active models
- Author
-
Joseph A. Awad, Elaine O'Riordan, Aaron Fenster, Grace Parraga, Amir Owrangi, and Lauren Villemaire
- Subjects
medicine.medical_specialty ,business.industry ,Intraclass correlation ,Coefficient of variation ,Partial volume ,General Medicine ,Image segmentation ,Pearson product-moment correlation coefficient ,symbols.namesake ,medicine ,Medical imaging ,symbols ,Segmentation ,Radiology ,Tomography ,Nuclear medicine ,business ,Mathematics - Abstract
Purpose: Manual segmentation of lung tumors is observer dependent and time-consuming but an important component of radiology and radiation oncology workflow. The objective of this study was to generate an automated lung tumor measurement tool for segmentation of pulmonary metastatic tumors from x-ray computed tomography (CT) images to improve reproducibility and decrease the time required to segment tumor boundaries. Methods: The authors developed an automated lung tumor segmentation algorithm for volumetric image analysis of chest CT images using shape constrained Otsu multithresholding (SCOMT) and sparse field active surface (SFAS) algorithms. The observer was required to select the tumor center and the SCOMT algorithm subsequently created an initial surface that was deformed using level set SFAS to minimize the total energy consisting of mean separation, edge, partial volume, rolling, distribution, background, shape, volume, smoothness, and curvature energies. Results: The proposed segmentation algorithm was compared to manual segmentation whereby 21 tumors were evaluated using one-dimensional (1D) response evaluation criteria in solid tumors (RECIST), two-dimensional (2D) World Health Organization (WHO), and 3D volume measurements. Linear regression goodness-of-fit measures (r2 = 0.63, p
- Published
- 2012
- Full Text
- View/download PDF
12. Intracoronary Intimal Thickness in Recipients of Hepatitis C-Positive Donor Hearts
- Author
-
Chan Y. Chung, S.B. Sacks, S. Ruzevich-Scholl, Roman E. Perri, S. Smith, Rachel M. Hayes, Jonathan N. Menachem, Kelly Schlendorf, Matthew R. Danter, M. Brinkley, H. O'Dell, C. Darragh, Sandip Zalawadiya, H. Ooi, JoAnn Lindenfeld, Mark Wigger, Mary E. Keebler, Joseph A. Awad, and Elias V. Haddad
- Subjects
Pulmonary and Respiratory Medicine ,Transplantation ,medicine.medical_specialty ,business.industry ,Internal medicine ,medicine ,Surgery ,Hepatitis C ,Cardiology and Cardiovascular Medicine ,business ,medicine.disease ,Gastroenterology - Published
- 2018
- Full Text
- View/download PDF
13. Texture analysis of carotid artery atherosclerosis from three-dimensional ultrasound images
- Author
-
Adam Krasinski, Grace Parraga, Joseph A. Awad, and Aaron Fenster
- Subjects
medicine.medical_specialty ,Three dimensional ultrasound ,Wilcoxon signed-rank test ,business.industry ,Carotid arteries ,Feature extraction ,dBc ,General Medicine ,030204 cardiovascular system & hematology ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Image texture ,Classifier fusion ,Medical imaging ,Medicine ,Radiology ,business ,Biomedical engineering - Abstract
Purpose: To quantitatively evaluate local carotid arterial statin effects in 3D USimages using multiclassifier image texture analysis tools. Methods: Texture analysis tools were used to evaluate the effect of 80 mg atorvastatin administered daily to patients with carotid stenosis compared to those treated with placebo. Using three-dimensional carotid ultrasoundimages, 270 texture features from seven texture techniques were extracted from manually segmented carotid arteries based on the intima-media boundary [vessel wall (VW)]. Individual texture features were compared to the previously determined changes in VW volume (VWV) using the distance between classes, the Wilcoxon rank sum test, and accuracy of the classifiers. Texture features that resulted in maximal classification accuracy from each texture technique were selected using Pudil’s sequential floating forward selection (SFFS) as a method of ranking each technique. Finally, SFFS-selected texture features from all texture techniques were used in combination with 24 classifier fusion techniques to improve classification accuracy. Results: Using the measurement of change in VWV, the distance between classes (DBC), Wilcoxon rank sum (WRS) p -value, and median accuracy measures (ACC) were 0.3798, 0.076, and 54.50%, respectively. Texture features improved the detection of statin-related changes using DBC to 0.5199, using WRS to 0.002, and ACC to 63.87%, respectively. The texture techniques that most differentiated between atorvastatin and placebo classes were Fourier power spectrum and Laws texture energy measures. The average classification accuracy between atorvastatin and placebo classes was improved from 57.22 ± 12.11 % using VWV to 97.87 ± 3.93 % using specific texture features. Furthermore, the use of specific texture features resulted in the average area under the receiver-operator characteristic curve (AUC) a value of 0.9988 ± 0.0069 compared to 0.617 ± 0.15 using carotid VWV. Conclusions: Based on DBC, WRS, ACC, and AUC texture features derived from 3D carotid ultrasound were observed to be more sensitive in detecting statin-related changes in carotid atherosclerosis than VWV suggesting that texture classifiers can be used to detect changes in carotid atherosclerosis after therapy.
- Published
- 2010
- Full Text
- View/download PDF
14. Prospective Multicenter Study of Eligibility for Antiviral Therapy Among 4,084 U.S. Veterans with Chronic Hepatitis C Virus Infection
- Author
-
Timothy R. Morgan, Marcos C. Pedrosa, Lennox J. Jeffers, Ramsey Cheung, Hui Shen, Doris B. Strader, Sue Currie, Edmund J. Bini, Warren N. Schmidt, Paul R. King, Richard H. Moseley, B Anand, Charles L. Mendenhall, Norbert Bräu, Kyong-Mi Chang, Stephen J. Rossi, Ayse Aytaman, Anna W. Sasaki, Curt H. Hagedorn, Franz Simon, Teresa L. Wright, Samuel B. Ho, Joseph A. Awad, Ke-Qin Hu, Jawad Ahmad, David W. Johnson, and Bradford Waters
- Subjects
Male ,medicine.medical_specialty ,Substance-Related Disorders ,Antiviral Agents ,Virus ,Chronic hepatitis ,Internal medicine ,Ribavirin ,medicine ,Humans ,health care economics and organizations ,Veterans ,Hepatology ,business.industry ,Contraindications ,Mental Disorders ,Patient Selection ,Gastroenterology ,Antiviral therapy ,Interferon-alpha ,Hepatitis C, Chronic ,Middle Aged ,Patient Acceptance of Health Care ,United States ,humanities ,Surgery ,Treatment Outcome ,Multicenter study ,Female ,Viral disease ,business - Abstract
Many veterans may not be candidates for hepatitis C virus (HCV) treatment due to contraindications to therapy. The aims of this study were to determine the proportion of HCV-infected veterans who were eligible for interferon alfa and ribavirin therapy and to evaluate barriers to HCV treatment.We prospectively enrolled 4,084 veterans who were referred for HCV treatment over a 1-yr period at 24 Veterans Affairs (VA) Medical Centers. Treatment candidacy was assessed using standardized criteria and the opinion of the treating clinician.Overall, 32.2% (95% CI, 30.8-33.7%) were candidates for HCV treatment according to standardized criteria, whereas 40.7% (95% CI, 39.2-42.3%) were candidates in the opinion of the treating clinician. Multivariable analysis identified ongoing substance abuse (OR = 17.68; 95% CI, 12.24-25.53), comorbid medical disease (OR = 9.62; 95% CI, 6.85-13.50), psychiatric disease (OR = 9.45; 95% CI, 6.70-13.32), and advanced liver disease (OR = 8.43; 95% CI, 4.42-16.06) as the strongest predictors of not being a treatment candidate. Among patients who were considered treatment candidates, 76.2% (95% CI, 74.0-78.3%) agreed to be treated and multivariable analysis showed that persons/=50 yr of age (OR = 1.37; 95% CI, 1.07-1.76) and those with50 lifetime sexual partners (OR = 1.44; 95% CI, 1.08-1.93) were more likely to decline treatment.The majority of veteran patients are not suitable candidates for HCV treatment because of substance abuse, psychiatric disease, and comorbid medical disease, and many who are candidates decline therapy. Multidisciplinary collaboration is needed to overcome barriers to HCV therapy in this population.
- Published
- 2005
- Full Text
- View/download PDF
15. Urinary F2-isoprostanes in young healthy children at risk for type 1 diabetes mellitus
- Author
-
Marian Rewers, Richard H. Jones, Laura D Kauffman, Ronald J. Sokol, Jill M. Norris, and Joseph A. Awad
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,Urinary system ,Physiology ,medicine.disease_cause ,Biochemistry ,Tobacco smoke ,Risk Factors ,Surveys and Questionnaires ,Physiology (medical) ,Internal medicine ,Genotype ,medicine ,Humans ,Child ,F2-Isoprostanes ,Type 1 diabetes ,Newborn screening ,business.industry ,Vitamin E ,Infant, Newborn ,Infant ,medicine.disease ,Oxidative Stress ,Diabetes Mellitus, Type 1 ,Endocrinology ,Health ,Child, Preschool ,Female ,business ,Biomarkers ,Oxidative stress - Abstract
Oxidative stress has been linked to many diseases, but little information exists on biomarkers of oxidative stress in healthy children. The purpose of this study was to describe factors that correlate with urinary F2-isoprostanes, an indicator of oxidative stress, and to establish normal concentrations of F2-isoprostanes in children at risk to develop type 1 diabetes mellitus. Creatinine-adjusted urinary F2-isoprostanes were assessed in 342 Denver children under the age of 7 years, from whom we had collected data during 769 clinic visits from August 1997 through January 2001 (mean 2.3 visits per child). Children were identified by newborn screening for HLA-markers, of varying degrees of prediction, for the development of type 1 diabetes. Plasma antioxidants and carotenoids, age at clinic visit, vitamin supplement use, exposure to environmental tobacco smoke, gender, and race were evaluated as correlates to the degree of oxidative stress, using mixed models for longitudinal data. F2-isoprostane levels were highest in infancy and decreased nonlinearly until 7 years. Female gender, HLA-DR3/4 genotype, higher plasma γ-tocopherol:total lipids ratio, and lower α-carotene:total lipids ratio correlated with higher F2-isoprostane levels. Normal values in this healthy population can be used as the basis for future studies of disease mechanisms involving oxidative stress.
- Published
- 2003
- Full Text
- View/download PDF
16. Early Outcomes Using Hepatitis C-Positive Donors for Cardiac Transplantation in the Era of Effective Direct-Acting Antiviral Treatments
- Author
-
Mark Wigger, Matthew R. Danter, Joseph A. Awad, Roman E. Perri, Suzanne Brown Sacks, Marshall Brinkley, Sandip Zalawadiya, H. Ooi, Ashish S. Shah, Kelly Schlendorf, Chun Choi, JoAnn Lindenfeld, Chan Y. Chung, Mary E. Keebler, S. Smith, and Samuel H. Lewis
- Subjects
business.industry ,Hepatitis C ,030204 cardiovascular system & hematology ,medicine.disease ,Virology ,Transplantation ,03 medical and health sciences ,0302 clinical medicine ,030202 anesthesiology ,Immunology ,medicine ,Cardiology and Cardiovascular Medicine ,business ,Direct acting - Published
- 2017
- Full Text
- View/download PDF
17. Increased urinary F2-isoprostane excretion in alcoholic liver disease
- Author
-
Joseph A. Awad and Daniell B. Hill
- Subjects
medicine.medical_specialty ,Alcoholic liver disease ,Bilirubin ,Urinary system ,Urine ,Dinoprost ,Biochemistry ,Excretion ,Lipid peroxidation ,chemistry.chemical_compound ,Liver disease ,Reference Values ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Aspartate Aminotransferases ,Liver Diseases, Alcoholic ,Serum Albumin ,Creatinine ,Alanine Transaminase ,medicine.disease ,Endocrinology ,chemistry ,Lipid Peroxidation ,Biomarkers - Abstract
Free radical-induced lipid peroxidation (LP) is thought to be important in alcoholic liver disease (ALD), however, direct demonstration of increased LP in patients with ALD has been difficult. Quantification of F2-isoprostanes (F2-isoP), prostanoids produced by peroxidation of arachidonic acid, in plasma and urine are sensitive and specific indices of LP in vivo. To determine if LP is increased in ALD, 24-h urinary excretion of F2-isoPs were measured in 10 patients hospitalized because of ALD. The mean urinary excretion of the F2-isoP in the ALD patients' urine was 9.6+/-3.5 ng/mg creatinine, which was significantly elevated compared to controls' urinary excretion, which was 1.7+/-0.2 ng/mg creatinine (p
- Published
- 1999
- Full Text
- View/download PDF
18. THE ISOPROSTANES: UNIQUE PROSTAGLANDIN-LIKE PRODUCTS OF FREE-RADICAL-INITIATED LIPID PEROXIDATION*
- Author
-
William E. Zackert, J. Yang, J. Xu, Cynthia J. Brame, L. J. Roberts, Jason D. Morrow, Yan Chen, Stephanie C. Sanchez, and Joseph A. Awad
- Subjects
Clinical pharmacology ,Antioxidant ,Isoprostane ,Free Radicals ,medicine.medical_treatment ,Prostaglandin ,Human physiology ,Dinoprost ,Bioinformatics ,medicine.disease_cause ,Isoprostanes ,law.invention ,Lipid peroxidation ,Oxidative Stress ,chemistry.chemical_compound ,chemistry ,Biochemistry ,law ,Prostaglandins ,medicine ,Humans ,Pharmacology (medical) ,Lipid Peroxidation ,General Pharmacology, Toxicology and Pharmaceutics ,Oxidative stress - Abstract
The discovery of IsoPs as products of nonenzymatic lipid peroxidation has opened up new areas of investigation regarding the role of free radicals in human physiology and pathophysiology. The quantification of IsoPs as markers of oxidative stress status appears to be an important advance in our ability to explore the role of free radicals in the pathogenesis of human disease. An important need in the field of free-radical medicine is information regarding the clinical pharmacology of antioxidant agents. Because of the evidence implicating free radicals in the pathogenesis of a number of human diseases, large clinical trials are planned or underway to assess whether antioxidants can either prevent the development or ameliorate the pathology of certain human disorders. However, data regarding the most effective doses and combination of antioxidant agents to use in these clinical trials is lacking. As mentioned previously, administration of antioxidants suppresses the formation of IsoPs, even in normal individuals. Thus, measurement of IsoPs may provide a valuable approach to define the clinical pharmacology of antioxidants. In addition to being markers of oxidative stress, several IsoPs possess potent biological activity. The availability of additional IsoPs in synthetic form should broaden our knowledge concerning the role of these molecules as mediators of oxidant stress. Despite the fact that considerable information has been obtained since the initial report of the discovery of IsoPs [6], much remains to be understood about these molecules. With continued research in this area, we believe that much new information will emerge that will open up additional important new areas for future investigation.
- Published
- 1999
- Full Text
- View/download PDF
19. Identification of Free Radical Formation and F2-Isoprostanes in Vivo by Acute Cr(VI) Poisoning
- Author
-
Joseph A. Awad, L. J. Roberts, J. D. Morrow, Maria B. Kadiiska, and Ronald P. Mason
- Subjects
Chromium ,Male ,Free Radicals ,Chemistry ,Receptors, Prostaglandin ,Electron Spin Resonance Spectroscopy ,General Medicine ,Toxicology ,Photochemistry ,Thiobarbituric Acid Reactive Substances ,Rats ,Adduct ,Rats, Sprague-Dawley ,F2-Isoprostanes ,In vivo ,Animals ,Bile ,Lipid Peroxidation ,Free Radical Formation - Abstract
We previously reported the detection of a carbon-centered radical adduct of alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone (POBN) in the bile of rats acutely poisoned with Cr(VI) utilizing an electron spin resonance spin-trapping technique. These former studies suggested that the free radical metabolite was derived from a polyunsaturated fatty acid. The present studies were undertaken to further characterize this radical adduct and to determine whether its formation is associated with enhanced lipid peroxidation in vivo. This report demonstrates that electron spin resonance (ESR) spectra with hyperfine coupling constants aN of 15.71 G and of 2.90 G were present in bile from Cr(VI)-poisoned rats. We found out that virtually identical ESR spectra were obtained when authentic POBN-pentyl radical adducts generated from the reaction of POBN with either pentylhydrazine or linoleic or arachidonic acid with lipoxygenase were added to bile. The hyperfine coupling constants for the POBN-pentyl radical adducts added to bile were as follows: aN = 15.85 G and = 2.60 G for the reaction between pentylhydrazine and POBN; aN = 15.72 G and = 2.61 G for the reaction between arachidonic acid, lipoxygenase, and POBN; and aN = 15.85 G and = 2. 85 G for the reaction between linoleic acid, lipoxygenase, and POBN. In addition, the formation of this radical adduct was associated with lipid peroxidation as quantified by increases in F2-isoprostane levels in bile. These studies, therefore, provide additional evidence that acute Cr(VI) poisoning is associated with enhanced generation of F2-isoprostanes in vivo and tentatively identify the radical species that is produced as the POBN-pentyl radical adduct.
- Published
- 1998
- Full Text
- View/download PDF
20. Experience with Neoral versus Sandimmune in primary liver transplant recipients
- Author
-
D. H. Van Buren, William C. Chapman, J. K. Wright, Sunil K. Geevarghese, C. W. Pinson, David S. Raiford, Jerita L. Payne, Ellen B. Hunter, Joseph A. Awad, and Taylor K. Blair
- Subjects
Adult ,Graft Rejection ,Male ,Nephrology ,medicine.medical_specialty ,medicine.medical_treatment ,Urology ,Renal function ,Azathioprine ,Liver transplantation ,Postoperative Complications ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Prospective cohort study ,Adverse effect ,Transplantation ,business.industry ,Immunosuppression ,Middle Aged ,Liver Transplantation ,Surgery ,Cyclosporine ,Female ,Liver function ,business ,Immunosuppressive Agents ,medicine.drug - Abstract
We compared results using Neoral versus Sandimmune, each in combination with steroid and azathioprine immunosuppression, in primary liver transplantation recipients. There were 15 patients in each group with similar demographic distributions. Intravenous cyclosporine was stopped at 4.3 ± 1.9 days in the Neoral group vs 7.8 ± 4.9 days in the Sandimmune group (P < 0.025). Cyclosporine levels in the first 10 days were higher (mean 306 ng/ml vs 231 ng/ml) in the Neoral group than the Sandimmune group (P < 0.05). The Neoral dose was less than the Sandimmune dose (mean 5.5 ng/kg per day vs 7.9 ng/kg per day) to achieve these levels in that time period (P < 0.05). Two patients (13 %) experienced three episodes of biopsy-proven rejection in the Neoral group compared to nine patients (60 %) with 12 episodes of rejection in the Sandimmune group (P < 0.025). Incidences of neurological and renal complications were similar between the groups. Infections requiring treatment were also similar. Liver function, renal function, and marrow function, evaluated at days 7, 14, 21, 28, and 2, 4, 6, and 12 months post-transplant, were not different between the groups. In summary, shorter use of intravenous cyclosporine and quicker stabilization of trough cyclosporine levels was achieved with Neoral than with Sandimmune. In the early posttransplant period, higher levels with lower doses were achieved with Neoral than with Sandimmune. In our experience, the incidence of rejection was lower with Neoral than with Sandimmune. There were similar lengths of hospitalization, mortality, adverse events, retransplantation, and similar liver, renal, and marrow function up to 1 year posttransplantation. Because of this experience, we continued to use Neoral in a total of 59 primary liver transplant recipients. We have not used intravenous cyclosporine in the last 44 patients. Follow-up was a mean of 11.4 months, ranging from 1 to 27 months. The incidence of rejection was 24 % in these 59 patients compared to our historical experience of 70 % using Sandimmune.
- Published
- 1998
- Full Text
- View/download PDF
21. Nonenzymatic Free Radical-catalyzed Generation of Thromboxane-like Compounds (Isothromboxanes) in Vivo
- Author
-
William E. Zackert, Alice J. Wu, Jason D. Morrow, L. J. Roberts, Vincent C. Daniel, and Joseph A. Awad
- Subjects
Free Radicals ,Thromboxane ,Stereochemistry ,Biochemistry ,Mass Spectrometry ,Lipid peroxidation ,chemistry.chemical_compound ,Isomerism ,In vivo ,Phosphatidylcholine ,Animals ,Molecular Biology ,Phospholipids ,Esterification ,Cell Biology ,Isoprostanes ,Rats ,Thromboxane B2 ,Liver ,Models, Chemical ,chemistry ,Hemiacetal ,Arachidonic acid ,Hydrogenation ,Lipid Peroxidation ,Oxidation-Reduction - Abstract
The isoprostanes (IsoPs) are novel bioactive prostaglandin-like compounds produced in vivo by free radical-catalyzed peroxidation of arachidonyl-containing lipids. Previously, we have identified IsoPs containing F-type and D- and E-type prostane rings that are formed by reduction and rearrangement of IsoP endoperoxide intermediates, respectively. We now explore whether thromboxane B2 (TxB2)-like compounds, termed B2-isothromboxanes (B2-IsoTxs), are formed by rearrangement of IsoP endoperoxides. Detection of these compounds was carried out using a stable isotope dilution mass spectrometric assay originally developed for quantification of cyclooxygenase-derived TxB2. Incubations of arachidonic acid with Fe/ADP/ascorbate for 30 min in vitro generated a series of peaks representing putative B2-IsoTx at levels of 62.4 +/- 21.0 ng/mg arachidonate. Using various chemical modification and derivatization approaches, it was determined that these compounds contained hemiacetal ring structures and two double bonds, as would be expected for B2-IsoTx. Analysis of the compounds by electron ionization mass spectrometry yielded multiple mass spectra similar to those of TxB2. B2-IsoTxs are also formed esterified to phospholipids; oxidation of arachidonyl-containing phosphatidylcholine in vitro followed by hydrolysis resulted in the release of large amounts of these compounds. To explore whether B2-IsoTxs are also formed in vivo, a well characterized animal model of lipid peroxidation consisting of orogastric administration of CCl4 to rats was used. Levels of B2-IsoTx esterified in lipids in the liver increased 41-fold from 2.5 +/- 0.5 to 102 +/- 30 ng/g of liver. In addition, circulating levels of free compounds increased from undetectable (5 pg/ml) to 185 +/- 30 pg/ml after CCl4, a 37-fold increase. Thus, we have provided evidence that IsoTxs constitute another novel class of eicosanoids produced in vivo nonenzymatically by free radical-catalyzed lipid peroxidation. These studies thus expand our understanding of products of lipid peroxidation formed in vivo from the free radical-catalyzed peroxidation of arachidonic acid.
- Published
- 1996
- Full Text
- View/download PDF
22. ISOPROSTANES—RROSTAGLANDIN-LIKE COMPOUNDS FORMED IN VIVO INDEPENDENTLY OF CYCLOOXYGENASE
- Author
-
Joseph A. Awad, Lillian Roberts, Jason D. Morrow, and Raymond F. Burk
- Subjects
Isoprostane ,Antioxidant ,biology ,business.industry ,medicine.medical_treatment ,Gastroenterology ,medicine.disease_cause ,Isoprostanes ,Lipid peroxidation ,chemistry.chemical_compound ,Biochemistry ,chemistry ,In vivo ,biology.protein ,Medicine ,Cyclooxygenase ,business ,Homeostasis ,Oxidative stress - Abstract
F2-isoprostanes are prostanoids produced independently of cyclooxygenase by free radical-catalyzed peroxidation of arachidonic acid-containing lipids. Quantification of F2-isoprostanes from biologic fluids and tissues represents an important advance in the detection and measurement of lipid peroxidation in vivo. In addition, efforts to understand both the biophysical effects of isoprostane containing lipids and the biologic effects of free isoprostanes should lead to a better understanding of the mechanisms responsible for oxidant stress-related alterations in homeostasis. Continued application of F2-isoprostane measurement in experimental models of free radical-induced injury and human disease may allow better design and evaluation of antioxidant therapeutic strategies.
- Published
- 1996
- Full Text
- View/download PDF
23. Demonstration of Halothane-induced Hepatic Lipid Peroxidation in Rats by Quantification of Flourine2-Isoprostanes
- Author
-
John J. Franks, Jean-Louis Horn, L. Jackson Roberts, and Joseph A. Awad
- Subjects
Male ,medicine.medical_specialty ,Isoprostane ,Dinoprost ,Rats, Sprague-Dawley ,Lipid peroxidation ,chemistry.chemical_compound ,Internal medicine ,Isoniazid ,Animals ,Medicine ,Liver injury ,business.industry ,Enflurane ,medicine.disease ,Isoprostanes ,Rats ,F2-Isoprostanes ,Anesthesiology and Pain Medicine ,Endocrinology ,Liver ,Biochemistry ,chemistry ,Phenobarbital ,Anesthetics, Inhalation ,Lipid Peroxidation ,Halothane ,business ,medicine.drug - Abstract
Background Halothane can be reductively metabolized to free radical intermediates that may initiate lipid peroxidation. Hypoxia and phenobarbital pretreatment in Sprague-Dawley rats increases reductive metabolism of halothane. F(2)-isoprostanes, a novel measure of lipid peroxidation in vivo, were used to quantify halothane-induced lipid peroxidation in rats. Methods Rats were exposed to 1% halothane or 14% O(2) for 2 h. Pretreatments included phenobarbital, isoniazid, or vehicle. Rats also were exposed to halothane, enflurane, and desflurane at 21% O(2). Lipid peroxidation was assessed by mass spectrometric quantification of F(2)-isoprostanes. Results Exposure of phenobarbital-pretreated rats to 1% halothane at 21% O(2) for 2 h caused liver and plasma F(2)-isoprostane concentrations to increase fivefold compared to nonhalothane control rats. This halothane-induced increase was enhanced by 14% O(2), but hypoxia alone had no significant effect. Alanine aminotransferase activity at 24 h was significantly increased only in the 1% halothane/14% O(2) group. The effect of cytochrome P450 enzyme induction on halothane-induced F(2)-isoprostane production and liver injury was determined by comparing the effects of isoniazid and phenobarbital pretreatment with no pretreatment under hypoxic conditions. Halothane caused 4- and 11-fold increases in plasma and liver F(2)-isoprostanes, respectively, in non-pretreated rats, whereas isoniazid pretreatment had no effect. Phenobarbital pretreatment potentiated halothane-induced lipid peroxidation with 9- and 20-fold increases in plasma and liver F(2)-isoprostanes, respectively. Alanine aminotransferase activity was increased only in this group. At ambient oxygen concentrations, halothane but not enflurane or desflurane, caused F(2)-isoprostanes to increase. Conclusions Specific halothane-induced lipid peroxidation was demonstrated in Sprague-Dawley rats using quantification of F(2)-isoprostanes and was increased by hypoxia and phenobarbital pretreatment, but not isoniazid pretreatment.
- Published
- 1996
- Full Text
- View/download PDF
24. Excretion of F2-isoprostanes in bile: A novel index of hepatic lipid peroxidation
- Author
-
Joseph A. Awad and Jason D. Morrow
- Subjects
Liver injury ,medicine.medical_specialty ,Hepatology ,Phospholipase ,Biology ,medicine.disease ,Isoprostanes ,Diquat ,Excretion ,Lipid peroxidation ,chemistry.chemical_compound ,F2-Isoprostanes ,Endocrinology ,chemistry ,Internal medicine ,medicine ,Arachidonic acid - Abstract
Lipid peroxidation is believed to be an important mechanism of liver injury caused by some xenobiotics. However, it has been difficult to demonstrate and quantify this process in vivo. Moreover, little is known about the disposition of lipids oxidized in the liver. F2-isoprostanes are prostanoids produced by nonenzymatic free radical—catalyzed peroxidation of arachidonic acid esterified to phospholipids. Hydrolysis of F2-isoprostanes from phospholipids by phospholipases yields free F2-isoprostanes. Excretion of F2-isoprostanes, both free and esterified to phospholipids, was measured in bile after administration of CCI4. The concentration of lipid-esterified F2-isoprostanes in bile exceeded that of free F2-isoprostanes. CCI4 caused a dose-dependent increase in biliary F2-isoprostane excretion that correlated better with the increase in liver F2-isoprostanes than it did with the increase in plasma F2-isoprostanes. Pretreatment with colchicine ameliorated CCI4-liver injury but did not affect baseline or CC14-induced biliary F2-isoprostane excretion. Administration of diquat to selenium-deficient rats, which causes hepatic and renal necrosis, was associated with a 13-fold elevation of plasma F2-isoprostanes. However, both hepatic F2-isoprostane concentrations and biliary F2-isoprostane excretion were increased only threefold. These data suggest that quantification of F2-isoprostane excretion in bile may provide a sensitive and quantitative index of hepatic lipid peroxidation.
- Published
- 1995
- Full Text
- View/download PDF
25. Purification, Characterization, and N-Terminal Amino Acid Sequence of the Adenylyl Cyclase-Activating Protease from Bovine Sperm1
- Author
-
Maria Minuth, Roger A. Johnson, John S. Elce, Adejare J. Adeniran, Joseph A. Awad, and Ilana Shoshani
- Subjects
chemistry.chemical_classification ,Protease ,biology ,medicine.medical_treatment ,Cell Biology ,General Medicine ,Acrosin ,Sperm ,Molecular biology ,Adenylyl cyclase ,chemistry.chemical_compound ,Enzyme ,Reproductive Medicine ,Biochemistry ,chemistry ,Zymogen ,medicine ,biology.protein ,Enzyme inducer ,Peptide sequence - Abstract
We previously reported the extraction of a factor from bovine sperm that activated adenylyl cyclases of rat brain and human platelets, and identified it as a trypsin-like protease that was referred to as "ninhibin." This proteolytic activity was purified to near homogeneity from an alkaline extract of washed sperm particles by sequential chromatography on p-aminobenzamidine agarose and CM-Sephadex. Purification was greater than 100-fold with nearly 30% recovery of protease activity exhibiting a major band of approximately 40 kDa. An approximately 45-kDa form of the protease was also evident in crude extracts and was preferentially isolated when the enzyme was prepared in the presence of a mixture of protease inhibitors. The larger form of the protease was substantially less effective in stimulating adenylyl cyclase than was the smaller form; it is likely to be a zymogen form from which the smaller, more active form is derived. Purified forms of acrosin and ninhibin exhibited similar mobilities on PAGE, similar capacities for activating adenylyl cyclase, similar patterns of proteolytic fragmentation, and similar immunoblot patterns obtained with an antibody against purified bovine acrosin. More importantly, the N-terminal amino acid sequence of bovine ninhibin was found to be identical with that of bovine acrosin and caprine acrosin and more than 75% identical with porcine acrosin. The data support the conclusion that the adenylyl cyclase-activating protease previously referred to as ninhibin is, in fact, acrosin.
- Published
- 1995
- Full Text
- View/download PDF
26. Su1452 Treatment of Chronic Hepatitis C Genotype 2 With Simeprivir Plus Sofosbuvir With or Without Ribavirin in Veterans With and Without Cirrhosis
- Author
-
Jennifer Haglund, Diane Ellis, and Joseph A. Awad
- Subjects
medicine.medical_specialty ,Cirrhosis ,Hepatology ,Sofosbuvir ,business.industry ,Ribavirin ,Gastroenterology ,medicine.disease ,chemistry.chemical_compound ,chemistry ,Chronic hepatitis ,Internal medicine ,Genotype ,medicine ,business ,medicine.drug - Published
- 2016
- Full Text
- View/download PDF
27. Pathogenesis of diquat-induced liver necrosis in selenium-deficient rats: Assessment of the roles of lipid peroxidation and selenoprotein P
- Author
-
Tatsuko Kato, Raymond F. Burk, Kevin A. Cockell, Jason D. Morrow, Kristina E. Hill, P. Reid Lyons, and Joseph A. Awad
- Subjects
Liver injury ,medicine.medical_specialty ,Hepatology ,biology ,GPX3 ,Selenoprotein P ,chemistry.chemical_element ,medicine.disease ,Diquat ,Lipid peroxidation ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Alanine transaminase ,Selenium deficiency ,Internal medicine ,medicine ,biology.protein ,Selenium - Abstract
A dose of diquat below the amount injurious to selenium-replete animals causes lipid peroxidation and massive liver necrosis in selenium-deficient rats. The current study was undertaken to characterize the lipid peroxidation with respect to the liver injury and to correlate the presence of several selenoproteins with the protective effect of selenium. Lipid peroxidation was assessed by measurement of F2 isoprostanes. Diquat caused an increase in liver and plasma F2 isoprotanes. A gradient of these compounds was detected across the liver in some animals, indicating that this organ was a source of some of the plasma F2 isoprostanes. A time-course experiment showed that liver F2 isoprostane concentration increased before plasma alanine transaminase (ALT) levels rose. Selenium-deficient rats were injected with selenium doses from 2 to 50 micrograms/kg and studied 12 hours later. A dose of 10 micrograms/kg or more prevented diquat-induced lipid peroxidation and liver injury. This dose increased plasma selenoprotein P substantially, and a dose-response was present. Liver cellular and plasma glutathione peroxidase activities remained below 2% of their values in control rats for all selenium doses. In selenium-deficient rats given diquat, hepatic lipid peroxidation precedes hepatic necrosis and could therefore be an important mechanism of the necrosis. Selenoprotein P levels were increased by selenium injections, which protected against diquat injury, but glutathione peroxidase activity was not increased. This is consistent with selenoprotein P being the mediator of the selenium effect.
- Published
- 1995
- Full Text
- View/download PDF
28. Three-dimensional semi-automated segmentation of carotid atherosclerosis from three-dimensional ultrasound images
- Author
-
Joseph A. Awad, Grace Parraga, Eranga Ukwatta, Aaron Fenster, and D. Buchanan
- Subjects
Level set method ,Basis (linear algebra) ,business.industry ,Computer science ,Initialization ,Boundary (topology) ,Segmentation ,Computer vision ,Artificial intelligence ,Translation (geometry) ,business ,Energy (signal processing) - Abstract
Three-dimensional ultrasound (3DUS) provides non-invasive and precise measurements of carotid atherosclerosis that directly reflects arterial wall abnormalities that are thought to be related to stroke risk. Here we describe a threedimensional segmentation method based on the sparse field level set method to automate the segmentation of the mediaadventitia (MAB) and lumen-intima (LIB) boundaries of the common carotid artery from 3DUS images. To initiate the process, an expert chooses four anchor points on each boundary on a subset of transverse slices that are orthogonal to the axis of the artery. An initial surface is generated using the anchor points as initial guess for the segmentation. The MAB is segmented first using five energies: length minimization energy, local region-based energy, edge-based energy, anchor point-based energy, and local smoothness energy. Five energies are also used for the LIB segmentation: length minimization energy, local region-based energy, global region-based energy, anchor point-based energy, and boundary separation-based energy. The algorithm was evaluated with respect to manual segmentations on a slice-by-slice basis using 15 3DUS images. To generate results in this paper, inter-slice distance of 2 mm is used for the initialization. For the MAB and LIB segmentations, our method yielded Dice coefficients of more than 92% and sub-millimeter values for mean and maximum absolute distance errors. Our method also yielded a vessel wall volume error of 7.1% ± 3.4%. The realization of a semi-automated algorithm will aid in the translation of 3DUS measurements to clinical research for the rapid, non-invasive, and economical monitoring of atherosclerotic disease.
- Published
- 2012
- Full Text
- View/download PDF
29. Detection and Localization of Lipid Peroxidation in Selenium- and Vitamin E—Deficient Rats Using F2-Isoprostanes
- Author
-
Joseph A. Awad, Jason D. Morrow, Raymond F. Burk, L. J. Roberts, and Kristina E. Hill
- Subjects
Vitamin ,medicine.medical_specialty ,Chromatography, Gas ,medicine.medical_treatment ,Nutritional Status ,Medicine (miscellaneous) ,chemistry.chemical_element ,Weanling ,Pilot Projects ,Dinoprost ,Rats, Sprague-Dawley ,Lipid peroxidation ,Selenium ,chemistry.chemical_compound ,In vivo ,Selenium deficiency ,Internal medicine ,medicine ,Animals ,Vitamin E ,Vitamin E Deficiency ,Nutrition and Dietetics ,Body Weight ,medicine.disease ,Diet ,Rats ,Endocrinology ,Liver ,chemistry ,Lipid Peroxidation ,Vitamin E deficiency - Abstract
Data on the effect of vitamin E and selenium deficiency on lipid peroxidation in vivo have been limited. F2-isoprostanes are novel prostanoids that, free in plasma and esterified to phospholipids in tissues, are markers of lipid peroxidation in vivo. To address the importance of vitamin E and selenium in defense against lipid peroxidation in vivo, we determined F2-isoprostane concentrations in the plasma and organs of rats fed diets deficient in one or both nutrients. Weanling rats were fed a vitamin E- and selenium-deficient diet for 12 wk and then divided into four groups. One group continued to receive the doubly deficient diet, and the other three groups were fed the diet supplemented with vitamin E, selenium or both nutrients (control diet) for 4 wk. Plasma F2-isoprostanes in rats fed the doubly deficient diet were 5.2-fold higher than in animals changed to a control diet. In addition, there were significant differences in liver, lung, kidney, heart and skeletal muscle phospholipid-esterified F2-isoprostanes between these two groups. Lesser increases were noted in the group fed the vitamin E-deficient diet. Selenium deficiency alone was not associated with greater lipid peroxidation. Lipid peroxidation occurs in tissues of rats fed a vitamin E-deficient diet and is increased by concomitant selenium deficiency.
- Published
- 1994
- Full Text
- View/download PDF
30. Detection of the major urinary metabolite of prostaglandin D in the circulation: Demonstration of elevated levels in patients with disorders of systemic mast cell activation
- Author
-
Joseph A. Awad, Jason D. Morrow, and L. Jackson Roberts
- Subjects
medicine.medical_specialty ,integumentary system ,business.industry ,Metabolite ,Urinary system ,Immunology ,Prostaglandin ,medicine.disease ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Internal medicine ,Blood plasma ,medicine ,Immunology and Allergy ,lipids (amino acids, peptides, and proteins) ,Prostaglandin D2 ,Systemic mastocytosis ,business ,Anaphylaxis ,Niacin - Abstract
The symptoms and hemodynamic alterations that accompany episodes of systemic mast cell activation have been largely attributed to excessive prostaglandin (PG)D2 release. Quantification of the major urinary metabolite of PGD2 has been invaluable in elucidating a role for PGD2 in these clinical entities and in the biochemical evaluation of systemic mastocytosis. With the use of a modified mass spectrometric assay for the major urinary metabolite of PGD2, this metabolite was detected in plasma from 10 normal volunteers (3.5 +/- 1.4 pg/ml). Ingestion of niacin, which induces endogenous release of PGD2, increased plasma levels of this metabolite 6.3 to 33 times above the upper limit of normal by 2 hours. Thereafter, levels declined gradually but remained elevated for up to 6 to 8 hours. In contrast, circulating levels of 9 alpha, 11 beta-PGF2, the initial metabolite of PGD2, peaked by 30 minutes and returned to baseline by 2 hours. The clinical utility of measuring the major urinary metabolite in the circulation was demonstrated by detection of markedly increased levels in plasma and serum from patients with systemic mastocytosis and a patient with a severe type I allergic reaction. Thus in the biochemical evaluation of episodes of systemic mast cell activation and endeavors to further elucidate the role of PGD2 in human disease, there are kinetic advantages of measuring the major urinary metabolite of PGD2 in the circulation. One particular advantage is the evaluation of clinical events, which only in retrospect are suspected to be associated with excessive release of PGD2, yet plasma or serum was obtained proximate to the event.
- Published
- 1994
- Full Text
- View/download PDF
31. Effect of oxygen tension on the generation of F2-isoprostanes and malondialdehyde in peroxidizing rat liver microsomes
- Author
-
A W Longmire, Larry L. Swift, Raymond F. Burk, L J Roberts nd, Joseph A. Awad, and Jason D. Morrow
- Subjects
Male ,Isoprostane ,Thiobarbituric acid ,Dinoprost ,Biochemistry ,Rats, Sprague-Dawley ,Lipid peroxidation ,chemistry.chemical_compound ,Malondialdehyde ,Animals ,Pharmacology ,chemistry.chemical_classification ,Arachidonic Acid ,Dose-Response Relationship, Drug ,Carbon Tetrachloride Poisoning ,Rats ,Oxygen tension ,Oxygen ,F2-Isoprostanes ,chemistry ,Microsomes, Liver ,Arachidonic acid ,Lipid Peroxidation ,Polyunsaturated fatty acid - Abstract
Although numerous methods have been developed for the detection of lipid peroxidation, it is generally recognized that most of these lack specificity and/or sensitivity, particularly when applied to in vivo situations. We have reported recently that a series of prostaglandin F2-like compounds, termed F2-isoprostanes, are formed in vivo from the free radical catalyzed peroxidation of arachidonic acid and appear to be a useful marker of oxidant stress. Because of formation of other products of lipid peroxidation, such as alkanes and malondialdehyde (MDA), are affected by oxygen tension, which may influence their usefulness as markers of oxidant stress, we carried out a systematic study of the generation of F2-isoprostanes at various oxygen concentrations and compared these changes with the generation of MDA. The disappearance of the F2-isoprostane precursor, arachidonic acid, was used as a reference measure. Rat liver microsomes were peroxidized using an iron-ascorbate system. The incubations were carried out in sealed flasks at 37 degrees under N2 and various concentrations of O2 up to 100%. F2-isoprostanes were quantified by mass spectrometry and MDA by the thiobarbituric acid reaction. Microsomal fatty acids were measured by gas chromatography. Both MDA and F2-isoprostane formation increased in a time-dependent manner up to 15 min. Their formation correlated with a loss of polyunsaturated fatty acid and with an increase in O2 tension up to 21% O2. At oxygen tensions above 21%, MDA generation continued to increase, while F2-isoprostane generation and arachidonic acid loss did not. Levels of MDA and F2-isoprostanes increased a maximum of 65 and 9.4 times baseline values, respectively. These studies, therefore, define factors that influence the formation of F2-isoprostanes in an in vitro model of lipid peroxidation. Further, they demonstrate that higher O2 tensions do not block formation of F2-isoprostanes and validate their usefulness for assessing lipid peroxidation under high, as well as low, oxygen tension.
- Published
- 1994
- Full Text
- View/download PDF
32. Regulation of eicosanoid production and mitogenesis in rat intestinal epithelial cells by transforming growth factor-alpha and phorbol ester
- Author
-
Joseph A. Awad, Phyllis R. Bishop, L J Roberts nd, Raymond N. DuBois, and Jason D. Morrow
- Subjects
medicine.medical_specialty ,TGF alpha ,Indomethacin ,Stimulation ,Transfection ,Epithelium ,Gene Expression Regulation, Enzymologic ,Cell Line ,Electron Transport Complex IV ,Mice ,chemistry.chemical_compound ,Sulindac ,Microsomes ,Internal medicine ,medicine ,Animals ,RNA, Messenger ,Intestinal Mucosa ,Regulation of gene expression ,biology ,Epithelial Cells ,DNA ,General Medicine ,Transforming Growth Factor alpha ,Molecular biology ,Rats ,Kinetics ,Endocrinology ,chemistry ,Prostaglandin-Endoperoxide Synthases ,Cell culture ,Enzyme Induction ,biology.protein ,Phorbol ,Eicosanoids ,Tetradecanoylphorbol Acetate ,Cyclooxygenase ,DNA Probes ,Cell Division ,Thymidine ,Research Article ,Eicosanoid Production - Abstract
Growth factors and tumor promoters have been shown to play a role in intestinal epithelial growth regulation and transformation. In this study, transforming growth factor-alpha (TGF alpha) and the tumor promoter, tetradecanoyl phorbol acetate (TPA), are shown to stimulate the production of eicosanoids by rat intestinal epithelial (RIE-1) cells in culture. A 4.5-kb mRNA, which hybridizes to the mouse cyclooxygenase-2 cDNA probe, is elevated 18-fold within 30 min after TGF alpha or TPA treatment. Stimulation of RIE-1 cells with TGF alpha leads to the increase of a protein (M(r) approximately 69,000), which binds a monospecific antibody to the mouse cyclooxygenase-2 protein. Dexamethasone markedly inhibits the increase of the 4.5-kb mRNA. Pretreatment of TGF alpha or TPA-stimulated RIE-1 cells with dexamethasone or cyclooxygenase inhibitors prevents the increase in eicosanoid production by these cells. Treatment of quiescent RIE-1 cells with TGF alpha stimulates mitogenesis. This mitogenic activity is blocked by pretreating the cells with dexamethasone or cyclooxygenase inhibitors. A mitogen-inducible cyclooxygenase gene is thus shown to be regulated by TGF alpha and TPA in rat intestinal epithelial cells. We suggest that products of an intestinal growth factor-inducible cyclooxygenase may play a role in the regulation of mitogenesis.
- Published
- 1994
- Full Text
- View/download PDF
33. Lung tumours segmentation on CT using sparse field active model
- Author
-
Grace Parraga, Aaron Fenster, Laura Wilson, and Joseph A. Awad
- Subjects
Data set ,Level set ,medicine.diagnostic_test ,business.industry ,Computer science ,medicine ,Partial volume ,Computed tomography ,Segmentation ,Lung tumours ,Nuclear medicine ,business - Abstract
Three-dimensional (3D) manual segmentation of lung tumours is observer-dependent and time consuming, which are major limitations for use in clinical trials. In this paper we present a semi-automated 3D segmentation method, which is more time-efficient and less operator dependent than manual segmentation. We developed a semi-automated algorithm to segment lung tumours on chest computed tomography (CT) images using shape constrained multi-thresholding (SCMT) and sparse field active model (S FAM) techniques. For each 2D slice of CT tumour image, an initial contour was generated using SCMT. This initial contour was then deformed using SFAM. Seven energies were utilized in the SFAM technique to control the deformation namely: global region, local region, curvature, edge information, smoothness, anchor, and partial volume. The proposed algorithm was tested with 70 CT tumour slices (19 well-defined tumours (WD) located centrally in the lung parenchyma without significant vasculature and 51 vascularized or juxtapleural tumours (VJ)). Our results showed that the initial contour generated by the SCMT technique was sufficient to segment the well-defined (WD) tumours without any deformation. However, the deformation using SFAM was required to segment vascularized or juxtapleural (VJ) tumours. The results of the proposed segmentation algorithm were evaluated by comparing them to manual segmentation using the dice coefficient (DC). Th e average DC was 96.3±1.1% and 95.2±1.6% for WD and VJ tumour images respectively. The average DC obtained for the entire data set was 95.5±1.6%, which shows that the proposed algorithm can accurately segment lung tumours and can be utilized for monitoring tumours response to treatment. Keywords: Lung tumours, CT, level set, sparse field, segmentation, lung nodule, partial volume, anchor
- Published
- 2011
- Full Text
- View/download PDF
34. Segmentation of the lumen and media-adventitia boundaries of the common carotid artery from 3D ultrasound images
- Author
-
Adam Krasinski, Jagath Samarabandu, Grace Parraga, Joseph A. Awad, Aaron D. Ward, Eranga Ukwatta, and Aaron Fenster
- Subjects
Reproducibility ,medicine.diagnostic_test ,business.industry ,Ultrasound ,medicine.disease ,Stenosis ,medicine.anatomical_structure ,Adventitia ,medicine.artery ,medicine ,Segmentation ,3D ultrasound ,Common carotid artery ,business ,Nuclear medicine ,Lumen (unit) - Abstract
Three-dimensional ultrasound (3D US) vessel wall volume (VWV) measurements provide high measurement sensitivity and reproducibility for the monitoring and assessment of carotid atherosclerosis. In this paper, we describe a semi-automated approach based on the level set method to delineate the media-adventitia and lumen boundaries of the common carotid artery from 3D US images to support the computation of VWV. Due to the presence of plaque and US image artifacts, the carotid arteries are challenging to segment using image information alone. Our segmentation framework combines several image cues with domain knowledge and limited user interaction. Our method was evaluated with respect to manually outlined boundaries on 430 2D US images extracted from 3D US images of 30 patients who have carotid stenosis of 60% or more. The VWV given by our method differed from that given by manual segmentation by 6.7% ± 5.0%. For the media-adventitia and lumen segmentations, respectively, our method yielded Dice coefficients of 95.2% ± 1.6%, 94.3% ± 2.6%, mean absolute distances of 0.3 ± 0.1 mm, 0.2 ± 0.1 mm, maximum absolute distances of 0.8 ± 0.4 mm, 0.6 ± 0.3 mm, and volume differences of 4.2% ± 3.1%, 3.4% ± 2.6%. The realization of a semi-automated segmentation method will accelerat e the translation of 3D carotid US to clinical care for the rapid, non-invasive, and economical monitoring of atherosclerotic disease progression and regression during therapy. Keywords: Carotid segmentation, three-dimensional ultrasound, level set method, vessel wall volume, carotid atherosclerosis
- Published
- 2011
- Full Text
- View/download PDF
35. Three-dimensional ultrasound-based texture analysis of the effect of atorvastatin on carotid atherosclerosis
- Author
-
Grace Parraga, Joseph A. Awad, Adam Krasinski, Aaron Fenster, and David Spence
- Subjects
Carotid atherosclerosis ,Three dimensional ultrasound ,medicine.diagnostic_test ,Wilcoxon signed-rank test ,business.industry ,Atorvastatin ,Texture (music) ,Medicine ,3D ultrasound ,business ,Nuclear medicine ,Texture feature ,Analysis method ,medicine.drug - Abstract
Carotid atherosclerosis is the major cause of ischemic stroke, a leading cause of death and disability. This is driving the development of image analysis methods to quantitatively evaluate local arterial effects of potential treatments of carotid disease. Here we investigate the use of novel texture analysis tools to detect potential changes in the carotid arteries after statin therapy. Three-dimensional (3D) carotid ultrasound images were acquired from the left and right carotid arteries of 35 subjects (16 treated with 80 mg atorvastatin and 19 treated with placebo) at baseline and after 3 months of treatment. Two-hundred and seventy texture features were extracted from 3D ultrasound carotid artery images. These images previously had their vessel walls (VW) manually segmented. Highly ranked individual texture features were selected and compared to the VW volume (VWV) change using 3 measures: distance between classes, Wilcoxon rank sum test, and accuracy of the classifiers. Six classifiers were used. Using texture feature (L7R7) increases the average accuracy and area under the ROC curve to 74.4% and 0.72 respectively compared to 57.2% and 0.61 using VWV change. Thus, the results demonstrate that texture features are more sensitive in detecting drug effects on the carotid vessel wall than VWV change.
- Published
- 2010
- Full Text
- View/download PDF
36. Transforming growth factor alpha protection against drug-induced injury to the rat gastric mucosa in vivo
- Author
-
Carlos L. Arteaga, M J Wargovich, E R Kraus, W H Polk, C R Boland, Robert J. Coffey, Joseph A. Awad, Marco Romano, and L B Nanney
- Subjects
medicine.medical_specialty ,TGF alpha ,Time Factors ,Indomethacin ,Prostaglandin ,Biology ,Ornithine Decarboxylase ,Dinoprostone ,Rats, Sprague-Dawley ,Necrosis ,chemistry.chemical_compound ,Internal medicine ,Image Processing, Computer-Assisted ,medicine ,Gastric mucosa ,Animals ,Sulfhydryl Compounds ,Phosphorylation ,Phosphotyrosine ,Aspirin ,Ethanol ,Gastric Mucins ,Stomach ,Tyrosine phosphorylation ,General Medicine ,Transforming Growth Factor alpha ,Rats ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Ethylmaleimide ,Gastric Mucosa ,Type C Phospholipases ,Microscopy, Electron, Scanning ,Systemic administration ,Tyrosine ,Gastric acid ,Research Article ,Transforming growth factor - Abstract
This study was designed to determine whether transforming growth factor alpha (TGF alpha) protects rat gastric mucosa against ethanol- and aspirin-induced injury. Systemic administration of TGF alpha dose-dependently decreased 100% ethanol-induced gastric mucosal injury; a dose of 50 micrograms/kg delivered intraperitoneally 15 min before ethanol decreased macroscopic mucosal injury by > 90%. At the microscopic level, TGF alpha prevented deep gastric necrotic lesions and reduced disruption of surface epithelium. Pretreatment with orogastric TGF alpha (200 micrograms/kg) only partially (40%) decreased macroscopic ethanol damage. Intraperitoneal administration of TGF alpha at a dose of 10 micrograms/kg, which does not significantly inhibit gastric acid secretion, decreased aspirin-induced macroscopic damage by > 80%. TGF alpha protection does not seem to be mediated by prostaglandin, glutathione, or ornithine decarboxylase-related events, as evidenced by lack of influence of the inhibition of their production. Pretreatment with the sulfhydryl blocking agent N-ethylmaleimide partially abolished (40%) the protective effect of TGF alpha. In addition, systemic administration of TGF alpha resulted in a two-fold increase in tyrosine phosphorylation of phospholipase C-gamma 1 and in a time- and dose-dependent increase in levels of immunoreactive insoluble gastric mucin; these events occurred in a time frame consistent with their participation in the protective effect of TGF alpha.
- Published
- 1992
- Full Text
- View/download PDF
37. Black patients with chronic hepatitis C have a lower sustained viral response rate than non-Blacks with genotype 1, but the same with genotypes 2/3, and this is not explained by more frequent dose reductions of interferon and ribavirin*
- Author
-
Ayse Aytaman, S. Currie, Ramsey Cheung, Curt H. Hagedorn, Edmund J. Bini, Lennox J. Jeffers, Warren N. Schmidt, Hui Shen, Teresa L. Wright, Timothy R. Morgan, P. D. King, Marcos C. Pedrosa, Bhupinderjit S. Anand, Stephen J. Rossi, Kyong-Mi Chang, Norbert Bräu, D Johnson, Samuel B. Ho, Richard H. Moseley, Bradford Waters, F. R. Simon, J. Ahmad, Joseph A. Awad, Ke-Qin Hu, and Charles L. Mendenhall
- Subjects
Liver Cirrhosis ,Male ,medicine.medical_specialty ,Genotype ,Hepatitis C virus ,Biopsy ,Black People ,Hepacivirus ,medicine.disease_cause ,Gastroenterology ,Antiviral Agents ,White People ,chemistry.chemical_compound ,Interferon ,Virology ,Internal medicine ,Ribavirin ,medicine ,Sustained viral response ,Humans ,Prospective Studies ,Hepatology ,Dose-Response Relationship, Drug ,business.industry ,Interferon-alpha ,Alanine Transaminase ,Hepatitis C ,Odds ratio ,Hepatitis C, Chronic ,Middle Aged ,medicine.disease ,Confidence interval ,Infectious Diseases ,Logistic Models ,chemistry ,Immunology ,Multivariate Analysis ,RNA, Viral ,Female ,business ,medicine.drug - Abstract
Summary. In previous hepatitis C virus (HCV) treatment studies, Black patients not only had a lower sustained viral response (SVR) rate to interferon and ribavirin (RBV) than non-Black patients but also a higher frequency of HCV genotype 1 (GT-1) infection. The aim of this community-based study was to determine whether Black patients have a lower SVR rate independent of genotype. We prospectively enrolled 785 patients (24.8% Black, 71.5% White, 3.7% others) who received interferon alpha-2b 3 MU three times weekly + RBV 1000–1200 mg/day for 24 weeks (GT-2/3) or 48 weeks (GT-1). Black patients were more commonly infected with GT-1 (86.8%vs 64.8%, P
- Published
- 2006
38. Case of fulminant hepatic failure due to unrecognized peripartum cardiomyopathy
- Author
-
Lorraine B. Ware, Joseph A. Awad, and Kevin M. Fussell
- Subjects
Adult ,medicine.medical_specialty ,Digoxin ,Captopril ,Cardiotonic Agents ,Peripartum cardiomyopathy ,Critical Care ,Fulminant ,Pregnancy Complications, Cardiovascular ,Cardiomyopathy ,Critical Care and Intensive Care Medicine ,Fulminant hepatic failure ,Pregnancy ,Renal Dialysis ,Intensive care ,medicine ,Humans ,Diagnostic Errors ,Intensive care medicine ,Hepatic encephalopathy ,reproductive and urinary physiology ,Antihypertensive Agents ,Coma ,business.industry ,Blood Coagulation Disorders ,Liver Failure, Acute ,medicine.disease ,Treatment Outcome ,Heart failure ,Hypertension ,Female ,medicine.symptom ,Hypotension ,business ,Cardiomyopathies - Abstract
To describe a postpartum patient who presented with fulminant hepatic failure and hepatic coma as a result of unrecognized peripartum cardiomyopathy.Case report.Medical intensive care unit of a tertiary care academic medical center.A 35-yr-old woman 5 wks postpartum from an uneventful spontaneous vaginal delivery who was transferred to our institution with fulminant hepatic failure and worsening hepatic encephalopathy of unknown etiology for consideration of liver transplantation.An echocardiogram was obtained as part of an evaluation for refractory shock and the patient was found to have severe global hypokinesis with an ejection fraction of approximately 15%. She was diagnosed with peripartum cardiomyopathy and treatment with digoxin and afterload reduction was initiated.After initiation of appropriate treatment for dilated cardiomyopathy, the patient's hepatic failure resolved and she made a full recovery.Congestive heart failure is one of the few treatable causes of fulminant hepatic failure. Congestive heart failure must always be included in the differential diagnosis of fulminant hepatic failure of unknown pathogenesis.
- Published
- 2005
39. A three-part intervention to change the use of hormone replacement therapy in response to new evidence
- Author
-
Joseph A. Awad, Robert S. Dittus, Eric L. Grogan, Theodore Speroff, William J. Falbe, Tom A. Elasy, and Christianne L. Roumie
- Subjects
medicine.medical_specialty ,Medical Records Systems, Computerized ,Reminder Systems ,Pharmacotherapy ,Chart ,Patient Education as Topic ,Intervention (counseling) ,Internal Medicine ,medicine ,Outpatient clinic ,Humans ,Hormone replacement therapy ,Prospective Studies ,Practice Patterns, Physicians' ,Intensive care medicine ,Prospective cohort study ,Aged ,Randomized Controlled Trials as Topic ,Withholding Treatment ,business.industry ,Estrogen Replacement Therapy ,General Medicine ,Middle Aged ,medicine.disease ,Menopause ,Physical therapy ,Female ,Guideline Adherence ,business - Abstract
Slow adaptation of new information by providers may result in suboptimal care.To evaluate changes in prescriptions for combination hormone replacement therapy (HRT) after a multicomponent intervention to deliver new information to patients and providers.Quasi-experimental study with multiple baselines.Veterans Affairs Tennessee Valley Healthcare System (VA-TVHS).Female veterans age 50 to 79 years who had a prescription filled at the VA-TVHS for combination HRT between 1 January 2002 and 1 July 2002.Discontinuation of HRT.A 3-part intervention consisted of 1) notifying patients who were using combination HRT of the results of the Women's Health Initiative study (patient education component), 2) sending all providers an e-mail with the Women's Health Initiative study results (provider education component), and 3) placing an electronic alert in each eligible patient's chart (provider care component). The alert asked providers to reevaluate the need for combination HRT. The intervention was implemented at different VA-TVHS sites in a stepwise fashion to differentiate intervention effect from media effect. Study follow-up continued through 31 December 2002.The total rate of discontinuation of combination HRT was 70.3% in 2002. The proportion of discontinuation from time of media release until intervention was 23.3%. After initiation of the intervention, an additional 43% of the original cohort discontinued use of HRT; this percentage represents a 59% relative decrease in HRT use among patients. After adjustment for time, the discontinuation rate per day was 4.9 times higher after the multifacted intervention than after the media release (95% CI, 1.8 to 13.1).A true control group is lacking.A multifaceted approach in an integrated health care system with standardized methods of communication is an effective way to implement patient-centered, effective, and timely care with changing medical knowledge.
- Published
- 2004
40. Survival and quality of life after organ transplantation in veterans and nonveterans
- Author
-
William Nylander, Theodore Speroff, Javed Butler, Tarik Kizilisik, Ravi S. Chari, Derek E. Moore, J. Kelly Wright, C. Wright Pinson, Joseph A. Awad, Irene D. Feurer, D. Lee Gorden, and David Shaffer
- Subjects
Adult ,Male ,medicine.medical_specialty ,Time Factors ,Databases, Factual ,Hospitals, Veterans ,Single Center ,Gastroenterology ,Organ transplantation ,Quality of life ,Physical functioning ,Internal medicine ,Surveys and Questionnaires ,Medicine ,Humans ,University medical ,Karnofsky Performance Status ,Veterans Affairs ,Veterans ,business.industry ,Graft Survival ,Patient survival ,General Medicine ,Organ Transplantation ,Middle Aged ,Survival Analysis ,Tennessee ,United States ,Surgery ,Transplantation ,United States Department of Veterans Affairs ,Cross-Sectional Studies ,Case-Control Studies ,Quality of Life ,Female ,business ,Follow-Up Studies - Abstract
Background Some previous studies suggested that transplantation performed in Department of Veterans Affairs (VA) patients was associated with a higher rate of complications and poorer outcomes. We examined more than a decade of experience with solid organ transplantation at a single center and compared VA patients with nonveteran patients to assess long-term patient and graft survival and health-related quality of life (HRQOL). Methods Demographic, clinical, and survival data were extracted from a database that included all transplants from January 1990 through December 2002 at Vanderbilt University Medical Center (non-VA) and the Nashville VA Medical Center (VA). The HRQOL was assessed in a subset of patients using the Karnofsky functional performance (FP) index and the Short-Form-36 self-report questionnaire. Data were analyzed by Kaplan-Meier survival and analysis of variance methods. Results One thousand eight hundred nine adult patients receiving solid organ transplants (1,896 grafts) between 1990 and 2002 were reviewed: 380 VA patients (141 liver, 54 heart, 183 kidney, 2 lung) and 1429 non-VA patients (280 liver, 246 heart, 749 kidney, 154 lung). Mean follow-up time was 46 ± 1 months. Five-year graft survival for VA and non-VA patients, respectively, was liver 65% ± 5% versus 69% ± 3% (P = 0.97); heart 73% ± 8% versus 73% ± 3% (P = 0.67); and kidney 76% ± 5% versus 77% ± 2% (P = 0.84). Five-year patient survival was liver 75% ± 5% versus 78% ± 3% (P = 0.94); heart 73% ± 8% versus 74% ± 3% (P = 0.75); and kidney 84% ± 4% versus 87% ± 2% (P = 0.21) for VA and non-VA, respectively. In the first 3 years after transplant, the FP scores for VA versus non-VA patients were 85 ± 2 versus 87 ± 1 (P = 0.50). The SF-36 mental component scales were 47 ± 3 versus 49 ± 1 (P = 0.39); and the SF-36 physical component scales were 37 ± 2 versus 38 ± 1 (P = 0.59), respectively. Longer-term (through year 7) HRQOL scores for VA versus non-VA patients were FP 85 ± 1 versus 88 ± 1 (P = 0.17); mental component scales 47 ± 2 versus 49 ± 1 (P = 0.29); and physical component scales 35 ± 2 versus 39 ± 1 (P = 0.05), respectively. Conclusions The veteran patients have similar graft and patient survival as the nonveteran patients. Overall quality of life is similar between veterans and nonveterans during the first three years after transplantation. A trend toward a later decline in the veterans' perception of their physical functioning may stem from the increased prevalence of hepatitis C virus among VA liver transplant recipients, a known factor reducing late HRQOL.
- Published
- 2003
41. Bromfenac (Duract)-associated hepatic failure requiring liver transplantation
- Author
-
Joseph A. Awad, E B Hunter, Philip E. Johnston, C. W. Pinson, and G Tanner
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Bromfenac sodium ,Liver transplantation ,Gastroenterology ,chemistry.chemical_compound ,Benzophenones ,Fulminant hepatic failure ,Liver Function Tests ,Internal medicine ,Osteoarthritis ,medicine ,Adverse Drug Reaction Reporting Systems ,Humans ,Nonsteroidal ,Hepatology ,medicine.diagnostic_test ,business.industry ,United States Food and Drug Administration ,Anti-Inflammatory Agents, Non-Steroidal ,Long-Term Care ,United States ,Surgery ,Liver Transplantation ,Transplantation ,chemistry ,Toxicity ,Bromfenac ,Liver function tests ,business ,Liver Failure ,medicine.drug ,Bromobenzenes - Abstract
Bromfenac sodium (Duract) is a phenylacetic acid-derived nonsteroidal anti-inflammatory agent introduced in the United States in 1997 and withdrawn in 1998. We describe the first case of fulminant hepatic failure associated with this agent treated successfully with liver transplantation. Similarities to hepatotoxicity with related agents is discussed.
- Published
- 1999
42. Eicosanoid Production and Growth Regulation in Rat Intestinal Epithelial Cells
- Author
-
L. Roberts, Joseph A. Awad, Raymond N. DuBois, M. Tsujii, Jason D. Morrow, and Phyllis R. Bishop
- Subjects
Sulindac ,biology ,Eicosanoid metabolism ,business.industry ,Colorectal cancer ,Intestinal polyp ,medicine.disease ,medicine.disease_cause ,digestive system diseases ,Familial adenomatous polyposis ,medicine ,Cancer research ,biology.protein ,Cyclooxygenase ,business ,Carcinogenesis ,Eicosanoid Production ,medicine.drug - Abstract
The role of eicosanoids in regulating intestinal epithelial proliferation and differentiation is unknown. For years clinicians have been aware that patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) are at increased risk for development of ulcerations in the gastroenteric tract. These drugs are potent inhibitors of cyclooxygenase. Recent clinical studies indicate that NSAIDs may also affect intestinal polyp formation and/or the development of colon cancer in humans (1–6). One study demonstrated that colon polyp size and number decreased significantly in familial adenomatous polyposis patients treated with sulindac [a pro-drug which is converted to a cyclooxygenase inhibitor in the liver and colon] (5). In epidemiologic studies, cyclooxygenase inhibitors (like aspirin) have been shown to decrease the relative rate of colon cancer by about 40–50% in humans (1–4). The mechanism by which NSAIDs cause either polyp regression or lower the relative rate of colon cancer is unknown. The precise relationship between eicosanoid metabolism, intestinal epithelial growth regulation and carcinogenesis is presently an area of active investigation (2). We have recently reported that a mitogen inducible cyclooxygenase gene is activated in intestinal epithelial cells treated with growth factors or tumor promoters (7).
- Published
- 1997
- Full Text
- View/download PDF
43. Evidence of free radical-mediated injury (isoprostane overproduction) in scleroderma
- Author
-
S. Bobo Tanner, C. Michael Stein, L. Jackson Roberts, Jason D. Morrow, and Joseph A. Awad
- Subjects
Adult ,Male ,medicine.medical_specialty ,Pathology ,Isoprostane ,Immunology ,medicine.disease_cause ,Scleroderma ,Lipid peroxidation ,Pathogenesis ,chemistry.chemical_compound ,Rheumatology ,Internal medicine ,Immunology and Allergy ,Medicine ,Humans ,Pharmacology (medical) ,Aged ,Biologic marker ,Creatinine ,Scleroderma, Systemic ,business.industry ,Middle Aged ,medicine.disease ,Thromboxane B2 ,Oxidative Stress ,Endocrinology ,chemistry ,Prostaglandins F, Synthetic ,Arachidonic acid ,Female ,business ,Oxidative stress - Abstract
Objective. Free radical-induced oxidative stress with consequent lipid peroxidation and resultant tissue damage has been suggested as a potential mechanism of the pathogenesis of scleroderma. However, because reliable measurement of lipid peroxidation in vivo is difficult, it has not been possible to adequately examine this hypothesis. We have previously described a series of bioactive prostaglandin F 2 -like compounds, termed F 2 -isoprostanes, produced in vivo in humans by the non-cyclooxygenase, free radical-catalyzed, peroxidation of arachidonic acid and have shown them to be a reliable measure of lipid peroxidation in vivo. In the present study, we determined whether scleroderma is associated with enhanced oxidative stress. Methods. As a measure of oxidative stress, we determined urinary concentrations of a tetranordicarboxylic acid metabolite of F 2 -isoprostanes (F 2 IP-M) by mass spectrometry in 8 patients with scleroderma (representing a wide spectrum of disease, including limited disease with refractory digital ulceration or pulmonary hypertension, and diffuse disease) and in 10 healthy control subjects. Results. F 2 IP-M concentrations were significantly higher in patients with scleroderma (mean ± SEM 3.41 ± 0.64 ng/mg of creatinine) than in healthy controls (1.22 ± 0.14 ng/mg of creatinine) (P = 0.002). These elevations occurred in patients with limited disease and in those with diffuse disease. Conclusion. The increased level of urinary F 2 IP-M supports the hypothesis that free radical-induced oxidative injury occurs in scleroderma and provides a biologic marker whose relationship to disease activity and disease therapy may be important. These findings may also provide a rationale for exploring whether antioxidant therapy may influence the natural course of the disease.
- Published
- 1996
44. Comments on prostaglandin F2 alpha rises in response to hydroxyl radical generated in vivo
- Author
-
Joseph A. Awad, L. Jackson Roberts, and Jason D. Morrow
- Subjects
chemistry.chemical_compound ,Arachidonic Acid ,chemistry ,Free Radicals ,Stereochemistry ,In vivo ,Hydroxyl Radical ,Physiology (medical) ,Prostaglandin ,Humans ,Hydroxyl radical ,Dinoprost ,Biochemistry - Published
- 1995
45. Cloning and characterization of a growth factor-inducible cyclooxygenase gene from rat intestinal epithelial cells
- Author
-
Raymond N. DuBois, Phyllis R. Bishop, Joseph A. Awad, M. Tsujii, A. Lanahan, and K. Makita
- Subjects
DNA, Complementary ,Physiology ,medicine.medical_treatment ,Molecular Sequence Data ,Molecular cloning ,Kidney ,Transfection ,Epithelium ,Gene Expression Regulation, Enzymologic ,Cell Line ,Mice ,Physiology (medical) ,Microsomes ,Chlorocebus aethiops ,medicine ,Animals ,Amino Acid Sequence ,RNA, Messenger ,Cloning, Molecular ,Gene Library ,Cell Nucleus ,Expression vector ,Hepatology ,biology ,Base Sequence ,Sequence Homology, Amino Acid ,Growth factor ,Gastroenterology ,Brain ,Transforming Growth Factor alpha ,Blotting, Northern ,Molecular biology ,Rats ,Intestines ,Eicosanoid ,Cell culture ,Prostaglandin-Endoperoxide Synthases ,Enzyme Induction ,biology.protein ,Cyclooxygenase ,Transforming growth factor - Abstract
Growth factors have been shown to play a role in intestinal epithelial growth regulation and transformation. Utilizing standard differential cloning techniques, we have isolated a growth factor-inducible gene (RS-2) from rat intestinal epithelial cells that has approximately 95% homology to the mouse mitogen-inducible cyclooxygenase (COX-2) at the amino acid level. This cDNA hybridizes to a approximately 4.5-kb mRNA from transforming growth factor (TGF)-alpha-stimulated rat intestinal epithelial (RIE-1) cells and is constitutively expressed in vivo in adult rat kidney and brain. Nuclear run-on experiments demonstrate that the increase of RS-2 mRNA after TGF-alpha stimulation is in part due to an increased transcription rate of the gene. The coding region for RS-2 was subcloned into a pCMV-2 expression vector, and the RS-2 protein was expressed in COS-1 cells. Microsomal fractions isolated from the COS-1 cells transfected with the RS-2 expression vector contained cyclooxygenase activity. In addition to the production of prostaglandins, the recombinant RS-2 protein also catalyzed the formation of three other eicosanoid products. In summary, we have cloned a mitogen-inducible cyclooxygenase gene from rat intestinal cells that is induced following growth factor stimulation.
- Published
- 1994
46. Gamma-linolenic acid suppression of hepatic Ito cell mitogenesis: post-PDGF receptor prostaglandin-independent mechanism
- Author
-
Joseph A. Awad, B. H. Davis, and D. W. A. Beno
- Subjects
Male ,medicine.medical_specialty ,Platelet-derived growth factor ,Physiology ,Prostaglandin ,Protein Serine-Threonine Kinases ,Immediate-Early Proteins ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Internal medicine ,Proto-Oncogene Proteins ,medicine ,Animals ,Receptors, Platelet-Derived Growth Factor ,gamma-Linolenic acid ,gamma-Linolenic Acid ,Phosphotyrosine ,Cells, Cultured ,Early Growth Response Protein 1 ,Serine/threonine-specific protein kinase ,Platelet-Derived Growth Factor ,biology ,nutritional and metabolic diseases ,Prostanoid ,Genes, fos ,Tyrosine phosphorylation ,Zinc Fingers ,Cell Biology ,Molecular biology ,Immunohistochemistry ,Rats ,DNA-Binding Proteins ,Enzyme Activation ,Proto-Oncogene Proteins c-raf ,Kinetics ,Endocrinology ,chemistry ,Liver ,biology.protein ,Hepatic stellate cell ,Tyrosine ,lipids (amino acids, peptides, and proteins) ,hormones, hormone substitutes, and hormone antagonists ,Platelet-derived growth factor receptor ,Cell Division ,Transcription Factors - Abstract
Ito cell mitogenesis occurs during liver injury and fibrogenesis in vivo. Platelet-derived-growth factor (PDGF)-induced mitogenesis was studied in cultured rat hepatic Ito cells, which resemble the myofibroblast associated with liver injury. Pretreatment with gamma-linolenic acid (GLA), an essential fatty acid prostanoid precursor, markedly suppressed the PDGF response in a dose-dependent reversible fashion. Prostaglandins E1 and E2 were found to be the predominant prostanoids formed by cultured Ito cells. GLA depressed endogenous PG production, suggesting that the antimitogenic effect was independent of GLA conversion to a prostanoid metabolite. The PDGF-induced cascade was studied with and without GLA to determine the level of regulation that induced the observed suppression. GLA caused no apparent diminution in the abundance of the surface PDGF-beta receptor nor its subsequent activation and tyrosine phosphorylation after PDGF stimulation. Raf kinase activation and Raf perinuclear translocation were also intact despite the presence of GLA. PDGF induction of nuclear Egr and Fos also occurred with or without GLA. Activation of the serine threonine kinase c-Raf has previously been found to be sufficient to activate egr and fos and to induce mitogenesis. Therefore, the GLA suppressive effect is likely to be operative at a parallel non-Raf pathway or distal to Raf-induced early gene expression.
- Published
- 1993
47. Simplification of the mass spectrometric assay for the major urinary metabolite of prostaglandin D2
- Author
-
Joseph A. Awad, Jason D. Morrow, and L. Jackson Roberts
- Subjects
Male ,Chromatography ,integumentary system ,Prostaglandins D ,Urinary system ,Metabolite ,Reproducibility of Results ,General Chemistry ,Urine ,medicine.disease ,Mass spectrometric ,Gas Chromatography-Mass Spectrometry ,chemistry.chemical_compound ,chemistry ,Biochemistry ,medicine ,Humans ,lipids (amino acids, peptides, and proteins) ,Female ,Prostaglandin D2 ,Systemic mastocytosis ,Adverse effect ,Quantitative analysis (chemistry) ,Mastocytosis - Abstract
The symptoms and hemodynamic alterations that accompany systemic mast cell activation have been attributed in large part to an excessive release of prostaglandin D2 (PGD2). Further, PGD2 has been implicated in the adverse effects of some pharmacologic agents (e.g. nicotinic acid). Quantitation of the major urinary metabolite of PGD2 has been invaluable in elucidating a role for PGD2 in these clinical entities and in the biochemical diagnosis of the disease systemic mastocytosis. However, the stable-isotope mass spectrometric assay originally developed for quantification of this metabolite has been too cumbersome for routine use. We now report improvements in the assay that greatly increase its utility by shortening sample processing and eliminating the need for purification using thin-layer chromatography. The precision and accuracy of the modified assay was evaluated and found to be comparable with the previously described assay. These modifications potentially allow wider use of the assay to explore the role of PGD2 in human disease and in the routine biochemical diagnosis of systemic mastocytosis and other disorders of mast cell activation.
- Published
- 1993
48. Poster - Thur Eve - 05: Semi-Automated Segmentation of Lung Tumours on CT Scans Using Level Set Sparse Field Active Model
- Author
-
Grace Parraga, Aaron Fenster, L Wilson, and Joseph A. Awad
- Subjects
Ground truth ,medicine.diagnostic_test ,business.industry ,Automated segmentation ,Computed tomography ,General Medicine ,Standard deviation ,Level set ,Medical imaging ,medicine ,Segmentation ,Lung tumours ,Nuclear medicine ,business ,Mathematics - Abstract
We present a semi‐automated algorithm for segmenting lungtumours on chest computed tomography(CT)images to be utilized for monitoring tumour response or progression. Seven lungtumours were evaluated; each tumour was radially sliced into 10 slices for a total of 70 radial slices, and manually segmented. The manual segmentations were used as the ground truth for evaluating the proposed algorithm. The tumourimage on each radial slice was classified into two categories: (1) well‐defined boundaries, located centrally in the lung parenchyma without significant vasculature; and (2) vascularized or juxtapleural (VJ). To segment the well‐defined boundaries, a shape constrained multi‐thresholding technique with one user‐defined seed point on the tumour is applied. For vascularized and juxtapleural tumours, this multi‐thresholding technique provided an initial contour that was deformed by a level set sparse field active model to produce the final segmentation for these tumours. The dice index (DI) measure was adopted to evaluate the segmentation results. The average and standard deviation values of the DI for the well‐defined and VJ images were 96.32 ± 1.12% and 95.19 ± 1.58%, respectively. The DI overall average and standard deviation of the 70 slices was 95.50 ± 1.55%. The preliminary results show that using the proposed algorithm produced accurate results.
- Published
- 2010
- Full Text
- View/download PDF
49. Sci-Fri AM: Imaging - 07: Semi-Automated Segmentation of Carotid Artery Lumen and Wall from Three-Dimensional Ultrasound Images Using Level Sets
- Author
-
Adam Krasinski, Eranga Ukwatta, Joseph A. Awad, Aaron Fenster, and Aaron D. Ward
- Subjects
Three dimensional ultrasound ,medicine.medical_specialty ,business.industry ,Carotid arteries ,Automated segmentation ,General Medicine ,medicine.disease ,Stenosis ,Speckle pattern ,cardiovascular system ,medicine ,Medical imaging ,Segmentation ,Radiology ,business ,Lumen (unit) - Abstract
Three-dimensional (3D) carotid ultrasound (US) phenotypes are increasingly being investigated for quantifying carotid arthrosclerosis for monitoring and assessment of patients who are at a greater risk of stroke. Vessel wall volume (VWV), which is the 3D measurement of vessel wall thickness plus plaque within the carotid artery, provides a high measurement sensitivity and reproducibility for carotid arthrosclerosis. VWV computation requires lumen and media-adventitia boundaries of the carotid arteries to be outlined. Its use in current clinical practice is limited by the requirement for manual segmentation which is extremely time consuming and operator-dependent. Therefore the objective of this study is to develop and validate a semiautomatic segmentation algorithm for delineating the media-adventitia and lumen boundaries of carotid arteries for patients with asymptomatic carotid stenosis. Due to the presence of plaque, poor definition of the vessel boundaries, intensity heterogeneity, image speckle, and shadowing, the carotid arteries are extremely challenging to segment using image information alone. Therefore, we combine various image cues with domain knowledge of the vessel geometry and some user interaction into the segmentation framework. We adopted an energy minimization approach based on the level sets formulation to segment the vessel wall and lumen using edge-based and region-based objective functions respectively. The proposed segmentation method was evaluated with respect to manually outlined boundaries using several similarity measures on 60 2D US slices from ten patients. The realization of semi-automated methods will accelerate the translation of 3DUS to real-time clinical research and clinical care.
- Published
- 2010
- Full Text
- View/download PDF
50. Formation of novel non-cyclooxygenase-derived prostanoids (F2-isoprostanes) in carbon tetrachloride hepatotoxicity. An animal model of lipid peroxidation
- Author
-
T Kato, Joseph A. Awad, Raymond F. Burk, Kamal F. Badr, Jason D. Morrow, Kihito Takahashi, and L J Roberts nd
- Subjects
Male ,Lipid Peroxides ,Indomethacin ,Pharmacology ,Thioacetamide ,Lipid peroxidation ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Isoniazid ,Animals ,Buthionine sulfoximine ,Carbon Tetrachloride ,Phorone ,Acetaminophen ,biology ,Alanine Transaminase ,General Medicine ,Isoprostanes ,Rats, Inbred F344 ,Rats ,F2-Isoprostanes ,chemistry ,Biochemistry ,Eicosanoid ,Prostaglandin-Endoperoxide Synthases ,Phenobarbital ,biology.protein ,Prostaglandins ,Arachidonic acid ,Cyclooxygenase ,Research Article - Abstract
These studies examine the in vivo formation of a unique series of PGF2-like compounds (F2-isoprostanes) derived from free radical-catalyzed nonenzymatic peroxidation of arachidonic acid. We have previously shown that levels of these compounds increase up to 50-fold in rats administered CCl4. To understand further the formation of these compounds in vivo, we carried out a series of experiments assessing factors influencing their generation. After CCl4 (2 ml/kg) was administered to rats, plasma F2-isoprostanes increased 55-fold by 4 h. Levels declined thereafter, but at 24 h, they were still elevated 21-fold, indicating continued lipid peroxidation. Pretreatment of rats with isonicotinic acid hydrazide and phenobarbital to induce cytochrome P-450 enhanced the production of F2-isoprostanes after CCl4 administration eightfold and fivefold, respectively, whereas inhibition of the cytochrome P-450 system with SKF-525A and 4-methylpyrazole decreased formation of F2-isoprostanes after CCl4 by 55 and 82%, respectively. Further, the glutathione-depleting agents buthionine sulfoximine and phorone augmented the F2-isoprostane response to CCl4 by 22- and 11-fold, respectively. F2-isoprostanes are formed in situ esterified to lipids and, in addition to increases in levels of free F2-isoprostanes in the circulation, levels of F2-isoprostanes esterified to lipids in various organs and plasma also increase sharply during CCl4 poisoning. The measurement of F2-isoprostanes may facilitate investigation of the role of lipid peroxidation in human diseases.
- Published
- 1992
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.