[Influence of teas with fruit aroma and ice teas on pH and buffer capacity of saliva]

A number of teas with fruit aroma and ice teas has been tested on erosivity. The teas with a fruit taste have at their drinking temperature (45 degrees C) a pH between 6.2 to 7.4. Even teas with a citron or citrus flavour are neutral. The most acidic tea tested has a mango-peach-taste, but contains no buffer system. After mixing 1 ml of total saliva up to 10 ml tea or by rinsing the oral cavity with tea the pH of oral fluid was hardly lowered (minimum 6.3). In contrast, ice teas are rather acidic (pH < 4) and have a strong buffer capacity. Rinsing the oral cavity with 5 ml ice tea resulted in a decrease of the pH of the oral fluid to 4.1-4.9. However, within 2 minutes the pH in the oral fluid was already increased to 5.9-7.1 and after 5 minutes to 6.3-7.1. In other words, the teas with fruit aroma, based on organic taste components do not have an erosive potential. On the other hand, ice teas decrease the pH of the oral fluid drastically to a level that they become erosive. Therefore, from a dental point of view, teas with only a taste of fruit can be advised to replace drinking of soft drinks, but ice teas not.

Detection and quantification of MUC7 in submandibular, sublingual, palatine, and labial saliva by anti-peptide antiserum

The large carbohydrate moiety of low-Mr salivary mucin MUC7 (originally referred to as MG2) is subject to variations. Biochemical analysis and quantification of MUC7 in saliva samples require recognition tools that are independent of the carbohydrate moiety. Therefore, we have evoked three antisera to synthetic peptides of MUC7. One of these (CpMG2), raised against the C-terminal peptide, recognized native MUC7 in saliva and was characterized further. Recognition of MUC7 by CpMG2 turned out to be specific, resistant to dissociating and reductive treatments, and independent of glycosylation differences, as indicated by Western analysis and ELISA. The antiserum could be used to monitor MUC7 during purification procedures. MUC7 was demonstrated in small volumes of saliva from all (sero)mucous glands, including the palate and lip. Analysis with antibodies and lectins indicated large variations in amount as well as in glycosylation of MUC7. An ELISA was developed to determine the relative quantity of MUC7 in the glandular salivas: mean values of approximately 220, 980, and 100 microg mucin per mL were found in submandibular, sublingual, and palatine saliva, respectively.

Cystatin A in gingival crevicular fluid of periodontal patients

Cystatins are physiological inhibitors of cysteine proteinases which are widely distributed in human tissues and fluids. In the present study we analysed both the cystatin activity and the different cystatin isoforms in gingival crevicular fluid and saliva samples of nine periodontitis patients. All crevicular fluid samples, which were collected with filter paper points, showed cystatin activity ranging from 7-67 units/mg protein. The mean cystatin activity (24 units/mg protein) was significantly lower (p < 0.05) than that of the saliva samples (mean 93 units/mg protein). The cystatin isoforms in the crevicular fluid were further characterized by immunoblotting with specific antibodies against cystatin C, S, SN and A. While they were clearly present in saliva, cystatin C, cystatin S and cystatin SN could not be detected in any of the crevicular fluid samples. Remarkably, cystatin A was found in all the crevicular fluids as well as in the saliva samples. It is concluded that the cystatin activity found in crevicular fluid is caused, at least partially, by cystatin A. Furthermore, the gingival crevicular fluid is not a major contributor of cystatin C, S and SN activity in saliva.

Salivary protein composition in epileptic patients on different medications

Several salivary proteins were assayed in saliva from epileptic patients who were using different anti-epileptic drugs, viz, phenytoin, valproate and carbamazepine, and were compared with levels in unmedicated healthy control subjects. Flow rate and pH of the patient groups were not different from the controls. In all patient groups the specific amylase activity was increased up to twofold. In the phenytoin group only, the salivary IgA concentration was strongly reduced. Levels of salivary cystatin C were similar among all patient groups studied, and were not different from those of the control group. In contrast, the absolute and relative concentrations of cystatin S were diminished, particularly in patients using either valproate or phenytoin. These data suggest that use of anti-epileptic drugs over long periods may result in decreased levels of several salivary proteins such as sIgA and cystatins, which are involved in the protection of the oral cavity against microbial infections.

Effect of periodontal treatment on the protein composition of whole and parotid saliva

Cystatins are physiological inhibitors of cysteine proteinases and widely distributed in human tissues and fluids including saliva. Cystatins S, SA, SN, and D are only found in glandular saliva and tear fluid whereas cystatin C has been detected in all tested biological fluids. Previous studies demonstrated that total cystatin activity and cystatin C concentration were highest in whole and parotid saliva of periodontitis patients compared to healthy subjects suggesting a response of the salivary glands to an inflammatory condition of the oral cavity. Based on these results we studied a possible change in the concentration of cystatin S, cystatin C, albumin, IgA, amylase activity, and cystatin activity in a whole and parotid saliva of 20 periodontitis patients as a consequence of periodontal treatment. Saliva samples were quantified for cystatins S and C, albumin, and IgA by enzyme-linked immunosorbent assay. Amylase was determined in an activity assay and total cystatin activity was measured towards pa-pain. The clinical condition of the subjects improved significantly after 6 months of periodontal therapy whereas biochemical analyses of whole and parotid saliva indicated that significant changes in salivary protein composition occurred only in whole saliva. Total cystatin activity (P < 0.05) and cystatin C concentration (P < 0.05) of whole saliva samples collected after periodontal treatment decreased to normal healthy control values. Further, concentrations of cystatin S were unchanged during the periodontal treatment process. These results suggest that other sources of cystatins than the parotid gland i.e.; other salivary glands or crevicular fluid, are involved in the decrease of total cystatin activity in whole saliva after periodontal treatment.

Protein composition of whole and parotid saliva in healthy and periodontitis subjects. Determination of cystatins, albumin, amylase and IgA

Cystatins are physiological inhibitors of cysteine proteinases and they are widely distributed in human tissues and body fluids including saliva. We previously reported an increased cystatin activity in whole saliva of gingivitis and periodontitis subjects. Based on this result we decided to investigate the type and origin of cystatins involved in this increased cystatin activity by collecting both whole and parotid saliva of 25 healthy and 30 periodontitis subjects. Saliva samples were quantified for cystatins S and C by enzyme-linked immunosorbent assay and cystatin activities were measured toward papain. Besides, three other salivary proteins were determined: the plasma protein albumin, the typical parotid derived amylase and the salivary immunoglobulin IgA. The present investigation shows that levels of total protein and cystatin activity as well as the levels of glandular derived proteins amylase and cystatin C were significantly higher in whole and parotid saliva of subjects with periodontitis than in healthy controls. Cystatin S, the major salivary cystatin, however was higher in the whole saliva of the healthy group. Whole saliva concentrations of albumin and IgA, originating from sources other than the glandular cells, were not different between healthy and periodontitis subjects and were also not correlated with the typical salivary gland proteins. In conclusion, this study provides additional evidence that the human salivary glands may respond to an inflammatory disease of the oral cavity, periodontitis, by enhanced synthesis of some acinar proteins.

Comparison of a salivary 14 kD protein displaying cysteine proteinase inhibitory activity with other salivary cystatins

An acidic protein with a molecular weight of 14 kD and a cysteine proteinase inhibitory activity was isolated from human whole salive. It was classified therefore as a cystatin. Fractionation of whole saliva by FPLC ion-exchange chromatography, followed by immunochemical analysis with monoclonal antibodies, indicated that this protein, designated 14 kD/E8B, eluted in a single peak, which comprised 6% of the total salivary cystatin-activity. The 14 kD/E8B cystatin had nearby 5 times less apparent affinity for papain than chicken egg cystatin. In addition to 14 kD/E8B cystatin, four other cystatins were separated, having pI values of 4.5 and 4.7. One of these appeared together with amylase. Furthermore a protein having a pI of 6.7 was isolated, which accounted for approximately 50% of the total cystatin activity present in whole saliva. The total cystatin activity in unstimulated whole saliva showed at least a three fold difference between individuals. Specific cystatin activity, based on protein content, was highest in saliva derived from the submandibular gland. In addition, cystatin activity could be detected in sublingual and labial saliva, whereas parotid saliva displayed little activity and palatinal saliva no activity at all.