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)

A group A streptococcal strain rich in Fc receptors was selected by an immunoblotting technique and used as the source for isolation of a functionally active Fc receptor. A variety of extraction techniques were compared including (1) heat extraction at neutral, acid or alkaline pH, (2) treatment with the enzymes mutanolysin, hyaluronidase, trypsin, papain or phage lysin, or (3) autoclaving or heating in the presence of sodium dodecyl sulfate. The most homogeneous receptor was recovered following heat extraction and contained two molecular weight forms. The major form had a molecular weight of 56 000 daltons and the minor form had a molecular weight of 38 000 daltons. These two proteins could be isolated without loss of activity by binding to and elution from a column of immobilized human IgG. An antibody prepared against a single form of the affinity purified receptor demonstrated reactivity with both molecular weight forms of the heat extracted receptor. The group A receptor was found to be both antigenically and physicochemically distinct from either the type I receptor found on the majority of Staphylococcus aureus strains or the type III Fc receptors found on the majority of group C streptococcal strains.
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PMID:Isolation and partial characterization of a type II Fc receptor from a group A streptococcus. 352 Feb 93

Advanced human periodontitis is considered to be a B-cell lesion, but the cellular infiltrate contains several cell types, the distribution of which has not been determined. This experiment was designed to characterize and identify the immunocompetent cells on histological sections and in eluates from diseased human gingiva. Immunoglobulin-bearing cells were detected on histological sections by direct immunofluorescence with F(ab')2 antisera monospecific for human immunoglobulin G (IgG), IgA, or IgM. Plasma cells predominated in the central portion of the lamina propria, with the proportions positive for IgG, IgA, and IgM accounting for 65.2 +/- 9.5, 11.2 +/- 1.1, and 1.3 +/- 1.1% of the total infiltrating cells, respectively. T lymphocytes, identified by indirect immunofluorescence with monoclonal antibody (Leu-1) against human T cells, accounted for 29.3 +/- 10.0% of the total infiltrated cells. Most of the T cells were located subjacent to the pocket epithelium, but there were a few in the central lamina propria. Similarly, Fc receptor-bearing cells detected by EA rosetting and macrophages and monocytes detected by nonspecific esterase staining with alpha-naphthylbutyrate esterase were also localized to the region immediately subjacent to the pocket epithelium. Infiltrated cells were harvested from minced gingival tissue after digestion with collagenase, hyaluronidase, and DNase. The eluates contained 35.3 +/- 6.0% T lymphocytes, 30.0 +/- 14.9% Fc receptor-bearing cells, and 12.9 +/- 4.4% monocytes and macrophages. Whereas T gamma cells comprised 13.3 +/- 1.4% of peripheral blood T cells, they accounted for only 6.0 +/- 2.0% of the eluate T cells. In contrast, T mu cells accounted for 44.7 +/- 4.9% of the T cells in the eluates and 51.6 +/- 4.4% in the peripheral blood. The decreased proportion of T gamma cells in the gingiva may indicate a form of abnormal immune regulation concerned with T suppression of B-cell proliferation.
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PMID:Identification and distribution of immunocompetent cells in inflamed gingiva of human chronic periodontitis. 660 70

Absorption of monoclonal antibodies (mAbs) after s.c. injection results from the interplay among several kinetic processes. The aims of this study were to investigate the absorption mechanisms of rituximab in rats by using slow s.c. infusion and coadministration with nonspecific IgG or hyaluronidase, and to evaluate the predictive performance of the pharmacokinetic model previously developed to describe the nonlinear absorption behavior of mAbs. Rituximab serum concentrations were measured after s.c. coadministration with nonspecific IgG and hyaluronidase to rats. Several dose levels and different injection sites were evaluated. For the back site, 6.5- and 2.6-fold decreases in the area under the concentration-time curve were obtained after coadministration with IgG for 1 and 10 mg/kg doses compared with administration of rituximab alone. For the abdomen, only a minor reduction in concentrations was observed. Hyaluronidase increased the rate of s.c. absorption and the bioavailability (1.9- and 1.6-fold for the back and the abdomen injection of 10 mg/kg). Our previously established pharmacokinetic model provided excellent predictions of the effect of nonspecific IgG on rituximab absorption. In conclusion, the magnitude of the effect of absorption modifiers is dependent on the site of injection and the dose level of rituximab. Pharmacokinetic profiles further support the hypothesis that neonatal Fc receptor-mediated transport is a major determinant of s.c. absorption of mAbs.
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PMID:Mechanisms of subcutaneous absorption of rituximab in rats. 2312 12