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PubMed1988

Temporal association of calcium mobilization, inositol trisphosphate generation, and superoxide anion release by human neutrophils activated by serum opsonized and nonopsonized particulate stimuli.

We have investigated the involvement of phospholipase C mediated polyphosphoinositide turnover in activation of polymorphonuclear leukocytes by particulate stimuli. Results showed that stimulation of leukocytes with serum opsonized zymosan (ingestible particle), serum opsonized Candida albicans hyphae (noningestible particle), or nonopsonized hyphae was followed by a transient rise in cellular inositol phosphates as has been described for neutrophil activation via the formyl peptide receptor. The kinetics of inositol trisphosphate generation paralleled both the time course of changes in cytosolic calcium concentration and the onset of superoxide anion generation, suggesting that these may be related events.

Calcium↗
PubMed1993

Quantitative measurement of lymphocyte mediated growth inhibition of Candida albicans.

A rapid and reproducible assay has been developed to measure the capacity of lymphocytes to inhibit the growth of Candida albicans. Fungal growth inhibition was assessed optimally as the incorporation of [3H]uridine into preformed hyphae, following interaction of the hyphae with effector lymphocytes. The assay was sensitive to the detection of fungal growth inhibition by lymphocytes at low effector to target ratios and results correlated well with other methods for measurement of anti-C. albicans growth inhibition in vitro. Although the assay was developed for the measurement of lymphocyte mediated anti-fungal activity, other mammalian cell populations can be assayed for growth inhibition of C. albicans as well. The described assay utilizes the enzyme lyticase to reduce the surface binding of C. albicans. The use of this enzyme permits the efficient harvest of large numbers of experimental samples with a multiple automated sample harvester.

Animals↗
PubMed1991

In vivo fungal presence and growth on two resilient denture liners.

To determine whether two intraoral-setting resilient denture liners supported the in vivo presence or growth of oral commensal fungi, the liners were randomly placed in the mandibular complete dentures of 14 patients. Cytologic smears were made from the liner surfaces at 1 hour and 1, 2, 7, 14 and 30 days after intraoral placement. Yeast forms were observed in six patient trials of material A and in two trials of material B. Hyphae were observed in only one patient trial of material A and in two trials of material B. When yeast forms and hyphae findings were combined and were considered as indicative of fungal presence or growth, the prevalence up to 30 days was seven for material A and four for material B. Statistical analysis revealed no significant difference in the prevalence of fungal presence or growth between the two resilient denture liners tested.

Acrylic Resins↗
PubMed1982

The histopathological features of pale grain eumycetoma.

Histological findings in 24 cases of pale grain eumycetoma have been compared. The inflammatory response and morphology of grains caused by different organisms are very similar. However the histological appearances of Neotestudina rosatii infections, although reminiscent of dermatophyte mycetomas, are distinctive. The characteristic features include the presence of cement and the short swollen hyphal segments. Petriellidium boydii grains are more likely to contain numerous vesicles or swollen hyphae and be surrounded by a prominent eosinophilic fringe. In contrast, Fusarium and Acremonium grains usually have a minimal fringe and contain a dense mass of intermeshing hyphae. However the features separating P. boydii and Fusarium/Acremonium grains are not invariable and can only be used as an approximate guide to the correct identity of the organism.

Eosinophils↗
PubMed1991

Ultrastructural demonstration of specific IgG and IgE antibodies binding to Aspergillus fumigatus from patients with aspergillosis.

Aspergillus-induced diseases usually demonstrate elevated circulating antibodies belonging to different isotypes. The antigens currently used to detect antibodies are crude culture filtrate and mycelial extracts of A. fumigatus (Af). Most Af-associated diseases result from the inhalation of the spores of the organisms present in the environment. However, it is not known whether specific circulating antibodies directed only against spore or mycelia of Af exist in the sera of patients with Af-induced diseases. With colloidal gold we have investigated thin sections of spores and hyphae of Af for their reactivity with Af-specific IgG and IgE antibodies. The results indicate that both spores and hyphae reacted identically with IgG and IgE antibodies from patients. None of the sera from normal control subjects reacted in this system, although low levels of antibodies were detected in the sera by ELISA. Sera from both patients with allergic bronchopulmonary aspergillosis or aspergilloma reacted with cell envelope antigens, whereas sera from patients with invasive aspergillosis also bound to cell sap. This method therefore demonstrates localization of antigens binding to different isotypes in the sera from different clinical forms of aspergillosis and may be useful in purifying specific antigens for immunodiagnosis.

Antibodies, Anti-Idiotypic↗
PubMed1995

Histopathology of the thymus in Saprolegnia-infected wild brown trout, Salmo trutta L.

A comparative analysis was made of the thymic cytoarchitecture of healthy and Saprolegnia-infected wild brown trout. In Saprolegnia-infected fish, even when the thymus was not invaded by fungal hyphae, the thymic architecture was lost without signs of regionalization. Intercellular oedema, some thymocytes, hypertrophic and degenerated epithelial cells and increased phagocytic activity were also observed. In thymi invaded by the fungus, hyphae occurred isolated or in close apposition to epithelial cells, and the thymic disorganization was more noticeable. Most thymocytes were pyknotic and both epithelial cells and macrophages contained engulfed dead cells. However, no inflammatory response to the fungal invasion was observed. These results confirm the immunodepressed condition of Saprolegnia-infected wild brown trout previously observed in peripheral lymphoid organs. We discuss the secretion of fungal products and/or the high levels of corticosteroids observed in these fish as possible origins of the condition.

Animals↗
PubMed1995

Alterations in superoxide dismutase and catalase in Fusarium oxysporum during starvation-induced differentiation.

Vegetative hyphae of Fusarium oxysporum differentiate into chlamydospore by triggering with carbon-starvation. The current changes in the cellular detoxifying defenses against superoxide and hydrogen peroxide: superoxide dismutase (SOD) and catalase, were examined. Although there was a little change in catalase, a dramatic change in SOD was observed during the differentiation. In vegetative hyphae of F. oxysporum f. sp. raphani, three isozymes of SOD, all of which were not inhibited by hydrogen peroxide and cyanide, were present whereas in chlamydospore an isoenzyme, which was inhibited by hydrogen peroxide but not by cyanide, was present. Thus, as differentiation proceeded, Mn-type SOD disappeared and an Fe-type SOD appeared. The results suggest that the Fe-type SOD is specifically expressed during chlamydospore formation and that active intermediates of oxygen and/or its scavenging enzymes participate in the differentiation of Fusarium oxysporum.

Anaerobiosis↗
PubMedDate not supplied

[Morphogenesis and enzymes of a wild strain and a mutant of Aureobasidium pullulans].

A. pullulans was able to produce several morphological growth forms, including yeast forms (blastospores, swollen cells and chlamydospores) and filamentous forms (true hyphae and pseudomycelium). Morphological types were dependent on the chemical composition of the media. In nutrient broth medium, culture contained 71% blastospores and 29% pseudomycelium; in yeast extract (YE) medium, 59% blastospores and 41% true mycelium were observed, but not pseudomycelium. Mutagenic treatment by nitrosoguanidine, ethyl methyl sulphonate and orange acridine induced morphological mutant strains. In YE medium, the ratio between cellular and filamentous shapes of a mutant strain was inverted (78% hyphae versus 22% blastospores) compared to the wild type. At the same time, DNase and RNase activities were 5 to 10 times higher.

Culture Media↗
PubMed1993

Reactive oxygen species associated with cell differentiation in Neurospora crassa.

The conidiation process of Neurospora crassa is characterized by three morphogenetic events: adhesion of hyphae, development of aerial hyphae, and conidia formation. At the onset of all three events a spontaneous, low-level chemiluminescence was detected, indicating the formation of reactive oxygen species. Hyperoxic conditions increased chemiluminescence and accelerated differentiation. Hypoxic conditions abolished both chemiluminescence and differentiation. Chemiluminescence was enhanced by lucigenin and/or luminol. Butylated hydroxytoluene and antioxidants that do not readily enter the cells, like superoxide dismutase and catalase, did not lower the chemiluminescence nor had they an inhibitory effect on the differentiation process. In contrast, N,N'diphenyl-1,4-phenylene diamide, 1,3-dimethyl-2-thiourea, ammonium pyrrolinedimethyl-dithiocarbamate, and N-acetyl-L-cysteine retarded the onset or abolished both the chemiluminescence and the differentiation process. These results further support our hypothesis (Hansberg, W.; Aguirre, J. J. Theor. Biol. 142:201-221; 1990) that a hyperoxidant state triggers cell differentiation events.

Antioxidants↗
PubMed1996

Different effects of azole-antifungal agents on the regulation of intracellular calcium concentration of Trichophyton rubrum.

Prior studies have indicated that intracellular calcium concentration ([Ca2+]i) is involved in fungal cell growth. However, it has not been known whether antifungal drugs affect signal transduction via calcium in fungal cells. In this context, we examined the effects of antifungal drugs, itraconazole, bifonazole and ketoconazole, on [Ca2+]i in Trichophyton rubrum. Itraconazole (1-5 ng/ml) induced a rapid and transient [Ca2+]i increase, peaking at 15-20s in hyphal cells of T. rubrum, but not in spores. The slow descending phase of the [Ca2+]i increase induced by itraconazole was depleted by chelating extracellular calcium with ethylene glycol bis (beta-aminoethyl ether)-N, N,N',N'-tetraacetic acid (EGTA), suggesting that the increase in [Ca2+]i is biphasic: Ca2+ mobilization from the internal pool and influx from the outside of the cell. At 10 ng/ml and 100 ng/ml, however, itraconazole induced an explosive and sustained calcium increase in both spores and hyphae. At less than 1 ng/ml, no [Ca2+]i increase was caused in both hyphae and spores. On the other hand, although some hyphal cells showed a transient [Ca2+]i increase, most of the cells did not show any changes of [Ca2+]i after the addition of ketoconazole at 10 ng/ml. Both spores and hyphal cells incubated with 100 ng/ml of bifonazole or ketoconazole showed a gradual increase of intracellular calcium concentration until 5 min, when the measurement was ceased. These findings suggest that signal transduction via calcium might be involved in some biological effects of itraconazole on T. rubrum, and that bifonazole and ketoconazole could differently affect [Ca2+]i in T. rubrum from itraconazole. In addition, the determination of [Ca2+]i changes induced by antifungal agents may contribute to clarification of the biological effects on fungal membranes.

Antifungal Agents↗
PubMed2005

Lung infection due to opportunistic fungus, Phialemonium obovatum, in a bone marrow transplant recipient: an emerging infection with fungemia and Crohn disease-like involvement of the gastrointestinal tract.

We report the first case of Phialemonium obovatum fungemia with subsequent caseating granulomatas in the lung and Crohn disease-like involvement of the gastrointestinal tract in a bone marrow transplant recipient. This phaeoid fungus has been rarely described as an opportunistic infection in immunosuppressed patients. The patient was diagnosed with chronic myelogenous leukemia and underwent subsequent peripheral bone marrow transplant. After 6 months, he developed graft-versus-host disease of the skin and liver with fever and severe diarrhea. Fecal bacterial cultures and cytomegalovirus serologies were negative. Computed tomographic scan showed a peripheral pulmonary mass. A lung wedge biopsy of the lesion showed septate branching hyphae (4-5 microm in diameter) with terminal globular structures (10 microm in diameter). The hyphae were similar in width to that of an Aspergillus species but had a more moniliform appearance. Blood cultures grew a pure culture of P. obovatum. He was treated with amphotericin B and itraconazole for 6 months without remission of the diarrhea. Biopsies of the stomach, colon, and rectum showed granulomatous inflammation with marked crypt distortion simulating Crohn disease. In retrospect, the fungus was found to be resistant to both of the aforementioned drugs and susceptible to voriconazole and posaconazole. The gastrointestinal findings raise the possibility of further dissemination of a partially treated Phialemonium infection.

Amphotericin B↗
PubMed2005

Studies on mould growth and biomass production using waste banana peel.

Hyphomycetous (Aspergillus fumigatus) and Phycomycetous (Mucor hiemalis) moulds were cultivated in vitro at room temperature (28 + 20 degrees C) to examined their growth and biomass production on waste banana peel agar (BPA) and broth (BPB) using commercial malt extract agar (MEA) and broth (MEB) as control. The moulds grew comparatively well on banana peel substrates. No significant difference (p > 0.05) in radial growth rates was observed between moulds cultivated on PBA and MEA, although growth rates on MEA were slightly better. Slight variations in sizes of asexual spores and reproductive hyphae were also observed between moulds grown on MEA and BPA. Smaller conidia and sporangiospores, and shorter aerial hyphae (conidiophores and sporangiophores) were noticed in moulds grown on BPA than on MEA. The biomass weight of the test moulds obtained after one month of incubation with BPB were only about 1.8 mg and 1.4 mg less than values recorded for A. fumigatus and M. hiemalis respectively, grown on MEB. The impressive performance of the moulds on banana peel substrate may be attributed to the rich nutrient (particularly the crude protein 7.8% and crude fat 11.6% contents) composition of banana peels. The value of this agricultural waste can therefore be increased by its use not only in the manufacture of mycological medium but also in the production of valuable microfungal biomass which is rich in protein and fatty acids.

Agar↗
PubMedDate not supplied

Cryo-FE-SEM & TEM immuno-techniques reveal new details for understanding white-rot decay of lignocellulose.

High-resolution Cryo-Field Emission Scanning Electron Microscopy (HR-Cryo-FE-SEM) and immuno-cytochemistry were used to reveal novel details on the morphological events and spatial distribution of oxidoreductive enzymes during the degradation of birch wood by the white-rot fungi Phlebia radiata and mutant strain P radiata Cel 26. Cryo-observations of fractured fibres showed degradation across the cell wall by P. radiata (wild) to progress by delamination and removal of concentric orientated aggregates from the secondary S2 cell wall. Decay by P radiata Cel 26 progressed by removal of materials (lignin and hemicelluloses) between the aggregates (primarily cellulose) that remained even after advanced decay. With both decay patterns, extracellular slime materials were present uniting lumina hyphae with the attacked fibre wall. The extracellular slime material had two morphological forms: viz a fibrillar (often tripartite) and a 'gel-form', the former found in discrete bands progressing across the lumen onto the fibre wall. Using TEM immunocytochemistry, laccase, manganese peroxidase (MnP) and diarylpropane enzymes were localized in the periplasmic space of luminal hyphae, in association with the cell membrane, periplasmic vesicles and fungal cell wall. Extracellularly, the three enzymes were found associated with the slime and tripartite membranes and with the birch cell walls at all stages of attack through to middle lamella corner decay. Enzyme distribution was correlated with morphological changes in cell wall structure. The association of extracellular slime with these enzymes and sites of decay strongly suggests a major role for this matrix in fibre cell wall decomposition.

Betula↗
PubMed2005

Regulation of cell-surface genes and biofilm formation by the C. albicans transcription factor Bcr1p.

The impact of many microorganisms on their environment depends upon their ability to form surface bound communities called biofilms [1]. Biofilm formation on implanted medical devices has severe consequences for human health by providing both a portal of entry and a sanctuary for invasive bacterial and fungal pathogens [1 and 2]. Biofilm regulators and adherence molecules are extensively defined for many bacterial pathogens [3, 4, and 5], but not for fungal pathogens such as Candida albicans. Elongated filaments called hyphae are a prominent feature of C. albicans biofilms, and known genes that promote biofilm formation are required for hyphal development [2, 6, 7 and 8]. From a new library of transcription-factor mutants, we identify Bcr1p, a zinc finger protein required for formation of biofilms but not hyphae. Expression analysis shows that Bcr1p activates cell-surface protein and adhesin genes, including several induced during hyphal development. BCR1 expression depends upon the hyphal regulator Tec1p. Thus, BCR1 is a downstream component of the hyphal regulatory network that couples expression of cell-surface genes to hyphal differentiation. Our results indicate that hyphal cells are specialized to present adherence molecules that support biofilm integrity.

Biofilms↗
PubMed2005

Effects of arbuscular mycorrhizal fungi on the root uptake and translocation of radiocaesium.

Because mycorrhizal fungi are intimately associated with plant roots, their importance in radionuclide (RN) recycling and subsequent dispersion into the biosphere has received an increasing interest. Recently, the capacity of arbuscular mycorrhizal fungi to take up and translocate radiocaesium to their host was demonstrated. However, the relative contribution of these processes in comparison to the ones of roots remains unknown. Here, the respective contributions of the hyphae of a Glomus species and the transformed carrot (Daucus carota L.) roots on radiocaesium uptake and translocation were compared and quantified. We observed that radiocaesium uptake by hyphae was significantly lower as compared to that of the roots, while the opposite was noted for radiocaesium translocation/uptake ratio. We also observed that the intraradical fungal structures might induce a local accumulation of radiocaesium and concurrently reduce its translocation within mycorrhizal roots. We believe that intraradical fungal structures might induce the down-regulation of radiocaesium channels involved in the transport processes of radiocaesium towards the xylem.

Biodegradation, Environmental↗
PubMed2006

An unusual appearance of a common pollen type indicates the scene of the crime.

Forensic palynology is a useful source of evidence in cases of violence committed in the open. A young girl was grabbed off the street, threatened and brutally raped. During the investigation the exact place of the rape became an issue. Growing around the scene identified by the victim were shrubs identified as Coprosma, a common New Zealand plant and one that produces abundant, easily wind-dispersed pollen. Abundant Coprosma pollen was found at the scene. The pollen were unusual in that the site was very damp, encouraging fungal growth, and fungal hyphae had penetrated the pores of many of the tricolporate pollen grains. Some grains had fungal spores inside. Coprosma pollen identical in preservational characteristics and morphology to those from the scene and containing fungal hyphae and spores were found in considerable numbers on the victim's clothes. This and rare Coprosma pollen grains and fungal remains recovered from vaginal swabs provided evidence that she had been at the scene where she claimed to have been raped. The diversity of pollen types recovered from the clothing in this case provides further evidence of the usefulness of clothing in picking up and retaining pollen from crime scenes and that obvious staining on clothes is not a pre-requisite for good pollen recovery. It also demonstrates the importance of collecting samples from different parts of the same garment in order to get a full picture of events since different parts of a garment can come into contact with different plants or different parts of the ground in a scuffle. It is also demonstrated that significant evidential material can be collected from the body, in this case from vaginal swabs from the victim. Forensic palynology should be considered in every case of violent assault, especially, but not exclusively, when having occurred in an open area subject to extensive pollen settlement.

Adolescent↗
PubMed2005

Scanning electron microscopy of Fusarium damaged kernels of spring wheat.

Kernels of five wheat cultivars (Triticum aestivum) of different bread-making quality were examined. Grown under field conditions, heads of wheat were inoculated in the flowering stage with an aqueous suspension of Fusarium culmorum conidia. Wheat heads were collected from the control and inoculated plots at full maturity. Control (non-inoculated) kernels without any symptoms of disease and Fusarium damaged kernels (FDK) were examined under scanning electron microscopy (SEM). Examination of the FDK fraction confirmed localisation of Fusarium hyphae on the surface and inside the tissues of kernels. Observations of the endosperm from Fusarium infected kernels revealed presence of fungal hyphae in the endosperm and some characteristic structural changes in many of its regions, such as partial or complete lack of the protein matrix, damage to large and small starch granules caused by fungal amylolytic enzymes, disappearance of small starch granules as the colonisation progressed, complete disappearance of the starchy endosperm under severe infection. Fungal colonisation of the endosperm and structural changes in its area were highly variable traits within the FDK fraction of a given cultivar.

Food Contamination↗
PubMed2004

Human dendritic cells are less potent at killing Candida albicans than both monocytes and macrophages.

Dendritic cells (DC) function as professional phagocytes to kill Candida albicans and subsequently present it to the adaptive immune system. Monocytes, macrophages and DC were generated from five individual donors and their Candida-killing capacity and cytokine release were assessed. Compared to monocytes and macrophages, DC from healthy volunteers were significantly less effective in C. albicans--stimulated cytokine release, killing of C. albicans blastoconidia and damaging of C. albicans hyphae. In conclusion, while important as antigen-presenting cells and initiators of the adaptive immune system, DC are poor in both intracellular killing and damaging of C. albicans hyphae. Effective handling of large numbers of C. albicans is the prime task of the innate immune system consisting of large numbers of neutrophils and monocytes.

Candida albicans↗