The effects of Acacia arabica gum on the in vitro growth and protease activities of periodontopathic bacteria.

The antibacterial activity of acacia gum was assessed using fresh isolates and reference strains of Actinobacillus actinomycetemcomitans, Capnocytophaga spp., Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola. A fine aqueous suspension of gum was produced by sonication and then a soluble fraction isolated by centrifugation and membrane filtration.

Cathepsin B/L-, elastase-, tryptase-, trypsin- and dipeptidyl peptidase IV-like activities in gingival crevicular fluid: a comparison of levels before and after periodontal surgery in chronic periodontitis patients.

Gingival crevicular fluid (GCF) was collected from the deepest probing site of each tooth of 10 chronic periodontitis patients prior to treatment, after scaling and hygiene treatment, and after periodontal surgery. Surgery was carried out at sites which had persistent probing depths in excess of 5 mm. The patients were given a full periodontal examination, including measurements of probing depth, gingival index, bleeding index, and plaque index before each GCF collection.

Cathepsin B/L-, elastase-, tryptase-, trypsin- and dipeptidyl peptidase IV-like activities in gingival crevicular fluid. A comparison of levels before and after basic periodontal treatment of chronic periodontitis patients.

20 chronic periodontitis patients were given a full periodontal examination, including measurements of probing depth, clinical attachment loss, gingival index, bleeding index and plaque index. At a second visit, gingival crevicular fluid (GCF) was collected from the deepest accessible probing site of each tooth. The patients then received scaling, root planing and other appropriate nonsurgical treatment.

Correlation of gingival crevicular fluid proteases with clinical and radiological measurements of periodontal attachment loss.

Probing attachment loss and radiographical measurements of bone loss were made on 20 untreated chronic periodontitis patients. At a second visit, gingival crevicular fluid was collected on filter paper strips from the deepest accessible interdental probing site of each tooth. Gingival crevicular fluid volumes were determined and the samples eluted into buffer.

Dipeptidyl peptidase II- and IV-like activities in gingival tissue and crevicular fluid from human periodontitis lesions.

Gingival tissue and gingival crevicular fluid were collected from patients with chronic periodontitis. Gel filtration chromatography of crude tissue extracts yielded separate fractions active against Lys-Ala-7-amino-4-trifluoromethyl-coumarylamide (AFC) at acid pH and Gly-Pro-AFC at alkaline pH. The molecular weights, pH optima and inhibitor responses of these activities were consistent with those of dipeptidyl peptidases (DPP) II and IV, respectively.

Cathepsin B/L-, elastase-, tryptase-, trypsin- and dipeptidyl peptidase IV-like activities in gingival crevicular fluid: correlation with clinical parameters in untreated chronic periodontitis patients.

20 untreated chronic periodontitis patients were given a full periodontal examination, including measurements of probing depth (PD), clinical attachment loss (CAL), gingival index (GI), bleeding index (BI) and plaque index (Pl.I.).

Cathepsin B- and L-like activities at local gingival sites of chronic periodontitis patients.

The cysteine proteinases cathepsins B and L have the potential to degrade connective tissue in chronic periodontitis and this may progress episodically at individual tooth sites. The activities of cathepsin B- and L-like proteinases in homogenised gingival tissue from control and periodontitis patients were measured biochemically using the selective peptide substrate Z-Phe-Arg-AFC and the selective cathepsin L inhibitor Z-Phe-Phe-CHN2. Each tooth site was divided, where appropriate, into gingival tissue and granulomata.

Protease activities in peri-implant sulcus fluid from patients with permucosal osseointegrated dental implants. Correlation with clinical parameters.

The 15 patients included in this study each had 2-6 permucosal Branemark osseointegrated implants that had functioned successfully for 18 months or more. They were given a full oral examination which included measurements of probing depth and gingival, bleeding and plaque indices around the implants. Marginal bone reduction during the functional life of the implants was estimated from radiographs.

A study of mercury redistribution, excretion and renal pathology in guinea-pigs implanted with powdered dental amalgam for between 2 and 4 years.

Ten guinea-pigs were implanted subcutaneously with 2 x 25 mg of powdered amalgam for 2, 2.5, 3, 3.5, and 4 years, two animals at each time period.

A simple, combined fluorogenic and chromogenic method for the assay of proteases in gingival crevicular fluid.

Substrate impregnated paper discs were prepared using peptidyl derivatives of 7-amino-4-trifluoromethylcoumarin (AFC). After incubation with test solutions, the green, UV-induced fluorescence of AFC liberated by enzyme activity was distinguishable from the blue-violet fluorescence of the substrates. The AFC could then be coupled with p-dimethylaminocinnamaldehyde to form a colored Schiff base.

A biochemical study of serine proteinase activities at local gingival tissue sites in human chronic periodontitis.

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.

Androgen metabolism in gingival hyperplasia induced by nifedipine and cyclosporin.

Three cases of gingival overgrowth induced by cyclosporin and/or nifedipine have been reported. Patient A was under medication with cyclosporin plus nifedipine, patient B with nifedipine only and patient C with cyclosporin only. The significance of androgen metabolism in gingival tissue with respect to hyperplastic changes has been studied by several workers.

Detection of cathepsin B- and L-, elastase-, tryptase-, trypsin-, and dipeptidyl peptidase IV-like activities in crevicular fluid from gingivitis and periodontitis patients with peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin.

Crevicular fluid samples were collected from 20 gingivitis and periodontitis patients using filter paper strips; these were then eluted into buffer. Portions of each sample were combined and the activities of this pooled eluate against different peptidyl derivatives of 7-amino-4-trifluoromethyl coumarin (AFC) were examined with respect to their pH profiles and effector responses. Ca-thepsin B- and L-like activity was detected with Bz-Val-Lys-Lys-Arg-AFC; elastase-like activity with MeOSuc-Ala-Ala-Pro-Val-AFC; tryptase-like activity with Z-Ala-Ala-Lys-AFC; trypsin-like activity with Z-Gly-Gly-Arg-AFC; and dipeptidyl peptidase (DPP) IV-like activity with Ala-Pro-AFC.

Identification of a tryptase-like enzyme in extracts of inflamed human gingiva by effector and gel-filtration studies.

Inflamed gingiva contain a serine proteinase which could not previously be identified on the basis of its substrate specificity and inhibitor response. Using the substrate ZAlaArgArgAFC at alkaline pH, the enzyme was shown to be extracted more efficiently in high salt buffer. Inclusion of NaCl in assays, however, caused progressive reduction of activity.

Tryptase-like activity in crevicular fluid from gingivitis and periodontitis patients.

Crevicular fluid was collected from gingivitis and periodontitis patients on filter paper strips and then eluted into buffer. The eluates hydrolyzed ZAlaArgArgAFC at alkaline pH and the effector response at pH 8.5 indicated serine proteinase activity.

The effect of chronic low level lead exposure on blood-brain barrier function in the developing rat.

Blood-brain barrier (BBB) function was assessed in 19-21-day-old rats exposed to low level lead from birth. Newborn rats received lead via milk from lactating dams given drinking water containing 0.1% lead acetate [Pb(Ac)2].

Regional cerebral glucose metabolism and blood flow during the silent phase of methylmercury neurotoxicity in rats.

Methylmercuric chloride was given to rats in a neurotoxic dose regimen (six daily doses of 8 mg kg-1 p.o.).

Influence of a standard laboratory diet containing nutritionally adequate levels of selenium on renal pathology from mercury released by experimental amalgam tattoos.

Twenty-four guinea pigs were subcutaneously implanted with 2 X 25 mg of powdered dental amalgam for between 1 and 24 months. Four animals served as controls. All animals were fed a standard diet containing 0.

Multiple idiopathic external root resorption. A case report.

An unusual case of multiple idiopathic external apical root resorption affecting all four quadrants, in a patient with a history of narcotic intravenous drug addiction and liver disease, is reported. The literature relating to a systemic etiology for external root resorption is briefly reviewed.

Renal cortical mercury levels associated with experimental amalgam tattoos: effects of particle size and amount of implanted material.

Powdered dental amalgam that had passed through either a 106 microns or a 45 microns sieve was implanted subcutaneously in guinea pigs for periods of up to 2 yr. The renal cortical mercury levels associated with the 106 microns material were on average 16% of those produced by the 45 microns material. A reduction in the amount of 45 microns powder implanted, by a factor of 75%, resulted in a fall of only 27% in renal mercury concentrations.

Further investigations of the soft tissue reaction to the gamma 2 phase (Sn7-8Hg) of dental amalgam, including measurements of mercury release and redistribution.

Following the subcutaneous implantation in guinea pigs of powdered gamma 2 phase with a mercury content only slightly greater than that indicated by the stoichiometric formula Sn7Hg, there was a limited initial release of mercury from extracellular material. Thereafter, chronic granulomata developed around the implants and particles degraded slowly in macrophages and giant cells. Vast numbers of fine secondary particles containing tin were produced and these were associated with macroscopic staining.

Further investigations of the soft tissue reaction to the gamma 1 phase (Ag2Hg3) of dental amalgam, including measurements of mercury release and redistribution.

The subcutaneous implantation in guinea pigs of powdered gamma 1 phase induced a severe initial tissue response and the majority of the material was extruded from the healing wounds. This process was accompanied by the release of significant amounts of mercury which appeared in the body organs and excreta. The small numbers of particles which remained in the tissues were handled quite differently, undergoing slow degradation in macrophages and giant cells in chronic granulomata.