Defective neutrophil locomotion in human blastomycosis: evidence for a serum inhibitor

Unstimulated or stimulated locomotion, bactericidal, and metabolic activities of polymorphonuclear leukocytes (PMN) from 12 nonimmunosuppressed patients with invasive fungal infections proved by culture, were evaluated before and after treatment of the patients with antimicrobial drugs. The major observation was that PMN from patients with blastomycosis had a defect in stimulated locomotion. The specificity of the defect for blastomycosis was substantiated by the normal stimulated locomotion of PMN from uninfected control subjects or untreated patients with histoplasmosis, cryptococcosis, coccidioidomycosis, or sporotrichosis. The defect was due to a heat-stable, cell-directed, reversible serum inhibitor. In unheated or heated serum from untreated patients with blastomycosis, control PMN had decreased stimulated locomotion. Multiple washing followed by addition of control serum corrected locomotion of PMN from untreated patients with blastomycosis. The abnormality was not present in PMN from patients who had been treated with amphotericin B or had spontaneous resolution of their infections. Inhibition was not due to absence of chemoattractant activity because zymosan-activated patient serum or mixtures of patient and control serum stimulated PMN locomotion normally. The defect did not correlate with age, sex, neutrophil count, nitroblue tetrazolium reduction, serologic reactivity, or duration or severity of infection. No defect was found in bactericidal or metabolic activities of various combinations of PMN and serum from untreated or treated patients with blastomycosis or the 4 other fungal infections tested, indicating that the inhibitor was specific for stimulated locomotion.

Antioxidant enhancement of amphotericin B activity against Candida albicans

Results indicated that the antioxidant n-propyl gallate can enhance amphotericin B activity against Candida albicans by two different mechanisms. One involves drug stabilization. The second has not been characterized.

Synergistic action of amphotericin B and antioxidants against certain opportunistic yeast pathogens

Results of earlier turbidimetric growth experiments showed that certain antioxidants prolonged the antifungal activity of amphotericin B (AB) against Candida albicans, presumably by retarding autoxidative destruction of the drug. Viability studies were designed to examine this in more detail. Subinhibitory concentrations of either butylated hydroxyanisole, n-propyl gallate, or nordihydroguaiaretic acid in combination with fungistatic levels of AB exerted synergistic fungicidal activity against two strains of C. albicans and one of C. parapsilosis. Although synergism was not seen in tests with a strain of Torulopsis glabrata, antioxidants prolonged the inhibitory action of AB against this organism. On the basis of these findings and other considerations that are discussed, it is suggested that stabilization of AB and the ability to act synergistically with AB represent two distinctly different effects of the antioxidants.

The radiological appearance of pulmonary blastomycosis

A retrospective analysis of patients with pulmonary blastomycosis was made. Correlation of the mode of clinical presentation with the thoracic radiograph revealed a spectrum of clinical and radiological disease. The results substantiate the absence of specific clinico-radiological patterns, and amplify current concepts of clinical and radiological manifestations.

Endogenous activation in blastomycosis

Recent work established the fact that the portal of entry in blastomycosis is the lung. After the initial exposure to the fungus, a pneumonic process develops that may heal spontaneously or progress locally or at distant sites, or both. Frequently, however, patients present with disseminated disease, whose chest roentgenograms do not show any lesions. We have recently seen three patients with disseminated blastomycosis with negative chest roentgenograms at the time of diagnosis. Past history showed a pneumonic illness 33, 32, and 4 months before diagnosis. Chest roentgenograms from the time of the original illness showed a pneumonic process compatible with blastomycosis in all three. Examination of postbronchoscopy sputa showed the characteristic yeasts of Blastomyces dermatitidis. These three patients document for the first time apparent endogenous activation in blastomycosis. A possible explanation for this apparent endogenous activation may reside in the histopathologic similarity between blastomycosis and other chronic granulomatous diseases, especially tuberculosis.

Acute cavitary histoplasmosis

A case of acute cavitary histoplasmosis in the upper lobes is documented. The relationship of this entity to chronic cavitary histoplasmosis is discussed.

Apparent diminution of the blastomycin skin test; follow-up of an epidemic of blastomycosis

Eighteen persons involved in an epidemic of blastomycosis were followed for a period of 3 years. None of the symptomatic patients received antifungal therapy and all recovered spontaneously. During the period of follow-up observation all patients remained in excellent health, and none showed evidence of late exacerbation of the original illness. Two of the originally symptomatic patients continue to show stable pulmonary nodules on chest roentgenograms, whereas the previously abnormal chest roentgenograms in the other patients have become negative. Sixteen of these 18 patients showed a minimum of 5 mm of induration when tested with blastomycin skin test antigen. During the period of observation, the size of this induration tended to diminish.

Exfoliative cytology in the rapid diagnosis of pulmonary blastomycosis

Four patients with pulmonary blastomycosis are reported. Their bronchial washings, submitted for cytologic evaluation and stained by the standard Papanicolau technique, yielded the diagnosis, subsequently confirmed by cultural identification of the fungus. In three additional cases, retrospective evaluation of cytologic material also revealed the organism, even though the diagnostic significance was not appreciated originally. Since cytologic techniques are simple, readily available, and rapid, they can be helpful in differentiating pulmonary neoplasms from pulmonary blastomycosis, thus reducing the need for diagnostic thoracotomies.

Influence of antioxidants on the bioactivity of amphotericin B

Four antioxidants, propyl gallate, butylated hydroxyanisole, butylated hydroxytoluene, and d-alpha-tocopherol acid succinate were found to stabilize amphotericin B and to prolong its antifungal activity against Candida albicans. Although each of the antioxidants was effective in this respect, propyl gallate and butylated hydroxyanisole were better than butylated hydroxytoluene and d-alpha-tocopherol acid succinate. None of the antioxidants alone adversely affected normal cell growth. It is suggested that amphotericin B instability is due, at least in part, to lability of the carbon-carbon double bonds of the polyene moiety toward autoxidation. By protecting the drug molecule with an antioxidant, it is possible to significantly lower the quantity of AB necessary to obtain particular antifungal effects.

Isolation of Blastomyces dermatitidis from pigeon manure

We recently diagnosed and treated a 45-year-old white male horticulturist with acute progressive blastomycosis. Epidemiologic studies revealed that the patient used a load of pigeon manure as fertilizer approximately 6 weeks before becoming ill. He used the pigeon manure only once, resealed the remainder, and stored it in his hothouse. Samples of the pigeon guano were digested with 10 per cent KOH, and the characteristic yeast forms of Blastomyces dermatitidis were seen in large numbers. The fungus was cultured from another sample of the same material. This is the first time that the pathogenic fungus B. dermatitidis has been isolated from the environment in association with a human case.

Inhibition of potentially pathogenic yeastlike fungi by clotrimazole in combination with 5-fluorocytosine or amphotericin B

Clotrimazole (CTM) has a doubtful future with respect to use in treatment of the systemic mycoses. To assess the potential of CTM in combined drug regimens, antifungal effects of CTM together with 5-fluorocytosine (5-FC) or amphotericin B (AMB) were tested in a synthetic liquid medium against Candida albicans, Candida tropicalis, and Torulopsis glabrata. Viable counts were monitored over a 48-h incubation period. Weak inhibitory concentrations of CTM were tested in combination with levels of 5-FC or AMB that alone produced transient antifungal effects followed by rapid recovery of proliferative capacity. Results were similar for each of the organisms studied. Between 24 and 48 h, when cultures containing 5-FC or AMB alone were in the recovery phase, CTM plus 5-FC and CTM plus AMB continued to markedly suppress cell multiplication. It would appear that weak inhibitory concentrations of CTM can act together with 5-FC or AMB to produce antifungal effects greater than that obtained with either of the latter two drugs alone.

Synergistic action of amphotericin B and rifampin against Candida species

Amphotericin B and rifampin act synergistically against certain yeasts in vitro. Whether this synergism is a general phenomenon or whether the effect has strict species and strain requirements was studied. Included in a survey of the genus Candida were eight human isolates of Candida albicans and one strain each of Candida krusei, Candida tropicalis, Candida pseudotropicalis, Candida parapsilosis, Candida guilliermodnii, and Candida stellatoidea. Cultures in both control and drug-containing liquid medium were incubated at 37 C with aeration. Effects of the drugs were determined from viability assays performed at zero-time and at 17 hr. Amphotericin C and rifampin were judged to be synergistic if any one of three different sets of criteria was met. Combined activity greater than the sums of individual drug effects was required in each set of criteria. Partially inhibitory or fungistatic levels of amphotericin B and noninhibitory concentrations of rifampin acted synergistically against all strains of Candida examined. Within the genus Candida, synergism of amphotericin B and rifampin appears to be a rather general phenomenon.