Beschreibung
The tendency of fungi pathogenic for humans to have shapes in tissue distinct from their usual saprophytic morphologies has fascinated the pathologist and medical mycologist for almost a century. A primary rea son for this fascination is the possibility that fungal duality of form, or dimorphism, may be an important virulence factor that allows the zoo pathogenic fungus to survive host defenses. A second reason relates to the desire to gain basic insights into the regulation of cellular develop ment and morphogenesis among the etiological agents of human mycoses. Many excellent treatises have appeared within the recent past dealing with fungal dimorphism. However, it is becoming increasingly clear that it may be beyond the capability of one or a few authors to review this subject adequately. Instead, the ever-increasing volume ofliterature asso ciated with fungal dimorphism and the diversity offungi now recognized to exhibit a type of dimorphism suggest that a volume comprised of con tributions by numerous researchers may be more appropriate. This per ception provided me with the motivation to compile a multiauthor volume.
Autorenporträt
InhaltsangabeI. Introduction and General Morphology.- 1 An Introduction to Dimorphism among Zoopathogenic Fungi.- 1. Dimorphism: Application of the Term.- 2. Dimorphic Pathogenic Fungi.- 3. General Introductory Thoughts.- References.- 2 Cytological and Ultrastructural Aspects of Dimorphism.- 1. Introduction.- 2. Aspects of Ultrastructural Cytology.- 2.1. Yeast Cell.- 2.2. Hypha.- 2.3. Conidium.- 3. Ultrastructural Aspects of Dimorphism.- 3.1. Yeast-to-Hyphal Cell Transition.- 3.2. Hyphal-to-Yeast Cell Transition.- 3.3. Conidial-to-Yeast Cell Transition.- 4. Concluding Remarks.- References.- II. Fungi with Yeast Tissue Morphologies.- 3 Blastomyces dermatitidis.- 1. Introduction.- 2. Growth Requirements.- 3. Microscopy.- 4. Cell Walls.- 5. Metabolic Considerations.- 6. Summary.- References.- 4 Studies on Phase Transitions in the Dimorphic Pathogen Histoplasma capsulatum.- 1. Introduction.- 2. Experimental Studies on Dimorphism.- 2.1. Morphological Studies.- 2.2. Growth Requirements of the Two Phases: Cysteine Metabolism.- 2.3. Role of Cysteine in Regulating Morphogenesis and Mitochondrial Activity.- 2.4. RNA and Protein Synthesis.- 2.5. Cyclic AMP Levels.- 3. Discussion of Dimorphism.- References.- 5 Paracoccidioides brasiliensis.- 1. Introduction.- 2. Morphology of Dimorphism.- 3. Biochemistry of Dimorphism.- 4. Cell Wall and Dimorphism.- 5. A Model of Dimorphism.- 6. Regulation of Glucan Synthesis in Paracoccidioides brasiliensis Cell Walls.- 7. Conclusions.- References.- 6 Sporothrix schenckii.- 1. Introduction.- 2. Morphological Phase Transition.- 2.1. Sporothrix schenckii Cell Types: In Vitro and in Vivo Morphology.- 2.2. Growth Conditions and Cell Types.- 2.3. Morphologically Related Ceratocystis.- 2.4. Ultrastructure of the Phase Transition.- 3. Biochemical Activities and Cell Constituents.- 3.1. Teleomorph of Sporothrix schenckii.- 4. Cell-Surface Reactivity and Composition.- 4.1. Cell-Wall Composition in Different Cell Types.- 4.2. Reactivity with Lectins.- 4.3. Anionic Groups.- 4.4. Immunofluorescence Reactions.- 4.5. Surface Components and Yeast Phagocytosis.- 5. Sporothrix schenckii Polysaccharides.- 5.1. Rhamnomannans at Different Growth Temperatures.- 5.2. Rhamnomannans of Ceratocystis.- 5.3. Nuclear Magnetic Resonance Spectroscopy and Polysaccharide Structure.- 5.4. Galactomannans.- 5.5. Glucans in Different Cell Types.- 6. Immunochemistry of Sporothrix schenckii Antigens.- 6.1. Antigenic Determinants and Cross-Reactions.- 6.2. Delayed Hypersensitivity and Other Cell-Mediated Reactions.- 7. Perspectives.- References.- III. Fungi with Yeast and Hyphal Tissue Morphologies.- 7 Candida albicans.- 1. General Introduction.- 2. Phenotypic Repertoire of Candida albicans.- 3. Minimum Requirements for Growth in Culture.- 4. A Simple Method for Regulating Dimorphism Employing pH as the Sole Determining Factor.- 5. Stationary Phase, the Cell Cycle, and Hyphal Induction.- 6. Phenotypic Commitment, Septum Formation, and Filament-Ring Formation.- 7. Biochemical and Physiological Comparisons of the Two Growth Forms.- 7.1. Cyclic AMP.- 7.2. Chitin Synthesis.- 8. Macromolecular Synthesis during Outgrowth in the Two Growth Forms of Candida.- 9. Genetics of Candida.- 10. Conclusion.- References.- 8 Exophiala werneckii.- 1. Introduction and Brief History of Exophiala werneckii as a Pathogen.- 2. Taxonomic Position of the Organism.- 3. Morphological Forms of Exophiala werneckii.- 4. Control of Morphology.- References.- 9 Polymorphism of Wangiella dermatitidis.- 1. Introduction.- 2. Yeast Cell.- 2.1. Morphology.- 2.2. Yeast-Cell Division.- 2.3. Yeast-Cell Cycle.- 3. Hypha.- 4. Multicellular Form.- 4.1. Stage I.- 4.2. Stage II.- 5. Transitions between Morphologies.- 5.1. Hyphae to Yeasts.- 5.2. Yeasts to Multicellular Forms.- 5.3. Stage I Forms to Yeasts.- 5.4. Stage I and II Forms to Hyphae.- 6. Cell-Wall Alterations during Multicellular-Form Development.- 6.1. Quantitative Analyses of Cell Walls.- 6.2. Cell-Wall Polymers.- 6.3. Dynamics of Polysacc
