Publications by authors named "Issam Raad"

MEDTA (minocycline-edetate calcium disodium), taurolidine (2%)-polyvinylpyrolidine (5%) (T/PVP), and ethanol as potential catheter lock solutions have a unique mechanism of action, broad-spectrum activity, and anticoagulant properties. Traditional lock solutions minocycline (M), rifampin (R), ciprofloxacin (C), and vancomycin, except pharmacologic concentrations of C and R and of M and R, were less effective than MEDTA and T/PVP.

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Rats immunosuppressed by the administration of cyclophosphamide and cortisone acetate and then infected with Aspergillus fumigatus were treated with an antifungal drug, EDTA, or a combination of one of the antifungal agents, amphotericin B lipid complex (ABLC; 5 mg/kg of body weight/day for 7 days), and EDTA (30 mg/kg/day for 7 days). The mortality rate was reduced, the duration of survival was increased, fewer A. fumigatus organisms were recovered from the lungs, and less-severe lung lesions were seen histopathologically in the rats receiving the combination treatment than in the rats receiving either an antifungal agent or EDTA alone.

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Background: Cytomegalovirus (CMV) antigenemia (CMV-A) and CMV disease (CMV-D), known causes of morbidity and mortality among patients with leukemia and recipients of hematopoietic stem cell transplantations, are described sporadically in patients with lymphoma. We sought to determine the risk factors and outcome of CMV-A and CMV-D among patients with lymphoma.

Patients And Methods: We conducted a retrospective cohort study with such patients identified between 1997 and 2003 at The University of Texas M.

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Background: Conventional amphotericin B-based antifungal therapy for invasive fusariosis in patients with a hematologic malignancy results in a > or = 70% failure rate. Posaconazole is a broad-spectrum antifungal agent with in vitro and in vivo activity against Fusarium species.

Methods: In this retrospective analysis of patients from 3 open-label clinical trials, we evaluated posaconazole for the treatment of invasive fusariosis.

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Endocarditis is uncommon in patients with cancer. The characteristics of culture-positive (CPE) and culture-negative endocarditis (CNE) in high-risk cancer patients are not known; therefore we sought to evaluate the disease characteristics in patients with endocarditis at a comprehensive cancer center. We retrospectively reviewed the transthoracic (TTE) and transesophageal (TEE) echocardiograms obtained from 654 consecutive cancer patients in whom endocarditis was suspected between 1994 and 2004.

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Background: Stenotrophomonas maltophilia bacteremia is frequently found in cancer patients. This study attempted to determine how often the catheters were the source of this infection and the risk factors associated with catheter-related bacteremias.

Methods: The microbiology records were retrospectively reviewed of all cancer patients having S.

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Background: Invasive pulmonary aspergillosis (IPA) is a life-threatening infection in immunocompromised patients. The outcome of such infections depends on early diagnosis and prompt initiation of therapy. The objective of the current study was to determine the significant predictive factors that characterize IPA in patients with cancer.

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We reviewed the epidemiology, clinical manifestations, and outcomes of 3 cases of chest tube-related empyema due to methicillin-resistant Staphylococcus aureus (MRSA). Antiseptic-impregnated chest tubes were inserted in cultures containing MRSA isolates from these 3 patients, and zone of inhibition were measured. Chest tube-related MRSA empyema might complicate tube thoracostomy, and coating the chest tube with antiseptic agents could prevent this complication.

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Objectives: To determine the current spectrum of Gram-positive bloodstream infections (BSI) in patients with hematologic malignancies at our institution, and to determine the in vitro activity of various fluoroquinolones against clinical Gram-positive isolates collected from such patients.

Methods: Institutional microbiology records from 493 consecutive episodes of Gram-positive BSI were reviewed. The in vitro activity of six fluoroquinolones against 477 clinical isolates was determined using an NCCLS approved, broth-dilution method.

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We studied the efficacy of pentamidine (PNT) as prophylaxis or early treatment in acute pulmonary fusariosis in neutropenic mice. PNT-preexposed mice had significantly improved survival and reduced fungal burden compared to amphotericin B-preexposed and untreated mice. PNT-treated mice had increased survival but no difference in fungal burden versus untreated mice.

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Invasive fungal infection remains the most common cause of infectious death in acute leukemia. In this open-label, randomized study, we compared the efficacy and safety of caspofungin with that of intravenous itraconazole for antifungal prophylaxis in patients undergoing induction chemotherapy for acute myelogenous leukemia or myelodysplastic syndrome. Of 200 patients, 192 were evaluable for efficacy (86 for itraconazole, 106 for caspofungin).

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Posaconazale is a new triazole drug being investigated in phase III clinical trials for the treatment and prevention of invasive fungal infections. In-vitro and in-vivo studies showed that posaconazole has broad-spectrum activity against most Candida species, Cryptococcus neoformans, Aspergillus species, Fusarium species, zygomycetes, and endemic fungi. Posaconazole is given orally two to four times daily.

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To evaluate the molecular characteristics and antibiotic susceptibility in biofilm of vancomycin-resistant Enterococcus faecium (VREF) organisms that had caused catheter-related VREF bacteremia (VREF-CRB), we compared 22 isolates causing bacteremia obtained from patients with VREF-CRB with 30 isolates from control patients with gastrointestinal colonization by VREF. Using pulsed-field gel electrophoresis, we identified 17 unique strains among the 22 VREF-CRB isolates and 23 strains among the gastrointestinal isolates. The esp gene was detected in 53% (9 of 17) of the VREF-CRB and 61% (14 of 23) of the control strains (P = 0.

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Catheter-related bloodstream infection is a potentially serious condition with a mortality rate of 12% to 25%. Catheter-related bacteremia is difficult to diagnose, and clinical manifestations of the condition have proved to be unspecific and often inconclusive. Microbiologic techniques to diagnose catheter-related bloodstream infection have been developed, some of which require catheter removal whereas others do not.

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In the current era of multidrug-resistant organisms, the clinical spectrum of Streptococcus pneumoniae infection remains unclear, especially in immunosuppressed patients with cancer. We sought to define the characteristics of pneumococcal bacteremia in patients who were receiving care at a comprehensive cancer center. All consecutive episodes of S.

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Although gastrointestinal cytomegalovirus disease (GI-CMVd) is not common in cancer patients, it is associated with high morbidity and mortality. Herein, we review our 2-decade experience with GI-CMVd in such patient population at The University of Texas M.D.

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Objective: To study the clinical and molecular epidemiology of vancomycin-resistant Enterococcus faecium organisms causing catheter-related bacteremia in patients with cancer.

Design: Retrospective case-control study.

Setting: University of Texas M.

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Background: Even when treated with antiviral therapy, cytomegalovirus pneumonia (CMVp) is associated with high morbidity and mortality in immunocompromised patients. CMVp has been rarely reported in patients with lymphoma.

Methods: The authors reviewed the records of patients treated at The University of Texas M.

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Objective: We sought to compare the impact of antimicrobial impregnation to that of tunneling of long-term central venous catheters on the rates of catheter colonization and catheter-related bloodstream infection.

Summary Background Data: Tunneling of catheters constitutes a standard of care for preventing infections associated with long-term vascular access. Although antimicrobial coating of short-term central venous catheters has been demonstrated to protect against catheter-related bloodstream infection, the applicability of this preventive approach to long-term vascular access has not been established.

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Background And Objective: We previously demonstrated that minocycline-EDTA was efficacious at preventing catheter-related bloodstream infections (BSIs) in three patients with recurrent infections. This study compared heparin with minocycline-EDTA as flush solutions used among dialysis patients with central venous catheters, a high-risk group for catheter-related BSI.

Methods: Patients were enrolled within 72 hours of catheter insertion and randomized to receive heparin or minocycline-EDTA as a flush after each dialysis session.

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Background: Pseudomonas aeruginosa is responsible for a wide range of infections. In immunocompromised patients with cancer, the emergence of multidrug resistant P. aeruginosa may have grave consequences.

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Invasive aspergillosis (IA) can occur despite prior prophylactic or empiric use of triazoles or amphotericin B (AMB). Although profound immunosuppression may account for breakthrough IA, resistance of Aspergillus to antifungals may also play a role. To examine this question, we measured the minimal inhibitory concentration of 105 Aspergillus isolates recovered from 105 cancer patients (64 with IA, 41 with Aspergillus colonization) to AMB, itraconazole (ITC), and voriconazole (VRC) using the National Committee for Clinical Laboratory Standards (NCCLS) M38-A microdilution and E-test methods.

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Background: Invasive aspergillosis (IA) is associated with poor outcome in patients with hematologic malignancy treated with amphotericin B (AMB)-based therapy. Itraconazole (ITC), a triazole with activity against Aspergillus, has been used in combination with AMB or lipid formulations of AMB (LipoAMB) in the treatment of IA, although the efficacy of this strategy is uncertain.

Methods: To determine whether the addition of ITC to LipoAMB improves outcome of IA, the authors retrospectively studied 179 consecutive patients with hematologic malignancies and definite or probable IA who received primary antifungal therapy with either LipoAMB (n = 146), or lipoAMB plus ITC (n = 33) between June 1993 and June 2003.

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Objectives: The aim of this study was to compare the activity of linezolid and vancomycin in an in vitro pharmacodynamic model to assess potential differences in activity against biofilm-embedded organisms.

Methods: Single-lumen central venous catheters colonized with biofilm-embedded Staphylococcus aureus, Staphylococcus epidermidis or vancomycin-resistant Enterococcus faecium (VRE) were treated with simulated clinical dosing regimens of linezolid 600 mg every 12 h or vancomycin 1 g every 12 h in a one-compartment in vitro pharmacodynamic model. Quantitative cultures were sampled through the catheter and peripheral ports over 48 h to dynamically assess changes in the burden of catheter colonization and organism seeding, respectively.

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Background: Anecdotal evidence suggests a rise in zygomycosis in association with voriconazole (VRC) use in immunosuppressed patients.

Methods: We performed prospective surveillance of patients with zygomycosis (group A; n = 27) and compared them with contemporaneous patients with invasive aspergillosis (group B; n = 54) and with matched contemporaneous high-risk patients without fungal infection (group C; n = 54). We also performed molecular typing and in vitro susceptibility testing of Zygomycetes isolates.

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