PubMed Health⌕ Search

Biomedical subjects

L G Simonson

Publications and source records attributed to L G Simonson.

36 records · Page 2Linked to original sources
PubMed1988

Quantitative relationship of Treponema denticola to severity of periodontal disease.

The Treponema denticola content of plaque was quantitatively estimated for samples taken from periodontitis patients as well as periodontally healthy subjects among two separate human populations. The populations studied included military volunteers and civilians at a university dental clinic. The plaque samples from each population were grouped according to pocket depth measurements at the collection site. A biotin-avidin enzyme-linked immunosorbent assay procedure was developed with a monoclonal antibody specific for a serovariety of T. denticola. T. denticola was present at significantly elevated levels in plaque samples collected from deep-pocket sites of patients with severe periodontitis relative to the healthy controls and a group with moderate disease. The ratio of T. denticola content per milligram of plaque in the deep pocket groups to that of the other two groups was about 2:1 for both populations. This is the first quantitative evidence of a positive relationship between a specific spirochete species and severe periodontitis.

Antibodies, Monoclonal↗
PubMed1988

Diagnostic value of a coagglutination procedure using monoclonal antibodies to Bacteroides gingivalis.

A specific monoclonal antibody against Bacteroides gingivalis was bound to particles coated with protein A and evaluated for use in a coagglutination test. B. gingivalis was the only organism tested which gave a specific positive reaction with the CoA reagent. Subgingival plaque samples were collected from 217 patients diagnosed as having periodontitis. Organisms that gave biochemical reactions which indicated they were B. gingivalis were isolated from eleven of the 217 gingival pockets. These eleven strains were the only organisms which gave a positive reaction using the CoA test.

Adolescent↗
PubMed1986

Production and characterization of monoclonal antibodies to Bacteroides gingivalis.

The rapid detection of Bacteroides gingivalis by immunological methods using monoclonal antibodies could greatly improve the diagnosis and prognosis of severe periodontal disease in adults. In this study, three distinct hybridomas were produced which secrete monoclonal antibodies to soluble and whole-cell antigen preparations of B. gingivalis. The BGII, V F9/2D hybridoma produced a murine antibody that can detect all of the B. gingivalis isolates studied while never cross-reacting with the other oral microbial antigens tested.

Animals↗
PubMed1985

The effects of basic and acidic synthetic polypeptides on the adherence of the oral bacteria, Streptococcus mutans and Streptococcus sanguis, to hydroxyapatite.

Two basic and two acidic synthetic polypeptides that bind strongly to hydroxyapatite at neutral pH were tested to determine their influence on adsorption of two Streptococcus mutans and two Streptococcus sanguis strains to hydroxyapatite. The adsorption of the strains was significantly enhanced or reduced by the basic and acidic agents, respectively. Study of acidic polypeptides provided evidence of competition between the polypeptides and the bacterial cells for hydroxyapatite adsorption sites.

Adsorption↗
PubMed1982

Purification and properties of endo-1, 3-alpha-D-glucanase from Pseudomonas.

An endo-1, 3-alpha-D-glucanase (EC 3.2.1.59) was purified from cell-free culture supernatants of Pseudomonas NRRL-B-12324. The enzyme was purified 8.7-fold to a specific activity of 78.1 U/mg of protein. The enzyme was inducible and had an isoelectric point of 4.6 and a Km of 80.0 mM in terms of anhydroglucose units. Two distinct peaks of activity were resolved by gel filtration with two different supporting media, whereas only one peak of activity was resolved by isoelectricfocusing. The two peaks were assigned molecular weight values of 67,400 and 279,000. The pH optimum was near 5.0 and the temperature optimum was near 56 degrees C. Additional gel filtration data indicated that the enzyme functions as an endohydrolase.

Chromatography, Gel↗
PubMed1979

T and B-RFC inhibiting factor in plasma from patients with active Hodgkin's disease.

We report the presence of a rosette inhibiting factor (RIF) in the plasma of patients with active Hodgkin's disease. This factor suppresses the rosette forming ability of autologous Active T, Total T, and B lymphocytes with sheep red blood cells, and tends to disappear when clinical remission is achieved. To a lesser extent, the RIF also lowers the Active T, Total T and B-RFC percentages of lymphocytes obtained from normal donors. Although carcinoma and non-Hodgkin's lymphoma patients, as a group, did not exhibit rosette inhibitive properties, certain individuals with these diagnoses did show isolated RIF activity. The RIF could be adsorbed out of plasma using peripheral blood lymphocytes (PBL) from normal controls and appears to be a large heat stable molecule which does not affect PBL viability.

Adult↗
PubMed1979

Effects of dextranases on attachment of Streptococcus mutans to hydroxyapatite.

A Fusarium dextranase and a Penicillium dextranase were compared for their relative ability to quantitatively reduce the adsorption of (3)H-labeled Steptococcus mutans cells onto hydroxyapatite. Fusarium dextranase-treated hydroxyapatite disks caused a statistically significant decrease in the hydroxyapatite adsorption of both the OMZ 176 and NCTC 10449 strains of S. mutans relative to untreated control disks. The extent of initial bacterial adsorption was not promoted by sucrose-dependent glucan synthesis. Since the Fusarium dextranase has a much greater affinity for hydroxyapatite than the Penicillium dextranase, it could represent an enzyme with improved decay-preventive therapeutic properties. This was concluded because the Fusarium dextranase may interfere with both the initial attachment and later glucan-dependent accumulation of dental plaque microorganisms.

Adhesiveness↗
PubMed1975

Characterization of an extracellular dextranase from Fusarium moniliforme.

An extracellular dextranase (EC 3.2.1.11) was purified approximately 75-fold from cell-free culture filtrates of Fusarium moniliforme. The purified dextranase was of the endo type, and isomaltose was identified as the primary end product of dextran hydrolysis. The molecular weight of the dextranase was determined to be 39,000 by gel permeation chromatography. The enzyme was most active at pH 5.5, and the temperature optimum was near 55 C. Activity was not inhibited by either ethylenediaminetetraacetic acid or iodoacetate. The Km for dextran with an average molecular weight of 10,000 was estimated to be 1.1 X 10(-4) M. The electrophoretic mobility of the dextranase was distinctly different from that of a Penicillium-derived commercial dextranase. The F. moniliforme dextranase was also found to differ from the commercial preparation by its greater relative activity against glucans isolated from Streptococcus mutans.

Cell-Free System↗
PubMedDate not supplied

Investigation of possible solvents for extracellular polysaccharides from Streptococcus mutans and Streptococcus sanguis.

The solubilities of extracellular polysaccharide fractions produced by 14 oral streptococcal strains were compared in water, aqueous lithium and guanidine salt solutions, dimethyl sulfoxide (DMSO), and a 9:1 DMSO-water mixture. The best results for solubilizing the fractions were obtained with the DMSO-water mixture procedure, which used the water and DMSO in sequence. By this method all fo the fractions were solubilized.

Dimethyl Sulfoxide↗