Archives of Oral Biology

Published by Elsevier
Online ISSN: 0003-9969
Publications
Article
Extracts from five plants used as chewing sticks, and tannic acid, gallic acid and methyl ester of gallic acid, were tested for their ability to inhibit proteolytic activities of three strains of Bacteroides gingivalis, three strains of Bacteroides intermedius and two strains of Treponema denticola. Aqueous extract from the plants Rhus natalensis and Euclea divinorum were the most inhibitory of those tested, inhibiting by 50% the proteolytic activity of the test organisms, at concentrations of up to 200 micrograms/ml. Tannic and gallic acids had similar effects at concentrations of less than 10 micrograms/ml, while the methyl ester of gallic acid was less inhibitory. These findings suggest that extracts from plants used as chewing sticks may possess enough inhibitory components to interfere with the virulence and growth of periodontopathic bacteria in vivo, provided they are able to gain access to the subgingival sites such bacteria preferentially inhabit.
 
Article
p-Nitrophenyl phosphatase (p-NPP-ase) and inorganic pyrophosphatase (PPi-ase) activities originate from the same alkaline phosphatase enzyme. Only the PPi-ase site has zinc (Zn2+) as a cofactor. Cadmium (Cd2+) in concentrations from 10(-5) mol/l upwards inhibited the PPi-ase activity, but did not inhibit the p-NPP-ase activity at all. In mineralizing tooth germs Cd2+ may replace Zn2+, thereby changing the specific stereoconfiguration in the active centre needed for PPi-ase activity, but not that for p-NPP-ase activity.
 
Article
The cysteine proteinases cathepsins B and L have collagenolytic potential and so have been implicated in connective-tissue breakdown in chronic periodontitis. Synthetic peptide substrates are often used to detect proteolytic enzymes. The action of homogenates of inflamed gingiva tissue against three such substrates of cathepsin B have been characterized here by protease inhibitors. Using the selective reagents ZPheAlaCHN2, BzValLysLysArgAFC, ZAlaArgArgAFC and ZPheArgAFC were susceptible to both cysteine and non-cysteine proteinase activity; the two types of enzymes had acidic and alkaline pH optima, respectively. The action of other inhibitors at acidic pH indicated the involvement of cathepsin B and, to a lesser extent, cathepsin L. The enzyme active at alkaline pH was a serine proteinase; it resembled glandular kallikrein in its inhibitor response and its ability to hydrolyse a fourth substrate, DValLeuArgAFC, but its greater reactivity with BzValLysLysArgAFC and ZAlaArgArgAFC was not consistent with kallikrein. ZPheArgAFC, though less sensitive than BzValLysLysArgAFC to cysteine proteinase action, was far less susceptible to hydrolysis by the serine proteinase and thus appears the best choice for selective assays of cathepsins B and L.
 
Article
This study sought to characterise the electromyographic (EMG) activity patterns of orofacial-muscles during trained tongue-protrusion and biting tasks in two awake monkeys (Macaca fascicularis). Chronic or acute EMG electrodes were placed in the anterior digastric (DIG), genioglossus (GG), masseter (MASS), platysma (PLAT), zygomaticus major (ZYGO), orbicularis oris superior (OOS), and orbicularis oris inferior (OOI) muscles and their EMG activity as well as the force signals of the tongue-protrusion and biting tasks were recorded. A total of 327 tongue-protrusion task trials and a total of 210 biting-task trials were successfully completed in several recording sessions and the EMG patterns were generally consistent between the different sessions. For the tongue task, the mean onset time of increase in GG activity significantly (p < 0.0001) led the mean onset time of increase in the force. The DIG, GG, and OOI (and also the OOS in one of the monkeys) showed a significant (p < 0.0001) increase in mean EMG amplitude during the holding phase, but the GG in both monkeys had the highest mean EMG amplitude ratio (MAR), i.e. the mean EMG amplitude during the holding or dynamic phase divided by the mean EMG amplitude during the pre-trial period. A similar EMG pattern was documented for different directions of the tongue-protrusion task (right, symmetrical, and left) and changes in the levels of EMG activities occurred in GG and OOI as the direction of the tongue-protrusion task changed from left to right. The task at different forces was associated with no apparent change in MAR for the holding phase for each muscle recorded. However, during the dynamic phase, only the GG showed a significant increase in EMG activity as the forces were increased. For the biting task, the mean onset times of the MASS activity and force were not significantly different. The MASS and ZYGO muscles (and the PLAT in one of the monkeys) showed a significant increase in mean EMG amplitude during the holding phase compared with the pre-trial period, and the MASS showed the highest MAR. It was also the only muscle showing a significant increase in the EMG activity when the bite-force level was increased. These findings reveal that certain orofacial muscles are selectively recruited during the two different orofacial tasks.(ABSTRACT TRUNCATED AT 400 WORDS)
 
Article
Kleinberg (1967) (Archs oral Biol. 12, 1457-1473) has observed that the incubation of a salivary sediment/supernatant mixture with a low concentration of glucose produces a pH drop followed by a pH rise. As this pH-rise effect could elevate oral pH in vivo, the degree of such activity could be directly related to caries resistance. The pH-rise of paraffin-stimulated whole saliva samples from 54 caries-free and 54 caries-active male naval recruits was compared in two assays. The first, conducted with sediment/supernatant/2.8 mM glucose mixtures, showed no significant differences for mean pH versus time profiles for 26 caries-free and 26 caries-active subjects. Concomitant assays, in which 3.33 mM arginine and water replaced the supernatants in the assay mixtures, showed slightly higher mean pH/time profiles, with higher minima for the caries-free subjects. These profile differences were statistically significant for the arginine-containing mixtures, a result attributed to different microbial distributions for the caries-free and caries-active sediments. The second assays were conducted on saliva supernatants from 28 caries-free and 28 caries-active subjects, employing a strain of Lactobacillus casei in place of salivary sediment in the assay system. No statistically significant differences were evident between the mean pH/time profiles for the two groups of subjects, although a significant positive correlation was observed between pH minimum and bicarbonate content of the samples. Thus no relationship of salivary pH-rise activity and caries experience were found.
 
Article
This study aims to determine antibacterial activities of Cocos nucifera (husk fiber), Ziziphus joazeiro (inner bark), Caesalpinia pyramidalis (leaves), aqueous extracts and Aristolochia cymbifera (rhizomes) alcoholic extract against Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus mutans and Lactobacillus casei. The antioxidant activity and acute toxicity of these extracts were also evaluated. The plant extracts antibacterial activity was evaluated in vitro and the minimal inhibitory concentration (MIC) was determined by the broth micro-dilution assay. The bacterial killing kinetic was also evaluated for all extracts. In addition, the antibacterial effect of the extracts was tested in vitro on artificial oral biofilms. The acute toxicity of each extract was determined in according to Lorke [Lorke D. A new approach to practical acute toxicity testing. Arch Toxicol 1983;54:275-87] and the antioxidant activity was evaluated by DPPH photometric assay [Mensor LL, Menezes FS, Leitão GG, Reis AS, Santos TC, Coube CS, et al. Screening of Brazilian plants extract for antioxidant activity by the use of DPPH free radical method. Phytother Res 2001;15:127-30]. MIC and the bactericidal concentrations were identical, for each evaluated extract. However, microbes of artificial biofilms were less sensitive to the extracts than the planktonic strains. A. cymbifera extract induced the highest bactericidal effect against all tested bacteria, followed by C. nucifera, Z. joazeiro and C. pyramidalis extracts, respectively. All extracts showed good antioxidant potential, being C. nucifera and C. pyramidalis aqueous extracts the most active ones. In conclusion, all oral bacteria tested (planktonic or in artificial biofilms) were more susceptible to, and rapidly killed in presence of A. cymbifera, C. pyramidalis and C. nucifera than Z. joazeiro extracts, respectively. Thus, these extracts may be of great interest for future studies about treatment of oral diseases, considering their potent antioxidant activity and low toxicity.
 
Article
Free activities of collagenase and neutral protease were measured in the gingival washings collected with individual appliances before, during and after a 21-day period of experimental gingivitis in 8 male subjects who refrained from tooth-brushing. Collagenase was determined by measuring the release of soluble radioactivity from3H-labelled, reconstituted collagen fibrils and neutral protease by measuring the breakdown of haemoglobin. The concentration of collagenase and neutral protease increased significantly during abstention from tooth-brushing, as did the specific activities of the two enzymes (free enzyme activity/number of polymorphonuclear (leukocytes). SDS-polyacrylamide gel electrophoresis of the digestion products of native collagen mixed with concentrated gingival washings showed that the collagenase in the gingival crevice is partly of mammalian origin. The inhibition study with serum and EDTA suggested a minor contribution of bacterial collagenase.
 
Article
Serine proteinases have the potential to influence the degradation of connective tissue in chronic periodontitis, which may progress episodically at individual tooth sites. Elastase-, chymotrypsin- and tryptase-like proteinase activity in homogenized gingival tissue were measured using, respectively, the selective peptide substrates MeOSuc-Ala-Ala-Pro-Val-AFC. MeOSuc-Phe-Pro-Phe-AFC and Z-Ala-Arg-Arg-AFC. Each tooth site was assayed separately and divided, where appropriate, into gingival tissue and granulomata. Elastase-like activity was detected in only about half of the sites and with large variations. Chymotrypsin-like activity decreased with increasing pocket depth, clinical attachment level, gingival index and gingival bleeding index. Tryptase-like activity did not vary consistently with clinical measures. Chymotrypsin- and tryptase-like proteinase activity were much higher in gingival tissue than in granulomata. These effects are best explained by the likely influence (or lack of influence) of the endogenous serum and tissue inhibitors of serine proteinases, the different cellular origins of the enzymes, and their relative affinities for their substrates.
 
Article
The polymorphonuclear neutrophils (PMN) produced significantly-higher chemi-luminescence (CL) peak values than neutrophils of healthy-paired controls when each population of cells was challenged with zymosan pre-opsonized with autologous serum. This enhanced CL was not attributable to the metabolic activity of the cells, but was shown, by cross-over experiments and additional testing with a single source of cells, to be directly associated with the opsonizing capacity of the patient's serum. The results suggest that peripheral PMN from young periodontitis patients have oxidative metabolic activities similar to subjects free of this disease, and that the enhanced PMN metabolism of patients may be due to a corresponding increase of serum opsonins.
 
Article
Periodontal mechanosensitive units (PM units) responsive to mechanical stimulation of this tooth were recorded from single fibres isolated from the superior alveolar nerve. Mechanical stimulation was applied in a sequence of long-lasting strong pressure followed by a train of weak stimuli. Temperature was changed by perfusing the pulpal cavity of the stimulated tooth with saline solution at a temperature of 5-45 degrees C. The response of the PM units elicited by strong pressure was initially dynamic and subsequently static. The dynamic response was little affected by tooth temperature whereas, the static response increased with the rise in temperature. After strong pressure the excitability of the PM units was depressed transiently, followed by gradual recovery; this depression was especially prominent when tooth temperature was high.
 
Article
The activity of a peptidase (collagenase-like (CL)-peptidase) acting on a newly synthesized substrate for this enzyme (succinyl-Glycine-Proline-Leucine-Glycine-Proline)-4-methylcoumaryl-7-amide, and the activity of dipeptidylaminopeptidase IV (X-prolyl dipeptidyl-aminopeptidase, DAP-IV) acting on Gly-Pro-4-methylcoumaryl-7-amide, were examined in developing salivary glands of rats between 1 day and 10 weeks old. Hydroxyproline in the glands was measured after hydrolysis with 6 M HCl as an indicator of the amount of collagen present. The DAP-IV activity increased continuously during maturation of the glands. CL-peptidase activity and the total hydroxyproline first increased rapidly from 1 to 10 days, then decreased until 4 weeks of age. Natural inhibitors for CL-peptidase appeared at 5 weeks and then increased in activity. After subtracting the effect of the inhibitor, the true CL-peptidase activity also gradually increased with maturation after 5 weeks. The salivary CL-peptidase may thus have a significant role in collagen catabolism and DAP-IV may not be concerned with collagen degradation.
 
Article
The majority of cases of oral malodour are thought to be due to bacterial activities in the mouth, but many of the bacterial species responsible have not been identified. Volatile sulphide compounds have been proposed as constituents of oral malodour. Therefore, the relation between intensity of odour and numbers of bacteria in the mouth that are sulphide-producing from sulphate was investigated. Numbers of such dissimilatory sulphate-reducing bacteria (SRB) and sulphide reduction rates were evaluated in samples from different oral sites in relation to measures of oral malodour. Results showed that sulphate-reducing bacterial numbers and activities were negatively correlated with malodour, as determined by organoleptic assessment and measurement with a sulphide-monitoring instrument, the Halimeter. The data indicate that sulphide produced by oral SRB may not be an important contributor to oral malodour. A rather poor correlation was observed between Halimetric and organoleptic values, indicating that these methods may measure different aspects of oral malodour intensity.
 
Article
The activities of glucanhydrolase (EC 3.2.1.11) and glucosyltransferase (EC 2.4.1.5) in crude enzyme preparations of 44 strains of Streptococcus mutans of five serotypes were investigated. The strains were grown in a laboratory fermentor for 16 h and the enzymes were isolated by adding solid ammonium sulphate to the culture supernatant, resulting in a 12-fold enrichment of the enzymes. For glucanhydrolase, strains of serotype a showed the lowest total activity (0.768 U, approx. 120 ml), whereas strains of serotype d had an activity 39 times higher (29.9 U). The total activities of strains of serotypes b, c and e were 5.56, 6.30 and 7.06 U, respectively. For glucosyltransferase, strains of type e showed the highest total activity (293 U), whereas differences between strains of the other four types were insignificant (type a: 158 U; type b: 175 U; type c: 191 U; type d: 225 U; approx. 120 ml). A strong correlation was found between the glucanhydrolase activity and the percentage of insoluble glucan synthesized in vitro by the respective strains. This correlation was not substantially changed if the enzyme activities were expressed as specific activities, or as total activities against bacterial weight.
 
Article
The alkaline phosphatase (AP) and carbonic anhydrase (CA) activities were studied in male rats placed at weanling age on a diet containing 0.4 parts/106 of zinc for periods of 9, 18 and 27 days. Weight-matched pair-fed rats were kept on the same diet supplemented with 40 parts/106 of zinc. The body weight of controls showed a continuous increase; body weight of zinc-deficient animals remained unchanged. Zinc concentration in submandibular gland was the same in all groups of control and zinc-deficient animals. AP activity, chiefly localized in the myoepithelial cells, progressively increased in controls from day 9 to 27. AP activity in the zinc-deficient animals did not increase. It was lower than in controls even at 9 days and further decreased with prolonged zinc deficiency. CA activity, chiefly localized in cells of the duct system, rose with age in the controls at twice the rate of AP activity, a rise attributed to the steep rise in proportion of duct cells reported for this age span. By contrast, CA activity in the glands of zinc-deficient rats remained constant at all periods of deficiency, accounting for the increasing difference from controls with prolonged zinc deficiency. Failure of CA activity to rise with age in zinc-deficient rats is attributed to failing proliferation of duct cells, reflecting the inhibition of cell proliferation reported for many tissues of the zinc-deficient animals, a view supported by the maintenance of unchanged body weight over a 4-week-period. Inhibition studies using acetazolamide showed identical degress of inhibition in homogenates from control and deficient animals over a wide range of inhibitor concentrations. Rats fed for 9 days on the zinc-supplemented diet after 27 days on the deficient diet doubled their weight and showed AP and CA activities of the same level as controls that were pair-fed for 27 days and given unrestricted food for the last 9 days.
 
Article
The rate at which a standardized mouthful of toffee containing technetium (99mTc) tin colloid was cleared from the mouth during and after chewing was measured by counting the residual radioactivity in the mouth at short time intervals by external gamma counting. The clearance curve was resolved into three phases for each subject--chewing time (1), which coincided with the time to reach 10% of the initial counting rate, scavenging time (2), and a final slow diffusion phase (3). Although the mean chewing time was only 1.9 min, the technique allowed the pattern of clearance during this phase to be assessed for each of 10 normal children (mean age 11.1 yr) and 7 children (mean age 11.0 yr) diagnosed as having delayed articulation. Two measurements of sensory and motor functions of the tongue were made on the same subjects. These measurements were of oral stereognosis and tongue-tip manipulation. Within the control group, only the correlation between stereognosis error scores and the duration of phase 1 or phases 1 and 2 combined was statistically significant. The mean stereognosis and tongue manipulation scores were significantly lower in the poor articulation group than in normal children but, with one notable exception, the clearance curves were similar.
 
Article
Collagen concentration was fairly low in young bovine 3rd premolar pulps, about 9 per cent by dry weight of pulp in stage I, but it increased consistently up to more than 25 per cent at stage V as the pulp matured. The ratio of type III to type I collagen similarly increased from 13 per cent at stage I to 32 per cent at stage V. Both collagenase and possibly collagenolytic neutral peptidases showed significantly high activity in the early stage of pulp development where the rate of collagen synthesis was also elevated. Higher rates of both collagen synthesis and its degradation might explain the low concentration and content in the early stage of pulp development.
 
Article
Following the incorporation of [35S]-sulphate into rats, 35S-labelled sulphated glycoproteins were isolated from the minor salivary gland secretions of pilocarpine-stimulated, immobilized animals. The secretory products were initially resolved on Sepharose 4B into two major radioactive fractions, one of which appeared at the void volume and represented only 7 per cent by weight of the applied fraction. The bulk of the products were of lower molecular weight and were further resolved by DEAE-Sephacel anion-exchange chromatography. Four distinct radioactive fractions were obtained all of which possessed blood-group A reactivity and aggregated Streptococcus sanguis NCTC 7864 but not Streptococcus mutans OMZ61. The radioactive fractions possessed protein/carbohydrate ratios in the range 1.6:1-5.8:1. Ester-sulphate contents ranged from 2.5 to 5.3 per cent with a higher value of 14.0 per cent being obtained for the most anionic fraction. Sialic acid was in the range 5.1 to 21.6 per cent. None of the fractions tested contained sulphated glycosaminoglycans.
 
Article
The activity of a peptidase (PZ-peptidase) acting on a synthetic collagenase substrate, 4-phenylazobenzyloxycarbonyl-L-prolyl-L-leucyl-glycyl-L-prolyl-D-arginine and the activity of a peptidase (glycylprolyl β-naphthylamidase) acting on glycyl-L-prolyl β-naphthylamide, were examined in bovine and human oral tissues and in rat experimental granuloma. Both enzyme activities were high in the dental follicle beneath the deciduous tooth undergoing resorption, and they were increased in the developing rat granuloma tissue. However, human submaxillary gland and human duct saliva contained only glycylprolyl β-naphthylamidase activity.
 
Article
In the presence of added optimal concentrations of H2O2 (0.024 M), many polymorphonuclear neutrophils (PMN) in the sediment of human oral lavages exhibited intense nitro-blue tetrazolium (Nitro-BT) reducing enzyme activity. This H2O2-dependent reaction in PMN was inhibited markedly by cyanide, azide, hydroxylamine and catalase, and totally by 0.15 M H2O2, indicating the participation of a peroxidase (probably myeloperoxidase). In contrast, intense endogenous Nitro-BT reducing enzyme activity in granular masses (GM) was inhibited by all concentrations of H2O2 employed until 100 per cent inhibition was obtained at 0.15 M. Small numbers of PMN also yielded intense endogenous activity, which was correlated with the phagocytosis of microorganisms and the formation of H2O2 in the PMN. As the endogenous reactions in the PMN and GM were not inhibited by cyanide, azide, hydroxylamine or catalase, it is postulated that critical concentrations of endogenous bound H2O2 and peroxidase are present in these GM and PMN and are required for the endogenous activities. The exogenous H2O2-dependent reaction in the PMN and endogenous reactions in the GM and PMN were inhibited completely after 10 min exposure to 60 °C and by low concentrations of iodoacetate and cupric ion. The latter indicates that the system involved in both PMN and GM consists of a complex containing one or more heat-labile and -SH group-dependent components in addition to peroxidase.
 
Article
To assess antimicrobial activities of aqueous crude khat (Catha edulis) extracts against a panel of oral microorganisms and to test their ability to modify bacterial resistance to tetracycline and penicillin in vitro. Lyophilized aqueous extracts were prepared from three khat cultivars. The agar dilution method of the NCCLS was used to test the extracts, at concentrations of 20-1.25 mg/ml, against 33 oral strains. MIC was defined as the lowest concentration at which there was no visible growth. Slight growth was defined as marked growth reduction (MGR). The E-test was used to determine the MICs of tetracycline and penicillin-G for three resistant strains in absence and presence of a sub-MIC of the khat extracts (5mg/ml). Eighteen strains (55%) were sensitive to the extracts (MICs 5-20 mg/ml). Most of these were periodontal pathogens with Porphyromonas gingivalis and Tannerella forsythensis being the most susceptible (MIC 5-10mg/ml). Veillonella parvula, Actinomyces israelii and some streptococci were not sensitive. Except for Lactobacillus acidophilus that showed MGR at 1mg/ml, cariogenic species were neither sensitive. The extracts were active against Streptococcus pyogenes (MIC 10-20 mg/ml) but not against Candida albicans and Staphylococcus aureus. The presence of the khat extracts at a sub-MIC resulted in a 2-4-fold potentiation of the tested antibiotics against the resistant strains. Khat has water-soluble constituents possessing selective antibacterial activity against oral bacteria. There is preliminary evidence for presence of an antibiotic resistance-modifying component. Further investigation is needed to identify the active components and assess their clinical relevance.
 
Article
Human salivary alpha-amylase participates in the initial digestion of starch and may be involved in the colonization of viridans streptococci in the mouth. To elucidate the role of histidine residues located near the starch-binding site on the streptococcal-binding activity, the wild type and three histidine mutants, H52A, H299A and H305A were constructed and expressed in a baculovirus system. While His52 is located near the non-reducing end of the starch-binding pocket (subsite S3/S4), the residues His299 and His305 are located near the subsites S1/S1'. For the wild type, the cDNA encoding the leader and secreted sequences of human salivary amylase was amplified by polymerase chain reaction from a human submandibular salivary-gland cDNA library, and subcloned into the baculovirus shuttle vector pVL1392 downstream of the polyhedrin promoter. Oligonucleotide-based, site-directed mutagenesis was used to generate the mutants expressed in the baculovirus system. Replacing His52 or His299 or His305 to Ala residue did not alter the bacterial-binding activity significantly, but these mutants did show differences in their catalytic activities. The mutant H52A showed negligible reduction in enzymatic activity compared to that of wild type for the hydrolysis of starch and oligosaccharides. In contrast, the H299A and H305A mutants showed a 12 to 13-fold reduction (90-92%) in starch-hydrolysing activity. In addition, the k(cat) for the hydrolysis of oligosaccharides by H299A decreased by as much as 11-fold for maltoheptaoside. This reduction was even higher (40-fold) for the hydrolysis of p-nitrophenyl maltoside, with a significant change in K(M). The mutant H305A, however, exhibited a reduction in k(cat) only, with no changes in the K(M) for the hydrolysis of oligosaccharides. The reduction in the k(cat) for the H305A mutant was almost 93% for maltoheptaoside hydrolysis. The pH activity profile for the H305A mutant was also significantly different from that of the wild type and the other two mutants. These results suggest that, although histidines at the starch-binding site of salivary amylase are involved in starch binding and catalysis, they may not participate in Streptococcus gordonii G9B binding.
 
Article
The activity of some enzymes in human dental plaque fluid was measured. Plaque of 24 h growth was collected from 9 adults, and plaque of indeterminate age obtained from children attending the Pedodontic Clinic at UCSF. Resting parotid saliva samples from the adult subjects were also assayed. Amylase activity was lower and lysozyme activity higher in plaque fluid than in saliva. The optimum pH for both enzymes in both fluids was between 6.5 and 7.5. Salivary and plaque fluid amylase was not inactivated by short incubations with two bacterial proteases. Trace levels of acid phosphatase and low alkaline phosphatase activity were detectable in plaque fluid, the latter being labile during incubation and storage. No glucosyl-transferase activity synthesizing insoluble polysaccharide from sucrose was detectable in plaque fluid. Protease activity against bovine serum albumin and human serum IgA, IgG and IgM was detectable in plaque fluid.
 
Article
Dopa-decarboxylase activity was high at 2-3 weeks of age, low at 5-6 weeks, and very low in adult rats; protease activity increased with age. Trypsin-like proteases, which decrease dopa-decarboxylase activity, were detected in the gland and were inhibited by a protease inhibitor, leupeptin. High concentrations (20 mg/ml) of leupeptin increased dopa-decarboxylase activity in the glands of adult rats to the level found at 5-6 weeks of age. The low activity of dopa decarboxylase in adult gland may be due in part to endogenous proteases.
 
Article
These activities were measured simultaneously, using synthetic fluorescent protease substrates, in gingival crevicular fluid collected at 6 pre-determined sites from 10 individuals with mild to moderate gingivitis. The three enzyme activities were detected in 85, 18 and 93% of the sites, respectively. The volume of fluid collected from discrete sites was significantly correlated with the total amount of substrate hydrolysed, but not with the specific rate of substrate hydrolysis. Log10 (total trypsin-like activity) was significantly correlated with the Gingival Index, Plaque Index and probing depth (r = 0.319, 0.423 and 0.336), while total glycylprolyl dipeptidase activity was significantly correlated with probing depth (r = 0.381). These findings add to knowledge of the biochemistry of gingival crevicular fluid, but the usefulness of such assays for diagnostic or monitoring purposes in periodontal diseases needs to be determined.
 
Article
Carbohydrate metabolism was examined in the developing rat salivary glands by analysing enzymatic activity and glycogen content in the postnatal parotid and submandibular glands. The following enzymes of the carbohydrate metabolism, hexokinase (HK), phosphofructokinase-1 (PFK-1), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD), and lactate dehydrogenase (LDH) as well as the content of glycogen were determined in the salivary glands of rats aged 2, 7, 14, 21, 30 and 60 days. The specific activity of HK increased from days 2 to 21 and then it decreased up to 60 days old. The values found for the submandibular glands were from 2.5 to 4.9 times higher than those found for the parotid gland, except for rats aged 60 days. PFK-1 showed a different pattern of variation between the glands. In the submandibular gland there was a statistically significant increase in PFK-1 specific activity from 2 to 30 days of age and then, in the 60 days old group a return to level of the rats aged 2 days. In parotid gland, the specific activity of PFK-1 decreased between 2 and 7 days of age, from 7 to 14 days the specific activity increased markedly and from 14 to 60 days old it gradually decreased. The specific activity of PK followed the same pattern of variation in the submandibular and parotid glands, showing no great variation. The specific activity of LDH decreased from 2 to 60 days old in the submandibular glands. In the parotid glands the mean values for this enzyme were higher for the 2 days old group, and then decreased to remained more or less constant. The potential capacity of the pentose phosphate pathway was greater than that of glycolysis at early ages. The glycogen content showed similar variation in both glands. It was initially high and then decreased. In conclusion, our results on the activities of enzymes involved in carbohydrate metabolism in submandibular and parotid glands may be relevant to the initiation of saliva secretion in these animals.
 
Article
To investigate interactions between hyaluronic acid (HA), lysozyme, and the glucose oxidase-mediated lactoperoxidase (GO-LPO) system in enzymatic and candidacidal activities. The influences of HA (0.5, 1.0, and 2.0mg/mL) and lysozyme (30μg/mL hen egg white lysozyme) on the enzymatic activity of GO-LPO system (25μg/mL bovine LPO, 1mM KSCN, 10units/mL GO, and 30μg/mL glucose) were determined by measuring oxidized o-dianisidine production. The influence of the GO-LPO system on lysozyme activity was determined by measuring the turbidity of a Micrococcus lysodeikticus suspension. The effects of interactions between HA, lysozyme, the GO-LPO system on candidacidal activity were examined by pre-incubating various combinations of components. Candidacidal activity was determined by comparing the numbers of colony forming units using Candida albicans ATCC strains 10231, 18804, and 11006. HA inhibited the enzymatic activity of the GO-LPO system in a dose-dependent manner. HA inhibited the candidacidal activities of the GO-LPO system. However, the inhibitory activity of HA was not significantly different according to concentration of HA. The GO-LPO system enhanced the enzymatic activity of lysozyme, though lysozyme did not affect the enzymatic activity of the GO-LPO system. The candidacidal activities of the GO-LPO system and lysozyme were not additive. HA inhibited the enzymatic and candidacidal activity of the GO-LPO system. The GO-LPO system enhanced the enzymatic activity of lysozyme, but the candidacidal activities were not additive.
 
Article
The possible effects of food consistency on the number of chews and the lapse of time in a chewing sequence, the jaw-movement pattern and velocity, and jaw and lip muscle activity during chewing were investigated. Fifteen healthy children with good occlusion were selected. First, each subject freely chewed hard (HJ) and soft (SJ) types of jelly without specifying the chewing side. The number of chews and elapsed time in a masticatory sequence (from the start of chewing to the completion of the final swallow) were measured. Second, the subjects performed right- and left-sided chewing of the same food. The electromyograms (EMG) of posterior temporalis (PT) and inferior orbicularis oris (OI) muscles on the right and left sides and associated jaw movement records were sampled. The HJ was chewed more times and with a longer time until finally swallowed (p < or = 0.0007) than the SJ. The HJ chewing also showed broader masticatory loops (p < or = 0.0199) in the frontal view and higher peak activities (p < or = 0.0007) for the PT muscle. The closing phase was longer when chewing the HJ than SJ, but the opening and intercuspal phases remained stable. More lateral excursion of the jaw was seen when chewing the HJ, but the jaw-movement trajectories in the sagittal and vertical directions were not affected by the change in consistency of the food. The jaw-closing velocities for the HJ chews were significantly slower (p < or = 0.0351) than those for the SJ chews in three directions. The HJ chews also revealed a longer duration between the onset of EMG burst for the PT muscle and the beginning of the centric occlusion (p < or = 0.0146). The OI muscle showed increased activity in accord with jaw opening, and consistent reciprocal cyclic activity with the PT muscle in terms of temporal associations (r > or = 0.5250; p < or = 0.0495). The OI muscle started to burst at a later part of the intercuspal phase, and frequently showed secondary activity in the jaw-closing and intercuspal phases. The peak activity for the ipsilateral OI muscle was significantly higher (p < or = 0.0106) than that for the contralateral OI muscle for both the HJ and SJ. The OI muscle activity, however, did not differ between the hard and soft jellies.(ABSTRACT TRUNCATED AT 400 WORDS)
 
Article
Antibodies, directed against the partially-purified glucosyltransferase-A (synthesizing primarily insoluble glucans) and purified glucosyltransferase-B (producing predominantly soluble glucans) of Streptococcus mutans GS5 (serotype c), were used to assess the antigenic relatedness of the corresponding enzyme activities of strains MT703 (serotype e) and OMZ-175 (serotype f). Both anti-GTF-A and anti-GTF-B inhibited the corresponding activities from strains GS5, MT703 and OMZ-175 equally well. Furthermore, the cell-associated activities and sucrose-dependent adherence capabilities of all three organisms were strongly inhibited in a similar way by anti-GTF-A. The adherence-inhibiting activity of anti-GTF-A was demonstrated to be directed against a heat-sensitive component of the cell surface, probably the cell-associated GTF activity. The results are discussed in terms of the previously proposed close genetic relationship between Strep. mutans serotype c, e and f organisms.
 
Article
The content of several lysosomal enzymes was measured in the rat parotid gland when the normal secretory cycle was altered by either reducing or enhancing secretion. The findings support the concept that lysosomes play a role in regulating the gland content of secretory products. The secretory protein, amylase, began to accumulate when secretion was reduced. This was immediately followed by an increase in lysosomal enzymes (cathepsin D and acid phosphatase). Thereafter, amylase activity decreased rapidly followed by a smaller reduction in lysosomal enzymes. When secretion was enhanced by an injection of isoprenaline, amylase was reduced by 95 per cent within two hours; the lysosomal enzymes were decreased by 15–30 per cent. Within 24 h, amylase was restored and increased by 50 per cent whereas the lysosomal enzymes were increased only 10–30 per cent.The activity of acid phosphatase was measured with two different substrates. Activity measured with β-glycerophosphate paralleled that of cathepsin D whereas that measured with p-nitrophenylphosphate did not when secretion was reduced but did when secretion was enhanced. The results support the hypothesis that acid phosphatase activity measured with β-glycerophosphate is lysosomal whereas that measured with p-nitrophenylphosphate may have another cellular location in addition to lysosomes.
 
Article
Fasting parotid saliva was collected from six human subjects four times a day on five different days. Analysis of variance of data detected significant differences among subjects for all parameters examined. There was no consistent pattern of differences within or among subjects due to time of day or day of the week. The greatest variations within subjects were in glucose concentration and lactic dehydrogenase (LDH) activity. Correlations of flow rate with pyruvate, lactate and total protein were positive, with glucose and LDH activity negative and with amylase activity insignificant. Positive correlations of pyruvate with lactate and of amylase activity with total protein were noted.
 
Article
Basic neurophysiological mechanisms for sleep bruxism remain unknown. Analyses of masseter muscle activity during sleep in guinea pigs have shown that the duration and activity of masseter bursts differ between non-rapid eye movement (NREM) and rapid eye movement (REM) sleep and that some repetitive burst episodes do occur. Furthermore, masseter bursts occurred in association with a transient heart rate increase. These results suggest that various patterns of masseter bursts occur in association with transient arousal activity during sleep in guinea pigs.
 
Article
The aim of the present study was to compare the effect of mastication on non-nociceptive orofacial sensory transmission of the somatosensory pathways and that on the jaw reflex arc. To achieve this, single-unit activities of the face primary somatosensory cortex (face-SI) neurons responding to low-intensity electrical stimulation of the inferior alveolar nerve (IAN) and the jaw-opening reflex (JOR) were recorded during mastication in awake rabbits. The entire masticatory sequence was divided into the preparatory period (PP), the rhythmic-chewing period (RC) and the preswallow period (PS). A total of 112 face-SI neurons were tested for the effects of mastication. The responsiveness of most neurons and the JOR were modulated during different periods of mastication. The IAN-evoked activity was attenuated in a majority of the neurons during at least one of the masticatory periods. The JOR was suppressed during the RC and PS, while the modulatory effect was variable during the PP. Regression analysis showed that the modulatory effect of mastication on the IAN-evoked neuronal activity and that on the JOR was not well correlated. It was notable that a considerable number of face-SI neurons showed mastication-related activity although their responsiveness to IAN stimulation was strongly suppressed (i.e. almost "gated out") during mastication. The findings indicate that (1) sensory transmissions of the somatosensory and reflex pathways may be modulated in a different manner during mastication, and that (2) activity of face-SI neurons during mastication may not necessarily be a simple reflection of movement-induced stimulation of orofacial mechanoreceptors.
 
Article
The mass response of a nerve bundle and the unitary discharges from a functional single nerve fibre evoked by mechanical stimulation of the upper canine tooth were recorded from the superior alveolar nerves of 10 anaesthetized cats. When the pulpal cavity of the mechanically stimulated tooth was perfused with a 0.9% NaCl solution at temperatures from 10 to 45 degrees C, the mass response of the nerve bundle to that stimulation increased linearly with the rise in perfusate temperature (hereafter, tooth temperature). In the unitary discharge recordings, the activities of 30 (88%) of 34 slowly adapting periodontal mechanosensitive units were modulated by tooth temperature. The optimal temperature, at which the periodontal mechanoreceptor shows extreme excitation by mechanical tooth stimulation, was distributed widely from 10 to < or = 45 degrees C with a peak at < or = 45 degrees C. A shift in tooth temperature away from the optimal value caused a decrease in, or sometimes the disappearance of, the response. This decrease was the result of the decrease in the excitability of the periodontal mechanoreceptor; i.e. an increase in threshold stimulus intensity and a shortening of the adaptation time to sustained pressure applied to the tooth.
 
Article
Although the inactivation or removal of motoneurones and muscles are known to affect development and growth of the craniofacial skeleton and masticatory muscles, the effect of these on functional activity patterns is not clear. The goal of this study was to evaluate the immediate responses of masticatory muscle activities to temporary nerve blocks of individual jaw-closing muscles. Nineteen experiments were made with four miniature pigs (Sus scrofa). Electromyograms of the masticatory muscles and jaw movements were recorded during natural chewing. Then, the function of individual jaw-closing muscles was removed unilaterally by local anaesthesia, and the recording repeated. The results showed a general increase in the activities of the other jaw-closing muscles, particularly those that were synergistic with the blocked muscle in producing lateral movements. Furthermore, the lateral pterygoid showed stronger activity, and accordingly the lateral movement was increased. Digastric muscle activity and the magnitude of jaw opening also tended to increase. Thus, the response to loss of a muscle is a strong, immediate compensation by synergists.
 
Article
Saline extracts of pooled dental plaque from donors in Scotland and New York State (NYS) contained the same high and low molecular wt toxic substances as described previously (Levine et al., 1974b). The high mol. wt substances separated into two toxic components (I and II) which precipitated on saturation with ammonium sulphate and the low one was a single toxic component (III). Component I bound to DEAE-Sephadex at pH 8 and eluted as the ionic strength increased from 0.1 to 0.2 M NaCl. Component II activity was increased by incubating the plaque for 2 h at 37 °C before extracting it. It is concluded that the toxic components in plaque are similar, irrespective of donor age and geographic distribution. Older donors from NYS had significantly more plaque than younger donors, but correspondingly less activity per g wet plaque.
 
Article
The accumulation of ribonuclease activity in the perinatal submandibular gland and its decrease with adulthood was not due to the presence of inhibitors or activators and thus reflects real differences in enzyme concentration. The RNase activities of parotid and submandibular glands of the 4-day old and adult rat were purified by DEAE-Sephadex and/or by affinity chromatography and their properties were compared. RNases from the different sources were identical in their behaviour on DEAE-Sephadex chromatography, and in their pH optima, acid-stability, heat-stability and lack of activity against polyadenylic acid. The 4-day submandibular RNase was identical to the adult parotid enzyme in its electrophoretic mobility on polyacrylamide gel. Measurements were made of the relative activity of the various RNases against polycytidylic acid (poly C) versus RNA; all had greater activity against poly C. In general, considerable variability in the poly C:RNA activity ratio among different preparations precludes a confident conclusion about their similarity or difference. However, the poly C:RNA ratio of the adult submandibular gland RNase was lower than that of all of the others, and this enzyme may be different from both the RNase of the neonatal submandibular gland and that of the adult parotid gland.
 
Article
Phenol-water extracted lipopolysaccharide (LPS) from Bacteroides melaninogenicus was lethal for mice and prepared rabbits for the local Shwartzman reaction. The endotoxic potency was, however, considerably lower than that of LPS from Salmonella typhi. The B. melaninogenicus LPS had an infection-enhancing effect in mice and affected the migration of human leucocytes in vivo.RésuméLe lipopolysaccharide extrait avec une solution aqueuse de phénol (LPS) de Bacteroides melaninogenicus a été létal pour la souris et les lapins préparés pour la réaction locale Schwartzman. Cependant, la puissance endotoxique a été considérablement plus basse que celle du LPS de Salmonella typhi. Le B. melaninogenicus LPS eût un effet de rehaussement de l'infection chez la souris et affecta la migration des leucocytes in vivo.ZusammenfassungPhenolwasser extrahierte lipolytisches Saccharid (LPS) aus Bacteroides melaninogenicus, welches sich bei Mäusen tödlich erwies und Kaninchen für die lokale Schwartzman Reaktion vorbereitete. Die endotoxische Potenz war jedoch bedeutend geringer als das aus Salmonella typhi entzogene LPS. Das B. melaninogenicus LPS hatte eine infektions-intensive Wirkung auf Mäuse und regte Wanderung von menschlichen Leukozyten in vivo an.
 
Article
Monoamine oxidase activities in the salivary glands of rats aged 1–70 days were measured using tyramine, dopamine, serotonin and noradrenaline as substrates. The total activities of the glands increased with age and were, at 70 days, approximately 27-fold with dopamine, 20-fold with serotonin, 12-fold with tyramine and 19-fold with noradrenaline, those of 1-day-old rats. Activities of the enzyme per unit weight did not vary significantly during development.
 
Article
The purpose of this study was to investigate the candidacidal activity of the glucose oxidase-mediated lactoperoxidase system at various levels of glucose and glucose oxidase. Candida albicans ATCC strains 18804, 10231, 11006, bovine lactoperoxidase (25 and 50 μg/mL), and KSCN (1 mM) were used. Different levels of glucose oxidase (1, 5, 10, and 20 units/mL) and glucose (0.03, 0.3, and 3.0 mg/mL) were added to complete the system. The candidacidal activity of the system was examined by preincubating its components for 0-60 min, and then with C. albicans. Candidacidal activity was determined by comparing the numbers of CFU and calculating the percent loss of cell viability. The system displayed 13.9-27.4% (without preincubation) to 28.6-34.3% (preincubation for 60 min) loss of viability at 25 μg/mL of bovine lactoperoxidase, 10 units/mL of glucose oxidase, and 0.03 mg/mL of glucose; similar results were obtained with 20 units/mL of glucose oxidase or 0.06 mg/mL of glucose. The candidacidal activity of the system increased markedly as the glucose concentration increased. The candidacidal activity displayed 87.2% (without preincubation) to 100.0% (preincubation for 60 min) at 3.0 mg/mL of glucose. At 3.0 mg/mL of glucose, the system containing 1 or 5 units of glucose oxidase also showed significant levels of candidacidal activity. The candidacidal activity of the glucose oxidase-mediated lactoperoxidase system at physiological concentrations of salivary glucose was moderate, but was greatly elevated with increases of glucose level.
 
Article
The activities of arylaminopeptidases in the microsomal and soluble fractions of bovine dental pulp were examined using 25 amino acid β-naphthyl-amides as substrates. The arylaminopeptidase activities towards β-naphthylamides of alanine, leucine, norleucine, lysine, arginine, phenylalanine, norvaline and methionine were high in microsomal and soluble fractions of bovine dental pulp. Glycyl-prolyl β-naphthylamidase and methionyl β-naphthylamidase activities were predominantly localized in the microsomal fraction of dental pulp, whereas leucyl β-naphthylamidase activity was in the soluble fraction.RésuméLes activités des arylaminopeptidases dans les fractions microsomiales et solubles de la pulpe dentaire bovine ont été étudiées en utilisant 25 amino-acides β-naphthylamides comme substrats. Les activités en arylaminopeptidases envers les β-naphthylamides de l'analine, leucine, norleucine, lysine, arginine, phenylalanine, norvaline et methionine sont élevées dans les fractions microsomiales et solubles de la pulpe dentaire bovine. Les activités en glycyl-prolyl-β-naphthylamidase et methionyl-naphthylamidase sont localisées de façon prédominante dans la fraction microsomiale de la pulpe dentaire, alors que l'activité en leucyl β-naphthylamidase est trouvée dans la fraction soluble.ZusammenfassungMit Hilfe von 25 Aminosäure-β-Naphthylamiden als Substraten wurden die Aktivitäten der Arylaminopeptidasen in den mikrosomalen und löslichen Fraktionen der Zahnpulpa vom Rind untersucht. Die Arylaminopeptidase-Aktivitäten waren im Vergleich zu der β-Naphthylamiden von Alanin, Leucin, Norleucin, Lysin, Arginin, Phenylalanin, Norvalin und Methionin in den mikrosomalen und löslichen Fraktionen der untersuchten Zannpulpen hoch, Glycyl-prolyl-β-naphthylamidase und Methionyl-β-naphthylamidaseaktivitäten waren vorwiegend in der mikrosomalen Fraktion der Zahnpulpa vorhanden, während sich die leucyl-β-naphthylamidaseaktivität in der löslichen Fraktion fand.
 
Article
Lactate dehydrogenase (LDH; EC 1.1.1.27), malate dehydrogenase (MDH; 1.1.1.37) and aspartate aminotransferase (ASAT; EC 2.6.1.1) activities of human dental pulp were measured in various physiological and pathological states. The assay method was based on the oxidation of reduced nicotinamide-adenine dinucleotide (NADH2) at 340 nm via the reduction of either Na-pyruvate (LDH) or oxalacetate (MDH, ASAT). The activity was determined per mg protein or per mg dry weight of the sample. The results were calculated as the means of the values. The means of LDH activity for teeth with enamel or dentine caries or pulpitis differed little from those of developing teeth. A highly-significant increase in LDH activity was observed in teeth with gangrenous pulps compared to intact teeth. The activity pattern of ASAT resembled that of LDH. The MDH activity present appeared to increase with completion of root development. Zero values were obtained in teeth with pulps reduced to cell debris. It is concluded that the pattern of MDH activity and the increase of LDH and ASAT activity with pulp gangrene are partly due to the presence of microbes and are in accord with tissue findings in other injuries.
 
Article
Static mechanical analyses of the masticatory apparatus often assume that jaw muscle activity, as measured using electromyography (EMG), is linearly and constantly related to magnitude of bite force during biting, regardless of bite force-induced tooth-tipping moments. The objective of this study was to test the hypothesis that the relationship between EMG of the jaw muscles and bite force varies with the magnitude and sign of tooth-tipping moments. Seven healthy male subjects produced unilateral static occlusal forces at five biting positions, resulting in sequential changes from buccal (+) to lingual (-) tipping moments on the mandibular first molar. Jaw muscle activities were recorded bilaterally using surface (for temporalis and masseter muscles) and indwelling (for lateral pterygoid muscles) electrodes. Bite forces were recorded and controlled using custom devices. EMG versus bite force data were plotted and regression relationships were calculated for each subject, muscle and biting position. Linear regression analysis, analysis of variance and Bonferroni adjusted least significant difference tests were used to determine the effects of muscle, side (ipsilateral, contralateral) and biting position within subjects. It was found that the relationship between EMG and bite force for different tipping moments differed significantly within a subject and muscle. This was most common in the lateral pterygoid and temporalis muscles (all P</=0.042), where slopes of the EMG:bite force relationship varied between 3:1 and >25:1. In the masseter muscle, the EMG:bite force relationship for different tipping moments differed significantly in one subject (P<0.008); slopes varied up to 4.6:1. In conclusion, the relationship between EMG and bite force was linear. However, the slopes of the relationship changed significantly depending on sign (+, -) and magnitude of tipping moments acting on the molars.
 
Article
Human labial and palatine gland secretion was collected by aspiration after pilocarpine stimulation. In both secretions, blood group antigens and virus-haemagglutination inhibition activity were found in high concentrations, alpha-amylase in low concentration and kallikrein as traces. Lysozyme activity was detectable only in the labial secretion. The biological activities present indicated that proteins of the minor salivary gland secretions may participate in the formation of the acquired dental pellicle.
 
Article
To investigate the effects of peroxidase or the peroxidase system on the enzymatic and candidacidal activities of lysozyme. The effects of peroxidase on lysozyme were examined by incubating hen egg-white lysozyme (HEWL) with bovine lactoperoxidase (bLPO). The influence of the peroxidase system on lysozyme was examined by the subsequent addition of potassium thiocyanate and hydrogen peroxide. Lysozyme activity was determined by the turbidity measurement of a Micrococcus lysodeikticus substrate suspension. Candidacidal activity was determined by comparing the colony forming units of Candida albicans ATCC 10231, ATCC 18804, and ATCC 11006. The Wilcoxon signed rank test was used to analyze the effects of variables. bLPO at physiological concentrations enhanced the enzymatic activity of HEWL and its effect was dependent on bLPO concentration. The enhancement of enzymatic activity of HEWL by bLPO was affected by pH and ionic strength. The addition of potassium thiocyanate and hydrogen peroxide did not lead to an additional enhancement of the enzymatic activity of HEWL, as compared with bLPO alone. HEWL displayed candidacidal activity in all 3 strains of C. ablicans. The addition of bLPO alone did not affect the candidacidal activity of HEWL, but the bLPO system enhanced candidacidal activity of HEWL in all 3 strains of C. ablicans. bLPO enhanced the enzymatic activity of HEWL, but the bLPO system did not show additional enhancement of the enzymatic activity of HEWL. The addition of bLPO did not affect the candidacidal activity of HEWL, but the bLPO system did enhance the candidacidal activity of HEWL.
 
Article
The catecholamine concentrations and activities of tyrosine hydroxylase, DOPA decarboxylase, dopamine β-hydroxylase, catechol 0-methyltransferase and monoamine oxidase in the submandibular and sublingual glands of developing rats ranging in age from 1 to 70 days were measured. The total concentration of catecholamines and the total activities of tyrosine hydroxylase and monoamine oxidase increased markedly up to 56 days and then remained at about the same levels. The total activities of dopamine β-hydroxylase increased steadily between 1 and 70 days of age. The total activity of DOPA decarboxylase increased rapidly to approximately 55-fold up to 21 days of age, thereafter decreasing markedly and at 70 days of age was only 2.6-fold higher than that at 1 day of age, probably because endogenous inhibitors are present in the submandibular gland of rats older than 42-days. The total activity of catechol 0-methyltransferase increased 38-fold up to 56 days of age, and thereafter decreased. Catecholamine concentrations and activities of the enzymes per unit weight reached maximal levels at the age of 14 or 21 days except for catechol 0-methyltransferase which reached maximal activity at 42 days of age. After 14 days, the catecholamine concentrations remained at almost the same level. The activity of dopamine β-hydroxylase and catechol 0-methyltransferase increased 2–3-fold reaching maxima at 21 and 28 days respectively. The monoamine oxidase activity remained at about the same level after birth.
 
Article
Microbial infection is thought to modulate allergic disorders, and we previously demonstrated that not only mast cells (which release histamine), but also platelets are involved in the anaphylaxis induced in mice sensitised to ovalbumin (OVA). Here, we examined the effects of a lipopolysaccharide (LPS) from the oral bacterium Prevotella intermedia (Pi) on OVA-induced anaphylaxis. Upon intraperitoneal co-injection of Pi-LPS plus OVA into BALB/c mice, the Pi-LPS displayed a potent adjuvant effect comparable to that of alum (a standard adjuvant) in terms of its abilities to induce both anaphylactic shock and histamine-release following an antigen (OVA)-challenge. Moreover, an injection of Pi-LPS given to OVA+alum-sensitised mice shortly before an OVA-challenge augmented the shock-response. This LPS-pretreatment did not affect histamine-release, but did augment pulmonary platelet accumulation. Histamine was not by itself causal for shock-induction in sensitised mice. These results suggest that oral bacteria and/or their constituents (such as LPS) may help to sensitise the host to an antigen or exacerbate the host's allergic reactions ("aggravation effect"), probably by enhancing the platelet response to the antigen OVA.
 
Article
In the current study, we performed taste and salivary analysis on patients suffering from burning mouth syndrome and xerostomia or taste disturbances. A total of 180 patients who complained of idiopathic burning mouth syndrome (BMS) and taste aberrations and/or xerostomia that may accompany BMS were evaluated. These patients were compared with 90 healthy, age- and sex-matched controls. Salivary flow rate, biochemical and immunological analysis and taste acuity by the forced-choice drop technique were performed for all subjects. These analyses were found to be conclusive in distinguishing controls from patients with complaints. The great similarity of both salivary and taste analysis in the BMS, taste aberration and xerostomia groups, which were significantly different from the results obtained in the control group, was found to be the most striking result. Higher salivary concentrations in the experimental group were consistent with a lower saliva (water) flow rate. An oral neuropathy and/or neurological transduction interruption induced by salivary compositional alterations is suggested as the possible aetiology for the complaints. This report may add an important objective diagnostic tool to the clinician treating these patients.
 
Article
To ascertain the relative contributions of individual salivary gland secretions in the maintenance of taste acuity, we arbitrarily divided 28 rats into four groups of seven each. Group A: sham-operated controls; Group B: surgical removal of parotid glands only; Group C: removal of all major salivary glands; and Group D: removal of submandibular-sublingual gland complexes. Taste acuity was measured with a 2-bottle technique and a wide concentration range of NaCl, sucrose (S), hydrochloric acid (HCl) and quinine sulphate (QS) solutions. Daily fluid consumption was used to calculate percentage preference. Groups A and B showed marked rejection of most QS solutions (range 1-53 per cent) while Groups C and D exhibited significantly (p < 0.01) less rejection (32-52 per cent). Groups A and B showed a similar rejection of most HCl solutions (range 2-57 per cent) while Group C showed significantly (p < 0.01) greater acceptance of four of the solutions and Group D showed a variable response. Groups A and B exhibited a marked preference for the more concentrated S solutions (range 40-98 per cent) while Groups C and D did not increase their S solution intake until very high concentrations and never showed as great a preference as controls (range 48-80 per cent) the differences generally being significant at p < 0.01. Groups A and B exhibited an essentially normal preference-aversion curve for the NaCl solutions. Groups C and D showed less rejection of the more concentrated solutions, the differences generally being significant. Thus it seems that removal of the major glands produces a severe taste defect that is closely mimicked by removal of the submandibular-sublingual glands alone.
 
Top-cited authors
Colin Dawes
  • University of Manitoba
Lakshman Perera Samaranayake
  • The University of Hong Kong
Anthony Smith
  • University of Birmingham
Israel Kleinberg
  • Stony Brook University
Grayson William Marshall
  • University of California, San Francisco