Biomedical subjects

Hend Hanna

Publications and source records attributed to Hend Hanna.

28 records · Page 2Linked to original sources

PubMed2003

Antibiotic-coated hemodialysis catheters for the prevention of vascular catheter-related infections: a prospective, randomized study.

PURPOSE: To determine the efficacy of minocycline-rifampin-coated hemodialysis catheters in reducing catheter-related infections in patients requiring hemodialysis for acute renal failure. METHODS: Between May 2000 and March 2002, 66 patients were randomly assigned to receive a minocycline-rifampin-impregnated central venous catheter and 64 were randomly assigned to receive an unimpregnated catheter. Patients were followed prospectively until the catheter was removed. Catheter-related infection was determined through quantitative catheter cultures, quantitative blood cultures, or both. RESULTS: Both groups of patients were similar in age, sex, underlying disease, type of dialysis (continuous vs. intermittent), neutropenia during catheterization and its duration, catheter insertion difficulties, and administration of blood products or medication. The mean (+/- SD) catheter dwell time was the same in both groups (8 +/- 6 days, P = 0.7). There were seven catheter-related infections (11%), all associated with the use of unimpregnated catheters. Kaplan-Meier estimates for the risk of catheter-related infection showed that coated catheters were less likely to be associated with infection (P = 0.006). CONCLUSION: The use of polyurethane hemodialysis catheters impregnated with minocycline and rifampin decreases the risk of catheter-related infection in patients with acute renal failure.

Acute Kidney Injury↗

PubMed2003

Clinical experience with minocycline and rifampin-impregnated central venous catheters in bone marrow transplantation recipients: efficacy and low risk of developing staphylococcal resistance.

In this retrospective evaluation of the 4-year clinical use of minocycline and rifampin-impregnated catheters in bone marrow transplantation (BMT) patients, we report low risk of development of staphylococcal resistance to the antibiotics coating the catheters and efficacy in preventing primary staphylococcal bloodstream infections.

Adult↗

PubMed2003

In vitro and ex vivo activities of minocycline and EDTA against microorganisms embedded in biofilm on catheter surfaces.

Minocycline-EDTA (M-EDTA) flush solution has been shown to prevent catheter-related infection and colonization in a rabbit model and in hemodialysis patients. We undertook this study in order to determine the activities of M-EDTA against organisms embedded in fresh biofilm (in vitro) and mature biofilm (ex vivo). For the experiment with the in vitro model, a modified Robbin's device (MRD) was used whereby 25 catheter segments were flushed for 18 h with 10(6) CFU of biofilm-producing Staphylococcus epidermidis, Staphylococcus aureus, and Candida albicans per ml. Subsequently, each of the catheter segments was incubated in one of the following solutions: (i) streptokinase, (ii) heparin, (iii) broth alone, (iv) vancomycin, (v) vancomycin-heparin, (vi) EDTA, (vii) minocycline (high-dose alternating with low-dose), or (viii) M-EDTA (low-dose minocycline alternating with high-dose minocycline were used to study the additive and synergistic activities of M-EDTA). All segments were cultured quantitatively by scrape sonication. For the experiment with the ex vivo model, 54 catheter tip segments removed from patients and colonized with bacterial organisms by roll plate were longitudinally cut into two equal segments and exposed to either saline, heparin, EDTA, or M-EDTA (with high-dose minocycline). Subsequently, all segments were examined by confocal laser electron microscopy. In the in vitro MRD model, M-EDTA (with a low concentration of minocycline) was significantly more effective than any other agent in reducing colonization of S. epidermidis, S. aureus, and C. albicans (P < 0.01). M-EDTA (with a high concentration of minocycline) eradicated all staphylococcal and C. albicans organisms embedded in the biofilm. In the ex vivo model, M-EDTA (with a high concentration of minocycline) reduced bacterial colonization more frequently than EDTA or heparin (P < 0.01). We concluded that M-EDTA is highly active in eradicating microorganisms embedded in fresh and mature biofilm adhering to catheter surfaces.

Anti-Bacterial Agents↗

PubMed2002

Minocycline-ethylenediaminetetraacetate lock solution for the prevention of implantable port infections in children with cancer.

In this prospective cohort study, minocycline-ethylenediaminetetraacetate (M-EDTA) was used as a lock solution in indwelling ports inserted in 14 children with cancer. No port infections, thrombotic events, or other adverse events were observed, compared with 10 port infections that occurred in 48 control patients whose ports were flushed with heparin. M-EDTA is a promising lock solution in long-term catheters.

Anti-Bacterial Agents↗

PubMed2002

Polymerase chain reaction on blood for the diagnosis of invasive pulmonary aspergillosis in cancer patients.

BACKGROUND: The premortem diagnosis of invasive pulmonary aspergillosis (IPA) is difficult to make and often missed. Several retrospective studies have suggested that Aspergillus polymerase chain reaction (PCR) performed on serum or whole blood is useful in diagnosing IPA. Two prospective studies confirmed this finding but included a small number of IPA cases. METHODS: The current study was performed to determine the diagnostic role of Aspergillus PCR performed on whole blood specimens from 54 patients with cancer and pulmonary infiltrates for which bronchoscopy with fungal stains and cultures were performed. PCR through amplified Aspergillus mitochondrial DNA and alkaline protease genes was performed on whole blood samples. RESULTS: The cohort in the current study was comprised of 4 patients with definite IPA, 7 patients with probable IPA, 7 patients with possible IPA, and 36 control patients with no evidence of IPA. The sensitivity, specificity, and positive and negative predictive values all were 100% for definite IPA cases and 57%, 100%, 100%, and 92%, respectively, for each of the probable and possible IPA cases. CONCLUSIONS: Aspergillus PCR on whole blood samples is highly sensitive for the detection of IPA and is predictive for IPA. The sensitivity appears to be correlated with the certainty of diagnosis as proven by tissue invasion.

Adolescent↗

PubMed2002

Masking of neutropenic patients on transport from hospital rooms is associated with a decrease in nosocomial aspergillosis during construction.

To prevent nosocomial pulmonary aspergillosis during hospital construction, neutropenic patients with hematologic malignancy were required to wear high-efficiency masks when leaving their rooms. The rate of nosocomial aspergillosis decreased from 0.73 per 1,000 hospital patient-days during fiscal years 1993 to 1996 to 0.24 per 1,000 hospital patient-days during fiscal years 1996 to 1999 (P < .001). High-efficiency masks reduced nosocomial aspergillosis during hospital construction.

Air Pollutants↗

PubMed2002

Risk factors for vancomycin-resistant Enterococcus (VRE) infection in colonized patients with cancer.

To determine the risk factors for vancomycin-resistant Enterococcus (VRE) infection in colonized patients with cancer, we conducted a case-control study. According to multivariate analysis, the only significant factors were neutropenia (< 500 cells/mm3) for more than 1 week and the use of oral vancomycin. Therefore, colonized neutropenic patients with cancer who have previously used oral vancomycin are most prone to VRE infection.

Adolescent↗

PubMed2002

Epidemiology, molecular mycology, and environmental sources of Fusarium infection in patients with cancer.

OBJECTIVE: To investigate the epidemiology and environmental sources of Fusarium infections in patients with cancer. DESIGN: Retrospective case-control study conducted following surveillance environmental cultures and DNA analysis of isolated organisms. SETTING: A tertiary-care, university cancer center. METHODS: In 1996 and 1997, environmental cultures were performed on air samples and water systems. A retrospective chart review was performed for 70 patients with cancer identified with fusariosis between 1987 and 1997. Patients with fusariosis were compared with 49 uninfected control patients who occupied hospital rooms with positive environmental cultures for Fusarium. With the use of random amplification of polymorphic DNA, organisms isolated from infected patients were compared with environmental organisms. RESULTS: Most of the patients with Fusarium (40, 57%) were infected on or within 3 days of admission, indicating community rather than nosocomial acquisition. Patients were comparable in terms of underlying immunocompromised status to 49 uninfected control patients. However, the duration from admission to infection in the patients with fusariosis tended to be shorter than the duration from admission to discharge in the exposed control patients (P = .06). Water cultured from the hospital tanks and from sinks and water fountains was negative for Fusarium. With the use of polymerase chain reaction, environmental isolates did not match clinical ones. Quantitative air sampling showed that the quantitative outdoor Fusarium levels were eightfold higher than the indoor levels. During the rainy summer season, outdoor air concentrations of Fusarium were at their highest, coinciding with the peak incidence of fusariosis at our center. CONCLUSION: The most likely source of fusariosis was the external environment rather than nosocomial sources, such as water.

Adolescent↗

PubMed2002

Breakthrough candidemia in patients with cancer differs from de novo candidemia in host factors and Candida species but not intensity.

OBJECTIVES: To evaluate the risk factors associated with breakthrough candidemia in patients with cancer and to compare them with those of de novo candidemia in this patient population. DESIGN: Retrospective case series of 120 episodes of candidemia, 90 de novo and 30 breakthrough candidemias. SETTING: University-affiliated, tertiary-care cancer center in Houston, Texas. PATIENTS: All patients with cancer who acquired candidemia between January 1993 and December 1998 were included if they had non-catheter-related candidemia and information about quantitative blood cultures. RESULTS: Although less frequent, breakthrough candidemia was seen more often in neutropenic patients with leukemia. The intensity of breakthrough candidemia was comparable to that of de novo candidemia. Most (70%) of the breakthrough candidemias were due to Candida glabrata or C. krusei. CONCLUSIONS: In breakthrough candidemia, the same risk factors seen in de novo candidemia were encountered, although more frequently. C. glabrata and C. krusei are the leading causes of breakthrough candidemia in patients with cancer.

Adolescent↗

PubMed2002

Diagnosis of invasive pulmonary aspergillosis using polymerase chain reaction-based detection of aspergillus in BAL.

STUDY OBJECTIVE: To assess the value of Aspergillus polymerase chain reaction (PCR) test performed on the BAL in diagnosing invasive pulmonary aspergillosis (IPA). DESIGN: Between January 1996 and 1997, we prospectively followed up 249 cancer patients with pulmonary infiltrates suggestive of pneumonia. Bronchoscopy with fungal stains, cultures, and PCR was performed on all patients. PCR was used for the detection of Aspergillus mitochondrial and alkaline protease gene DNA. The PCR products were visualized either directly on polyacrylamide gel or after Southern transfer and probing with specific probes for mitochondrial and alkaline protease DNA. RESULTS: The 249 patients consisted of 10 patients with proven IPA (tissue invasion), 22 patients with probable IPA (microbiologic culture), 18 patients with possible IPA (consistent clinical and radiologic findings), and 199 control patients with no evidence of IPA. PCR positivity was strongly associated with all forms of IPA (p < 0.002). The sensitivity, specificity, positive predictive value, and negative predictive value of PCR were 80%, 93%, 38%, and 99%, respectively, for proven IPA, and 64%, 93%, 52%, and 96%, respectively, for probable IPA. Southern blotting analysis did not improve the diagnostic yield of the PCR test. CONCLUSION: PCR performed on BAL is associated with high specificity and negative predictive value for IPA. The low positive predictive value could be related to the transient colonizing presence of aspergilli in the respiratory tract. The sensitivity correlates with the certainty of the diagnosis based on tissue invasion.

Adolescent↗