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M Huppert

Publications and source records attributed to M Huppert.

At least 37 records · Page 2Linked to original sources
PubMed1979

Electron microscopic studies of saprobic and parasitic forms of Coccidioides immitis.

During studies of both saprobic and parasitic cycles of Coccidioides immitis, we found that the hyphae contained septa with simple pores, Woronin bodies, pinocytotic vesicles and/or lomasomes. The alternating thallic arthroconidia were released by fracturing of the adjacent sterile cells. The endospores were formed by progressive cleavage of the spherules. The taxonomic classification of C. immitis still remains obscure.

Cell Division↗
PubMed1979

Common antigens among systemic disease fungi analyzed by two-dimensional immunoelectrophoresis.

The interpretation of immunological results in systemic mycoses has been complicated by cross-reactions among specimens from patients with blastomycosis, coccidioidomycosis, and histoplasmosis. The fungal preparations used in these tests evidently contained one or more antigens in common. Two-dimensional immunoelectrophoresis techniques were used to determine the number of antigens contained in several soluble extracts from Blastomyces dermatitidis and Histoplasma capsulatum that were common with those demonstrable in a coccidiodin-anticoccidioidin reference system. A total of 12 and 10 common antigens were found in preparations from B. dermatitidis and H. capsulatum, respectively. In addition, the crude preparations from each species of fungus exhibited some qualitative and quantitative differences in composition of antigens. Use of two-dimensional immunoelectrophoresis for standardization of fungus extracts, for monitoring separation of species-specific antigens, and for testing humoral antibody response should add further refinement to correlations with clinical disease.

Antigens, Fungal↗
PubMed1978

Antigenic analysis of coccidioidin and spherulin determined by two-dimensional immunoelectrophoresis.

Immunological tests are valuable aids for diagnosis of mycotic infections and, in some cases, as objective guides for clinical management and prognosis. The usefulness of these procedures is limited to the extents that crude antigen preparations are employed, that these are difficult to standardize uniformly, and that they contain antigens common to several species of pathogenic fungi. Analysis by two-dimensional immunoelectrophoresis methods of the two crude preparations used for coccidioidomycosis demonstrated that coccidioidin contained at least 26 antigens, with 10 of these found also in spherulin. In addition, spherulin contained two antigens not demonstrated in coccidioidin. No single test detected all antigens present, and multiple procedures were required to display the complete array of antigens. A reference system was established for coccidioidin and precipitated immunoglobulins from a burro hyperimmunized with coccidioidin. Evaluation of the reference system demonstrated that it was highly reproducible with respect to the reagents used, to repeated tests by the same person, and to comparative tests by two individuals using the same reagents. Applications of this reference system for standardization of reagents, for detecting common antigens, for monitoring successive steps during fractionation of crude preparations, and for fingerprinting strains for ecological and epidemiological studies are presented.

Antigens, Fungal↗
PubMed1978

Combined methenamine-silver nitrate and hematoxylin & eosin stain for fungi in tissues.

Initial examination of hematoxylin & eosin-stained tissue from a human brain specimen did not reveal the fungi which were seen in subsequent tissue sections stained with methenamine-silver nitrate. Microabscesses seen in the hematoxylin & eosin-stained sections were not apparent in the methenamine--silver nitrate-stained tissue. Staining with methenamine--silver nitrate and counterstaining with hematoxylin & eosin proved excellent not only for detecting fungus cells, but also for revealing their relationship to the host cellular response in this case and in examples of experimental murine coccidioidomycosis and histoplasmosis.

Animals↗
PubMed1977

Comparison of coccidioidin and spherulin in complement fixation tests for coccidioidomycosis.

Coccidioidin, an extract from the saprophytic mycelial form of Coccidioides immitis, has been a very useful antigen preparation in serological tests for coccidioidomycosis. Its sensitivity has been very good for detecting most types of clinical disease, but tests with coccidioidin have been negative for 40% or more of patients with chronic pulmonary disease, the clinical entity which must be differentiated from other cavitary, nodular, or fibrotic pulmonary disease, e.g., tuberculosis and cancer. The specificity of coccidioidin has also been good although it results in positive tests for an average of 16% among patients with noncoccidioidal mycoses. Recently spherulin, an extract from the parasitic endosporulating spherule form of C. immitis, was reported to be more sensitive than coccidioidin in concurrent complement fixation tests with sera from selected cases. We have compared coccidioidin and spherulin in concurrent complement fixation tests with 614 sera submitted routinely for coccidioidal serology and with 159 selected sera from patients with noncoccidioidal mycoses. Among the former, spherulin was positive with 25% and coccidioidin with 23%, and correlation of titer scores was highly significant. Statistical analysis revealed no significant differences with respect to frequency of positive specimens, titer scores, or diagnosis for current coccidioidomycosis. The results with sera from noncoccidioidal mycoses revealed marked differences. Coccidioidin was positive with 20%, and spherulin was positive with 48%. The titer scores with spherulin were consistently and significantly higher, and there was no correlation for results with the two antigens. Thus, coccidioidin and spherulin were equally sensitive, but spherulin was considerably less specific.

Antigens, Fungal↗
PubMed1976

Effect of amphotericin B and rifampin against Coccidioides immitis in vitro and in vivo.

Amphotericin B, the principal drug used for treating systemic mycoses, possesses undesirable toxic properties. The ability of this antibiotic to potentiate antifungal activity of other compounds suggests that lower doses of amphotericin B could be used in combination with a second drug without loss of therapeutic efficacy. In vitro tests demonstrated that amphotericin B potentiated rifampin against the mycelial growth phase of Coccidioides immitis but not against the spherule-endospore phase. Therapy for murine coccidioidomycosis with a combined amphotericin B-rifampin regimen was not better than treatment with amphotericin B alone; in fact, combined drugs may have been even less effective. This would have clinical significance for therapy of concurrent infections.

Amphotericin B↗
PubMed1976

Lung weight parallels disease severity in experimental coccidioidomycosis.

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.

Amphotericin B↗
PubMed1976

Rapid in vitro conversion and identification of Coccidioides immitis.

Since many contaminating nonpathogenic fungi resemble Coccidioides immitis culturally, isolates from patients must be inoculated into laboratory animals to confirem identification as C. immitis. This procedure is time-consuming, expensive, and not generally available in clinical laboratories. When cultures of C. immitis were grown in slide cultures on modified Converse liquid medium in purified agar and incubated at 40 C in a candle jar, all 57 isolates demonstrated inhibition of mycelial growth and conversion of arthrospores to endosporulating spherules in 3 to 5 days. Representative isolates of six species of nonpathogenic fungi that resembled C. immitis culturally either did not grow or failed to produce endosporulating spherules under the same conditions. This procedure is recommended for confirming the identication of a culture as C. immitis.

Coccidioides↗
PubMed1976

A cytological study of morphogenesis in Coccidioides immitis.

Coccidioides immitis is still classified as a Deuteromycete because the perfect stage is unknown. Mating experiments have been unsuccessful. Some investigators consider the endosporulating spherule to be a sporangium with sporangiospores, but others describe it as an ascus. The development of a reproducible method for cultivation of the spherule-endospore cycle in vitro provided an opportunity to study cytological changes occuring throughout the arthrospore-hyphae-arthrospore cycle and the arthrospore-spherule-endospore cycle. Our observations of the arthrospore-mycelial cycle confirm an earlier report by another investigator demonstrating a resting stage followed by ring formation, a V-form, and a filament stage. In addition, we describe four pairs of chromosomes and formation of possible spindles and nucleoli. The spherule-endospore cycle is initiated by an arthrospore with a single large nucleus, most probably derived from the multinucleate arthrospores in the inoculum. This uninucleate arthrospore is present for less than 24 hours. During continued incubation, the arthrospore becomes a round cell with four pairs of chromosomes. Subsquently, the cell enlarges to become a spherule and this growth is accompanied by a series of synchronous divisions of the nuclei. Although endospores are formed apparently progressive cleavage, clusters of uninucleate endospores are enclosed in a membranous sac as seen in squashed spherule preparations. The question of a relationship to the phycomycetes or the ascomycetes remains unresolved.

Animals↗
PubMed1975

Delayed-type hypersensitivity responses to a cell wall fraction of the mycelial phase of Coccidioides immitis.

A skin test-active fraction was isolated from the mycelial-phase cell walls of Coccidioides immitis. This alkali-soluble, water-soluble antigen (C-ASWS) elicited positive reactions in 22 of 24 (92%) of the Coccidioides-sensitized guinea pigs whereas only 14 (54%) of the same guinea pigs reacted to commercial coccidioidin (BioCox). None of the 21 Histoplasma-sensitized guinea pigs cross-reacted with the C-ASWS antigen. Footpad tests in mice actively infected with Coccidioides further established the efficacy of the C-ASWS antigen in eliciting a delayed-type hypersensitivity response. One-microgram doses of C-ASWS produced reactions comparable to 100-mug doses of nondialyzable coccidioidin (Smith's lot 64 D4). The C-ASWS fractions isolated from three different C. immitis strains showed similar reactivity in terms of the number of positive reactions produced in Coccidioides-sensitized guinea pigs. However, the induration responses (diameter in millimeters) elicited by the C-ASWS fraction of one strain were significantly less than those elicited by the C-ASWS fractions of the other two C. immitis strains.

Administration, Intranasal↗
PubMed1975

Rapid methods for identification of yeasts.

Opportunistic infections by yeasts have been implicated as one of the major causes of complications in the compromised patient. Rapid recognition and identification of these yeasts is essential for patient management, but conventional liquid medium methods for completing identification tests are cumbersome and time consuming. Rapid tests have been devised based on modifications of methods commonly used in bacteriology. These rapid methods included tests for carbohydrate and nitrate assimilation, fermentation, and urease production. These were compared with several current methods for accuracy of results, for time to final identification, and for economy of time and reagents. In addition, the usual tests for pseudogerm tube formation, for production of hyphae or pseudohyphae, and for growth temperatures were included. The rapid tests achieved 96% or better accuracy compared with expected results, and 46 species of yeasts were identified in 1 to 2 days compared with the 10 to 14 days required by conventional liquid culture methods.

Blastomyces↗
PubMed1974

Combined amphotericin B-tetracycline therapy for experimental coccidioidomycosis.

Although amphotericin B is the principal antibiotic for treating systemic mycoses, its clinical use is restricted, primarily because of the toxicity associated with the required prolonged therapy. Other investigators have reported results from in vitro experiments demonstrating that amphotericin B can potentiate antifungal activity of other antibiotics which are ineffective when used alone. In the present study, amphotericin B was used in combination with tetracycline for treating experimental coccidioidomycosis in mice. The results show that the combination of antibiotics is effective with a dosage of amphotericin B reduced 2.5 to 4 times of that required for effective chemotherapy with amphotericin B alone.

Amphotericin B↗
PubMed1972

Evaluation of an experimental animal model for testing antifungal substances.

Accumulated evidence indicates that infection by fungi capable of causing systemic disease usually results in a relatively strong acquired resistance. The working hypothesis for this study was that an antifungal substance, even one with only slight fungistatic activity, could be an effective chemotherapeutic agent by arresting progression of the infection until acquired resistance became effective. The present study involved establishing and evaluating an experimental animal model (coccidioidomycosis in mice) which could be used to test this hypothesis. This model was reasonably similar to the natural disease. Results with infected nontreated animals indicated that the plot of mortality frequency against survival time did not follow a normal distribution curve. Thus, nonparametric procedures were used for evaluation. Use of this model with an established antibiotic (amphotericin B), with a crude preparation of a new antibiotic (CB-310), and with synthetic organoselenium compounds demonstrated that even low levels of antifungal activity could be detected. The model should be useful not only to test the original hypothesis but also to screen antifungal substances for their potential as chemotherapeutic agents.

Animals↗