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Biomedical subjects

R L Gregory

Publications and source records attributed to R L Gregory.

At least 73 records · Page 4Linked to original sources
PubMed1991

Effect of immune bovine milk on Streptococcus mutans in human dental plaque.

The use of a mouthrinse of bovine milk containing antibodies to Streptococcus mutans resulted in an initial reduction in the numbers of recoverable Strep. mutans in a group of 9 individuals. Ten volunteers who used control bovine milk that contained no antibody activity to Strep. mutans had variable levels of plaque Strep. mutans. In addition, after culture on Mitis Salivarius and Gold's agar, the plaque Strep. mutans from subjects who used the immune bovine milk rinse formed smaller colonies than those from pre-treatment plaque and from all plaque samples of subjects who used the control rinse.

Adult↗
PubMed1991

Virtually real.

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Afterimage↗
PubMed1990

At first blush.

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Arousal↗
PubMed1990

Function of anti-Streptococcus mutans antibodies: inhibition of virulence factors and enzyme neutralization.

The levels of parotid salivary IgA and serum IgG antibodies from dental caries-resistant (CR) and caries-susceptible (CS) individuals to Streptococcus mutans antigens were determined. In general, the levels of salivary IgA and serum IgG antibodies to S. mutans antigens were significantly higher in CR subjects than in CS individuals. There were significantly higher levels of IgA2, but not IgA1, salivary antibodies to S. mutans whole cells in CR subjects than in CS individuals. These results led us to investigate the functional effects parotid saliva and sera containing these antibodies had on several factors associated with S. mutans virulence. Parotid saliva and sera from CR subjects significantly inhibited S. mutans growth, adherence, acid production, glucosyltransferase and glucose-phosphotransferase activities to a greater extent than saliva and sera from CS individuals. The data suggest that neutralization of S. mutans enzymes and inhibition of S. mutans virulence factors by saliva and serum may be responsible for the lower numbers of carious lesions in CR subjects.

Adolescent↗
PubMed1990

Effects of smokeless tobacco on the ability of secretory component to bind to the IgA/J chain complex.

Previously, we reported that smokeless tobacco users have significantly higher levels of immunoglobulin A and J chain in whole saliva than non-tobacco users. Because there was no difference in levels of secretory component between the two groups, the proportion of secretory component/immunoglobulin A was significantly lower in users than non-users. There was no significant difference in antibody function. In the present study, we examined immunoglobulin A from whole saliva of users and non-users to determine the effect of smokeless tobacco on the ability of secretory component to bind to immunoglobulin A containing J chain. Whole saliva was passed over an affinity chromatography filter unit coupled with anti-alpha heavy chain-specific antibody followed by passage over a molecular sieve high-performance liquid chromatography column. Peaks were collected and examined for immunoglobulin A, J chain and secretory component by enzyme-linked immunosorbent assay. Saliva from users had three significantly larger peaks (3-4 fold) at 280 nm than non-users, confirming the presence of a higher concentration of immunoglobulin A in users. The secretory component/J chain and secretory component/immunoglobulin A ratios for the largest peak were significantly less in users. This indicates that smokeless tobacco has an effect on the ability of secretory component to bind to immunoglobulin A without a loss in antibody function. This may occur either prior to immunoglobulin A/J chain binding to secretory component receptors on secretory epithelial cells or internal to the epithelial cells. These studies provide further evidence for the role of secretory component in mucosal immunity.

Adolescent↗
PubMed1990

Immunodominant antigens of Streptococcus mutans in dental caries-resistant subjects.

Previously, we reported that dental caries-resistant subjects, who have significantly fewer Streptococcus mutans in whole saliva than caries-susceptible patients, have significantly higher levels of naturally occurring binding and neutralizing parotid salivary immunoglobulin A and serum immunoglobulin G antibodies to native S. mutans antigens than caries-susceptible patients. Recent animal studies indicated that the immunogenicity of swallowed S. mutans may be altered by either saliva-coating or stomach acid-denaturation. These results suggest a difference not only in the quantity of antibody to S. mutans, but also in the antigenic epitopes that caries-resistant subjects synthesize antibody to as compared with caries-susceptible patients. In the present report, sodium dodecyl sulfate-polyacrylamide gel electrophoresis/immunoblotting studies indicate that caries-resistant subjects produce salivary immunoglobulin A and serum immunoglobulin G antibodies to several different (molecular weight: 94, 80, 40, and 35 kilodaltons) as well as several similar (molecular weight: 67, 55, and 30 kilodaltons) S. mutans epitopes as compared to caries-susceptible patients. This provides additional confirmation for our previous binding and functional antibody studies, indicating that caries-resistant subjects synthesize antibodies of different specificities than caries-susceptible patients. This study supports the concept of immune regulation of dental caries by naturally occurring antibodies induced by swallowing S. mutans antigens in saliva.

Antibodies, Bacterial↗
PubMed1989

Estimation of immunoglobulin protease activity by quantitative rocket immunoelectrophoresis.

Previous methods for estimating immunoglobulin protease activity have involved the use of enzyme-linked immunosorbent assays (ELISA) or sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography or Western blotting techniques. An alternative method has been developed to estimate proteolytic activity on human IgA1 and IgG using quantitative rocket immunoelectrophoresis. The method uses agarose containing anti-human IgA or anti-human IgG heavy chain-specific reagent to which protease-digested human immunoglobulin samples are applied to wells and electrophoresed overnight. Because proteolytic activity of immunoglobulins results in many smaller fragments, the optimal antigen-antibody ratio for precipitation changes and migration in an electric field results in a larger rocket. Consequently, the area of the rocket will be larger in a protease-treated immunoglobulin sample than a saline-treated immunoglobulin control. These increased rocket areas are correlated with our ELISA protease results (r greater than or equal to 0.90), as well as with our immunoblot results. The method is sensitive to increasing exposure to proteolysis, as well as to increasing amounts of protease. This technique can be used to quickly estimate the ability of a sample to cleave immunoglobulins.

Bacteria↗