Linda J. Riggan

Interrelations of Oral Microorganisms, Immunoglobulins, and Dental Caries Following Radiotherapy

Of 42 head and neck cancer patients with radiotherapy-induced xerostomia, 36 survived to permit a postirradiation caries evaluation. Twenty-three developed an average of 17.6 caries lesions and 13 had no new lesions within 30 months postirradiation. All caries-inactive patients had been initially assigned to daily self-application of a 1% sodium fluoride gel. The preirradiation caries experience and the oral microbial profile were comparable in both groups. After tumoricidal irradiation, the mean plaque increase of Streptococcus mutans was 25 times greater in the caries-active than in the caries-inactive group. Postirradiation caries was also associated with increased plaque Lactobacillus sp, Candida sp, and Streptococcus sp, and serum IgD and IgG concentrations. Conversely, plaque Staphylococcus sp, Streptococcus salivarius, and Veillonella sp and saliva IgA concentrations were significantly higher in the caries-inactive than in the caries-active group. Both groups demonstrated decreases in plaque Streptococcus sanguis, Neisseria sp, Fusobacterium sp, and Bacteroides sp.

Application of a microbial model to biologic calcification

Abstract The purpose of this research was to examine the role of proteolipid in biologic calcification. Calcification of the oral microorganism, Bacterionema matruchotii , has been shown to be proteolipid dependent. Studies with a B. matruchotii strain with impaired ability to calcify suggest that the amount of membrane surface may be a factor in calcification of that species. Actinomyces naeslundii , a noncalcifying microorganism, contains a proteolipid capable of calcification in vitro . However, this microorganism has a significantly lower percentage of proteolipid than does B. matruchotii . Concentration of ions at the membrane surface is also a factor in microbial calcification. Using techniques adapted from those used in this study of microbiologic calcification a proteolipid was isolated from membrane-bound cartilage matrix vesicles. This proteolipid constituted 1–2 percent of the matrix vesicle organic material.

Proteolipid and Bone Matrix Calcification In Vitro

Proteolipid was demonstrated to contain the nucleator of bone matrix calcification, in vitro. Crude Phospholipid extracted from bone matrix was fractionated by gel filtration. A single, protein-containing fraction induced apatite crystallization in a metastable calcium phosphate solution. The fraction was identified as proteolipid. The result supports the validity of a microbiologic analogue for vertebrate calcification.

Characterization of Bacterionema matruchotii Calcification Nucleator

The nucleator of Bacterionema matruchotii calcification was characterized. Parameters examined were: proteolipid purity and singularity, amino acid composition and relative polarity, phospholipid composition, apoprotein homogeneity, essentiality of the complex for nucleation, and ordered structure. The data fulfill a requirement for comparisons among apatite-nucleating proteolipids.

Calcification by proteolipid from atherosclerotic aorta

Calcified atherosclerotic aorta was examined for proteolipid capable of nucleating apatite, the crystal species of aortic calcification. Appropriate tissue pieces were decalcified with dilute formic acid and extracted with chloroform-methanol. Lipid fractionation yielded proteolipid which, upon incubation in metastable calcium phosphate solution, induced apatite crystallization. The proteolipid was partially characterized as a hydrophobic protein, acidic phospholipid complex. It resembles the nucleator previously demonstrated for bone matrix calcification.

Phospholipids of a Bone Matrix Calcification Nucleator

Phospholipids of a bone matrix calcification nucleator wre identified as mono-and diphosphoinositides and phosphatidyl serine. The nucleator, a protein-phospholipid complex, was dissociated by acidified-solvent porous-glass column chromatography. Analysis was by gas-liquid chromatography.

Proteolipid and Calculus Matrix Calcification In Vitro

The initiator of calculus matrix calcification, in vitro, was isolated. Crude phospholipid, known to contain the factor, was separated into five fractions by column chromatography. A single protein-containing fraction induced apatite formation during incubation in a metastable calcium phosphate solution. The nucleating fraction was identified as a proteolipid.

Characterization of Calculus Matrix Calcification Nucleator

The nucleator of dental calculus matrix calcification, in vitro, was analyzed. Attention focused on proteolipid singularity, amino acid composition and related polarity, and phospholipid components. The data were compared to those of the nucleator of Bacterionema matruchotii calcification.

Clinical and Materials Sciences The Effect of Skylab on the Chemical Composition of Saliva

The levels of specific proteins and electrolytes in stimulated whole saliva were monitored in Skylab crew members before and after each mission. With few exceptions, mission-associated compositional changes in saliva were relatively minimal. There were no changes in Ca++, K+, PO≡ 4, Cl-, albumin, or IgG concentrntions. There were slight decreases in total protein coinciding with moderate saliva flow rate increases iminediately before and after each flight. Other changes included diminutions in Na+ and lysozyme, and elevations in Mg++ and IgA. The IgA increase was the most pronounced mission-associated change observed.

Proteolipid and bovine aorta calcification, in vitro

Proteolipid was examined for nucleation of bovine aorta calcification. Tissue homogenates were tested for in vitro calcifiability before and after lipid extraction followed by similar tests of the extract and its fractions. The tissue calcified before but not after lipid extraction. Of the lipid fractions, only proteolipid calcified. Within the constraints imposed, proteolipid is required for initiation of bovine aorta calcification, in vitro.