Induction of laccase in Basidiomycetes: the laccase-coding messenger.

Formation of the mRNA specific for the inducible forms of laccase was evidenced in Coriolus versicolor, Pleurotus ostreatus and Pholiota mutabilis. The half-life time of these mRNAs in the fungi species studied were, respectively, 30, 37 and 24 min. Molecular weight of the newly synthesized mRNA in Pleurotus ostreatus was about 4.5X10(5), consistently with the size of the inducible laccase protein. The polysome obtained from the ferulic acid-treated mycelium, synthesized in vitro a polypeptide with the electrophoretic mobility similar to that of laccase.     

New form of lignolytically active mycelium generated by immobilization of protoplasts isolated from the white rot fungi Heterobasidion annosum and Polyporus pinsitus

Summary Immobilized mycelia regenerated from immobilized protoplasts isolated from lignin-degrading Basiodiomycetes have been shown to be able to decompose specifically ¹⁴C-labelled dehydropolymers of coniferylalcohol (DHP-lignin) and monomeric lignin-related compounds more intensively than native mycelium, by decarboxylation, demethylation, ring and side chain cleavage. Protoplasts of two white rot fungi were immobilized by entrapment in Na- alginate gel and remained intact after the immobilization procedure. Within the first 3 days of incubation in culture medium, regeneration of hyphal cells occurred. Since hyphal cells regenerated from protoplasts within gel beads were hindered from stretching by the matrix, the microbial immobilized cells differed from native mycelium in terms of their morphology. The time course and extent of lignin degradation by native mycelium and regenerated mycelium of the examined white rot fungi also differed, a sign that there may also be differences between them in terms of the physiology of lignin degradation.     

Epitopes that span the tau molecule are shared with paired helical filaments

Tau protein has been shown to be an integral component of Alzheimer paired helical filaments (PHF). However, the extent to which tau is incorporated into PHF has not been clear because the antibodies used to label PHF generally do not have precisely defined epitopes. Here we define the antigenic sites for five monoclonal antibodies that react with tau and cross-react with SDS-extracted neurofibrillary tangles. The reactive sites were determined by screening a lambda gt11 sublibrary expressing small fragments of the tau sequence. The mapped epitopes were found to span almost the entire length of tau, suggesting that PHF contains tau in its entirety or nearly in its entirety. One antibody was found to cross-react with microtubule-associated protein 2, implying some degree of homology between the two proteins.     

Leptomeningeal carcinomatosis presenting as eosinophilic meningitis

The case of a 67-year-old man with underlying carcinomatous meningitis who presented with meningismus and cerebrospinal fluid (CSF) eosinophilia is reported. CSF eosinophilia can reflect a number of underlying conditions; however, carcinomatous meningitis is not generally considered. In this case, studies for bacterial, fungal and parasitic agents were negative. Cytologic examination of a lumbar puncture specimen revealed malignant epithelial cells in an inflammatory background. When unexplained eosinophilia is found in the CSF, a thorough search for coincident meningeal carcinomatosis should be undertaken.     

Combined immunostaining of neurofilaments, neuron specific enolase, GFAP and S-100. A possible means for assessing the morphological and functional status of the enteric nervous system

Neurofilaments, part of the cytoskeletal network, and neuron specific enolase, a major enzyme in glycolysis, are both present in central and peripheral neurons. Glial fibrillary acidic protein and S-100, on the other hand, are soluble proteins which are found exclusively in the supportive cells of the nervous system, i.e. the glial cells. Examination was made, using immunocytochemistry, of all main areas of the gastrointestinal tract of three mammalian species, rat, pig and man. By applying serial tissue sectioning, it was possible to study the relative occurrences of the two neuronal markers in the same cell bodies and to examine the relationships of the neurons with the glial cells as revealed by the antibodies to glial fibrillary acidic protein and S-100. Both neurofilaments and neuron specific enolase were localised to an extensive system of enteric nerves, with the level of neuron specific enolase-immunoreactivity showing greater variability than that observed using antibodies to neurofilaments. Comparison of the occurrence of neuron specific enolase and neurofilament immunoreactivity in serially sectioned neuronal cell bodies revealed that a minor population stained only with antibodies to neurofilaments. The equivocal or absent neuron specific enolase-immunoreactivity in some perikarya may reflect variations in functional status within the nervous system. Glial fibrillary acidic protein- and S-100-immunoreactivities were confined to glial cells which, in this normal tissue, were always in close association with the neurons.(ABSTRACT TRUNCATED AT 250 WORDS)     

Distinct cleavage patterns of normal and pathologic forms of alpha-synuclein by calpain I in vitro

Parkinson's disease (PD) is characterized by fibrillary neuronal inclusions called Lewy bodies (LBs) consisting largely of alpha-synuclein (alpha-syn), the protein mutated in some patients with familial PD. The mechanisms of alpha-syn fibrillization and LB formation are unknown, but may involve aberrant degradation or turnover. We examined the ability of calpain I to cleave alpha-syn in vitro. Calpain I cleaved wild-type alpha-syn predominantly after amino acid 57 and within the non-amyloid component (NAC) region. In contrast, calpain I cleaved fibrillized alpha-syn primarily in the region of amino acid 120 to generate fragments like those that increase susceptibility to dopamine toxicity and oxidative stress. Further, while calpain I cleaved wild-type alpha-syn after amino acid 57, this did not occur in mutant A53T alpha-syn. This paucity of proteolysis could increase the stability of A53T alpha-syn, suggesting that calpain I might protect cells from forming LBs by specific cleavages of soluble wild-type alpha-syn. However, once alpha-syn has polymerized into fibrils, calpain I may contribute to toxicity of these forms of alpha-syn by cleaving at aberrant sites within the C-terminal region. Elucidating the role of calpain I in the proteolytic processing of alpha-syn in normal and diseased brains may clarify mechanisms of neurodegenerative alpha-synucleinopathies.