Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A novel replicating agent (IFDO) was isolated from ileal fluid. Growth occurred in vitro under aerobic and anaerobic conditions, and was faster at 37 degrees C than at room temperature. The doubling time was 15.8 min. Colonies were dark brown in colour and occurred beneath the surface of agar after conventional surface inoculation. Provisional data indicate that the agent may be a normal intestinal commensal. The agent was remarkably resistant to inactivation by steam at 134 degrees C, formaldehyde and glutaraldehyde; it was relatively resistant to ionising radiation, and it was filterable through membranes with a nominal pore diameter of 10 nm. Such properties, with the exception of growth in cell-free medium, are shared by "unconventional agents" such as those of Creutzfeldt-Jakob disease and scrapie. Further comparison of the properties of the intestinal agent and of slow viruses revealed additional shared characteristics, including resistance to proteinase K and trypsin, and inactivation by guanidine thiocyanate, diethyl pyrocarbonate, phenol and sodium hydroxide. The agent differs from that of scrapie in being inactivated by ethidium bromide, zinc nitrate, EDTA, hydroxylamine in the presence Sarkosyl, and, under certain circumstances, by ribonuclease. Broth cultures of the agent contained particles possessing considerable size heterogeneity. The smaller filterable particles were generally more susceptible to inactivation, did not survive autoclaving, and were inactivated by papaya protease and lipase. It is possible that the replicating agent may be formed by crystallisation from constituents of the medium, and not by a biological process. This does not exclude the postulated relationship to slow viruses.
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PMID:A novel replicating agent isolated from the human intestinal tract having characteristics shared with Creutzfeldt-Jakob and related agents. 265 97

To elucidate possible abnormalities of cerebellar basket cells of Creutzfeldt-Jakob disease (CJD), seven sporadic cases were examined neuropathologically. Recently, parvalbumin-positive, GABAergic cerebral interneurons have been demonstrated to show early, selective loss in CJD, and the phenomenon is postulated as a cause of characteristic neurological symptoms of CJD. In this study, however, we demonstrated that the basket cells, cerebellar counterparts, were resistant even in patients with severe brain atrophy, and their processes showed intense argyrophilia and immunopositivity to phosphorylated neurofilament. They can newly be listed as CJD-resistant neurons similar to those of the hippocampus and brainstem nuclei. The mechanism to escape cell loss is of great interest, and there might be unknown factors modulating susceptibility within parvalbumin-positive neuronal subgroups. Furthermore, one case showed abnormal positivity with hematoxylin, crystal violet and pyronin in the basket cells. The pyronin positivity was reduced after ribonuclease digestion, suggesting that the causative substance was composed of RNA. Ultrastructurally, the fibers contained free ribosomes and amorphous electron-dense deposits. To our knowledge, such a finding has also not been previously reported.
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PMID:Cerebellar basket cells of Creutzfeldt-Jakob disease: immunohistochemical and ultrastructural study. 1084 14