Previous Article | Next Article 
Antimicrobial Agents and Chemotherapy, January 1998, p. 147-150, Vol. 42, No. 1
0066-4804/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
KY-62, a Polyene Analog of Amphotericin B, for
Treatment of Murine Candidiasis
John R.
Graybill,1,2,*
Laura K.
Najvar,2
Annette
Fothergill,2
Thomas
Hardin,2
Michael
Rinaldi,1,2
Chris
Lambros,3 and
Steven
L.
Regen4
University of Texas Health Science
Center1 and
South Texas Veterans Health
Care System,2 San Antonio, Texas 78284;
Lehigh University, Bethlehem, Pennsylvania
180153; and
National Institute of
Allergy and Infectious Diseases, Bethesda, Maryland
208924
Received 14 July 1997/Returned for modification 21 August
1997/Accepted 16 October 1997
 |
ABSTRACT |
KY-62 is a water-soluble analog of amphotericin B. In vitro testing
of five clinical isolates of Candida albicans showed KY-62 to have potency similar to that of amphotericin B. KY-62 was
administered to mice infected intravenously with C. albicans. In vivo, KY-62 was effective in immunocompetent mice,
with potency similar to that of amphotericin B. KY-62 was well
tolerated up to 30 mg/kg of body weight per dose, an amount that would
be lethal with amphotericin B. KY-62 was less effective in mice
rendered neutropenic with 5-fluorouracil. The addition of flucytosine
had little effect. KY-62 may have potential for clinical development.
| |
INTRODUCTION |
Of the currently available polyene
antifungals, amphotericin B is the only one used systemically. The
reason is that these drugs are poorly water soluble and highly toxic.
Efforts have been made to increase the maximum daily dose by
reformulating amphotericin B in a variety of lipid preparations
(1, 4, 11, 14, 18, 22). Three of these are now licensed in
the United States. These include amphotericin B in liposomes (AmBisome; Nextar), amphotericin B colloidal dispersion (Amphotec; Sequus), and
amphotericin B lipid complex (Abelcet; The Liposome Company). All of
these formulations permit higher dosages of amphotericin B, 
5 mg/kg
of body weight per dose, with minimal to no nephrotoxicity, but they
have not eliminated the infusion toxicities of amphotericin B. Alternatively, the polyene molecule has been esterified to increase
solubility, but there has been severe central nervous system toxicity
alleged to be due to some of these drugs (5, 8, 9). Another
drug (BRL49574A) has been shown to be effective but is limited by
chemical instability, tending to precipitate after long-term storage
(10). Despite these failures, a water-soluble, nontoxic
polyene remains a highly desirable alternative to amphotericin B. KY-62
is a candidate water-soluble polyene with a unique structure, shown in
Fig. 1. In the present studies, KY-62 was
compared with amphotericin B in vitro against Candida
albicans and in vivo in mice infected intravenously (i.v.) with
clinical isolates of C. albicans.
| |
MATERIALS AND METHODS |
Antifungal drugs.
Amphotericin B deoxycholate was purchased
from Adria Laboratories. KY-62 was synthesized by one of the
investigators (S.L.R.) and made available in a powder form. KY-62 was
prepared from amphotericin B as indicated in the studies of Yamashita
et al. (25). In this reference, KY-62 is labelled
amphotericin B conjugate 2. For parenteral administration, drugs were
dissolved in sterile water to the desired dose. Flucytosine (ANCOBON;
Roche Laboratories, Nutley, N.J.) was dissolved in distilled drinking
water. The daily dose was calculated by estimating that 27- to 30-g
mice each consumed 4 ml per day. In prior studies, we had determined
that the rate of water consumption was relatively constant at 4 to 4.5 ml/mouse/day, up until the last 24 to 48 h of life.
In vitro assay.
Five clinical isolates of C. albicans were used. All were clinical isolates obtained from the
Fungus Testing Laboratory, University of Texas Health Science Center,
San Antonio. They were stored frozen on Sabouraud dextrose agar until
utilized for MIC testing. KY-62 was dissolved in water for testing.
Testing of MICs at 24, 48, and 72 h was done by the National
Committee for Clinical Laboratory Standards macrodilution method, with
twofold dilutions downwards from 12.5 µg/ml (15, 17).
Measurement of KY-62 in serum.
For each data point, groups
of four to five uninfected mice were treated with KY-62 either
intraperitoneally (i.p.) or subcutaneously (s.c.) at the indicated dose
and bled by cardiac puncture. Their serum was pooled and assayed. Serum
samples were frozen at 
20°C until thawed for assay. High-pressure
liquid chromatography analysis of KY-62 was performed with samples
extracted in chloroform-methanol (8:2).
A Novapak C
18 reverse-phase column (4 mm by 15 cm; 5 µm;
Waters) was used as the stationary phase. The mobile phase consisted
of
methanol-acetonitrile-1.5 mM EDTA in a volumetric ratio of
10:7.5:4.
The injection volume was 100 ml, and a flow rate of
1.5 ml/min was
employed with a Waters 510 pump. Additional equipment
used included a
Waters 717 WISP Autosampler, Waters 486 absorbance
detector set at 382 nm, and a Millenium 2010 chromatography manager
(Millipore Corp.).
Under these conditions, KY-62 had a retention
time of 4.35 min. The
range of quantification was 0.025 to 40
µg/ml. Mice were treated with
KY-62 at 1 mg/kg/day i.p. or 5 mg/kg
twice daily s.c. for 10 days, with
serum being obtained 1 or 6
h after the final dose was given. Mice
treated with 30 mg of KY-62
per kg i.p. received a single dose of drug
and were bled at various
times after that dose.
Infection model.
Isolate 92-343 was used for infection. This
isolate was maintained between studies at 4°C on Sabouraud dextrose
agar. Before studies, the isolate was transferred to brain heart
infusion broth and grown at 37°C overnight. Inoculum was washed three
times in saline, and an aliquot was used for hemacytometer counting.
The inoculum was adjusted to an 0.2-ml/mouse volume, and the count of
viable organisms (as reported in the text and the tables) was determined by colony count dilutions. Groups of 7 to 10 ICR outbred mice of 25 g were used. Mice were infected i.v. with doses of C. albicans ranging from 2.8 × 105 to
3.2 × 106 CFU/mouse. One day later, treatment was
initiated at 0.2 ml/mouse i.v. or i.p. For studies of survival,
treatment was continued through day 10 after infection, and mice were
observed to 30 days after infection. For studies of tissue burden, mice
were treated from day 1 through 6 and were sacrificed 2 days after the
last treatment dose for quantitative cultures of the spleens and
kidneys. For survival studies, mice appearing moribund were sacrificed and their deaths were recorded as occurring on the next day.
Quantitative tissue counts were done by homogenizing the tissue in 2 ml
of sterile saline and performing serial 10-fold colony count dilutions.
In some studies, mice were rendered neutropenic by treatment 1 day
before infection with 5-fluorouracil at 150 mg/kg i.v.
This reduced the
peripheral blood absolute neutrophil count to
<100/µl within 1 day
after treatment. The absolute neutrophil
count remained in that range
for up to 10 days.
Statistics.
For survival, comparisons were made by the log
rank test and Wilcoxon test of life tables. The rank sum test was used
for comparison of tissue counts. Overall significance was determined at
P < 0.05 for comparison for two groups, with
adjustment of P values when more than two groups were
compared.
| |
RESULTS |
The in vitro susceptibilities of the five Candida
isolates are presented in Table 1. All
had a 48-h MIC of 3.03 µg/ml. Concentrations of KY-62 in serum (Table
2) did not reach the MIC after 10 days of
1 mg/kg/day i.p. or 5 mg/kg s.c. twice daily. After a single 30-mg/kg
dose, concentrations were still well above the MIC by 8 h after
the dose but had fallen below it by 24 h. We did not have enough
data points to determine the initial distribution half-life, but the
terminal half-life of KY-62 in the mouse was approximately 12 h.
View this table:
[in this window]
[in a new window]
|
TABLE 2.
KY-62 serum concentrations in mice treated for 10 days with either 1 mg/kg daily i.p., 5 mg/kg twice daily s.c., or a
single dose of 30 mg/kg i.p.
|
|
For studies of efficacy, groups of 10 immunocompetent mice were
infected i.v. with 7.3 × 105 CFU of C. albicans per mouse and then treated with either KY-62 at 1, 5, 10, 20, or 30 mg/kg/day i.p. or amphotericin B given at 1 mg/kg/day i.v. or
5 mg/kg/day i.p. As shown in Table 3, by
30 days after infection mice treated with 1 mg of amphotericin B per kg
per day had 90% survival, and those treated with 5 mg/kg/day had 100%
survival. For KY-62, survival was similarly and significantly prolonged
for all doses from 1 up through 30 mg/kg/day. The study was repeated
with amphotericin B at 1 mg/kg/day and KY-62 at 30 mg/kg/day i.p., and
results were similar. There was 90% survival of treated mice at day 30 versus 100% deaths by day 7 for controls (data not shown). A companion
study, with treatment from day 1 to 6, and sacrifice for tissue counts
on day 8, is presented in Table 4. Both
KY-62 (30 mg/kg) and amphotericin B (1 mg/kg) sharply reduced spleen
counts more than 2 logs beneath the lowest count for control mice.
Kidney counts in both treatment groups were over 1 log less than that
of controls.
View this table:
[in this window]
[in a new window]
|
TABLE 3.
Survival (in days) of groups of 10 mice infected with
7.3 × 105 CFU of C. albicans per mouse and
treated from day 1 through 10 with amphotericin B
or KY-62a
|
|
View this table:
[in this window]
[in a new window]
|
TABLE 4.
Tissue counts for mice infected with 9 × 105 CFU of C. albicans per mouse, treated
from day 1 through 6 with amphotericin B or KY-62, and sacrificed
on day 8a
|
|
In a subsequent study comparing routes of treatment, groups of 9 to 10 neutropenic mice were infected with 1.5 × 106 CFU of
C. albicans per mouse. Amphotericin B was given at 1 mg/kg/day i.v. or 5 mg/kg/day i.p. and compared with KY-62 given i.v.
at 1, 5, or 10 mg/kg/day. Mean survival of control mice was 7.9 ± 2.6 days. All treated groups survived significantly longer, to between
day 26 and day 30, the end of the observation period (data not shown).
Additionally, neutropenic mice were infected with 3 × 105 CFU of C. albicans per mouse. Mice were
treated with amphotericin B at 1 mg/kg i.v. or 5 mg/kg i.p. or KY-62 at
1, 5, 20, or 30 mg/kg i.v. or i.p. Results are presented in Table
5. Amphotericin B at 1-mg/kg/dose and
KY-62 at 5 and 10 mg/kg/dose were the only groups to achieve
significant protection. Two early deaths in the KY-62 group at
30-mg/kg/dose suggested acute toxicity. An additional study explored
twice-daily dosing with KY-62. Neutropenic mice were infected with
2.8 × 105 CFU of C. albicans per mouse and
treated from day 1 through day 10. Survival of controls was 3.7 ± 0.4 days, survival of the group receiving amphotericin B at 1 mg/kg/day
was 17.6 ± 4.5 days, survival of the group receiving KY-62 at 15 mg/kg twice daily was 6.7 ± 0.3 days, and that of the group
receiving KY-62 at 30 mg/kg twice daily was 6.3 ± 0.3 days.
Although all treatment groups lived significantly longer than controls,
only the amphotericin B group had a meaningful extension of survival.
Clearly, the benefit of KY-62 is best appreciated in immunocompetent
mice.
View this table:
[in this window]
[in a new window]
|
TABLE 5.
Survival of neutropenic mice after i.v. infection
with 3 × 105 CFU of C. albicans per
mouse and treatment from day 1 through 10 with amphotericin B
or KY-62, given i.v. or i.p.
|
|
Finally, the potential benefit of combining KY-62 with flucytosine was
explored. Two studies are summarized in Table
6. Although mice receiving combined
therapy survived longer than those receiving KY-62, the difference was
not significant compared with those receiving flucytosine alone.
View this table:
[in this window]
[in a new window]
|
TABLE 6.
Survival of groups of 10 neutropenic mice infected
i.v. with 1.7 × 106 CFU of C. albicans per mouse and treated with KY-62 i.p., flucytosine in
drinking water, or botha
|
|
| |
DISCUSSION |
Amphotericin B is well known to be a highly effective but highly
toxic antifungal polyene. The amphotericin B controls in our studies
confirm these characteristics. Our appreciation for the complexity of
action(s) of amphotericin B continues to increase. Amphotericin B was
thought to act by preferential binding to ergosterol in fungal cell
membranes (over cholesterol in mammalian cell membranes) and by
destabilizing the integrity of the membrane, permitting uncontrolled
leakage of potassium out of the cell and of sodium into the cell
(2, 3). More recently appreciated have been the disruptive
effects of amphotericin B on the oxidative mechanism within fungal
cells (3). Amphotericin B may act by internalization in both
plasma membranes and endosomal fractions of mammalian cells and may in
high concentrations block fusion of endosomes and lysosomes
(21). This may have the consequence of reducing cell
protease activity and may have other metabolic consequences (21). Also, amphotericin B has immunological activity in
augmenting macrophage production of interleukin-1 and tumor necrosis
factor, at least partially augmenting their antifungal activity by
enhancement of macrophage nitric oxide and superoxide production
(19, 24).
These effects may contribute to both efficacy of amphotericin B against
fungi and toxicity of amphotericin B against mammalian cells
(12). For mice, the maximal nonlethal dose of amphotericin B
is about 1 to 1.5 mg/kg when given i.v. Above this dose, mice die
within minutes of injection. Amphotericin B can be given at higher
doses i.p. without acute toxicity. As shown in our studies, 1 mg of
amphotericin B per kg per day i.v. is effective in prolonging survival
of normal and neutropenic mice. At 1 mg/kg/day, amphotericin B also
sharply reduces the spleen and kidney counts of C. albicans.
KY-62 is a highly water-soluble analog of amphotericin B and is stable
in powder at 4°C for more than 3 months. KY-62 causes no acute
clinical toxicity in mice at doses up to 30 mg/kg twice daily. In one
study, 30 mg/kg rapidly caused death in 2 of 10 mice. In
immunocompetent mice given a lethal infection with C. albicans, KY-62 has potency similar to that amphotericin B and can
be safely administered at much larger doses than amphotericin B. Protection is manifested both in prolongation of survival and in marked
reduction of spleen and kidney fungal burden.
In addition to demonstrating the efficacy of KY-62, these results are
of interest because they highlight the importance of host immune status
rather than serum concentration in distinguishing the drugs. In studies
of murine cryptococcosis and histoplasmosis, we have found that
immunosuppressed (athymic) mice respond less well to antifungals than
do immunocompetent mice (6, 7, 23). The present studies
suggest that a decreased response to at least some antifungals may be
present in neutropenic mice with candidiasis. For our immunocompetent
mice, KY-62 is effective at doses as low as 1 mg/kg, even though the
concentration in serum does not exceed the MIC of 3.03 µg/ml for
C. albicans. However, in neutropenic mice, amphotericin B
retains potency while KY-62 markedly decreases in potency. This occurs
all the way up to 30 mg/kg, a dose at which the serum concentrations
markedly exceed the MIC for the C. albicans infecting
isolate for more than 12 h after the dose. Further, flucytosine,
which may be additive in effect with amphotericin B, gave no
significant increase in survival when combined with KY-62. The reason
for decreased potency of KY-62 in immunosuppressed mice is unclear. It
is possible that the higher water solubility of KY-62 may reduce both
toxicity and penetration into tissue or cell sites of fungal infection, including intracellular cytoplasm. Alternatively, immunomodulatory effects of amphotericin B on macrophages may be stronger than those of
KY-62 and may be preserved even in neutropenic mice.
Tumor necrosis factor, one of the cytokines increased by amphotericin B
both in vitro and in vivo, is protective in murine candidiasis
(13, 20). KY-62 has been designed specifically to reduce the
damage and subsequent leakage of ions from mammalian cells, and a
consequence of this may be reduced immunomodulatory effects on
macrophages (25). Decreased mammalian cell toxicity has been
observed for other analogs of amphotericin B, specifically its
monomethyl ester derivative (16).
Therefore, the present studies emphasize that in vitro and in vivo
activity of antifungal drugs do not always correlate and that immune
status may be more important than measurement of levels in serum. At
this point, it is unclear whether in vivo antifungal activity of KY-62
or similar drugs will have a similar dependence on neutrophil function
in other animal species and in humans. The effect of KY-62 in other
mycoses in immunocompetent and immunodeficient animals also
requires definition before one may conclude that reduced activity in
immunodeficient animals is specific for candidiasis or is more
generalizable.
| |
ACKNOWLEDGMENT |
This work was supported by NIAID contract NO1-AI-25141.
| |
FOOTNOTES |
*
Corresponding author. Mailing address: Division of
Infectious Diseases (111F), Audie L. Murphy Veterans Hospital, 7400 Merton Minter Blvd., San Antonio, TX 78284. Phone: (210) 617-5111. Fax: (210) 614-6197. E-mail: graybill{at}uthscsa.edu.
| |
REFERENCES |
| 1.
| Adler-Moore, J. 1994. AmBisome targeting to
fungal infections. Bone Marrow Transplant. 14(Suppl.
5):S3-S7.
|
| 2.
|
Brajtburg, J.,
G. Medoff,
G. S. Kobayashi, and S. Elberg.
1980.
Influence of extracellular K+ or Mg2+ on the stages of the antifungal effects of amphotericin B and filipin.
Antimicrob. Agents Chemother.
18:593-597[Abstract/Free Full Text].
|
| 3.
|
Brajtburg, J.,
W. G. Powderly,
G. S. Kobayashi, and G. Medoff.
1990.
Amphotericin B: current understanding of mechanisms of action.
Antimicrob. Agents Chemother.
34:183-188[Free Full Text].
|
| 4.
|
de Marie, S.,
R. Janknegt, and I. A. J. M. Bakker-Woudenberg.
1994.
Clinical use of liposomal and lipid-complexed amphotericin B.
J. Antimicrob. Chemother.
33:907-916[Abstract/Free Full Text].
|
| 5.
|
Ellis, W. G.,
R. A. Sobel, and S. L. Nielsen.
1982.
Leukoencephalopathy in patients with amphotericin B methyl ester.
J. Infect. Dis.
146:125-137[Medline].
|
| 6.
|
Graybill, J. R.
1986.
Animal models for treatment of cryptococcosis, p. 131-145.
In
O. Zak, and M. A. Sande (ed.), Experimental models in antimicrobial chemotherapy. Academic Press, New York, N.Y.
|
| 7.
|
Graybill, J. R.,
P. C. Craven,
L. Mitchell, and D. J. Drutz.
1978.
Interaction of chemotherapy and immune defense in experimental murine cryptococcosis.
Antimicrob. Agents Chemother.
14:659-667[Abstract/Free Full Text].
|
| 8.
|
Hoeprich, P. D.
1982.
Amphotericin B methyl ester and leukoencephalopathy: the other side of the coin.
J. Infect. Dis.
146:173-176[Medline].
|
| 9.
| Hoeprich, P. D. 1992. Clinical use of
amphotericin B and derivatives: lore, mystique, and fact. Clin. Infect.
Dis. 14(Suppl. 1):S114-S119.
|
| 10.
|
Hunter, P.,
P. Murdock,
G. Randall,
S. Anthony,
S. Jones,
A. Everett,
C. Winch, and I. Burbidge.
1992.
Comparative activity in vivo and toxicity of a new polyene, BRL 49594A and amphotericin B (amB), abstr. 1043, p. 284.
In
Program and abstracts of the 32nd Interscience Conference on Antimicrobial Agents and Chemotherapy. American Society for Microbiology, Washington, D.C.
|
| 11.
|
Jangnegt, R.,
S. de Marie,
I. A. J. M. Bakker-Woudenberg, and D. J. A. Crommelin.
1995.
Liposomal and lipid formulations of amphotericin B.
Clin. Pharmacokinet.
23:279-291.
|
| 12.
|
Jullien, S.,
A. Contrepois,
J. E. Sligh,
Y. Domart,
P. Yeni,
J. Brajtburg,
G. Medoff, and J. Bolard.
1989.
Study of the effects of liposomal amphotericin B on Candida albicans, Cryptococcus neoformans, and erythrocytes by using small unilamellar vesicles prepared from saturated phospholipids.
Antimicrob. Agents Chemother.
33:345-349[Abstract/Free Full Text].
|
| 13.
|
Louie, A.,
A. L. Baltch,
R. P. Smith,
M. A. Franke,
W. J. Ritz,
J. K. Singh, and M. A. Gordon.
1994.
Tumor necrosis factor alpha has a protective role in a murine model of systemic candidiasis.
Infect. Immun.
62:2761-2772[Abstract/Free Full Text].
|
| 14.
|
Mills, W.,
R. Chopra,
D. C. Linch, and A. H. Goldstone.
1994.
Liposomal amphotericin B in the treatment of fungal infections in neutropenic patients: a single-centre experience of 133 episodes in 116 patients.
Br. J. Haematol.
86:754-760[Medline].
|
| 15.
|
National Committee for Clinical Laboratory Standards.
1992.
Reference method for broth dilution antifungal susceptibility testing for yeasts: proposed standard M27-P.
National Committee for Clinical Laboratory Standards, Villanova, Pa.
|
| 16.
|
Racis, S. P.,
O. J. Plescia,
H. M. Geller, and C. P. Schaffner.
1990.
Comparative toxicities of amphotericin B and its monomethyl ester derivative on glial cells in culture.
Antimicrob. Agents Chemother.
34:1360-1365[Abstract/Free Full Text].
|
| 17.
|
Rex, J. H.,
M. A. Pfaller,
J. N. Galgiani,
M. S. Bartlett,
A. Espinel-Ingroff,
M. A. Ghannoum,
M. Lancaster,
F. C. Odds,
M. G. Rinaldi,
T. J. Walsh,
A. L. Barry, and National Committee for Clinical Laboratory Standards.
1997.
Development of interpretive breakpoints for antifungal susceptibility testing: conceptual framework and analysis of in vitro-in vivo correlation data for fluconazole, itraconazole, and Candida infections.
Clin. Infect. Dis.
24:235-247[Medline].
|
| 18.
| Schmitt, H. J. 1993. New methods of delivery
of amphotericin B. Clin. Infect. Dis. 17(Suppl.
2):S501-S506.
|
| 19.
|
Tohyama, M.,
K. Kawakami, and A. Saito.
1996.
Anticryptococcal effect of amphotericin B is mediated through macrophage production of nitric oxide.
Antimicrob. Agents Chemother.
40:1919-1923[Abstract].
|
| 20.
|
Van der Horst, C.,
M. Saag,
G. Cloud,
R. Hamill,
R. Graybill,
J. Sobel,
P. Johnson,
C. Tuazon,
T. Kerkering,
J. Fisher,
H. Henderson,
J. Stansell,
D. Mildvan,
L. Riser,
D. Schneider,
R. Hafner,
C. Thomas,
B. Weisinger, and B. Moskovitz.
1995.
Part I. Randomized double blind comparison of amphotericin B plus flucytosine (AMB+FC) to AMB alone (step 1) followed by a comparison of fluconazole to itraconazole (step 2) in the treatment of acute cryptococcal meningitis in patients with AIDS, abstr. I216, p. 244.
In
Abstracts of the 35th Interscience Conference on Antimicrobial Agents and Chemotherapy. American Society for Microbiology, Washington, D.C.
|
| 21.
|
Vertut-Doï, A.,
S.-I. Ohnishi, and J. Bolard.
1994.
The endocytic process in CHO cells, a toxic pathway of the polyene antibiotic amphotericin B.
Antimicrob. Agents Chemother.
38:2373-2379[Abstract/Free Full Text].
|
| 22.
|
Walsh, T. J., and D. M. Dixon.
1989.
Nosocomial aspergillosis: environmental microbiology, hospital epidemiology, diagnosis, and treatment.
Eur. J. Epidemiol.
5:131-142[Medline].
|
| 23.
|
Williams, D. M.,
J. R. Graybill, and D. J. Drutz.
1979.
Experimental chemotherapy of histoplasmosis in nude mice.
Am. Rev. Respir. Dis.
120:837-842[Medline].
|
| 24.
|
Wilson, E.,
L. Thorson, and D. P. Speert.
1991.
Enhancement of macrophage superoxide anion production by amphotericin B.
Antimicrob. Agents Chemother.
35:796-800[Abstract/Free Full Text].
|
| 25.
|
Yamashita, K.,
V. Janout,
E. M. Bernard,
D. Armstrong, and S. L. Regen.
1995.
Micelle/monomer control over the membrane-disrupting properties of an amphiphilic antibiotic.
J. Am. Chem. Soc.
117:6249-6253.
|
Antimicrobial Agents and Chemotherapy, January 1998, p. 147-150, Vol. 42, No. 1
0066-4804/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Espuelas, M. S., Legrand, P., Campanero, M. A., Appel, M., Cheron, M., Gamazo, C., Barratt, G., Irache, J. M.
(2003). Polymeric carriers for amphotericin B: in vitro activity, toxicity and therapeutic efficacy against systemic candidiasis in neutropenic mice. J Antimicrob Chemother
52: 419-427
[Abstract]
[Full Text]
-
Al-Abdely, H. M., Graybill, J. R., Bocanegra, R., Najvar, L., Montalbo, E., Regen, S. L., Melby, P. C.
(1998). Efficacies of KY62 against Leishmania amazonensis and Leishmania donovani in Experimental Murine Cutaneous Leishmaniasis and Visceral Leishmaniasis. Antimicrob. Agents Chemother.
42: 2542-2548
[Abstract]
[Full Text]
Top
Abstract
Introduction
