Lung weight parallels disease severity in experimental coccidioidomycosis.
(1/2502)
Evidence provided by histopathological study of lesions is a valuable adjunct for evaluating chemotherapeutic efficacy in experimental animal models, In addition, this should be correlated with a measure of disease severity in the same animal. The latter could be obtained by homogenization of infected organs and quantitative enumeration of viable cells of the etiological agent, but this would preclude histopathological studies in the same animal. Progression of disease in pulmonary infection is associated with replacement of air space by fluid, cells, and cellular debris. Therefore, an increase in lung weight should reflect severity of disease. Results with the murine model of coccidioidomycosis demonstrate that increasing lung weight parallels the increasing census of fungus cells in the lungs of both treated and nontreated infected mice. This was supported with evidence obtained from microscopic studies of lesions indicating that specific chemotherapy limited spread of the infection and inhibited multiplication of the fungus in the lung. Therefore, lung weight can be used as a measure of disease severity in the murine model of coccidioidomycosis. (+info)
U.S. Food and Drug Administration approval of AmBisome (liposomal amphotericin B) for treatment of visceral leishmaniasis.
(2/2502)
In August 1997, AmBisome (liposomal amphotericin B, Nexstar, San Dimas, CA) was the first drug approved for the treatment of visceral leishmaniasis by the U.S. Food and Drug Administration. The growing recognition of emerging and reemerging infections warrants that safe and effective agents to treat such infections be readily available in the United States. The following discussion of the data submitted in support of the New Drug Application for AmBisome for the treatment of visceral leishmaniasis shows the breadth of data from clinical trials that can be appropriate to support approval for drugs to treat tropical diseases. (+info)
Early mycological treatment failure in AIDS-associated cryptococcal meningitis.
(3/2502)
Cryptococcal meningitis causes significant morbidity and mortality in persons with AIDS. Of 236 AIDS patients treated with amphotericin B plus flucytosine, 29 (12%) died within 2 weeks and 62 (26%) died before 10 weeks. Just 129 (55%) of 236 patients were alive with negative cerebrospinal fluid (CSF) cultures at 10 weeks. Multivariate analyses identified that titer of cryptococcal antigen in CSF, serum albumin level, and CD4 cell count, together with dose of amphotericin B, had the strongest joint association with failure to achieve negative CSF cultures by day 14. Among patients with similar CSF cryptococcal antigen titers, CD4 cell counts, and serum albumin levels, the odds of failure at week 10 for those without negative CSF cultures by day 14 was five times that for those with negative CSF cultures by day 14 (odds ratio, 5.0; 95% confidence interval, 2.2-10.9). Prognosis is dismal for patients with AIDS-related cryptococcal meningitis. Multivariate analyses identified three components that, along with initial treatment, have the strongest joint association with early outcome. Clearly, more effective initial therapy and patient management strategies that address immune function and nutritional status are needed to improve outcomes of this disease. (+info)
Systemic candidiasis with candida vasculitis due to Candida kruzei in a patient with acute myeloid leukaemia.
(4/2502)
Candida kruzei-related systemic infections are increasing in frequency, particularly in patients receiving prophylaxis with antifungal triazoles. A Caucasian male with newly diagnosed acute myeloid leukaemia (AML M1) developed severe and persistent fever associated with a micropustular eruption scattered over the trunk and limbs during induction chemotherapy. Blood cultures grew Candida kruzei, and biopsies of the skin lesions revealed a candida vasculitis. He responded to high doses of liposomal amphotericin B and was discharged well from hospital. (+info)
In vitro and in vivo activities of NS-718, a new lipid nanosphere incorporating amphotericin B, against Aspergillus fumigatus.
(5/2502)
We evaluated the in vitro and in vivo potencies of a new lipid nanosphere that incorporates amphotericin B (AmB), NS-718, against Aspergillus fumigatus. The in vitro activity of NS-718 (the MIC at which 90% of strains are inhibited [MIC90], 0.25 microgram/ml) against 18 isolates of A. fumigatus was similar to that of deoxycholate AmB (D-AmB; Fungizone; MIC90, 0.25 microgram/ml), but NS-718 was more potent than liposomal AmB (L-AmB; AmBi-some; MIC90, 1.0 microgram/ml). The in vivo efficacy of NS-718 in a rat model of invasive pulmonary aspergillosis was compared with those of D-AmB and L-AmB. A low dose (1 mg/kg of body weight) of L-AmB was ineffective (survival rate, 0%), although equivalent doses of D-AmB and NS-718 were more effective (survival rate, 17%). However, a higher dose of NS-718 (3 mg/kg) was more effective (survival rate, 100%) than equivalent doses of D-AmB and L-AmB (survival rate, 0%). To explain these differences, pharmacokinetic studies showed higher concentrations of AmB in the plasma of rats treated with NS-718 than in the plasma of those treated with D-AmB. Our results suggest that NS-718, a new preparation of AmB, is a promising antifungal agent with activity against pulmonary aspergillosis. (+info)
Effect of fasting on temporal variation in the nephrotoxicity of amphotericin B in rats.
(6/2502)
Evidence for temporal variation in the nephrotoxicity of amphotericin B was recently reported in experimental animals. The role of food in these variations was determined by studying the effect of a short fasting period on the temporal variation in the renal toxicity of amphotericin B. Twenty-eight normally fed and 28 fasted female Sprague-Dawley rats were used. Food was available ad libitum to the fed rats, while the fasted animals were fasted 12 h before and 24 h after amphotericin B injection to minimize stress for the animals. Water was available ad libitum to both groups of rats, which were maintained on a 14-h light, 10-h dark regimen (light on at 0600 h). Renal toxicity was determined by comparing the levels of excretion of renal enzyme and the serum creatinine and blood urea nitrogen (BUN) levels at the time of the maximal (0700 h) or the minimal (1900 h) nephrotoxicity after the intraperitoneal administration of a single dose of dextrose (5%; control group) or amphotericin B (50 mg/kg of body weight; treated group) to the rats. The nephrotoxicities obtained after amphotericin B administration at both times of day were compared to the nephrotoxicities observed for time-matched controls. In fed animals, the 24-h urinary excretion of N-acetyl-beta-D-glucosaminidase and beta-galactosidase was significantly higher when amphotericin B was injected at 0700 and 1900 h. The excretion of these two enzymes was reduced significantly (P < 0.05) in fasting rats, and this effect was larger at 0700 h (P < 0.05) than at 1900 h. The serum creatinine level was also significantly higher (P < 0.05) in fed animals treated at 0700 h than in fed animals treated at 1900 h. Fasting reduced significantly (P < 0.05) the increase in the serum creatinine level, and this effect was larger in the animals treated at 0700 h. Similar data were obtained for BUN levels. Amphotericin B accumulation was significantly higher (P < 0.05) in the renal cortexes of fed rats than in those of fasted animals, but there was no difference according to the time of injection. These results demonstrated that fasting reduces the nephrotoxicity of amphotericin B and that food availability is of crucial importance in the temporal variation in the renal toxicity of amphotericin B in rats. (+info)
Amphotericin B- and fluconazole-resistant Candida spp., Aspergillus fumigatus, and other newly emerging pathogenic fungi are susceptible to basic antifungal peptides.
(7/2502)
The present study shows that a number of basic antifungal peptides, including human salivary histatin 5, a designed histatin analog designated dhvar4, and a peptide from frog skin, PGLa, are active against amphotericin B-resistant Candida albicans, Candida krusei, and Aspergillus fumigatus strains and against a fluconazole-resistant Candida glabrata isolate. (+info)
In-vitro activity of voriconazole, itraconazole and amphotericin B against filamentous fungi.
(8/2502)
The in-vitro fungistatic and fungicidal activities of voriconazole were compared with those of itraconazole and amphotericin B. MICs for 110 isolates belonging to 11 species of filamentous fungi were determined by a broth microdilution adaptation of the method recommended by the National Committee for Clinical Laboratory Standards. Minimum lethal concentrations (MLCs) of the three antifungal agents were also determined. The MIC ranges of the three compounds were comparable for Aspergillus flavus, Aspergillus fumigatus, Cladophialophora bantiana and Exophiala dermatitidis. Voriconazole and itraconazole were more active than amphotericin B against Fonsecaea pedrosoi, but the two azole agents were less active against Sporothrix schenckii. Voriconazole was more active than itraconazole or amphotericin B against Scedosporium apiospermum, but less active than the other two agents against two mucoraceous moulds, Absidia corymbifera and Rhizopus arrhizus. Voriconazole and amphotericin B were more active than itraconazole against Fusarium solani. With the exception of S. apiospermum, all the moulds tested had MLC50 values of < or =2 mg/L and MLC90 values of < or =4 mg/L against amphotericin B. Voriconazole and itraconazole showed fungicidal effects against five of the 1 1 moulds tested (A. flavus, A. fumigatus, C. bantiana, E. dermatitidis and F. pedrosoi) with MLC90 values of < or =2 mg/L. In addition, voriconazole was fungicidal for Phialophora parasitica. Our results suggest that voriconazole could be effective against a wide range of mould infections in humans. (+info)