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A M Sugar

Publications and source records attributed to A M Sugar.

At least 19 recordsLinked to original sources

A controlled trial of fluconazole or amphotericin B to prevent relapse of cryptococcal meningitis in patients with the acquired immunodeficiency syndrome. The NIAID AIDS Clinical Trials Group and Mycoses Study Group.

BACKGROUND: After primary treatment for cryptococcal meningitis, patients with the acquired immunodeficiency syndrome (AIDS) require some form of continued suppressive therapy to prevent relapse. METHODS: We conducted a multicenter, randomized trial that compared fluconazole (200 mg per day given orally) with amphotericin B (1 mg per kilogram of body weight per week given intravenously) in patients with AIDS who had completed primary therapy for cryptococcal meningitis with amphotericin B (greater than or equal to 15 mg per kilogram). To be eligible, patients had to have at least two negative cultures of cerebrospinal fluid immediately before randomization. The primary end point was relapse of cryptococcal disease as confirmed by biopsy or culture. RESULTS: Of 218 patients initially enrolled, 119 were assigned to fluconazole and 99 to amphotericin B. Twenty-three patients were found not to have met the entry criteria; six other patients assigned to amphotericin B did not receive it and were lost to follow-up. Of the remaining 189 patients, after a median follow-up of 286 days 14 of 78 receiving amphotericin B (18 percent) and 2 of 111 assigned to fluconazole (2 percent) had relapses of symptomatic cryptococcal disease (P less than 0.001 by Fisher's exact test). There was a difference of 19 percent in the estimated probability of remaining relapse-free at one year between the fluconazole group (97 percent) and the amphotericin B group (78 percent) (95 percent confidence interval, 7 percent to 31 percent; P less than 0.001). Serious drug-related toxicity was more frequent in the amphotericin B group (P = 0.02), as were bacterial infections (P = 0.004) and bacteremia (P = 0.002). CONCLUSIONS: Fluconazole taken by mouth is superior to weekly intravenous therapy with amphotericin B to prevent relapse in patients with AIDS-associated cryptococcal meningitis after primary treatment with amphotericin B.

Acquired Immunodeficiency Syndrome

Comparison of amphotericin B with fluconazole in the treatment of acute AIDS-associated cryptococcal meningitis. The NIAID Mycoses Study Group and the AIDS Clinical Trials Group.

BACKGROUND: Intravenous amphotericin B, with or without flucytosine, is usually standard therapy for cryptococcal meningitis in patients with the acquired immunodeficiency syndrome (AIDS). Fluconazole, an oral triazole agent, represents a promising new approach to the treatment of cryptococcal disease. METHODS: In a randomized multicenter trial, we compared intravenous amphotericin B with oral fluconazole as primary therapy for AIDS-associated acute cryptococcal meningitis. Eligible patients, in all of whom the diagnosis had been confirmed by culture, were randomly assigned in a 2:1 ratio to receive either fluconazole (200 mg per day) or amphotericin B. Treatment was considered successful if the patient had had two consecutive negative cerebrospinal fluid cultures by the end of the 10-week treatment period. RESULTS: Of the 194 eligible patients, 131 received fluconazole and 63 received amphotericin B (mean daily dose, 0.4 mg per kilogram of body weight in patients with successful treatment and 0.5 mg per kilogram in patients with treatment failure; P = 0.34). Treatment was successful in 25 of the 63 amphotericin B recipients (40 percent; 95 percent confidence interval, 26 percent to 53 percent) and in 44 of the 131 fluconazole recipients (34 percent; 95 percent confidence interval, 25 percent to 42 percent) (P = 0.40). There was no significant difference between the groups in overall mortality due to cryptococcosis (amphotericin vs. fluconazole, 9 of 63 [14 percent] vs. 24 of 131 [18 percent]; P = 0.48); however, mortality during the first two weeks of therapy was higher in the fluconazole group (15 percent vs. 8 percent; P = 0.25). The median length of time to the first negative cerebrospinal fluid culture was 42 days (95 percent confidence interval, 28 to 71) in the amphotericin B group and 64 days (95 percent confidence interval, 53 to 67) in the fluconazole group (P = 0.25). Multivariate analyses identified abnormal mental status (lethargy, somnolence, or obtundation) as the most important predictive factor of a high risk of death during therapy (P less than 0.0001). CONCLUSIONS: Fluconazole is an effective alternative to amphotericin B as primary treatment of cryptococcal meningitis in patients with AIDS. Single-drug therapy with either drug is most effective in patients who are at low risk for treatment failure. The optimal therapy for patients at high risk remains to be determined.

Acquired Immunodeficiency Syndrome

Fluconazole.

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Animals

Mucormycosis.

Mucormycosis refers to the disease caused by a growing number of members of the Mucorales. Typically an airborne infection, primary disease is initiated in the upper or lower airways and is associated with the clinical development of sinusitis, rhinocerebral mucormycosis, or pulmonary infection. Dissemination of infection to skin, brain, and other sites is less common, but direct extension of the infection to contiguous sites is common if patients do not receive aggressive surgical and medical therapy. Risk factors for the development of mucormycosis include diabetic ketoacidosis; neutropenia; protein-calorie malnutrition; and iron overload, with or without the concomitant use of deferoxamine. This last association has only recently been recognized and has emerged as a major life-threatening complication for patients who are undergoing hemodialysis. Intravenous drug abusers may inject spores of Mucorales with their drugs and may present with space-occupying lesions of the CNS. The underlying immunologic defects that are responsible for predisposing different populations of patients to the development of mucormycosis are not well understood, and there is no unifying theory to explain why most individuals have innate immunity to this group of fungi. Patients with mucormycosis who are managed aggressively (i.e., those who undergo surgical debridement and who receive therapy with iv amphotericin B) may have increased rates of survival. The role of new azole derivatives in the treatment of mucormycosis is unknown.

Amphotericin B

Overview: cryptococcosis in the patient with AIDS.

Cryptococcosis is currently the most common life threatening mycoses found in patients with the acquired immunodeficiency syndrome (AIDS). Extrapulmonary involvement is most frequently seen, especially in the central nervous system and skin. Clinical findings are non-specific, even in patients with meningitis. Threshold for diagnosis of this infection should be low, with serum cryptococcal antigens, blood, urine and sputum cultures for Cryptococcus neoformans performed in febrile AIDS patients. Lumbar puncture should also be performed if unexplained headaches are included in a patient's complaints. There is currently no consensus for the most appropriate treatment strategy and the role of oral azoles versus amphotericin B or amphotericin B with flucytosine remains a serious question in need of further controlled studies. Patients eligible for multicentered trials should be encouraged to participate. Therapy for others should be individualized. This review will address some of these issues.

Acquired Immunodeficiency Syndrome

Macrophage- and oxidant-mediated inhibition of the ability of live Blastomyces dermatitidis conidia to transform to the pathogenic yeast phase: implications for the pathogenesis of dimorphic fungal infections.

Conidia, produced by the mycelial phase of dimorphic fungi, are thought to represent the infectious form of the organism but must complete a transition to the tissue-invasive, yeast-like phase for infection to ensue. Preventing such transition should effectively eliminate pathogenicity. Using Blastomyces dermatitidis as a target, murine bronchoalveolar macrophages preferentially blocked phase transition after 4 h of incubation with conidia, relatively sparing the ability of conidia to produce hyphae. H2O2, in relatively high concentrations, demonstrated the same activity. The effects of H2O2 seem irreversible, since H2O2-treated conidia that germinated at 48 h at 25 degrees C were still unable to produce yeasts over the next 5 days when incubated at 37 degrees C. Catalase could not reverse the macrophage-induced inhibition of phase transition, suggesting that nonoxidative defense mechanisms may be operative in vivo. Since conidia do not form mycelia at temperatures found in mammalian hosts, these effects may represent a novel host defense mechanism against dimorphic fungal pathogens.

Animals

Treatment of murine invasive candidiasis with amphotericin B and cilofungin: evidence for enhanced activity with combination therapy.

The in vivo interactions of cilofungin, an echinocandin antifungal agent, and amphotericin B, a polyene derivative, in a murine model of disseminated candidiasis have been investigated. While single therapy with either drug alone prolonged survival of infected mice, kidney colony counts were not appreciably reduced. In contrast, combination therapy, especially at higher doses of both drugs, resulted in significant prolongation of survival and suppression of growth of yeast cells in the kidneys. Combination therapy of experimental candidiasis with cilofungin and amphotericin B did not result in antagonism; rather, additive or synergistic effects were seen. Future preclinical work with other echinocandin and polyene derivatives should include studies evaluating the in vivo interactions of both classes of compounds.

Amphotericin B

Interactions of amphotericin B and SCH 39304 in the treatment of experimental murine candidiasis: lack of antagonism of a polyene-azole combination.

Mice infected intravenously with Candida albicans were treated with SCH 39304, a new triazole antifungal compound, amphotericin B, or both. Two dose levels of each drug were evaluated in an attempt to identify potential helpful or harmful effects on survival and kidney colony counts. Contrary to theoretical predictions, combination therapy was not antagonistic and some additive or synergistic effects were observed. The results obtained in this study suggest that antagonism between polyene and azole antifungal drugs is not inevitable and that additive or synergistic effects may be possible.

Amphotericin B

Pneumocystis carinii pneumonia complicating somatostatin therapy of Cushing's syndrome in a patient with metastatic pancreatic islet cell carcinoma and Zollinger-Ellison syndrome.

Described is the case of a 73-yr-old woman with metastatic pancreatic islet carcinoma that manifested initially as Zollinger-Ellison syndrome followed by onset of endogenous Cushing's syndrome, who developed Pneumocystis carinii pneumonia while on therapy with a long-acting somatostatin analog. Although P. carinii pneumonia has been observed in patients with Cushing's syndrome associated with other conditions, this is the first reported case in a patient with Zollinger-Ellison syndrome. Heightened awareness of the possibility of opportunistic infections in patients receiving somatostatin therapy for Cushing's syndrome of any cause, particularly Zollinger-Ellison syndrome, may be warranted.

Adenoma, Islet Cell

Attachment of Blastomyces dermatitidis conidia to murine bronchoalveolar macrophages: characterization of binding and elicitation of respiratory burst.

We studied the mechanisms of adherence of Blastomyces dermatitidis conidia to murine bronchoalveolar macrophages and the ability of the conidia to elicit an increase in macrophage O2- production, using an avirulent fungal strain. The number of cell associated conidia was counted by visual inspection of 2 hour macrophage monolayers incubated with conidia and O2- was measured by reduction of ferricytochrome c. Adherence of conidia to bronchoalveolar macrophages was time dependent and reached a plateau after 30 min (36 +/- 5%, 51 +/- 22%, and 36 +/- 17% macrophages with adherent conidia after 15, 30, and 60 min, respectively). Both Ca+2 and Mg+2 were required. The carbohydrates mannose, mannan, fucose, alphamethylmannoside, beta-glucan, galactose, N-acetylglucosamine and chitotriose (100-1000 micrograms/ml) did not inhibit adherence of conidia to macrophages. Trypsin treatment of macrophages or conidia did not affect binding. Conidia did not stimulate bronchoalveolar macrophage production of O2- above baseline concentrations (2.0 +/- 0.9 vs 0.8 +/- 0.5 nmol O2-, p greater than 0.05). We conclude that murine bronchoalveolar macrophage--B. dermatitidis conidia interactions occur primarily by a non-lectin-like attachment and do not result in the production of macrophage derived O2-.

Animals

Treatment of murine pulmonary blastomycosis with SCH 39304, a new triazole antifungal agent.

SCH 39304, a broad-spectrum azole derivative, was evaluated in an experimental mouse model of blastomycosis pneumonia. Five days after being inoculated with Blastomyces dermatitidis, infected mice were treated with either oral SCH 39304, fluconazole, or intraperitoneal amphotericin B. A dose response protective effect was observed with SCH 39304 at 5 to 100 mg/kg of body weight per day, with 5 mg of SCH 39304 per kg per day providing activity similar to that of 100 mg of fluconazole per kg per day. Colony counts of yeasts in the lungs of mice sacrificed while on therapy with SCH 39304 were consistently below those of controls, and several lungs were sterile. We conclude that SCH 39304 is effective in murine blastomycosis treatment and deserves to be evaluated in the treatment of human blastomycosis.

Amphotericin B

Treatment of fungal infections in patients infected with the human immunodeficiency virus.

Mycoses due to a variety of organisms have been implicated as opportunistic pathogens in patients infected with HIV. These infections are a cause of significant morbidity and mortality, and most often require life-long antifungal medication to suppress reactivation of the fungal process. With the advent of newer antifungal drugs, such as fluconazole and itraconazole, options are available so that appropriate nontoxic, long-term therapy can be administered. As the number of HIV-infected people increases and their longevity is extended, fungi will continue to pose challenging problems in diagnosis and therapy.

Candidiasis

Empiric treatment of fungal infections in the neutropenic host. Review of the literature and guidelines for use.

Persistent fever that is refractory to broad-spectrum antibacterials is common in neutropenic patients undergoing induction chemotherapy of acute leukemia. Clinical experience suggests that many of these patients are infected with fungi. Until recently, data supporting the role of empiric antifungal therapy in this setting were limited to small groups of patients or postmortem reports. Evolving evidence in larger patient populations supports data from smaller series: febrile neutropenic patients who have failed to respond to a 4- to 7-day course of broad-spectrum antibacterials may benefit from the early initiation of antifungal therapy. Patients with fungal colonization or pulmonary infiltrates and adult patients who have not received previous fungal prophylaxis may especially benefit from the early use of antifungal drugs. Amphotericin B has been the "gold standard" for empiric antifungal therapy, although the newer azoles may be useful in certain situations.

Acute Disease

Fungal meningitis.

Fungal meningitis tends to be a subacute or chronic process; however, it may be just as lethal as bacterial meningitis if untreated. There are many similarities between the pathogenic fungi. Most of the fungi are aerosolized and inhaled, and initiate a primary pulmonary infection which is usually self-limited. Hematogenous dissemination may follow the initial infection, with subsequent involvement of the CNS. Rarely, trauma or local extension provides the route to CNS infection. The host is frequently, although not always, immunosuppressed. The hyphae of molds generally cause focal disease with hemorrhagic necrosis secondary to vascular thrombosis. The yeasts tend to cause a more diffuse process with the base of the brain being primarily affected, such that hydrocephalus is seen as a frequent complication of chronic disease. Diagnosis may be difficult, as the CSF may be normal, with negative smears and sterile cultures, although more often there is at least one abnormality indicating disease. Serologies (if available, depending on the fungus) may point towards the proper diagnosis, as may a careful travel history. Currently, amphotericin B is still the drug of choice in most situations; however, the newer azole antifungal agents offer great promise, especially in the treatment of cryptococcal meningitis. The precise role of such agents will remain unclear until appropriate large-scale studies of their effectiveness have been completed. The treatment of the unusual CNS mycoses will continue to be based on clinical experience, and reports of the use of new azoles in these diseases need to be critically evaluated.

Blastomycosis