Characterization of the human B cell stimulatory factor 1 receptor.

125I-labeled recombinant human B cell stimulatory factor 1 (BSF-1) was used to characterize receptors specific for this lymphokine on in vitro cell lines representing human B, T, and hematopoietic lineages, as well as on adherent cell lines of epithelial and endothelial origin, and on primary human gingival fibroblasts. BSF-1 binding was extremely rapid and saturable at both 4 and 37 degrees C, with a slow dissociation rate. On all human cell types examined, BSF-1 bound to a single class of high-affinity receptor (less than 3,000 receptors per cell) with a Ka of 0.5-1.0 X 10(10)/M. Human BSF-1 also bound to cell lines of simian but not murine origin. Comparison of kinetic characteristics obtained with a yeast-derived hyperglycosylated form of BSF-1 (Mr 60,000) and N-glycanase-treated, sugar-free BSF-1 (Mr 15,000) showed no significant differences. Among a panel of lymphokines and growth hormones, only unlabeled human BSF-1 was able to compete for the binding of 125I-labeled human BSF-1. Affinity crosslinking experiments resulted in the identification on both Raji cells and on primary human gingival fibroblasts of a receptor subunit with an average Mr of 139,000. These studies show that the BSF-1 receptor on human cells has an extremely broad cellular distribution, while further supporting the notion that the ability of BSF-1 to mediate a spectrum of biological activities cannot be accounted for by overt differences in the receptor for this lymphokine on different cell lineages.

Determinants of nicotine intake while chewing nicotine polacrilex gum.

Nicotine polacrilex gum is widely used as substitution therapy during cigarette smoking cessation. We studied circadian blood nicotine concentrations, daily intake of nicotine, and extraction of nicotine from gum in smokers switched experimentally to 2 or 4 mg nicotine gum, 12 pieces per day. Nicotine levels and intake were much lower while chewing gum than during ad libitum smoking. Extraction of nicotine from gum by the chewer was incomplete, averaging 53% and 72% for 2 and 4 mg gum, and variable (more than twofold) among individuals. The systemic dose of nicotine was less than expected based on analysis of nicotine in the chewed gum. Disproportionately higher metabolite-to-nicotine ratios while chewing gum compared with smoking suggested that some nicotine was swallowed and underwent first-pass metabolism. Nicotine and metabolite data were used to estimate buccal vs. gastrointestinal absorption. Relative buccal absorption vs. swallowing of nicotine appears to be an important determinant of systemic nicotine intake.

A routine method for contrasting elastin at the ultrastructural level.

A reliable, simple, and inexpensive method for ultrastructural investigation of elastin is described. This method uses uranyl acetate dissolved in absolute methanol, followed by an optional lead citrate counterstain. The procedure was tested on a number of animal and human tissues that had been fixed and processed differently.

The distribution of fibronectin in rat tooth and periodontal tissues: an immunofluorescence study using a monoclonal antibody.

The distribution of fibronectin (FN) in longitudinal, buccolingual sections of decalcified adult rat periodontium and teeth was studied by indirect immunofluorescence using a monoclonal antibody. FN was present in virtually all regions of the periodontium, including the gingiva, periodontal ligament, many blood vessel walls, alveolar bone, incisor and molar predentine and dentine, and molar acellular and cellular cementum. The cementum of the incisor, ameloblasts, stratum intermedium and stellate reticulum, and the connective tissue of the pulp and the surface of ondontoblasts facing the pulp in the incisor and molar were not labeled for FN. FN distribution was not always uniform either within a given connective tissue or between different connective tissues of the same organ.

Smokers' melanosis. Occurrence and localization in the attached gingiva.

The aim was to clinically study the frequency and extension of the melanin pigmentation in the attached gingiva and its relation to tobacco smoking. The population examined consisted of patients and dental nurse students at the School of Dentistry in Umeå, Sweden. All of the patients with pigmentation proved to be tobacco smokers. The pigmentation was given to name "smokers' melanosis.". Between 12.9% and 14.9% of those examined and between 25.5% and 31.0% of those who smoked had smokers' melanosis. Patients with smokers' melanosis had a significantly higher tobacco consumption than smokers without pigmentation. In 95.2%, smokers' melanosis was found in the mandible and was most common in the attached gingiva on the labial side of the canines and incisors. Smokers' melanosis is thus condidered to be caused by tobacco smoking and is expected to be found in other parts of the oral mucosa.

Study on the composition of bovine gingival lipids.

The lipids in bovine gingival tissue were characterized qualitatively and quantitatively. The total lipid content was 2.35% on wet weight. The total nonpolar lipids and total polar lipids were 70.69 and 29.31% of the total lipids, respectively. Cholesterol esters, free fatty acids, and triglycerides were the major nonpolar lipids. Polar lipids were predominantly phosphatidyl choline, phosphatidyl ethanolamine, and sphingomyelin. Traces of glycolipids, lysophosphatidyl choline, phosphatidyl inositol, phosphatidyl serine, and prostaglandins were present. Oleic, palmitic, and stearic acids were found to be the major fatty acids in all lipid classes. Cholesterol esters, total polar lipids, and free fatty acids were more unsaturated than glycerides. Linolenic and arachidonic acid contents were highest in cholesterol esters and total polar lipids.

Detection of prostaglandins in bovine gingival tissue.

It has been characterized earlier that bovine gingival lipids contain a fairly high level of arachidonic acid, a potential precursor of prostaglandin biosynthesis. The purpose of the present study was to investigate whether prostaglandins are natural components of bovine gingival tissues. Qualitative analysis of the lipid extract by a combination of thin-layer chromatography on plain and silver nitrate-impregnated silical gel plates and ultraviolet absorption spectroscopy strongly indicate the presence of PGE1, PGE2, and PGF2. There was also an indication for the occurrence of other prostaglandins, such as PGB, PGE3, PGF1, and PGF3.

Isolation of noncollagenous proteins from gingival connective tissue.

Noncollagenous proteins form an integral part of gingiva and other connective tissues. We have performed studies aimed at purification and partial characterization of the gingival noncollagenous proteins. Healthy gingival tissues from mongrel dogs were extracted in neutral buffers, acetic acid, and 6 mol/L urea. Immunoblots using anti-keratin antibodies and CNBr peptide patterns revealed that the majority of the proteins present in these extracts were keratins. To exclude keratins, gingival connective tissue was separated from the epithelium and then extracted. Acid extracts of the connective tissue contained very little protein, whereas urea extracts contained collagen and other noncollagenous proteins. The noncollagenous proteins present in the urea extract were partially purified by DEAE-cellulose chromatography and separated by affinity chromatography through a Sepharose 4B-type I collagen column. At least eight proteins, which ranged in molecular size from 15 to 75 kilodaltons, were obtained by this procedure. We conclude that keratins are major components of whole gingiva extracts and that epithelium must first be removed in order for connective tissue proteins to be obtained. The gingival connective tissue appears to contain several collagen-binding proteins, and these proteins may play an important role in the structure and function of the gingival matrix.

The relationship between inflammation and cAMP level in human gingiva.

The levels of cAMP were measured by means of radioimmunoassay in 20 gingival samples free from inflammatory cells and 43 samples with moderately dense and dense aggregations of inflammatory cells. The average values were found to be 340 +/- 44 and 552 +/- 59 pmol/gm wet tissue, respectively. The increase in cAMP levels in inflammation is suggested to be modulated by an increase in endogenous prostaglandin synthesis and could be one of the natural mechanisms by which the host protects itself from dangerous consequences of unregulated immune response.

Comparative collagen biochemistry of bovine periodontium, gingiva, and dental pulp.

Cross-linking patterns of the collagen from bovine gingiva, periodontium, and dental pulp were analyzed chromatographically. The ratios of two main cross-links, dihydroxylysinonorleucine to hydroxylysinonorlecuine, were 0.18, 0.31, and 0.49 for the bovine gingiva, periodontium, and dental pulp collagen, respectively. These ratios are similar to that of skin collagen rather than that of bone and dentin collagen.

Gingival matrix collagen in chronic periodontitis.

The isolation and characterization of cyanogen bromide peptides derived from the human gingival collagen of patients with chronic periodontitis revealed the presence of both Type I and Type III collagens in this tissue. The amount of TYPE III collagen, however, was found to be lower than that in normal gingival tissue. In addition, a non-collagenous protein fraction, accounting for approximately 20% of the insoluble matrix, was relatively rich in acidic, hydrophobic, and hydroxy-containing amino acids. Amino acid analysis, likewise, revealed qualitative and quantitative differences between the normal and diseased tissues.

Immunofluorescent detection of actin and myosin in healing gingival epithelium.

Indirect immunofluorescent labeling shows a sequential increase in detectable epithelial cell actin and myosin during wound repair migration and maturation. While actin shows a substantial increase between pre-wound and migration levels, the relative detectable myosin is omnipresent at apparently high levels, and it increases only slightly during active migration.

Surface and lamina propria lipids of bovine gingiva.

In terms of both quality and quantity, the surface lipids are noticeably different from the lamina propria lipids. The surface lipids are mainly structural in nature (cholesterol, cholesterol esters, and phospholipids), whereas the lamina propria lipids are mostly of storage types (triglycerides). The surface lipids are also more unsaturated, whereas the lamina propria lipids are more saturated. Even though gingiva is histologically similar to skin, bovine gingival surface lipids are different from the bovine skin surface lipids. Further studies are needed to investigate the importance of surface lipids in regulating the various physiologic functions of gingiva.

Local immunoglobulin synthesis in juvenile periodontitis: initial findings.

An electro-immunoassay technique was used to determine simultaneously immunoglobulin G (IgG) and albumin concentrations in serum and extracts of gingival tissue comprising the pocket wall. Assays of samples obtained from seven patients with juvenile periodontitis (mean age, 18 years) indicated that local synthesis accounted for 72% of the IgG found in the gingiva.

Study of the noncollagenous components of the periodontium.

Periodontal ligament and gingivae of bovine and porcine periodontium were analyzed for relative amounts of carbohydrates, collagen, and acid mucopolysaccharides. The sugar content was 3.6% and 3.4% of dry weight in bovine and porcine periodontal ligament, respectively. The values were lower in the gingivae being 2.34% and 2.30%, respectively. Approximately 50% of hexosamine in gingivae was present in acid mucopolysacchrides as compared to 36% in periodontal ligament. Relative to collagen there was a considerable amount of non-collagenous glycoproteins present in the periodontium as judged by carbohydrate content of the tissue.

Human gingival lymphocytes. I. Methodology for the isolation of human gingival lymphocytes.

Various methodologies were examined for the isolation of inflammatory cells from diseased human gingiva. The best recovery of viable gingival lymphocytes (gMNC) was achieved by a method which combined initial collagenase digestion followed by gentle teasing with an 18-gauge needle.

Confirmation that neither phenotype nor hydroxylation of collagen is altered in overgrown gingiva from diphenylhydantoin-treated patients.

Collagens, solubilized by pepsin-digestion of diphenylhydantoin-induced overgrown gingiva, appeared similar to collagens solubilized from inflamed gingiva with regard to: ratio of type I to type III collagen, ratio of alpha1 to alpha2 of type I collagen, and degree of hydroxylation of type I collagen.

Trauma affects cyclic AMP and DNA levels at injured and non-injured distal oral mucosal sites.

Experiments in rats were conducted to test the hypothesis that gingival trauma affects cyclic AMP and DNA levels at the gingival wound, and non-injured distal (gingival, palatal) sites. Cyclic AMP and DNA levels rose and fell in a cyclic fashion during the time (0.5-24 h) periods analyzed. Significant increases in cAMP levels occurred at 8 and 20 h and at 8 and 16 h, respectively, at the wound and non-injured palatal site, peripheral to the wound. Similar increases (not significant) in cAMP levels were also noted at the non-injured gingival contralateral site at the same time intervals. DNA distributions were found to be significantly greater 10 and 16 h after injury at the gingival wound, and distal non-injured gingival and palatal sites.

Sulcular exudate protein levels as an indicator of the clinical inflammatory response.

Protein concentrations in gingival fluid exudate were obtained in both the clinically minimal and severe inflammatory states. A comparison of the results indicated no significant differences in the two groups studied. Since total protein concentrations do not appear to reflect accurately the clinical inflammatory status of the gingival tissues, specific components of the protein molecule should be studied.

Evidence for hydroxyacyl-ceramides and hydroxyacyl-cerebrosides in female rhesus monkey gingiva.

Materials believed to be hydroxyacyl-ceramides (HO-Cer) and hydroxyacyl-cerebrosides (HO-Ceb) have been analyzed by high performance liquid chromatography (HPLC) from the glycolipid components of six female rhesus monkey gingivae. These recovered materials show identical behavior by (HPLC) with authentic standards.