Phylogenetic relationship of the genus Gilbertella and related genera within the order Mucorales based on 5.8 S ribosomal DNA sequences

The complete ITS (internal transcribed spacer) region coding the ITS1, the ITS2 and the 5.8S rDNA was amplified by polymerase chain reaction from two strains of Gilbertella persicaria, six strains in the Mucoraceae (Mucor piriformis, M. rouxii, M. circinelloides, Rhizomucor miehei, R. pusillus and R. tauricus) and four strains representing three species of the Choanephoraceae (Blakeslea trispora, Choanephora infundibulifera and Poitrasia circinans). Sequences of the amplified DNA fragments were determined and analysed. G. persicaria belongs to the monogeneric family (Gilbertellaceae), however, originally it was described as Choanephora persicaria. The goal of this study was to reveal the phylogenetic relationship among fungi belonging to Gilbertellaceae, Choanephoraceae and Mucoraceae. Our results support that the "intermediate" position of this family is between Choanephoraceae and Mucoraceae.     

An in vitro study of the toxic effects of Stachybotrys chartarum metabolites on lung cells

During a study of indoor fungal colonisation, several isolates of Stachybotrys chartarum were recovered, and the effects of metabolites from four isolates on lung epithelial Type II cells and alveolar macrophages were studied in vitro. All the isolates showed toxic effects on both cell types, and they differed only in the extent of the changes induced. In Type II cells, the number of alkaline phosphatase positive cells was reduced, the pattern of Maclura pomifera agglutinin (MPA) binding was changed, and acid phosphatase activity in alveolar macrophages was diminished. In both cell types, the production of monocyte chemotactic protein-1 (MCP-1) and tumour necrosis factor-alpha (TNF-alpha) was changed, and parameters related to antioxidant status (superoxide dismutase, glutathione peroxidase, glutathione) were decreased.     

Effect of intratracheal fibres exposure on the rat lung

The changes in antioxidant status of rat lung after intratracheal instillation of stone-wool and glass fibres were studied. The animals were exposed to 2 or 8 mg of fibres for 4 or 16 weeks, the bronchoalveolar lavage was performed and the activity of superoxide dismutase, glutathione peroxidase and the total amount of glutathione was estimated both in tissue and in cell free fraction of bronchoalveolar lavage and the ascorbic acid was determined in lung tissue. The results showed the higher burden by stone-wool. Most changes were detected in groups exposed to higher dose of fibres for shorter time period, the most sensitive parameter was superoxide dismutase. The lung tissue was studied also by light microscopy and transmission electron microscopy.     

Extracellular proteases of Trichoderma species. A review

Cellulolytic, xylanolytic, chitinolytic and beta-1,3-glucanolytic enzyme systems of species belonging to the filamentous fungal genus Trichoderma have been investigated in details and are well characterised. The ability of Trichoderma strains to produce extracellular proteases has also been known for a long time, however, the proteolytic enzyme system is relatively unknown in this genus. Fortunately, in the recent years more and more attention is focused on the research in this field. The role of Trichoderma proteases in the biological control of plant pathogenic fungi and nematodes has been demonstrated, and it is also suspected that they may be important for the competitive saprophytic ability of green mould isolates and may represent potential virulence factors of Trichoderma strains as emerging fungal pathogens of clinical importance. The aim of this review is to summarize the information available about the extracellular proteases of Trichoderma. Numerous studies are available about the extracellular proteolytic enzyme profiles of Trichoderma strains and about the effect of abiotic environmental factors on protease activities. A number of protease enzymes have been purified to homogeneity and some protease encoding genes have been cloned and characterized. These results will be reviewed and the role of Trichoderma proteases in biological control as well as their advantages and disadvantages in biotechnology will be discussed.     

Morphological and molecular diversity and abundance of tomentelloid ectomycorrhizae in broad-leaved forests of the Hungarian Plain

The most common representatives of tomentelloid ectomycorrhizae (EM) collected in broad-leaved forests (Populus and Quercus) of the Hungarian Plain during a 4-year project are demonstrated. Eighteen specimens of nine tomentelloid EM morphotypes were investigated. Five of these, introduced here for the first time, were characterized by microscopical–morphological and anatomical methods. Molecular identification was carried out using sequence analysis of the nrDNA ITS region. Altogether, 54 ITS sequences (6 previously published and 12 new sequences from our mycorrhizae and 36 from GenBank derived from fruitbodies) were compared by phylogenetic analyses using neighbor-joining, maximum parsimony and maximum likelihood methods. Identification to species level was successful in the case of six EM morphotypes (Tomentella galzinii, T. subtestacea, T. sublilacina, T. pilosa, T. ferruginea and T. stuposa), and the possible taxonomic position of the remaining three was approached. These results are supported by morphology, as compared with literature data. Relative abundance of the EM morphotypes within the soil samples was estimated. Our results confirm that tomentelloid EM are constant, diverse and abundant members of the EM communities in temperate-continental broad-leaved forests.     

Enzyme-catalysed synthesis of galactosylated 1D- and 1L-chiro-inositol, 1D-pinitol, myo-inositol and selected derivatives using the beta-galactosidase from the thermophile Thermoanaerobacter sp. strain TP6-B1

The products from the enzymatic beta-D-galactopyranosylation of 1D-chiro-inositol, 1D-pinitol, 1D-3-O-allyl-4-O-methyl-chiro-inositol, 1D-3,4-di-O-methyl-chiro-inositol, 1L-chiro-inositol and myo-inositol in combined yields ranging from 46% to 64% have been obtained using the beta-galactosidase isolated from an anaerobic extreme thermophile, Thermoanaerobacter sp. strain TP6-B1 and p-nitrophenyl beta-D-galactopyranoside as the donor. Analysis of the products from these reactions reveals information about the acceptor preferences of the enzyme.     

Occupational epidemiological study of workers in an acrylonitrile using factory with particular attention to cancers and birth defects

An occupational epidemiological study was organised among workers in an acrylonitrile using factory in Hungary. Of the 888 workers, 783 were included in the study and three groups were differentiated: Group A (N = 452) with direct and continuous exposure, Group B (N = 171) with direct but occasional exposure and Group C (N = 160) without direct exposure, as referent. There were two main objectives: to determine the occurrence of cancer in workers and congenital abnormalities in their liveborn infants. The study did not indicate a higher occurrence of cancer among workers: only one lung cancer patient was found, prostate cancer did not occur. Among congenital abnormalities, the group of specified multiple congenital abnormalities showed a higher rate than expected but characteristic defect-pattern was not found among seven multimalformed babies, though five had cardiovascular malformations. In conclusion, our study did not indicate the carcinogenic, mutagenic and teratogenic effect of acrylonitrile among workers using this chemical in the factory.     

Phospholipids can switch the GTPase substrate preference of a GTPase-activating protein

The major cellular inhibitors of the small GTPases of the Ras superfamily are the GTPase-activating proteins (GAPs), which stimulate the intrinsic GTP hydrolyzing activity of GTPases, thereby inactivating them. The catalytic activity of several GAPs is reportedly inhibited or stimulated by various phospholipids and fatty acids in vitro, indicating a likely physiological role for lipids in regulating small GTPases. We find that the p190 RhoGAP, a potent GAP for the Rho and Rac GTPases, is similarly sensitive to phospholipids. Interestingly, however, several of the tested phospholipids were found to effectively inhibit the RhoGAP activity of p190 but stimulate its RacGAP activity. Thus, phospholipids have the ability to "switch" the GTPase substrate preference of a GAP, thereby providing a novel regulatory mechanism for the small GTPases.     

Role of vascular adrenergic mechanisms in the haemodynamic and PGI2 stimulating effects of angiotensin in diabetic dogs

In aware of the well-known altered vascular responsiveness in the diabetic vasculature, this study aimed to compare the haemodynamic and PGI₂ releasing effects of angiotensin in metabolically healthy (12) and alloxan-(560 umol/kg) diabetic (12) dogs as well as to analyze the role of vascular adrenoceptors in this. In vivo the effect of intracoronarially administered angiotensin (63-125-250-500-1000 pmol/kg/min) on coronary blood flow, mean arterial blood pressure, myocardial contractile force and heart rate was investigated without and with pretreatment of 2 umol/kg phentolamine. In vitro PGI₂ release by isolated coronary rings was induced by 50 nmol/1 angiotensin before and after pretreatment with 5 umol/1 phentolamine and measured by radioimmunoassay. Angiotensin enhances dose-dependently both the mean arterial blood pressure and coronary blood flow, while it provokes a considerable (p < 0.05) increase of PGI₂ formation by isolated coronary arterial rings. These alterations could be prevented by phentolamine administration both in vivo and in vitro, while this drug did not affect the angiotensin-induced enhancement of diabetic coronary blood flow. On the other hand the increase of blood pressure by angiotensin was found to be more (p < 0.05) expressed in diabetes and it could be further potentiated by phentolamine. PGI₂ synthesis by isolated diabetic coronary rings could not be modified either by angiotensin alone or in combination with phentolamine. On the basis of above data, the lack of stimulated vascular PGI₂ formation mediated by alpha-adrenergic mechanisms is supposed to causatively contribute to the diminished sensitivity of diabetic coronary arteries to vasodilation.