Ageing-associated thiol loss in Bacterionema matruchotii.

This work tested the concept that thiol loss, proposed as a cause of animal ageing, occurs in ageing cultures of Bacterionema matruchotii. Paired comparisons were made between thiol levels of exponential- and stationary-phase cultures. Values for stationary phase were consistently and significantly (P less than 0.01) lower. If bacterial thiol loss is an effect of culture ageing rather than a cause, the same possibility must be considered with respect to tissue. However, if thiol loss is a cause of ageing, the role for thiol loss in tissue ageing would be strengthened. A major problem in the biology of ageing is to distinguish between cause and consequence. Bacterial culture could provide a relatively simple model for such inquiry.

Proteolipid and human aorta calcification, in vitro.

The objective of this study was to determine whether in vitro calcification of human aorta is proteolipid dependent. Homogenates were prepared from tissue with no gross pathologic manifestations. Samples were examined for calcifiability in a metastable calcium phosphate solution before and after lipid extraction. Fractions of the extracted lipid were similarly examined. The tissue calcified before but not after lipid extraction. Calcifiability was restricted to the proteolipid portion of the lipid extract. Under the conditions employed, therefore, proteolipid is required for calcification of human aorta, in vitro.

Proteolipid and collagen calcification, in vitro.

Initiation of in vitro calcification with insoluble type I collagen appears to be a function of tightly-bound proteolipid. The collagen preparation calcified during incubation in a metastable calcium phosphate solution before but not after lipid extraction. Calcifiability of the extracted lipid, similarly incubated, was restricted to the proteolipid fraction.

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.

Immunoglobulin class of agglutinins to oral microorganisms in post-irradiation cancer patients.

Fractionation of serum samples from head and neck cancer patients and their assay for agglutination activity toward oral microorganisms showed that the activity was derived from IgG, 7S IgA, 10S (dimeric) IgA, and IgM, with considerable activity in the 10S IgA region. These findings probably account for the lack of a significant relationship among levels of individual serum immunoglobulins, agglutination titers, and caries activity presented in an earlier study. Conversely, most of the agglutinating activity in fractionated saliva was attributed to 11S IgA, presumably secretory IgA, with some activity from a 19S substance and, in the caries-active patients, from a higher molecular weight factor. These data correspond to positive correlations between saliva IgA levels, agglutination titers, and absence of caries in these patients.

Relationship between saliva and serum agglutination titers and post-irradiation caries activity in cancer patients.

Agglutination titers in 444 saliva and 481 serum samples from 36 head and neck cancer patients and 16 control subjects were determined against formalinized cellular antigens of Streptococcus and Lactobacillus species. Saliva agglutination titers were significantly higher in cancer patients before radiotherapy than in control subjects. Changes in specific saliva agglutination titers to oral isolates following radiotherapy reflected changes in saliva IgA and post-irradiation caries activity. Patients with no post-irradiation caries activity had significantly higher saliva agglutination titers to S. mutans, S. sanguis, and L. fermenti, lower plaque S. mutans counts, and higher saliva IgA levels than those with post-irradiation caries activity. Serum agglutination titers were unrelated to either serum immunoglobulin levels, microbial counts, or caries activity.

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.

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.

Phospholipids of a bone matrix calcification nucleator.

Phospholipids of a bone matrix calcification nucleator are 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.

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.

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(formula see text), Cl-, albumin, or IgG concentrations. There were slight decreases in total protein coinciding with moderate saliva flow rate increases immediately 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 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.

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. The nucleating fraction was indentified as a proteolipid.