Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Frederick K. Askari is active.

Publication


Featured researches published by Frederick K. Askari.


Hepatology | 2005

Prognosis of hepatocellular carcinoma: Comparison of 7 staging systems in an American cohort

Jorge A. Marrero; Robert J. Fontana; Ashley Barrat; Frederick K. Askari; Hari S. Conjeevaram; Grace L. Su; Anna S. Lok

Currently there is no consensus as to which staging system is best in predicting the survival of patients with hepatocellular carcinoma (HCC). The aims of this study were to identify independent predictors of survival and to compare 7 available prognostic staging systems in patients with HCC. A total of 239 consecutive patients with cirrhosis and HCC seen between January 1, 2000, and December 31, 2003, were included. Demographic, laboratory, and tumor characteristics and performance status were determined at diagnosis and before therapy. Predictors of survival were identified using the Kaplan–Meir test and the Cox model. Sixty‐two percent of patients had hepatitis C, 56% had more than 1 tumor nodule, 24% had portal vein thrombosis, and 29% did not receive any cancer treatment. At the time of censorship, 153 (63%) patients had died. The 1‐ and 3‐year survival of the entire cohort was 58% and 29%, respectively. The independent predictors of survival were performance status (P < .0001), MELD score greater than 10 (P = .001), portal vein thrombosis (P = .0001), and tumor diameter greater than 4 cm (P = .001). Treatment of HCC was related to overall survival. The Barcelona Clinic Liver Cancer (BCLC) staging system had the best independent predictive power for survival when compared with the other 6 prognostic systems. In conclusion, performance status, tumor extent, liver function, and treatment were independent predictors of survival mostly in patients with cirrhosis and HCC. The BCLC staging system includes aspects of all of these elements and provided the best prognostic stratification for our cohort of patients with HCC. (HEPATOLOGY 2005.)


JAMA Neurology | 1996

Treatment of Wilson Disease With Ammonium Tetrathiomolybdate: III. Initial Therapy in a Total of 55 Neurologically Affected Patients and Follow-up With Zinc Therapy

George J. Brewer; Peter Hedera; Karen J. Kluin; Martha D. Carlson; Frederick K. Askari; Robert B. Dick; Julia Sitterly; John K. Fink

BACKGROUND It is unclear what anticopper drug to use for patients with Wilson disease who present with neurologic manifestations because penicillamine often makes them neurologically worse and zinc is slow acting. OBJECTIVE To evaluate the frequency of neurologic worsening and drug adverse effects with ammonium tetrathiomolybdate. DESIGN Open-label study of 55 untreated patients (22 of them new) presenting with neurologic Wilson disease treated with tetrathiomolybdate varying from 120 to 410 mg/d for 8 weeks and then followed up for 3 years. Neurologic function was assessed with scored neurologic and speech tests. SETTING A university hospital referral setting. PATIENTS All untreated, newly diagnosed patients with neurologic Wilson disease. INTERVENTION Treatment with tetrathiomolybdate. MAIN OUTCOME MEASURES Neurologic function was evaluated by neurologic and speech examinations. Drug adverse effects were evaluated by complete blood cell counts and biochemical measures. RESULTS Only 2 (4%) of 55 patients treated with tetrathiomolybdate showed neurologic deterioration, compared with an estimated 50% of penicillamine-treated patients. Five of the 22 new patients exhibited bone marrow suppression and 3 had aminotransferase elevations. These numbers are higher than in the original 33 patients and appear to be due primarily to a more rapid dose escalation. CONCLUSIONS Tetrathiomolybdate shows excellent efficacy in patients with Wilson disease who present with neurologic manifestations. With rapid escalation of dose, adverse effects from bone marrow suppression or aminotransferase elevations can occur.


Cancer Epidemiology, Biomarkers & Prevention | 2012

Effectiveness of Hepatocellular Carcinoma Surveillance in Patients with Cirrhosis

Amit G. Singal; Hari S. Conjeevaram; Michael L. Volk; Sherry Fu; Robert J. Fontana; Frederick K. Askari; Grace L. Su; Anna S. Lok; Jorge A. Marrero

Background: Surveillance for hepatocellular carcinoma (HCC) is recommended in patients with cirrhosis, but the effectiveness of a surveillance program in clinical practice has yet to be established. Aims: To evaluate the effectiveness of a surveillance program with ultrasound and alpha-fetoprotein (AFP) to detect early HCCs. Methods: Four hundred and forty-six patients with Child A/B cirrhosis were prospectively enrolled between January 2004 and September 2006 and followed until July 2010. HCC surveillance using ultrasound and AFP was conducted per the treating hepatologist, although the standard was every 6 to 12 months. HCC was diagnosed using American Association for the Study of Liver Disease (AASLD) guidelines and early HCC defined by Barcelona Clinic Liver Cancer (BCLC) staging. Performance characteristics were determined for surveillance using AFP, ultrasound, or the combination. Results: After a median follow-up of 3.5 years, 41 patients developed HCCs, of whom 30 (73.2%) had early HCCs. The annual incidence of HCC was 2.8%, with cumulative 3- and 5-year incidence rates of 5.7% and 9.1%, respectively. Surveillance ultrasound and AFP had sensitivities of 44% and 66% and specificities of 92% and 91%, respectively, for the detection of HCCs. Sensitivity significantly improved to 90%, with minimal loss in specificity (83%) when these tests were used in combination. Conclusions: When used as a surveillance program in a real-world clinical setting, combination of ultrasound and AFP is the most effective strategy to detect HCC at an early stage. Impact: Our results differ from the guidelines of the AASLD. Cancer Epidemiol Biomarkers Prev; 21(5); 793–9. ©2012 AACR.


Liver Transplantation | 2007

Sustained virologic response to therapy of recurrent hepatitis C after liver transplantation is related to early virologic response and dose adherence

Pratima Sharma; Jorge A. Marrero; Robert J. Fontana; Joel K. Greenson; Hari S. Conjeevaram; Grace L. Su; Frederick K. Askari; Patricia Sullivan; Anna S. Lok

Sustained virologic response (SVR) after antiviral therapy for recurrent hepatitis C virus (HCV) infection in liver transplant (LT) recipients is consistently lower than that achieved in non‐LT patients. We evaluated efficacy and safety of pegylated interferon (IFN) and ribavirin (RBV) therapy in LT recipients with recurrent HCV and factors associated with SVR. All subjects with histologic evidence of recurrent HCV were intended to be treated for 48 weeks with full‐dose pegylated IFN; target dose of RBV was 800 mg/day. Thirty‐five LT recipients with recurrent HCV, median age 48.5 years, 77% genotype 1, and median pretreatment HCV RNA 6.4 log10 IU/mL were treated between January 2000 and February 2006. Antiviral therapy was discontinued prematurely in 15 subjects as a result of adverse events. Median overall treatment duration was 46 weeks. Early virologic response at week 12 was seen in 17 (49%) and an end‐of‐treatment virological response in 19 (54%) patients. SVR was achieved in 13 patients (37%), and all 9 patients followed for >1 year after treatment had durable response. Patients with SVR had significantly lower pretreatment HCV RNA (5.7 vs. 6.5 log10 IU/mL, P = 0.003), more likely to have a week 12 virological response (85% vs. 27%, P = 0.0009) and received higher cumulative doses of pegylated IFN (75% vs. 33%, P = 0.029) and RBV (90% vs. 26%, P = 0.016) compared with patients whose disease did not respond to therapy. In conclusion, SVR was achieved in 37% of patients with recurrent hepatitis C after LT. Similar to non‐LT patients, those with lower pretreatment HCV RNA, a week 12 virological response, and pegylated IFN and RBV dose adherence were more likely to achieve SVR. Liver Transpl, 2007.


Journal of Laboratory and Clinical Medicine | 2003

Treatment of Wilson's disease with zinc. XVIII. Initial treatment of the hepatic decompensation presentation with trientine and zinc

Frederick K. Askari; Joel K. Greenson; Robert D. Dick; Virginia Johnson; George J. Brewer

We have treated 9 patients who presented with hepatic decompensation resulting from Wilsons disease with a combination of trientine and zinc, generally for at least 4 months, followed by transition to zinc maintenance therapy. All of these patients had hypoalbuminemia, all but 1 had hyperbilirubinemia, and 7 had ascites. All of these patients would have been candidates for liver transplantation on the basis of their initial Child-Turcotte-Pugh (CTP) scores. The minimal listing criteria for transplant candidates is a score greater than 7. Eight of the 9 patients had demonstrated a CTP score of 10 or higher. The other scoring system that has been used in Wilsons disease to determine need for transplantation is the prognostic index of Nazer, in which a score over 6 indicates that the patient is unlikely to survive without a transplant if treated with penicillamine. Two of our patients had Nazer scores higher than 6. With our medical therapy, all 9 of these patients have recovered normal liver function as reflected by normalization of their CTP scores to 5. Because of coexisting neurologic disease, 1 of our 9 patients was initiated on a neurologic protocol and by chance randomized to receive tetrathiomolybdate (TM) and zinc after 2 weeks of trientine/zinc treatment. This patients liver function recovered much more rapidly than did that of the other 8 patients, all of whom were treated with trientine/zinc, suggesting that TM therapy offers a further advantage. In summary, we were able to take 9 patients who presented with liver failure -8 of whom had CTP scores indicating a potential need for liver transplantation and 2 of whom had Nazer prognostic scores indicating that they were not likely to survive if treated only with penicillamine - and treat them medically, with recovery in all 9. We believe the trientine/zinc combination therapy should be the standard for initial treatment of liver failure in Wilsons disease because its efficacy is equal or slightly superior to that of penicillamine and because it has a much lower incidence of side effects. Moreover, TM warrants study to determine whether therapy for hepatic Wilsons disease can be further improved.


Somatic Cell and Molecular Genetics | 1992

Targeted delivery of antisense oligonucleotides by molecular conjugates

Bruce A. Bunnell; Frederick K. Askari; James M. Wilson

Antisense oligonucleotides efficiently inhibit gene expression in vitro; however, the successful therapeutic application of this technology in vivo will require the development of improved delivery systems. In this report we describe a technique that efficiently delivers antisense oligonucleotides into cells using molecular conjugates. This technique, which was initially developed for the delivery of eukaryotic genes, is based on the construction of DNA-protein complexes that are recognized by the liver-specific asialoglycoprotein receptor. Binding of poly(l-lysine)-asialoorosomucoid (AsOR) protein conjugates with phosphorothioate antisense oligonucleotides to chloramphenicol acetyltransferase (CAT) led to the formation of 50- to 150-nm toroids. Exposure of the antisense molecular complexes (3 µM oligonucleotide) to NIH 3T3 cells genetically modified to express both the AsOR receptor and CAT, inhibited CAT expression by 54%, which was completely blocked by excess AsOR. Equivalent inhibition of CAT activity with purified oligonucleotide alone was observed at a 30 µM concentration. Furthermore, examination of the cells using indirect immunofluorescence for the presence of CAT protein showed 28% of cells exposed to the molecular conjugates lacked any detectable CAT enzyme. Cells exposed to oligonucleotide alone showed a highly variable staining pattern, and only a few of the cells were completely void of CAT protein. Together these data demonstrate that molecular conjugates provide a highly specific and efficient system for the delivery of antisense oligonucleotides.


Biochemical Pharmacology | 1996

Identification of bilirubin UDP-GTs in the human alimentary tract in accordance with the gut as a putative metabolic organ

W. Michael McDonnell; Eri Hitomi; Frederick K. Askari

The initial identification of traditionally hepatic enzymes expressed in the gut has led to the hypothesis that the gut may function as a metabolic organ. The UDP glucuronosyltransferases (UDP-GTs) play an important role as phase II metabolizing enzymes. Previously members of this family have been identified in the gut by non-isoform specific immunoreactivity, and a small amount of bilirubin glucuronosyltransferase activity was detected in the colon. Recent reports of gut transplantation to reverse the metabolic defect in Gunn rats raised further interest in the expression and distribution of human bilirubin (UDP-GTs (HUG Br 1 and HUG Br 2) in the human alimentary tract. The availability of molecular genetic probes for HUG Br 1 and HUG Br 2 permits the screening of the alimentary tract for the presence of isoform specific message. RNA samples extracted from pinch biopsy specimens of buccal mucosa, esophagus, stomach body, antrum, duodenum, and colon were analyzed for expression of HUG Br 1 and HUG Br 2. HUG Br 1 hybridization was detected in duodenum > colon, whereas HUG Br2 hybridization was detected in duodenum > esophagus > colon. Immunoreactivity data confirmed the presence of HUG Br 1 protein at low levels in the duodenum, whereas the less abundant HUG Br 2 protein was below the limits of detection of isoform specific anti-peptide antibodies. Bilirubin specific reactivity was demonstrated in duodenal samples but not antrum samples, consistent with the molecular genetic data. The presence of functional bilirubin UDP-GT isoforms in human alimentary tract supports the notion that the gut may function as a metabolic organ and may have diagnostic and therapeutic implications for disorders of bilirubin metabolism.


Experimental Biology and Medicine | 2004

Tetrathiomolybdate therapy protects against concanavalin A and carbon tetrachloride hepatic damage in mice

Frederick K. Askari; Robert P. Dick; Maria Mao; George J. Brewer

Tetrathiomolybdate, an anticopper drug, has been shown to protect mice against pulmonary fibrosis from bleomycin. Our hypothesis is that it does so by inhibiting fibrosis-inducing cytokines. Indeed, we have good evidence, not yet published, that tetrathiomolybdate inhibits pulmonary levels of transforming growth factor–β and tumor necrosis factor-α expression in these bleomycin experiments. Herein, we evaluate tetrathiomolybdates effectiveness in mitigating hepatitis and fibrosis in mice from the hepatotoxins, concanavalin A and carbon tetrachloride, and its inhibition of cytokines as a possible mechanism. In short-term experiments, concanavalin A elevated serum amino leucine transferase levels several fold, and tetrathiomolybdate completely prevented this increase. In additional experiments, tetrathiomolybdate therapy reversed the elevated serum transaminase levels despite continued concanavalin A injections, with nearly significant serum interleukin-1β inhibition. Concanavalin A given for 12 weeks produced mild fibrosis, whereas concomitant tetrathiomolybdate treatment resulted in normal histology. Carbon tetrachloride given for 12 weeks resulted in very high serum amino leucine transferase levels, high serum transforming growth factor–β levels, cirrhosis as seen histologically, and increase in liver hydroxyproline, a measure of fibrosis. Concomitant tetrathiomolybdate partially and significantly protected against increases in amino leucine transferase and transforming growth factor–β, fully protected against the increase in hydroxyproline, and resulted in normal histology. In conclusion, tetrathiomolybdate protects against the hepatitis and fibrosis produced by these hepatotoxins, probably by inhibiting the excessive increase in inflammatory and fibrotic cytokines.


Translational Research | 2010

Treatment of primary biliary cirrhosis with tetrathiomolybdate: results of a double-blind trial.

Frederick K. Askari; Dawna Innis; Robert B. Dick; Guoqing Hou; Jorge A. Marrero; Joel K. Greenson; George J. Brewer

The results of a double-blind trial of tetrathiomolybdate therapy and standard of care, versus placebo and standard of care treatment, in primary biliary cirrhosis patients are presented. Baseline studies of liver function, various safety variables, ceruloplasmin, a liver biopsy for histologic analysis, and for various cytokine analyses were carried out. Patients were observed every 4 months for up to 2 years of treatment by a hepatologist for clinical evaluation and repeat of all the baseline studies except liver biopsy, which was repeated at 2 years. The primary end points were improvement in 2 liver function tests and in 1 inflammatory cytokine. Fifteen placebo patients were followed for an average of 13 months, and 13 tetrathiomolybdate patients were followed for an average of 14 months. The predefined primary end points for efficacy were met. Tetrathiomolybdate was well tolerated. Because tetrathiomolybdate has been shown in numerous animal studies to inhibit autoimmune and inflammatory processes, and because primary biliary cirrhosis is an autoimmune attack on bile ducts, these positive findings on efficacy of tetrathiomolybdate therapy in primary biliary cirrhosis fit with the animal studies and suggest the need for a longer clinical trial to examine transplant-free survival.


Hepatology | 2007

Quality of Life and Everyday Activities in Patients with Primary Biliary Cirrhosis

Carlo Selmi; M. Eric Gershwin; Keith D. Lindor; Howard J. Worman; Ellen B. Gold; Mitchell Watnik; Jessica Utts; Pietro Invernizzi; Marshall M. Kaplan; John M. Vierling; Christopher L. Bowlus; Marina G. Silveira; Ilaria Bossi; Frederick K. Askari; Nancy Bach; Nathan M. Bass; Gordon D. Benson; Andres T. Blei; Andrea D. Branch; Thomas A. Capozza; David J. Clain; Robert G. Gish; Richard M. Green; M. Edwyn Harrison; Steven K. Herrine; Emmet B. Keeffe; Natasha Khazai; Kris V. Kowdley; Edward L. Krawitt; John R. Lake

Primary biliary cirrhosis (PBC) is generally a slowly progressive disease that may lead to cirrhosis and liver failure. However, patients with PBC often suffer from a variety of symptoms long before the development of cirrhosis that include issues of daily living that have an impact on their work environment and their individual quality of life. We therefore examined multiple parameters by taking advantage of the database of our cohort of 1032 patients with PBC and 1041 matched controls. The data were obtained from patients from 23 tertiary referral centers throughout the United States and from rigorously matched controls by age, sex, ethnicity, and random‐digit dialing. The data showed that patients with PBC were more likely than controls to have significant articular symptoms, a reduced ability to perform household chores, and the need for help with routine activities. Patients with PBC rated their overall activity similar or superior to that of controls; however, more of them reported limitations in their ability to carry out activities at work or at home and difficulties in everyday activities. PBC cases also more frequently reported limitations in participating in certain sports or exercises and pursuing various hobbies; however, they did not report significant limitations in social activities. In a multivariable analysis, household income, a diagnosis of systemic lupus erythematosus, limitations in work activities, a reduction in work secondary to disability, and church attendance were independently increased in PBC cases with respect to controls. Conclusion: Our data indicate that the quality of life of patients with PBC in the United States is generally well preserved. Nevertheless, patients with PBC suffer significantly more than controls from a variety of symptoms that are beyond the immediate impact of liver failure and affect their lifestyle, personal relationships, and work activities. (HEPATOLOGY 2008.)

Collaboration


Dive into the Frederick K. Askari's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge