Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In biopsies obtained from syphilitic chancres of varying ages in 10 patients, a total of 766 ultrathin sections of Treponema pallidum were studied by electron microscopy. The course and number of axial filaments observed reveal that one bunch of 3-4 filaments without interruption entwine the whole cytoplasmic body. In 9.2% of the sections a trilaminar or a fragmentary trilaminar periplastic membrane was observed outside the cytoplasmic membrane and the axial filaments. The occurrence of the periplastic membrane decreased with advancing ages of the chancres. A protective function of the membrane is discussed. A peritreponemal fine reticular halo demonstrable in most fragments is supposed to be due to fixation induced shrinkage of treponemal hyaluronidase-influenced semifluid glycosaminoglycans. Peritreponemal reticular halos were also observed in collagen tissue. A destructive effect of the treponemes on collagen fibres could explain how the organisms penetrate through the collagen rich meninges into the central nervous system. A surface associated narrow border of electron dense amorphous substance, probably originating from the host organism, yields to tangentially cut treponemes a spiny caterpillar-like appearance.
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PMID:Treponema pallidum in human chancre tissue: an electron microscopic survey. 243 81

The present work is based on the direct relationship, revealed in our investigations, between the hyaluronidase activity of meningococcal strains and their capacity to penetrate into the blood and the liquor. The use of the intranasal route (i.e. the natural route) for infecting previously untreated mice with meningococci in the presence of hyaluronidase made it possible to follow the generalized form of meningococcal infection in all its stages from the period of incubation and microbial invasion to bacteriemia, accompanied by the penetration of the infective agent into the meninges, and toxinemia. This route of infection ensured the penetration of the infective agent, but the natural specific resistance of mice to meningococci prevented their multiplication with the subsequent liberation of a sufficient amount of endotoxin killing the animals. To overcome natural immunity and increase toxicity, actinomycin D was injected intraperitoneally in a volume of 0.5 ml (5 gamma) simultaneously with the administration of the microbial culture and hyaluronidase, thus ensuring 40-60% mortality among the animals. Our model of the generalized form of meningococcal infection can be used in the study of pathogenesis and for the development of the methods of treatment and microbiological diagnosis.
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PMID:[Natural reproduction of all stages of a generalized meningococcal infection in mice]. 643 17

Effective laboratory animal models of bacterial meningitis are needed to unravel the pathophysiology of this disease. Previous models have failed to simulate human meningitis by using a directly intracerebral route of infection. Hyaluronidase is a virulence factor of Streptococcus pneumoniae. In this study, a novel model of murine meningitis is described. Intranasal administration of S. pneumoniae with hyaluronidase induced meningitis in 50% of inoculated mice, as defined by a positive cerebrospinal fluid (CSF) culture and an inflammatory infiltrate in the meninges. None of the mice inoculated without hyaluronidase developed meningitis. Hyaluronidase was found to facilitate pneumococcal invasion of the bloodstream after colonization of the upper respiratory tract. Meningitis was characterized by pleocytosis of CSF and the induction of proinflammatory cytokines and CXC chemokines in brain tissue. These results indicate that this murine model mimics important features of human disease and allow for the use of this model for studying issues related to the pathophysiology and the treatment of pneumococcal meningitis.
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PMID:Experimental pneumococcal meningitis in mice: a model of intranasal infection. 1123 45

To determine the role of endogenous interleukin-18 (IL-18) in pneumococcal meningitis, meningitis was induced in IL-18 gene-deficient (IL-18(-/-)) and wild-type (WT) mice by intranasal inoculation of Streptococcus pneumoniae with hyaluronidase. Induction of meningitis resulted in an upregulation of both pro- and mature IL-18 in brain tissue in WT mice. IL-18(-/-) and WT mice were equally susceptible to develop meningitis after intranasal infection, yet IL-18(-/-) mice showed a prolonged survival and a suppressed inflammatory response, as reflected by a less profound inflammatory infiltrate around the meninges and lower concentrations of cytokines and chemokines in brain tissue. These findings suggest that endogenous IL-18 contributes to a detrimental inflammatory response during pneumococcal meningitis and that elimination of IL-18 may improve the outcome of this disease.
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PMID:Interleukin-18 gene-deficient mice show enhanced defense and reduced inflammation during pneumococcal meningitis. 1274 50

Tuberculous meningitis is primarily a disease of the meninges of brain and spinal cord along with adjacent brain parenchyma. The characteristic pathological changes are meningeal inflammation, basal exudates, vasculitis and hydrocephalus. Tuberculous meningitis has a strong predilection for basal parts of the brain. Exudates, if dominantly present in the interpeduncular, suprasellar and Sylvian cisterns, result in optochiasmatic arachnoiditis and tuberculoma. Optochiasmatic arachnoiditis and tuberculoma are devastating forms of tuberculous meningitis and often associated with profound vision loss. This clinical entity more frequently affects young adults. In a recent study, on the multivariate logistic regression analysis, female sex, younger age and raised cerebrospinal fluid protein content were identified as predictors for developing optochiasmatic arachnoiditis. Frequently, optochiasmatic tuberculoma and optochiasmatic arachnoiditis develop paradoxically while a patient is being treated with anti-TB drugs. MRI reveals confluent enhancing lesions that are present in the interpeduncular fossa, pontine cistern, and the perimesencephalic and suprasellar cisterns. Management of tuberculous optochiasmatic arachnoiditis and optochiasmatic arachnoiditis tuberculoma has been variable. Treatment of optochiasmatic arachnoiditis continues to be a challenge and the response is generally unsatisfactory. In isolated case reports and in small series, corticosteroids, methyl prednisolone, thalidomide and hyaluronidase have been used with variable success. The benefit from neurosurgery is controversial and deterioration may follow the initial temporary improvement. Management of paradoxical optochiasmatic arachnoiditis is also controversial. Some patients regain vision following treatment with anti-TB drugs and continued usage of corticosteroids. Neurosurgery may be considered in the patients with either treatment failure or when diagnosis is in doubt. In conclusion, presence of optochiasmatic arachnoiditis or tuberculoma has important therapeutic and prognostic implications for patients of tuberculous meningitis.
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PMID:Tuberculous optochiasmatic arachnoiditis: a devastating form of tuberculous meningitis. 2190 82