51
|
Yeo EJ, Ryu JH, Cho YS, Chun YS, Huang LE, Kim MS, Park JW. Amphotericin B blunts erythropoietin response to hypoxia by reinforcing FIH-mediated repression of HIF-1. Blood 2006; 107:916-23. [PMID: 16189267 DOI: 10.1182/blood-2005-06-2564] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AbstractAmphotericin B (AmB) is widely used for treating severe systemic fungal infections. However, long-term AmB treatment is invariably associated with adverse effects such as anemia. The erythropoietin (EPO) suppression by AmB has been proposed to contribute to the development of anemia. However, the mechanism whereby EPO is suppressed remains obscure. In this study, we investigated the possibility that AmB inhibits the transcription of the EPO gene by inactivating HIF-1, which is a known key transcription factor and regulator of EPO expression. EPO mRNA levels were markedly attenuated by AmB treatment both in rat kidneys and in Hep3B cells. AmB inactivated the transcriptional activity of HIF-1α, but did not affect the expression or localization of HIF-1 subunits. Moreover, AmB was found to specifically repress the C-terminal transactivation domain (CAD) of HIF-1α, and this repression by AmB required Asn803, a target site of the factor-inhibiting HIF-1 (FIH); moreover, this repressive effect was reversed by FIH inhibitors. Furthermore, AmB stimulated CAD-FIH interaction and inhibited the p300 recruitment by CAD. We propose that this mechanism underlies the unexplained anemia associated with AmB therapy.
Collapse
Affiliation(s)
- Eun-Jin Yeo
- Department of Pharmacology, Seoul National University College of Medicine, Seoul, Korea
| | | | | | | | | | | | | |
Collapse
|
52
|
Mantadakis E, Samonis G. Novel preventative strategies against invasive aspergillosis. Med Mycol 2006; 44:S327-S332. [DOI: 10.1080/13693780600849113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
|
53
|
Abstract
Posaconazole is a triazole antifungal agent, administered as an oral suspension, with an extended spectrum of in vitro activity. Posaconazole 800 mg/day demonstrated clinically relevant activity against a range of fungi in patients with invasive fungal infections who were refractory to, or intolerant of, other antifungal therapy in an open-label, multicentre, phase III study (330 patients received posaconazole and 279 patients served as external controls). In aspergillosis, the global response success rate at the end-of-therapy visit (primary endpoint) was significantly higher in posaconazole recipients than in external controls (42% vs 26%). Posaconazole was also associated with overall success rates of 54% in zygomycosis, 46% in fusariosis, 43% in Pseudallescheria infection, 80% in phaeohyphomycosis and 100% in histoplasmosis. Success rates were 48% in refractory candidiasis, 69% in refractory coccidioidomycosis, 48% in refractory cryptococcal infection and 82% in refractory chromoblastomycosis or mycetoma. Posaconazole also demonstrated potential in febrile neutropenia in an open-label phase II study (success rate of 81% 7 days after the end of treatment). In a noncomparative, multicentre, phase III study in patients with advanced HIV infection who had azole-refractory oropharyngeal and/or oesophageal candidiasis, posaconazole 400 or 800 mg/day resulted in a clinical response in 132 of 176 patients (75%). Oral posaconazole suspension was generally well tolerated in patients with invasive fungal infections, including patients who received treatment for >or=1 year.
Collapse
|
54
|
Philip A, Odabasi Z, Rodriguez J, Paetznick VL, Chen E, Rex JH, Ostrosky-Zeichner L. In vitro synergy testing of anidulafungin with itraconazole, voriconazole, and amphotericin B against Aspergillus spp. and Fusarium spp. Antimicrob Agents Chemother 2005; 49:3572-4. [PMID: 16048988 PMCID: PMC1196215 DOI: 10.1128/aac.49.8.3572-3574.2005] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The in vitro interactions of anidulafungin with itraconazole, voriconazole, and amphotericin B were evaluated by using the checkerboard method. For Aspergillus spp., anidulafungin with amphotericin B showed indifference for 16/26 isolates, while anidulafungin with either azole showed a synergy trend for 18/26 isolates. All drug combinations showed indifference for 7/7 Fusarium sp. isolates.
Collapse
Affiliation(s)
- Annie Philip
- Laboratory of Mycology Research, Division of Infectious Diseases, University of Texas-Houston Medical School, 6431 Fannin, MSB 2.112, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|
55
|
|
56
|
Bonfante L, Nalesso F, Cara M, Antonello A, Malagoli A, Pastori G, Guizzo M, D'Angelo A, Gambaro G. Aspergillus fumigatus peritonitis in ambulatory peritoneal dialysis: A case report and notes on the therapeutic approach (Case Report). Nephrology (Carlton) 2005; 10:270-3. [PMID: 15958040 DOI: 10.1111/j.1440-1797.2005.00370.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aspergillus peritonitis is a rare disease in continuous peritoneal dialysis. It is a severe form of peritonitis, which is frequently lethal. We report a case of Aspergillus fumigatus peritonitis in a female patient on automated peritoneal dialysis (APD), who was successfully treated with intravenous amphotericin B and the removal of the peritoneal catheter. As delayed treatment has an increased mortality rate, it is mandatory to remove the catheter and to start intravenous treatment with amphotericin B empirically.
Collapse
Affiliation(s)
- Luciana Bonfante
- Department of Medical and Surgical Sciences, Division of Nephrology, Policlinico Universitario, University of Padua, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
57
|
Moyssakis I, Vassilakopoulos TP, Sipsas NV, Perakis A, Petrou A, Kosmas N, Pangalis GA. Reversible dilated cardiomyopathy associated with amphotericin B treatment. Int J Antimicrob Agents 2005; 25:444-7. [PMID: 15848302 DOI: 10.1016/j.ijantimicag.2005.02.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Accepted: 02/18/2005] [Indexed: 11/16/2022]
Abstract
We report two patients, who developed dilated cardiomyopathy and subsequent congestive heart failure after treatment with amphotericin B (AmB). The echocardiographic findings and the symptoms of heart failure resolved after the discontinuation of the drug. The clinical data from our cases and two similar cases reported in the literature suggest that the presence of other factors predisposing to cardiac dysfunction may facilitate the occurrence of this rare side effect.
Collapse
|
58
|
Sipsas NV, Bodey GP, Kontoyiannis DP. Perspectives for the management of febrile neutropenic patients with cancer in the 21st century. Cancer 2005; 103:1103-13. [PMID: 15666328 DOI: 10.1002/cncr.20890] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Over the past several decades, there has been substantial progress in the management of patients with febrile neutropenia. However, the ever-changing patterns of infection, ecology, and antibiotic-resistance trends do not allow the development of treatment guidelines that could be applied universally. Hence, the institution's predominant pathogens and resistance patterns should guide the empirical choice of antimicrobials. Prompt initiation of antimicrobial therapy remains the gold standard. Monotherapy with the newer broad-spectrum antimicrobials has tended to replace the classic combination therapy. Empirical administration of glycopeptides, such as vancomycin, without documentation of a gram-positive infection is not favored. The development of risk-stratification models has allowed for identification of low-risk patients with additional treatment options, such as early discharge and exclusively outpatient treatment with oral antimicrobials. The initiation of empirical antifungal therapy in persistently febrile neutropenic patients has become common practice, especially recently, since the introduction of new, effective, less toxic antifungal drugs. It is hoped that the development of new nonculture-based diagnostic methods will allow for the early detection of invasive fungal infections and, thus, the replacement of empirical antifungal therapy with pathogen-specific, preemptive therapy.
Collapse
Affiliation(s)
- Nikolaos V Sipsas
- Infectious Diseases Unit, Pathophysiology Department, Laikon General Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | | | | |
Collapse
|
59
|
Khan MA, Jabeen R, Nasti TH, Mohammad O. Enhanced anticryptococcal activity of chloroquine in phosphatidylserine-containing liposomes in a murine model. J Antimicrob Chemother 2004; 55:223-8. [PMID: 15590713 DOI: 10.1093/jac/dkh522] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES The anticryptococcal activity of chloroquine was assessed after incorporation in phosphatidylserine (PS)-containing negatively charged liposomes in a murine model. METHODS In the present study, we investigated the antifungal activity of chloroquine entrapped in PS liposomes against Cryptococcus neoformans in the macrophage cell line J 774 and in a murine model. Mice were treated with free as well as liposomal formulations of chloroquine before and after challenging with C. neoformans infection. The anticryptococcal activity of chloroquine was also evaluated in combination with fluconazole in the treatment of systemic murine cryptococcosis. The efficacy of chloroquine treatment was assessed by continued survival as well as by colony forming units (cfu) in liver and brain of treated mice. RESULTS Chloroquine entrapped in PS liposomes shows increased activity against C. neoformans infection both in in vitro and in vivo studies. Moreover, the antifungal activity of fluconazole increases when used in combination with liposomal chloroquine. Chloroquine in PS liposomes was found to be more effective in comparison with the same dose of free chloroquine or chloroquine entrapped in neutral liposomes. CONCLUSIONS The enhanced anticryptococcal activity of chloroquine in PS liposomes seems to be due to uptake of drug-containing PS liposomes by macrophages. It can be assumed that liposome-mediated delivery of chloroquine to macrophages results in an unfavourable (alkaline) environment for the growth of C. neoformans inside macrophages.
Collapse
Affiliation(s)
- Masood A Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh-202002, India.
| | | | | | | |
Collapse
|
60
|
Cuenca-Estrella M. Combinations of antifungal agents in therapy--what value are they? J Antimicrob Chemother 2004; 54:854-69. [PMID: 15375111 DOI: 10.1093/jac/dkh434] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Concurrent or sequential antifungal treatment for invasive mycoses has been typically considered as an option to improve results of monotherapy. However, data on the efficacy of combination therapy are sparse and consist largely of results from studies in vitro and experimental animal models. These studies have yielded controversial results depending on the criteria used to evaluate the antifungal interaction. Several combinations that showed synergy in vitro failed to do so in animal models. Overall, apart from cryptococcal infections, combined antifungal therapy is not significantly better than monotherapy in terms of clinical efficacy. It is questionable whether combination therapy should be used in most cases as there is a lack of evidence from well-designed clinical trials. However, combination therapy could be an alternative to monotherapy for patients with invasive infections that are difficult to treat, such as those due to multi-resistant species and for those who fail to respond to standard treatment.
Collapse
Affiliation(s)
- Manuel Cuenca-Estrella
- Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Majadahonda-Pozuelo Km 2, 28220 Majadahonda, Madrid, Spain.
| |
Collapse
|
61
|
Maheshwari A, Stromquist CI, Pereda L, Emmanuel PJ. Mixed infection with unusual fungi and staphylococcal species in two extremely premature neonates. J Perinatol 2004; 24:324-6. [PMID: 15116131 DOI: 10.1038/sj.jp.7211077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Systemic fungal infections are being recognized with increasing frequency in extremely premature neonates. We report two such infants with late-onset mixed infection with Staphylococcal species and unusual fungi. These cases are of interest in view of recent reports on the interaction of Staphylococcal cell wall components and neutrophils, as damaged skin sites could form a nidus and portal of entry for saprophytic fungal pathogens. It is also important to consider fungal infection as a possibility in sick premature infants with necrotic skin lesions even when the systemic signs have an alternative explanation with ongoing bacteremia.
Collapse
Affiliation(s)
- Akhil Maheshwari
- Division of Neonatology, Department of Pediatrics, All Children's Hospital and University of South Florida College of Medicine, St Petersburg/Tampa, FL 33701, USA
| | | | | | | |
Collapse
|
62
|
Avrahami D, Shai Y. Bestowing antifungal and antibacterial activities by lipophilic acid conjugation to D,L-amino acid-containing antimicrobial peptides: a plausible mode of action. Biochemistry 2004; 42:14946-56. [PMID: 14674771 DOI: 10.1021/bi035142v] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dramatically increased frequency of opportunistic fungal infections has prompted research to diversify the arsenal of antifungal agents. Antimicrobial peptides constitute a promising family for future antibiotics with a new mode of action. However, only a few are effective against fungal pathogens because of their ability to self-assemble. Recently, we showed that the conjugation of fatty acids to the potent antibacterial peptide magainin endowed it with antifungal activity concomitant with an increase in its oligomeric state in solution. To investigate whether a high potency of the parental peptide is prerequisite for antifungal activity, we conjugated undecanoic acid (UA) and palmitic acid (PA) to inactive diastereomers of magainin containing four d-amino acids ([D]-4-magainin), as well as to a weakly active diastereomeric lytic peptide containing Lys and Leu ([D]-K(5)L(7)). All lipopeptides gained potent activity toward Cryptococcus neoformans. Most importantly, [D]-K(5)L(7)-UA was highly potent against all microorganisms tested, including bacteria, yeast, and opportunistic fungi. All lipopeptides increased the permeability of Escherichia coli spheroplasts and intact C. neoformans, as well as their corresponding membranes, phosphatidylethanol (PE)/phosphatidylglycerol (PG) and phosphatidylcholine (PC)/PE/phosphatidylinositol (PI)/ergosterol, respectively. The extent of membrane-permeating activity correlated with their biological function, suggesting that the plasma membrane was one of their major targets. Circular dichroism (CD) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy revealed that their mode of oligomerization in solution, structure, and organization in membranes have important roles regarding their antibacterial and antifungal activities. Together with the advantage of using diastereomers versus all l-amino acid peptides, this study paves the way to the design of a new group of potent antifungal peptides urgently needed to combat opportunistic fungal infection.
Collapse
Affiliation(s)
- Dorit Avrahami
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
| | | |
Collapse
|
63
|
Avrahami D, Shai Y. A new group of antifungal and antibacterial lipopeptides derived from non-membrane active peptides conjugated to palmitic acid. J Biol Chem 2004; 279:12277-85. [PMID: 14709550 DOI: 10.1074/jbc.m312260200] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We report on the synthesis, biological function, and a plausible mode of action of a new group of lipopeptides with potent antifungal and antibacterial activities. These lipopeptides are derived from positively charged peptides containing d- and l-amino acids (diastereomers) that are palmitoylated (PA) at their N terminus. The peptides investigated have the sequence K(4)X(7)W, where X designates Gly, Ala, Val, or Leu (designated d-X peptides). The data revealed that PA-d-G and PA-d-A gained potent antibacterial and antifungal activity despite the fact that both parental peptides were completely devoid of any activity toward microorganisms and model phospholipid membranes. In contrast, PA-d-L lost the potent antibacterial activity of the parental peptide but gained and preserved partial antifungal activity. Interestingly, both d-V and its palmitoylated analog were inactive toward bacteria, and only the palmitoylated peptide was highly potent toward yeast. Both PA-d-L and PA-d-V lipopeptides were also endowed with hemolytic activity. Mode of action studies were performed by using tryptophan fluorescence and attenuated total reflectance Fourier transform infrared and circular dichroism spectroscopy as well as transmembrane depolarization assays with bacteria and fungi. The data suggest that the lipopeptides act by increasing the permeability of the cell membrane and that differences in their potency and target specificity are the result of differences in their oligomeric state and ability to dissociate and insert into the cytoplasmic membrane. These results provide insight regarding a new approach of modulating hydrophobicity and the self-assembly of non-membrane interacting peptides in order to endow them with both antibacterial and antifungal activities urgently needed to combat bacterial and fungal infections.
Collapse
Affiliation(s)
- Dorit Avrahami
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | | |
Collapse
|