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Reeves DS, MacGowan AP, Holt HA, Lovering AM, Warnock DW, White LO. Therapeutic monitoring of antimicrobials: a summary of the information presented at the UK NEQAS for antibiotic Assays meeting for participants, October 1993. J Antimicrob Chemother 1995; 35:213-26. [PMID: 7768771 DOI: 10.1093/jac/35.1.213] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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102
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Johnson EM, Warnock DW, Luker J, Porter SR, Scully C. Emergence of azole drug resistance in Candida species from HIV-infected patients receiving prolonged fluconazole therapy for oral candidosis. J Antimicrob Chemother 1995; 35:103-14. [PMID: 7768758 DOI: 10.1093/jac/35.1.103] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We examined the effect of different fluconazole treatment regimens on the emergence of azole drug resistance among Candida species recovered from the mouths of 54 HIV-infected individuals. Patients were assigned to one of three treatment groups depending on their history of oral candidosis and fluconazole use. Mouthwashes obtained at regular intervals were cultured and isolates identified using standard methods. Antifungal broth micro-dilution tests were performed to determine IC30s of fluconazole and ketoconazole. Sixty-four Candida albicans isolates from 20 patients with no evidence of oral candidosis who had not received fluconazole all had IC30s of < or = 4 mg/L. Thirty-four (83%) of 41 C. albicans isolates from ten patients receiving intermittent, short-term fluconazole treatment for oral candidosis had IC30s of < or = 4 mg/L, but only two isolates (5%) had IC30s > or = 64 mg/L. In contrast, 26 (40%) of 65 C. albicans isolates from 15 patients given long-term fluconazole (50-200 mg/day or 150 mg/week) were classified as resistant having IC30s of fluconazole of > or = 64 mg/L. Ten of these 26 fluconazole-resistant isolates were susceptible to ketoconazole with IC30s of < or = 4 mg/L suggesting azole drug cross-resistance is not inevitable. Tests on multiple colonies from individual isolation plates showed that it was not unusual to obtain differing IC30 values, indicating that a sweep inoculum is essential if resistance is to be detected. Nine (60%) of the 15 patients given long-term fluconazole harboured isolates of C. albicans that were resistant to fluconazole at some time during the study period. All had low CD4 counts and were approaching the final stage of their illness. Three patients on long-term treatment had resistant organisms at the outset of the study; in the remainder, resistant strains emerged during the study period. In six of the nine cases, emergence of resistance in vitro correlated with persistent clinical signs of oral infection. Thirty-six isolates of Candida species other than C. albicans were also recovered from patients receiving long-term fluconazole and 29 (81%) of these had IC30s of > or = 64 mg/L. Our experience with C. albicans in patients with HIV infection, suggests that the long-term azole drug use may be an important factor in the development of fluconazole resistance as such resistance was rare and transient in patients on intermittent short-term treatment.
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103
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Prentice AG, Warnock DW, Johnson SA, Phillips MJ, Oliver DA. Multiple dose pharmacokinetics of an oral solution of itraconazole in autologous bone marrow transplant recipients. J Antimicrob Chemother 1994; 34:247-52. [PMID: 7814285 DOI: 10.1093/jac/34.2.247] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The pharmacokinetics of itraconazole oral solution were measured in seven patients receiving chemotherapy followed by autologous bone marrow transplantation for leukaemia or lymphoma. Patients received 5 mg/kg/day itraconazole either as a once or twice daily dose. Drug concentrations reached steady state by day 15, in both groups. The mean pre-dose itraconazole serum concentration at hour 0, day 8 was 385 ng/mL in the od group and 394 ng/mL in the bd group, rising to 762 and 845 ng/mL by day 15, respectively. The mean AUCs for 0-24 h on day 8, 15 and 22 were 17,310 and 13,302 ng/mL/h, 24,476 and 25,154 and 22,621 and 21,423, for the od and bd groups, respectively. Thus serum concentrations of itraconazole suitable for antifungal prophylaxis can be attained in neutropenic patients, with the administration of an oral solution in a dosage of 5 mg/kg as either an od or bd schedule, following pre-autograft high-dose cytotoxic chemotherapy.
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104
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Humphreys H, Oliver DA, Winter R, Warnock DW. Liposomal amphotericin B and continuous venous-venous haemofiltration. J Antimicrob Chemother 1994; 33:1070-1. [PMID: 8089061 DOI: 10.1093/jac/33.5.1070-a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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105
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Lim KK, Potts MJ, Warnock DW, Ibrahim NB, Brown EM, Burns-Cox CJ. Another case report of rhinocerebral mucormycosis treated with liposomal amphotericin B and surgery. Clin Infect Dis 1994; 18:653-4. [PMID: 8038329 DOI: 10.1093/clinids/18.4.653] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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106
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Vanden Bossche H, Warnock DW, Dupont B, Kerridge D, Sen Gupta S, Improvisi L, Marichal P, Odds FC, Provost F, Ronin O. Mechanisms and clinical impact of antifungal drug resistance. JOURNAL OF MEDICAL AND VETERINARY MYCOLOGY : BI-MONTHLY PUBLICATION OF THE INTERNATIONAL SOCIETY FOR HUMAN AND ANIMAL MYCOLOGY 1994; 32 Suppl 1:189-202. [PMID: 7722785 DOI: 10.1080/02681219480000821] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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107
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Hitchcock CA, Pye GW, Troke PF, Johnson EM, Warnock DW. Fluconazole resistance in Candida glabrata. Antimicrob Agents Chemother 1993; 37:1962-5. [PMID: 8239613 PMCID: PMC188100 DOI: 10.1128/aac.37.9.1962] [Citation(s) in RCA: 158] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We report a case of infection with Candida glabrata in which the organism became resistant to fluconazole and in which pre- and posttreatment isolates were available for comparison. The organism was cross-resistant to ketoconazole and itraconazole, in common with other azole-resistant yeasts. Fluconazole was a potent inhibitor of cytochrome P-450-dependent 14 alpha-sterol demethylase (P-450DM) in lysates of cells from both susceptible and resistant cultures (50% inhibitory concentration, 0.2 microM), indicating that resistance was unrelated to changes in P-450DM. Instead, it appeared to arise from a permeability barrier to fluconazole, since resistant cells were unable to take up radiolabelled drug.
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108
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White DJ, Johnson EM, Warnock DW. Management of persistent vulvo vaginal candidosis due to azole-resistant Candida glabrata. Genitourin Med 1993; 69:112-4. [PMID: 8389723 PMCID: PMC1195041 DOI: 10.1136/sti.69.2.112] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
CASE REPORT--SUBJECTS--Three cases are described of long-standing vaginal candidosis due to Candida glabrata. These had failed to respond to local and systemic antifungals. In each case the infecting strain appeared resistant to a range of azole drugs in vitro. CLINICAL COURSE--Case one--This patient recovered following prolonged treatment with oral itraconazole in combination with oral and vaginal nystatin. Case two. Yeasts were eradicated from this patient following cyclical treatment with oral dydrogesterone; prolonged vaginal treatment with nystatin may have helped. Case three. This patient did not respond to a prolonged course of oral itraconazole in combination with vaginal and oral nystatin, oral medroxyprogesterone or intravaginal boric acid. Eradication of C glabrata was finally achieved by local application of 1% gentian violet. Shortly after eradication of the C glabrata infection, both Case two and Case three developed infections with other Candida species responsive to azole antifungals.
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109
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110
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Pfaller MA, Dupont B, Kobayashi GS, Müller J, Rinaldi MG, Espinel-Ingroff A, Shadomy S, Troke PF, Walsh TJ, Warnock DW. Standardized susceptibility testing of fluconazole: an international collaborative study. Antimicrob Agents Chemother 1992; 36:1805-9. [PMID: 1416871 PMCID: PMC192190 DOI: 10.1128/aac.36.9.1805] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
An international collaborative study of broth dilution (MIC) and disk diffusion susceptibility testing of fluconazole was conducted by using a chemically defined medium (High-Resolution Antifungal Assay Medium; Oxoid Ltd., Basingstoke, United Kingdom) and standard test methods performed in eight reference laboratories. Ten yeast isolates were tested by each test method in duplicate on each of 3 separate days. The intralaboratory reproducibility of the MIC test was excellent; 95.7% of the replicate tests (n = 220) were within 2 doubling dilutions of the other values in the set for the eight laboratories. The intralaboratory reproducibility of the disk test was also good, with 91% of the replicate tests (n = 234) agreeing with each other within an arbitrarily chosen value of 4 mm. Interlaboratory agreement of MIC test results was acceptable, with 84% of the MICs agreeing within 2 doubling dilutions. In contrast, the interlaboratory agreement of the disk test was not good, with only 59% of test results agreeing within 4 mm. Comparison of the rank order of MICs obtained in each laboratory with the reference rank order gave an agreement of 70 to 80% (median, 80%) with the MIC test and 70 to 90% (median, 80%) with the disk test. These preliminary results are encouraging for the development of standardized testing methods for testing fluconazole.
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111
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Pallister CJ, Johnson EM, Warnock DW, Elliot PJ, Reeves DF. In-vitro effects of liposome-encapsulated amphotericin B (AmBisome) and amphotericin B-deoxycholate (Fungizone) on the phagocytic and candidacidal function of human polymorphonuclear leucocytes. J Antimicrob Chemother 1992; 30:313-20. [PMID: 1452496 DOI: 10.1093/jac/30.3.313] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Liposomal amphotericin B (AmBisome), at concentrations > or = 20 mg/L, and amphotericin B-deoxycholate (DC) (Fungizone), at concentrations > or = 1 mg/L, both caused a significant reduction in neutrophil uptake of Candida albicans blastospores following simultaneous addition of the drug with the blastospores. The reduction in uptake was seen also in tests in which blastospores were pre-treated with the drugs for 60 min, but was not detected in tests in which neutrophils were pre-treated for 60 min. Neither formulation affected neutrophil killing of C. albicans blastospores following simultaneous addition of the drug with the blastospores. However, previous treatment of the neutrophils with either formulation at a concentration of 20 mg/L led to enhanced killing of ingested blastospores. The results suggest that much higher concentrations of liposomal amphotericin B (AmBisome) are required to produce deleterious effects on neutrophil phagocytic function than with the conventional formulation of the drug.
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112
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Brown NM, Blundell EL, Chown SR, Warnock DW, Hill JA, Slade RR. Acremonium infection in a neutropenic patient. J Infect 1992; 25:73-6. [PMID: 1522326 DOI: 10.1016/0163-4453(92)93585-e] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Acremonium species (previously Cephalosporium) are saprophytic moulds of low pathogenicity commonly found in the environment. We report a case of repeated acremonium fungaemia in a neutropenic patient, probably associated with a Hickman line. Fungaemia was accompanied by fever and a papular skin rash, both of which appeared to resolve when the neutrophil count recovered without antifungal chemotherapy, only to return when the patient next became neutropenic.
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113
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Bloom PA, Laidlaw DA, Easty DL, Warnock DW. Treatment failure in a case of fungal keratitis caused by Pseudallescheria boydii. Br J Ophthalmol 1992; 76:367-8. [PMID: 1320401 PMCID: PMC504288 DOI: 10.1136/bjo.76.6.367] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A case is presented of Pseudallescheria boydii fungal keratitis in an agricultural welder. Treatment with azole antifungal drugs (miconazole and itraconazole) and with penetrating keratoplasty was unsuccessful in eradicating the infection, and eventually the eye was eviscerated.
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114
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Warnock DW, Oliver DA, Cheung MM, Zurick NJ. Effect of methotrexate on the germination and growth of Aspergillus fumigatus and Aspergillus flavus strains. J Antimicrob Chemother 1992; 29:375-81. [PMID: 1607326 DOI: 10.1093/jac/29.4.375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Methotrexate at concentrations of greater than or equal to 10(-5) M caused a significant reduction in the rate of germ tube formation of spores of Aspergillus fumigatus, but not of Aspergillus flavus, after 7 h incubation. At 10(-3) M the drug caused a significant reduction in germ tube elongation of A. fumigatus and A. flavus strains during the first 7 h of germination. After 18 h incubation, drug concentrations of greater than or equal to 4 x 10(-4) M produced greater than 80% reduction in growth of all strains tested. Potentiation of the antifungal effect against A. fumigatus was detected in tests in which methotrexate at 10(-4) M was used in combination with amphotericin B at 5 x 10(-7) M.
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115
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Hudson J, Scott GL, Warnock DW. Treatment of hepatic candidosis with liposomal amphotericin B in patient with acute leukaemia. Lancet 1991; 338:1534-5. [PMID: 1683961 DOI: 10.1016/0140-6736(91)92361-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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116
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Warnock DW, Foot AB, Johnson EM, Mitchell SB, Cornish JM, Oakhill A. Aspergillus antigen latex test for diagnosis of invasive aspergillosis. Lancet 1991; 338:1023-4. [PMID: 1681333 DOI: 10.1016/0140-6736(91)91890-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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117
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Bradford CR, Prentice AG, Warnock DW, Copplestone JA. Comparison of the multiple dose pharmacokinetics of two formulations of itraconazole during remission induction for acute myeloblastic leukaemia. J Antimicrob Chemother 1991; 28:555-60. [PMID: 1662191 DOI: 10.1093/jac/28.4.555] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
This double-blind cross-over study compares the serum pharmacokinetics of a polyethylene glycol formulation of itraconazole (ITRA-PEG; 4 x 50 mg once daily) with a new pelleted formulation (ITRA-PEL; 2 x 100 mg once daily) during remission induction for acute myeloblastic leukaemia. Each formulation was administered for 28 days with a seven day washout period. Five of eight patients (median age 52 years, range 18-65) entering completed both arms of the study. At day 7 for ITRA-PEL (n = 8) the mean +/- one standard deviation and median maximum concentrations (Cmax) were 307 +/- 155 ng/mL and 275 ng/mL respectively and for ITRA-PEG (n = 6) 272 +/- 212 ng/mL and 193 ng/mL. At day 14 for ITRA-PEL (n = 8) the mean +/- S.D. and median Cmax were 412 +/- 227 ng/mL and 375 ng/mL respectively and for ITRA-PEG (n = 5), 315 +/- 177 ng/mL and 327 ng/mL. The Cmax mean and median values were therefore greater with ITRA-PEL but the differences between the two formulations were not statistically significant. Adequate therapeutic levels of itraconazole can be achieved in this clinical setting. However, the wide variation within and between patients suggests that an ITRA-PEL dosage of 400 mg/day may ensure earlier and more consistent therapeutic levels. Measurement of serum levels may be indicated in suspected failure of prophylaxis or treatment.
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118
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Abstract
Amphotericin B has a broad spectrum of action that includes most of the major fungal pathogens of man. This drug binds to the membrane sterols of fungal cells, causing impairment of their barrier function and loss of cell constituents. Metabolic disruption and cell death are consequent upon membrane alterations. Investigations of the sterol content of mutant strains of Candida albicans and Cryptococcus neoformans has demonstrated that resistance is often associated with alterations in membrane sterol composition. Treatment failure due to the development of amphotericin B resistance is an uncommon problem. It has tended to occur in patients receiving treatment with cytotoxic drugs. Interactions between amphotericin B and a number of other antimicrobial drugs have been observed in tests in vitro and in vivo. However, apart from one report that the combination with flucytosine is superior to amphotericin B on its own in the treatment of cryptococcal meningitis, there have been no controlled trials to support the use of drug combinations in human infections.
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119
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Humphreys H, Johnson EM, Warnock DW, Willatts SM, Winter RJ, Speller DC. An outbreak of aspergillosis in a general ITU. J Hosp Infect 1991; 18:167-77. [PMID: 1680899 DOI: 10.1016/0195-6701(91)90141-t] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Over a 5-month period, six patients in a general intensive therapy unit became colonized by Aspergillus species including Aspergillus fumigatus, and invasive infection occurred in at least two of them. Broncho-alveolar lavage was unhelpful in discriminating between infection and colonization. The source of infection was presumed to be disturbance of an accumulation of spores in fibrous insulation material above the perforated metal ceiling. Patients in such units without clearly identifiable defects of defence against infection may be at risk from aspergillosis. The risk can be reduced by improved hospital design, satisfactory ventilation and thorough regular cleaning of environmental surfaces.
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120
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Shankland GS, Hopwood V, Forster RA, Evans EG, Richardson MD, Warnock DW. Multicenter evaluation of Microring YT, a new method of yeast identification. J Clin Microbiol 1990; 28:2808-10. [PMID: 2280014 PMCID: PMC268280 DOI: 10.1128/jcm.28.12.2808-2810.1990] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Microring YT was evaluated and compared with established methods for the identification of 142 clinical yeast isolates. Only 75 isolates (52.8%) were correctly identified by Microring YT. Results with this test were often difficult to read and subject to interlaboratory variations.
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121
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Warnock DW. J Infect 1990; 21:230-231. [DOI: 10.1016/0163-4453(90)92117-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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122
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Warnock DW. Itraconazole and fluconazole: new drugs for deep fungal infection. J Antimicrob Chemother 1989; 24:275-7. [PMID: 2553654 DOI: 10.1093/jac/24.3.275] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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123
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Warnock DW, Johnson EM, Burke J, Pracharktam R. Effect of methotrexate alone and in combination with antifungal drugs on the growth of Candida albicans. J Antimicrob Chemother 1989; 23:837-47. [PMID: 2547749 DOI: 10.1093/jac/23.6.837] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Methotrexate, at concentrations corresponding to drug levels found in vivo, caused a marked reduction in blastospore growth of Candida albicans strains in vitro, but did not affect germ tube elongation during the first 6 h after blastospores were shifted to conditions favouring hyphal formation. Combinations of methotrexate with amphotericin B, flucytosine and itraconazole showed no potentiation or antagonism of the antifungal effect of either component in tests with the blastospore form of C. albicans. In contrast, potentiation occurred when methotrexate-itraconazole combinations were tested for their effect on germ tube elongation of an azole-sensitive strain of C. albicans. This effect was not seen in tests with an azole-resistant strain.
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125
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Pallister CJ, Warnock DW. Effect of antimicrobial and antineoplastic drugs alone and in combination on the phagocytic and candidacidal function of human polymorphonuclear leucocytes. J Antimicrob Chemother 1989; 23:87-94. [PMID: 2663808 DOI: 10.1093/jac/23.1.87] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Four antimicrobial and three antineoplastic drugs were screened for their effects on phagocytosis and killing of Candida albicans blastospores by human neutrophil polymorphonuclear leucocytes. Amphotericin B caused significant impairment of both phagocytosis and killing, but cefuroxime and ketoconazole had no effect. Tobramycin did not affect phagocytosis, but impaired killing. Methotrexate, prednisolone and vinblastine all caused significant impairment of phagocytosis, but did not affect killing. Combinations of these seven drugs, such as are used in the treatment of acute lymphoblastic leukaemia in childhood, were also shown to inhibit phagocytosis, although no additive effects were detected. None of the drug combinations tested affected killing.
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