Network


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

Hotspot


Dive into the research topics where Thomas O. Kovacs is active.

Publication


Featured researches published by Thomas O. Kovacs.


The New England Journal of Medicine | 2000

Urgent colonoscopy for the diagnosis and treatment of severe diverticular hemorrhage

Dennis M. Jensen; Gustavo A. Machicado; Rome Jutabha; Thomas O. Kovacs

BACKGROUND Although endoscopy is often used to diagnose and treat acute upper gastrointestinal bleeding, its role in the management of diverticulosis and lower gastrointestinal bleeding is uncertain. METHODS We studied the role of urgent colonoscopy in the diagnosis and treatment of 121 patients with severe hematochezia and diverticulosis. All patients were hospitalized, received blood transfusions as needed, and received a purge to rid the colon of clots, stool, and blood. Colonoscopy was performed within 6 to 12 hours after hospitalization or the diagnosis of hematochezia. Among the first 73 patients, those with continued diverticular bleeding underwent hemicolectomy. For the subsequent 48 patients, those requiring treatment received therapy, such as epinephrine injections or bipolar coagulation, through the colonoscope. RESULTS Of the first 73 patients, 17 (23 percent) had definite signs of diverticular hemorrhage (active bleeding in 6, nonbleeding visible vessels in 4, and adherent clots in 7). Nine of the 17 had additional bleeding after colonoscopy, and 6 of these required hemicolectomy. Of the subsequent 48 patients, 10 (21 percent) had definite signs of diverticular hemorrhage (active bleeding in 5, nonbleeding visible vessels in 2, and adherent clots in 3). An additional 14 patients in this group (29 percent) were presumed to have diverticular bleeding because although they had no stigmata of diverticular hemorrhage, no other source of bleeding was identified. The other 24 patients (50 percent) had other identified sources of bleeding. All 10 patients with definite diverticular hemorrhage were treated endoscopically; none had recurrent bleeding or required surgery. CONCLUSIONS Among patients with severe hematochezia and diverticulosis, at least one fifth have definite diverticular hemorrhage. Colonoscopic treatment of such patients with epinephrine injections, bipolar coagulation, or both may prevent recurrent bleeding and decrease the need for surgery.


The New England Journal of Medicine | 1994

A Controlled Study of Ranitidine for the Prevention of Recurrent Hemorrhage from Duodenal Ulcer

Dennis M. Jensen; Susie Cheng; Thomas O. Kovacs; Gayle Randall; Mary Ellen Jensen; Terry J. Reedy; Harold D. Frankl; Gustavo A. Machicado; James W. Smith; Michael L. Silpa; Gary M. Van Deventer

BACKGROUND Hemorrhage is the most common complication of duodenal ulcer disease, but there is little information about the effectiveness and safety of long-term maintenance therapy with histamine H2-receptor blockers. METHODS We conducted a double-blind study in patients with endoscopically documented hemorrhage from duodenal ulcers. Patients were randomly assigned to maintenance therapy with ranitidine (150 mg at night) or placebo and were followed for up to three years. Endoscopy was performed at base line (to document that the ulcers had healed), at exit from the study, and when a patient had persistent ulcer symptoms unrelieved by antacids or had gastrointestinal bleeding. Symptomatic relapses without bleeding were treated with ranitidine; if the ulcer healed within eight weeks, the patient resumed taking the assigned study medication. RESULTS The two groups were similar at entry, which usually occurred about three months after the index hemorrhage. After a mean follow-up of 61 weeks, 3 of the 32 patients treated with ranitidine had recurrent hemorrhage, as compared with 12 of the 33 given placebo (P < 0.05). Half the episodes of recurrent bleeding were asymptomatic. One patient in the ranitidine group withdrew from the study because of asymptomatic thrombocytopenia during the first month. CONCLUSIONS For patients whose duodenal ulcers heal after severe hemorrhage, long-term maintenance therapy with ranitidine is safe and reduces the risk of recurrent bleeding.


Gastroenterology | 1989

Gastrin Is a Major Mediator of the Gastric Phase of Acid Secretion in Dogs: Proof by Monoclonal Antibody Neutralization

Thomas O. Kovacs; J.H. Walsh; V. Maxwell; Helen Wong; T. Azuma; E. Katt

We developed a monoclonal antibody, 28.2, that binds specifically to the amidated carboxyl terminal region common to gastrin and cholecystokinin. This immunoglobulin G1 antibody has high affinity (ID50 = 30-70 pM for gastrin and cholecystokinin peptides), binds labeled gastrin similarly at 37 degrees C and 4 degrees C, and shows minimal inhibition of binding in the presence of 40% canine serum. Antibody 28.2 was used to carry out in vivo immunoneutralization studies in 8 dogs previously prepared with chronic gastric fistulas. Preliminary studies revealed that a single intravenous dose of 0.75 mg of partially purified immunoglobulin G of monoclonal antibody 28.2 completely inhibited the acid stimulatory effect of exogenous gastrin-17 given intravenously at 200 pmol/kg.h, a physiologic dose, and inhibited by 70% the acid response to a supraphysiologic dose, 800 pmol/kg.h. The same dose of antibody decreased the acid secretory response obtained during distention of the stomach with 300 ml of 5.8% glucose solution by 98% and decreased the response to distention with 300 ml of 8% peptone solution by 68%. A 10-fold higher dose of antibody decreased the acid response to peptone by 96%. The gastrin antibody had no effect on the acid response to exogenous histamine. A control antibody, specific for the biologically inactive glycine-extended gastrin/cholecystokinin peptapeptide region, had no significant effect on gastric acid secretion stimulated by gastrin or by gastric distention with nutrients. These studies indicate that circulating gastrin is of major importance in the gastric phase of gastric acid stimulation caused by distention of the stomach with nutrients.


Alimentary Pharmacology & Therapeutics | 1999

Lansoprazole in the treatment of heartburn in patients without erosive oesophagitis.

Joel E. Richter; Thomas O. Kovacs; P. A. Greski-Rose; B. Huang; R. Fisher

: This randomized, double‐blind, multicentre study compared lansoprazole with placebo for symptomatic relief of patients with non‐erosive gastro‐oesophageal reflux disease (GERD).


Medical Clinics of North America | 2002

Recent advances in the endoscopic diagnosis and therapy of upper gastrointestinal, small intestinal, and colonic bleeding

Thomas O. Kovacs; Dennis M. Jensen

Endoscopy has become the first and primary diagnostic and therapeutic modality in the management of patients with severe gastrointestinal bleeding. Panendoscopy, push enteroscopy, and colonoscopy provide the diagnostic, prognostic, and therapeutic elements to improve patient outcomes and to reduce morbidity and mortality from severe GI hemorrhage. Recent improvements in endoscopic hemostatic techniques and in imaging modalities using wireless capsule endoscopy suggest that diagnostic and therapeutic endoscopy will be even more important in determining patient outcomes in the future.


Gastrointestinal Endoscopy | 1997

An economic analysis of patients with active arterial peptic ulcer hemorrhage treated with endoscopic heater probe, injection sclerosis, or surgery in a prospective, randomized trial☆☆☆★★★

Ian M. Gralnek; Dennis M. Jensen; Thomas O. Kovacs; Rome Jutabha; Mary Ellen Jensen; Susie Cheng; Jeffrey Gornbein; Martin L. Freeman; Gustavo A. Machicado; James C. Smith; Michael A. Sue; Gerald F. Kominski

BACKGROUND There are no published, detailed assessments of the direct costs of endoscopic hemostasis for actively bleeding peptic ulcers. We compared the direct costs of care for patients with active ulcer hemorrhage treated with endoscopic or medical-surgical therapies and correlated these costs with patient outcomes. METHODS In a prospective, randomized, controlled trial, 31 patients with active ulcer hemorrhage at emergency endoscopy were randomly assigned to heater probe, injection, or medical-surgical treatment. For further ulcer bleeding, heater probe and injection patients were re-treated endoscopically and medical-surgical patients were referred for surgery. Direct costs were estimated using fixed and variable costs for resources consumed and Medicare reimbursement rates for physician fees. RESULTS Compared to medical-surgical treatment, the heater probe and injection groups had significantly higher primary hemostasis rates (100% and 90% vs 8%) and lower rates of emergency surgery (0% and 10% vs 75%), blood transfusions, and median direct costs per patient (


The American Journal of Gastroenterology | 2001

Comparing lansoprazole and omeprazole in onset of heartburn relief: results of a randomized, controlled trial in erosive esophagitis patients

Joel E. Richter; Peter J. Kahrilas; Stephen J. Sontag; Thomas O. Kovacs; Bidan Huang; Jennifer L Pencyla

4153 and


Gastroenterology | 1992

Cholecystokinin receptor antagonist MK-329 blocks intestinal fat-induced inhibition of meal-stimulated gastric acid secretion.

K.C.K. Lloyd; V. Maxwell; Thomas O. Kovacs; Jeff F. Miller; J.H. Walsh

5247 vs


Gastrointestinal Endoscopy | 2011

Ischemic colitis as a cause of severe hematochezia: risk factors and outcomes compared with other colon diagnoses

Disaya Chavalitdhamrong; Dennis M. Jensen; Thomas O. Kovacs; Rome Jutabha; Gareth S. Dulai; Gordon V. Ohning; Gustavo A. Machicado

11,149). Furthermore, compared to medical-surgical treatment, the heater probe group had a significantly lower incidence of severe ulcer rebleeding (11% vs 75%). CONCLUSIONS Heater probe and injection sclerosis are similarly efficacious treatments for active ulcer hemorrhage, and both treatments yield significantly lower direct costs of medical care and cost savings.


Diagnostic Microbiology and Infectious Disease | 2011

Diagnostic accuracy of the Cepheid GeneXpert vanA/vanB assay ver. 1.0 to detect the vanA and vanB vancomycin resistance genes in Enterococcus from perianal specimens.

Erin S. Marner; Donna M. Wolk; Jeanne Carr; Carolyn Hewitt; Lorraine L. Dominguez; Thomas O. Kovacs; Desiree R. Johnson; Randall T. Hayden

Comparing lansoprazole and omeprazole in onset of heartburn relief: results of a randomized, controlled trial in erosive esophagitis patients

Collaboration


Dive into the Thomas O. Kovacs's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Rome Jutabha

University of California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ian M. Gralnek

Technion – Israel Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge