Study of the conidial development and cleistothecium-like structure of some strains of Fonsecaea pedrosoi

The reproduction of twenty-seven strains of Fonsecaea pedrosoi was studied. The denticulate type (asexual reproduction) showed three morphological variations: medium-size, long and sessile forms. These forms can be used to characterize the different strains isolated especially for epidemiological purposes.Only one strain (MR 1335) isolated from a chromomycosis case in Martinique showed a cleistothecium-like structure. This formation was compared to that observed in Phialophora verrucosa, another agent of chromomycosis, and to the cleistothecium of Dictyotrichiella mansonii, the perfect state of Wangiella mansonii which is a saprophyte fungus.     

Fungal Cell Gigantism during Mammalian Infection

The interaction between fungal pathogens with the host frequently results in morphological changes, such as hyphae formation. The encapsulated pathogenic fungus Cryptococcus neoformans is not considered a dimorphic fungus, and is predominantly found in host tissues as round yeast cells. However, there is a specific morphological change associated with cryptococcal infection that involves an increase in capsule volume. We now report another morphological change whereby gigantic cells are formed in tissue. The paper reports the phenotypic characterization of giant cells isolated from infected mice and the cellular changes associated with giant cell formation. C. neoformans infection in mice resulted in the appearance of giant cells with cell bodies up to 30 µm in diameter and capsules resistant to stripping with γ-radiation and organic solvents. The proportion of giant cells ranged from 10 to 80% of the total lung fungal burden, depending on infection time, individual mice, and correlated with the type of immune response. When placed on agar, giant cells budded to produce small daughter cells that traversed the capsule of the mother cell at the speed of 20–50 m/h. Giant cells with dimensions that approximated those in vivo were observed in vitro after prolonged culture in minimal media, and were the oldest in the culture, suggesting that giant cell formation is an aging-dependent phenomenon. Giant cells recovered from mice displayed polyploidy, suggesting a mechanism by which gigantism results from cell cycle progression without cell fission. Giant cell formation was dependent on cAMP, but not on Ras1. Real-time imaging showed that giant cells were engaged, but not engulfed by phagocytic cells. We describe a remarkable new strategy for C. neoformans to evade the immune response by enlarging cell size, and suggest that gigantism results from replication without fission, a phenomenon that may also occur with other fungal pathogens.     

Skin test-active substance prepared from culture filtrate of Fonsecaea pedrosoi

Ethanol-precipitated substance (EP) was prepared from culture filtrate of Fonsecaea pedrosoi. EP was separated into two components by passing through a Sephadex G-50 column; the faster passing component was referred to as EP-1, the slower as EP-2. EP-1 and EP-2 were evaluated as an antigen for detecting cutaneous delayed hypersensitivity in patients with chromomycosis. EP-1 elicited positive delayed skin reactions in all of 8 patients with chromomycosis, of which 7 caused by F. pedrosoi and one by Exophiala jeanselmei. Healthy subjects, patients with sporotrichosis and patients with tinea barbae failed to react to EP-1. These results indicate that EP-1 is a useful tool for detecting cutaneous delayed hypersensitivity in patients with chromomycosis caused by F. pedrosoi. It was found that precipitin test using EP-1 as an antigen had little diagnostic value in chromomycosis. EP-2 did not show antigenic activity in both skin and precipitin reactions.     

Hyperthermic treatment of chromomycosis with disposable chemical pocket warmers

A case of chromomycosis in which hyperthermia proved effective is reported. The patient was a 56-year-old male bean curd maker who, without any previous history of minor trauma, developed on the extensor side of the left upper arm an eczematous lesion that underwent gradual radial expansion. The lesion showed a well-defined, 7×10 cm infiltrated erythematous plaque with the central area healed and, at the upper and lower borders, adherent scales and crusts on the surface. Histological examination revealed granulomatous changes in the dermis, as well as sclerotic cells within giant cells and microabscesses. On culturing,Fonsecaea pedrosoi was isolated. The patient was treated with disposable chemical pocket warmers, which were secured over the lesion with a rather tight elastic bandage, so that they kept the affected area warm for 24 hours a day. After a month of such hyperthermic treatment, the erythema and infiltration had decreased considerably, and microscopic examination and culture of the crusts both yielded negative results. Examination of biopsy specimens of the lesion after the third month showed that it had cicatrized. The treatment was stopped after 4 months, and no relapse occurred. We also summarize the published results of local hyperthermic treatment of chromomycosis in Japan.     

Macrophagal polykaryons

The mechanisms of formation, morphology and functions of macrophagal polykaryons are discussed. These giant multinuclear cells are formed by means of macrophagal cell fusion ("natural hybridization") and specialized on the extra- and intracellular processes of resorption of the foreign body and tissues of the proper organism. The formation of macrophagal polykaryons seems to be one of the possible manifestation of reactive histiocytosis in chronic inflammation and tumor growth. The role of macrophagal polykaryons in such disease as giant cell arteritis, giant cell granuloma and fibrohistiocytic tumors is considered in details. It is proposed that one and the same mechanism of regulations served as a basis of developing of both osteoclastic remodelling of the bone tissue (morphogenetic process) and resorption of the foreign body and tissues of the proper organism in inflammation in the process of evolution.     

Disseminated cutaneous and vascular invasion byFusarium moniliforme in a fatal case of acute lymphocytic leukemia

A 35 year old female patient with acute lymphocytic leukemia developed fusariosis in which dissemination appeared to be limited to cutaneous and vascular invasion. The first evidence of fungemia occurred nearly seven months after initial hospitalization. The fungus was identified asFusarium sp. and was considered a contaminant. Two weeks later blood cultures were again positive forFusarium sp. and the patient was placed on amphotericin B and 5-fluorocytosine therapy. The following day developing lesions were noted on her forearms and face; lesions ultimately spread to her trunk, abdomen, and lower extremities. Skin lesion biopsy sections revealed abundant septate and branching hyphae throughout the dermis and within capillaries. Twenty-six days after the initial isolation the patient died. Post-mortem blood cultures gave rise to the same fungus, which was identified asFusarium monoliforme. Postmortem cultures and stains of spleen, liver, lung, and brain specimens were all negative for fungi. The primary source and portal of entry of the organism remained undetermined.     

Giant Cells: Contradiction to Two-Hit Model of Tuber Formation?

Tuberous sclerosis (TSC) is an autosomal dominant disease characterized by the formation of hamartomatous lesions in many organs, including brain, heart or kidneys. It has been found that TSC is caused by the mutation in one of the two tumor suppressor genes: TSC1 or TSC2, encoding hamartin and tuberin, respectively. According to Knudson’s two-hit model of tumorigenesis, second-hit mutation and resulting loss of heterozygosity (LOH) of a tumor suppressor gene is necessary for tumor formation. In fact, LOH is commonly found in several types of hamartomas formed in the process of tuberous sclerosis, but, interestingly, not in brain lesions, containing characteristic giant cells. In this paper, we review literature covering origination of giant cells and present several hypotheses explaining why in spite of the presence of hamartin and tuberin, brain lesions form in TSC patients.     

MULTINUCLEATE GIANT CELL FORMATION IN A PACHYPSYLLA GALL ON CELTIS

Dundon , Thomas R. (Saint Louis U., Saint Louis, Mo.) Multinucleate giant cell formation in a Pachypsylla gall on Celtis . Amer. Jour. Bot. 49(7): 800–805. Illus. 1962.—Cytological antecedents of the multinucleate giant cell in gall tissue of Pachypsylla mamma on leaves of hackberry, Celtis occidentalis, have been presented. The nymph's stylet punctured the epidermis and terminated in a single mesophyll cell where it remained fixed until a multinucleate giant cell formed there. An intracellular cytoplasmic reaction occurred at the tip of the stylet which was attributable either to the secretory or the sucking activity of the nymph. The walls of cells surrounding the tip of the stylet gradually became less distinct as demonstrated by a decreasing affinity for cellulose stain. Later, cellulolytic effects were easily visible as large breaches formed in the walls of cells grouped around the stylet. The cellulolytic process spread centrifugally from the tip of the stylet until complete dissolution of all but the outermost walls of 6–8 cells was accomplished, leaving a typically shaped multinucleate giant cell. In one instance, nuclei from adjacent cells were observed partially drawn through apertures in the cell walls into the protoplast of an incompletely formed giant cell containing the stylet. This nuclear movement was attributed to a centripetal flow of plant juice caused by the sucking activities of the nymph. These findings do not support an earlier theory that the multinucleate giant cell was a product of plant growth, namely, enlargement of a single mesophyll cell and multiple karyokinesis or amitosis.     

Black grain mycetoma: The ultrastructure of Madurella mycetomi

Madurella mycetomi, the fungus pathogen of black grain mycetoma, shows an elaborate development of mesosomes as its most striking ultrastructural feature. These occur in addition to mitochondria and endoplasmic reticulum. Condensations of hyphal cytoplasm and a recurring intrahyphal growth of new hyphal cells are features of the pigment-producing and pathogenic phases of the organism. The abundant pigment which histochemically resembled melanin was not traceable to any ultrastructural granule, nor was it built from a tyrosine precursor. The ultrastructural changes occurring in collagen through a sclerotizing action by the fungus are briefly noted.     

Effects of distant transplantation of the embryoniclocus coeruleus on the learning process and memory in rats

We studied the effects of distant transplantation (in the neck region, subcutaneously) of the embryoniclocus coeruleus tissue on the indices of the learning process and memory in recipient rats. The patterns of learning for a conditioned emotional avoidance reaction (CEAR) allowed us to classify experimental animals into two groups, with successful and hampered formation of the CEAR sterotype, respectively. In the first-group rats, after formation of this stereotype we electrolytically injured the frontal brain cortex, which resulted in some worsening of the CEAR reproduction and quality of differentiation. Distant transplantation of thelocus coeruleus tissue provided effective recovery of the CEAR reproduction in the first-group animals, while rather fast and successful formation of the CEAR stereotype became possible in the second group of rats. It is concluded that the transplantedlocus coeruleus tissue preserves its viability, undergoes differentiation, and exerts a stimulating influence on the learning process and memory formation (probably, due to activation of noradrenergic links in the brain systems).     

Effect of carbon source on conidiogenesis in fonsecaea dermatitidis,agent of chromomycosis

Hormiscium dermatitidis Kano is a well known etiological agent of cutaneous and generalized chromomycosis. However, the generic designation of this fungus has long been a much debated question. The results of the present study of the type culture ATCC 28869 indicate that the fungus is polymorphic, producing a Phialophora state in media containing glucose or maltose and a Cladosporium state in media containing galactose or melibiose. Morphologically and developmentally this chromomycotic agent is closely related to Fonsecaea pedrosoi (Brumpt) Negroni and should be classified as Fonsecaea dermatitidis (Kano) Carrión.     

<Emphasis Type="Italic">Trichophyton erinacei</Emphasis> Infection from a Hedgehog: A Case Report from Taiwan

Trichophyton erinacei is a fungus affecting hedgehogs. As these animals have become popular as exotic pets, human infections with this organism have been documented in many countries. In Taiwan, a 36-year-old woman developed tinea lesions at multiple sites after carrying a sick hedgehog. The animal subsequently lost its quills and died. On culture of the patient’s skin scrapings, the pathogen was identified mycologically as Trichophyton erinacei, which was confirmed by sequencing of the internal transcribed spacers of the fungal nuclear ribosomal DNA. The same fungus was isolated from the sawdust bed previously used by the diseased hedgehog. A careful contact history is important for identifying this emerging zoonosis.     

Cell bathing medium as a target for non thermal effect of millimeter waves

Non thermal (NT) effect of direct radiation 4 Hz-modulated 90–160 GHz of Millimeter Waves (MMW) and preliminary MMW-treated physiological solution (PS) influence were studied on snail isolated neuron, rat's brain tissue hydration and skin penetration. It was shown that the 4 Hz-modulated low intensity 90–160 GHz MMW direct radiation and MMW-treated PS leads to on single neuron shrinkage, skin and brain tissue dehydration. On the basis of obtained data it was suggested that the cell bathing aqua medium serve as a target through which the NT effect of MMW on cell hydration is realized. The MMW-induced brain tissue dehydration can considering as consequence of MMW-induced skin water structural changes leading to unknown messenger formation able to modulate the brain cell hydration. The extrasensitivity of cell hydration to low intensity of MMW radiation allow to recommend cell hydration as a cellular marker for estimation of the NT biological effect of MMW on cells and organisms.     

Subclinical Dissemination of Coccidioidomycosis in a Liver Transplant Recipient

Coccidioidomycosis is common in the southwestern United States, northern Mexico, and areas of South America. Coccidioides immitis and Coccidioides posadasii form arthroconidia that, if inhaled, can cause respiratory infection. Rarely, the organism disseminates throughout the body, causing disease in bones, lymph nodes, skin, joints, and brain in most severe cases. Certain populations are at higher risk for dissemination, including persons with compromised cellular immunity. This group includes patients with human immunodeficiency virus, patients undergoing immunosuppression for rheumatologic disorders, and patients receiving antirejection therapy after organ transplant. For patients undergoing a solid organ transplant in endemic areas, screening for past or present coccidioidal disease is completed pretransplantation. Those with known disease are given triazole therapy to prevent reactivation of disease posttransplantation. Usually, transplantation is postponed if the disease is active. We present a patient with known, active coccidioidomycosis who underwent successful liver transplant and later had subclinical posttransplantation peritoneal dissemination.     

A dorsiventral mycorrhizal root in the achlorophyllous<Emphasis Type="Italic"> Sciaphila polygyna</Emphasis> (Triuridaceae)

The star-like root system of the achlorophyllous Sciaphila polygyna (Triuridaceae) consists of roots up to 1.4 mm thick and 1 cm long seemingly radiating from a single origin. Internally, the roots show a bilateral symmetry when viewed in cross-section: the third root cell layer contains rather loose coils of the aseptate mycorrhizal fungus from the dorsal to the lateral sides, in contrast to the extremely dense coils of thin hyphae in its ventral part. Additionally, the hyphae develop vesicle-like swellings mainly in the central part of the dorsal side as well as the lateral parts of the third layer. The fourth root layer is anatomically heteromorphic, having exceptionally large cells, reaching up to 320×130 m in size (giant cells), in the lower lateral parts. The root-colonizing hyphae only degenerate in the fourth layer, most readily in the giant cells, where they may swell to 24 m in diameter, collapse and end as amorphous clumps. Hyphae in the third layer keep their definite structure. The structures are interpreted to be the result of a dynamic reaction of the root to the actual fungal penetration points in order to maximize the benefit from the subsequent colonization by compartmentation of the root tissue. The function of the third layer is to host the fungus and keep it alive within its cells, while mainly the giant cells serve for its digestion. Many indications suggest an arbuscular mycorrhiza for this association. Similarities and differences to other myco-heterotrophic species are discussed.     

Cell bathing medium as a target for non thermal effect of millimeter waves

Non thermal (NT) effect of direct radiation 4?Hz-modulated 90-160?GHz of Millimeter Waves (MMW) and preliminary MMW-treated physiological solution (PS) influence were studied on snail isolated neuron, rat's brain tissue hydration and skin penetration. It was shown that the 4?Hz-modulated low intensity 90-160?GHz MMW direct radiation and MMW-treated PS leads to on single neuron shrinkage, skin and brain tissue dehydration. On the basis of obtained data it was suggested that the cell bathing aqua medium serve as a target through which the NT effect of MMW on cell hydration is realized. The MMW-induced brain tissue dehydration can considering as consequence of MMW-induced skin water structural changes leading to unknown messenger formation able to modulate the brain cell hydration. The extrasensitivity of cell hydration to low intensity of MMW radiation allow to recommend cell hydration as a cellular marker for estimation of the NT biological effect of MMW on cells and organisms.     

The Skin-Reactive Antigens of Mycoplasma pneumoniae

Guinea pigs experimentally infected with Mycoplasma pneumoniae or immunized with the organism in combination with Freund's complete adjuvant developed a delayed hypersensitive skin reaction following on intradermal injection of the M. pneumoniae antigen. The amount of protein necessary to produce the delayed skin reaction was as low as 0.01 μg. When the sonicated whole cells were extracted with aqueous acetone, the delayed skin reactivity was found mostly in the acetone insoluble (lipid-depleted) fraction. On the other hand, the lipid fraction which was isolated by a chloroform–methanol extraction of the acetone-soluble fraction and had a high titer of complement-fixing activity, exhibited little delayed skin reactivity. The lipid-depleted antigens as the whole cell antigens produced delayed skin reactivities in human patients.     

Freezing avoidance in Andean giant rosette plants

Abstract Frost avoidance mechanisms were studied in Espeletia spicata and Espeletia timotensis, two Andean giant rosette species. The daily courses of soil, air and tissue temperatures were measured at a site at circa 4000 m. Only the leaves were exposed to subzero temperatures; the apical bud and stem pith tissues were insulated by surrounding tissues. The leaf tissues avoided freezing by supercooling rather than by undergoing active osmotic changes. The temperatures at which ice formed in the tissues (the supercooling points) coincided with injury temperatures indicating that Espeletia tissue does not tolerate any kind of ice formation. For insulated tissue (apical bud, stem pith, roots) the supercooling point was around - 5°C coinciding with the injury temperature. Supercooling points of about –13 to - 16°C were observed for leaves. These results contrast with those reported for Afroalpine giant rosettes which tolerate extracellular freezing. The significance of different adaptive responses of giant rosettes to similar cold tropical environments is discussed.     

Expanding fungal pathogenesis: Cryptococcus breaks out of the opportunistic box

Cryptococcus neoformans is generally considered to be an opportunistic fungal pathogen because of its tendency to infect immunocompromised individuals, particularly those infected with HIV. However, this view has been challenged by the recent discovery of specialized interactions between the fungus and its mammalian hosts, and by the emergence of the related species Cryptococcus gattii as a primary pathogen of immunocompetent populations. In this Review, we highlight features of cryptococcal pathogens that reveal their adaptation to the mammalian environment. These features include not only remarkably sophisticated interactions with phagocytic cells to promote intracellular survival, dissemination to the central nervous system and escape, but also surprising morphological and genomic adaptations such as the formation of polyploid giant cells in the lung.     

Morphologic aspects in primary cryptococcosis of the skin

Two cases of cryptococcus infection of the skin were presented. Both — of the mammary and of the lower lip region — were admitted as probable cancers. The right diagnosis has been proved by biopsy, Alcian-Blue stain and fungus culture. The morphologic investigation showed the following characteristic features: a granuloma with dispersed proliferation of foam, epithelioid and giant cells, and with suppuration. In the cells ‘empty holes’ with sharp borders and some minute unstained particles are present, that in Alcian-Blue stain give a positive reaction.