Antioxidant activity of polyphenols from solid olive residues of c.v. Coratina

The antioxidant profile of extracts from solid olive residue (SOR) of c.v. Coratina, a cultivar widely diffused in the south of Italy, using both cell-free and cell-based experimental models, was investigated. A total hydroalcoholic extract (polyphenols content 19.7%) and a purified extract (Oleaselecttrade mark) (polyphenols content 35.1%) were tested for their ability to quench the stable free radical DPPH, the peroxyl radicals (ORAC assay), by monitoring the loss in fluorescence of R-phycoerythrin induced by the peroxyl radical generator AAPH and their ability to inhibit the cumene hydroperoxide-induced lysis of rat red blood cells (RBC). The total hydroalcoholic extract showed IC(50) 26.96+/-1.53 microg/ml in the DPPH assay, that 10 microg/ml were equivalent to 2.11+/-0.12 microg/ml Trolox (ORAC assay) and IC(50) 1.7+/-0.20 microg/ml in the RBC hemolysis. The Oleaselect extract was 4 to 5 folds more active than the hydroalcoholic extract in all the experimental models, with IC(50) values of 7.36+/-0.38 microg/ml in the DPPH test and of 0.38+/-0.03 microg/ml in RBC; the antioxidant activity in the ORAC assay was slightly greater than that of Trolox (10 microg/ml equivalent to 11.45+/-0.40 microg/ml). The scavenging effect of the extract in the ORAC assay was compared to that of verbascoside (the main polyphenol component) and of caffeic acid (the basic constituent of verbascoside): the results indicate that caffeic acid (10 microg/ml equivalent to 35.70+/-2.95 microg/ml Trolox) is more potent than verbascoside (10 microg/ml equivalent to 15.42+/-1.21 microg/ml Trolox) in entrapping peroxyl radicals. Finally the antioxidant activity of the Oleaselect extract was confirmed in human umbilical endothelial cells (EC) exposed to the site-specific peroxyl radical inducer AAPH, where a massive lipid peroxidation process (marker the fluorescence probe BODIPY) takes place, paralleled by a marked loss of cell viability (calcein assay). The purified extract (1-20 microg/ml) pre-incubated with EC for 1 h dose-dependently inhibited both the lipid-peroxidation damage and cell death. Taking into account the total polyphenol content, these results clearly indicate a greater antioxidant activity for the purified extract, due to a cooperative antioxidant interaction among its polyphenol constituents.

[The preprosthetic preparation of the endodontically treated abutment tooth. Post and core technique: a questionnaire analysis]

The goal of the questionnaire was to determine the materials and methods that general dentists in Switzerland at present use for the treatment of non-vital abutment teeth. Questionnaires were sent to 1000 dentists from a computer generated random sample of the list of members of the SSO (Swiss Dental Society). The return ratio was 36%. The responses provided information on the current philosophies and prevailing techniques used to restore endodontically treated abutment teeth. Most of the answering dentists believed it was necessary to stabilize a root treated tooth with a post. The preferred restoration in anterior teeth was the cast post and core, while composite resin build-up with a prefabricated post was predominantly made for posterior teeth. Conical or combined cylindrical-conical posts, which had a sand-blasted surface, were predominantly used. Most of the answering dentists strove to stabilize the remaining tooth structure by circular enclosure of the tooth structure by the later crown (ferrule effect). Zinc phosphate cement was still preferred for cementation of metal posts and ceramic posts were most often fixed with the help of the acid etching technique. The most frequently described failures were retention loss or root fractures.

Mass spectrometric characterization and HPLC determination of the main urinary metabolites of nimesulide in man

A study was undertaken for the characterization and quantitative determination of the main urinary metabolites of the non-steroidal anti-inflammatory drug (NSAID) nimesulide (4-nitro-2-phenoxy-methanesulfonanilide) in man following single oral administration (200 mg). Urines were collected from six healthy volunteers at 12, 24, 48, 72 and 96 h post-administration and submitted to liquid liquid extraction before (free metabolites) and after enzymatic hydrolysis (conjugated metabolites). The structure of the metabolites, isolated by TLC separation, was elucidated by mass spectrometry (electron impact ionization) and confirmed by synthesis. Five metabolites were identified: they arise from hydroxylation to the phenoxy nucleus (M1 = hydroxynimesulide); reduction of the nitro group to an amino derivative (M2); concomitant hydroxylation and reduction (M3); N-acetylation of the M2 (M4) and of the M3 (M5) metabolites. Quantitation was by reverse phase high performance liquid chromatography (Supelcosil LC-18 DB column; mobile phase: sodium phosphate buffer (pH 3.0, 50 mM)-acetonitrile (gradient elution); flow rate: 1 ml min(-1); UV detection, 230 nm), procedure which allows in a single chromatographic run the simultaneous determination of the unchanged drug and of its metabolites. The urinary excretion of the drug and metabolites (free + conjugated) in the overall 96 h-interval accounts for approximately 40% of the administered dose: 17.55 +/- 3.6% M1; 0.72 +/- 0.43% M2; 2.45 +/- 1.22% M3; 19.07 +/- 4.3% M5. The bulk of the metabolites was in conjugated form. Percentages excretion of the unchanged drug and of M4 metabolite were below 0.5%. The described method is suited to specifically and quantitatively measure nimesulide and metabolites in human urine with acceptable precision and accuracy.

Do healing abutments influence the outcome of implant treatment? A three-year multicenter study

STATEMENT OF THE PROBLEM

It is not known if healing abutments replaced subsequently with permanent abutments adversely affect the soft tissues and marginal bone levels around dental implants.

PURPOSE

This study evaluated the mucosal condition and marginal bone levels 3 years after placement of healing abutments in patients provided with fixed prostheses supported by Brånemark implants.

MATERIAL AND METHODS

Data were analyzed retrospectively from 117 patients treated at five centers in which 318 healing abutments were placed on maxillary and 112 on mandibular implants. A prospective 3-year appraisal with a specific protocol assessed the response of mucosal cuffs and marginal bone levels surrounding surviving implants.

RESULTS

Exchange of abutments did not affect expected survival rates of implants (94% maxilla, 99% mandible) or produce mean levels of marginal bone loss greater than anticipated for the system. Mean marginal bone levels correlated significantly with the jaw. Most patients achieved good oral hygiene and favorable peri-implant soft tissue health.

CONCLUSION

No evidence was found to suggest abutment exchange adversely affects outcome of implant treatment.

An international comparative multicenter study of assessment of dental appearance using computer-aided image manipulation

PURPOSE

The aim of the present investigation was to perform an international multicenter comparison of dental appearance as evaluated by dentists, dental technicians, and nondental subjects.

MATERIALS AND METHODS

The participants were drawn from three groups: 203 dentists, 197 dental technicians and 254 nondental subjects. The methods developed in a previous study in Sweden were applied again in seven centers located in six countries. A questionnaire, accompanied by five sets of computer-manipulated images portraying one man and one woman, was used to prompt and record responses to different aspects of dental appearance and function.

RESULTS

The questionnaire revealed that both the dental appearance and function of teeth were important to most of the participants, but three quarters of the participants did indicate that good dental function was more important that esthetics. More women (30%) than men (18%), however, placed greater importance on appearance. Age or gender did not influence judgments of the computer-manipulated images, although judgments did vary greatly within the three groups and between the centers. Nonetheless, highly colored teeth were preferred more often by nondental subjects than by dentists or dental technicians.

CONCLUSION

Computer-aided image manipulation shows promise as a method for investigating the significance of dental-related beliefs, especially those relating to esthetics, in different population groups. The evaluation of dental appearance and function in this study indicated that dental function is held in greater regard, and that the significance of dental appearance varies widely among dentists, dental technicians, and nondental subjects.

Direct characterization of caffeoyl esters with antihyaluronidase activity in crude extracts from Echinacea angustifolia roots by fast atom bombardment tandem mass spectrometry

Fast atom bombardment (FAB-MS) and fast atom bombardment tandem mass spectrometry (FAB-MS/MS) techniques (negative ions) have been successfully applied for identification of the constituents responsible for the antihyaluronidase activity of Echinacea angustifolia roots, whose extracts are widely employed for the adjuvant therapy of chronic inflammatory diseases. Crude extracts from different solvents were tested for antihyaluronidase activity, and those with the greatest inhibitory action (the ethylacetate, butylacetate and chloroform fractions, IC50 0.44, 0.50 e 0.62 mg/ml) were directly analyzed by MS. Full scan mass spectra produced intense molecular anions: collisional activation of these resulted in tandem mass spectra rich in significant product ions. Four main caffeoyl conjugates were detected and identified by tandem mass spectrometry (daughter and parent ion mode): 2,3-O-dicaffeoyltartaric acid (chicoric acid) and 5-O-dicaffeoylquinic acid (cynarine) and 2-O-caffeoyltartaric acid (caffaric acid) in the ethylacetate fraction. Among these caffeoyl conjugates, chicoric and caftaric acids had the greatest antihyaluronidase activity: IC50 = 0.42 and 0.61 mM, while the IC50 of cynarine and chlorogenic acid were 1.85 and 2.25 mM.

Long-standing plaque and gingivitis at implants and teeth in the dog

The experiment was performed to evaluate the effects of long-standing plaque on the gingiva and peri-implant mucosa. 5 beagle dogs were used in the study. The mandibular right premolars were extracted. 3 months later, 3 titanium fixtures were installed and after another 3 months, abutment connection was performed. Plaque control, in the implant as well as the contralateral tooth regions, was maintained during a 4-month period prior to the start of the main experiment. On Day 0, the teeth and implant sections were examined with respect to plaque and gingivitis. The plaque control program was terminated. The animals were subsequently fed a diet which allowed gross plaque accumulation. After 90 days of undisturbed plaque formation, the dogs were re-examined and biopsies harvested from implants and contralateral teeth. On day 90, all teeth and implants had accumulated large amounts of plaque. The soft tissue at implants and teeth bled on gentle probing. The histological examination of the gingiva and the peri-implant mucosa revealed: (i) both tissues contained an inflammatory cell infiltrate; ICT, (ii) the apical extension of ICT was more pronounced in the peri-implant mucosa than in the gingiva and (iii) the composition of the 2 lesions had many features in common.

O6-alkylguanine DNA alkyltransferase is induced by human recombinant interferon-alpha A/D in mouse liver

Treatment of C57Bl or BALB/C mice with human interferon-alpha A/D (HuIFN-alpha A/D) significantly increased hepatic levels of the DNA repair enzyme O6-alkylguanine DNA alkyltransferase (AT). The maximum induction was seen 24 h after a single dose of 50-100 micrograms/kg IFN-alpha A/D. No induction was observed in rat liver hepatocytes cultured in vitro. Liver AT was also induced by poly(I:C), which is a potent IFN inducer. By increasing AT levels, IFN could protect against the potentially mutagenic alkylation at guanine O6 position caused by some carcinogens. Moreover this finding suggests a link between immune response and the DNA repair system, possibly acting in concert to defend the body from potentially toxic compounds.

Experimental breakdown of peri-implant and periodontal tissues. A study in the beagle dog

The objective of the present experiment was to study lesions in the peri-implant and periodontal tissues resulting from ligature placement and subgingival plaque formation. The experiment was performed in 5 beagle dogs which at the start of the study were about 15 months old. They were given a diet which allowed gross plaque formation. The mandibular right premolars were extracted, 3 fixtures (a.m. Brånemark) installed and abutment connection performed. Towards the end of a 6-month plaque control period, a clinical and radiographic examination was performed. Ligatures were placed in a subgingival position at 2 of the implants and the contralateral premolars. Plaque was allowed to accumulate. After 6 weeks, the ligatures were removed. 1 month later, the clinical and radiographical examination was repeated and samples from the subgingival microbiota obtained. Biopsies from the teeth and implant sites were harvested and processed for histometric and morphometric analyses. The results from the clinical and histological examinations revealed that: (i) clinical and radiographic signs of tissue destruction were more pronounced at implants than at teeth; (ii) the size of the soft tissue lesion was larger at implants than at teeth; (iii) the lesion at implants but not at teeth extended into the bone marrow.

Soft tissue reaction to de novo plaque formation on implants and teeth. An experimental study in the dog

The aim of the present investigation was to assess the effect of de novo plaque formation on the gingiva and masticatory mucosa around teeth and implants. The study was performed in 5 beagle dogs which at the initiation of the experiment were 15 months old. During a preparatory period, the mandibular right premolars were extracted, 3 fixtures installed, abutment connection performed and a 4-month period of plaque control completed. A clinical examination was performed and biopsies of the second mandibular premolar (P2) and the contralateral implant site (2P) were sampled. The dogs were allowed to form plaque during a period of 3 weeks. The clinical examination was repeated and biopsies harvested from the 2 remaining implants and the contralateral tooth sites. The tissue samples were prepared for histometric and morphometric analysis. Both the masticatory mucosa at implants and the gingiva responded to de novo plaque formation with the development of an inflammatory lesion. The size as well as the composition of the lesions in the 2 tissues had many features in common. It was concluded that the mucosa around implants and the gingiva around teeth had a similar potential to respond to early plaque formation.

O6-Alkylguanine-DNA alkyltransferase content in synchronised human cancer cells

The DNA repair enzyme O6-alkylguanine-DNA alkyltransferase (AT) was analysed in the human ovarian-cancer SW626 cell line and in the human promonocytic leukemia U937 cell line following their synchronisation with low non-toxic concentrations of methotrexate. In SW626, AT increased in the early S phase of the cell cycle and then declined during progression of the S phase to levels found in the G1 phase of unsynchronised cells. In contrast, at the G1/S-phase boundary and in the S phase, U937 cells showed a lower AT content than did exponentially growing unsynchronised cells. In addition, AT activity was greatly reduced in resting U937 cells but was not reduced appreciably in resting SW937 cells but was not reduced appreciably in resting SW626 cells. The results of these studies indicate that AT fluctuations do not follow a constant pattern during the cell cycle of different cell lines.

Interferon inducers increase O6-alkylguanine-DNA alkyltransferase in the rat liver

We investigated whether treatment with the interferon inducer polyinosinic-polycytidylic acid and other cytokines (interleukin-1, tumor necrosis factor) or the cytokine inducer lipopolysaccharide modified O6-alkylguanine-DNA alkyltransferase (AT) in rat liver. AT levels were determined in liver extracts using N-[3H]methyl-N-nitrosourea alkylated calf thymus DNA as substrate and an HPLC procedure to measure O6-methylguanine. Doses as low as 0.1 mg/kg i.p. of polyinosinic-polycytidylic acid caused a highly significant increase (P less than 0.01) in AT levels in the liver, evident either 24 or 48 h after treatment. Lipopolysaccharide at the dose of 80 micrograms/kg i.p. also induced AT whereas interleukin-1 (60 micrograms/kg) or tumor necrosis factor (60 micrograms/kg) were inactive. Treatment with human recombinant interferon alpha A/D caused a highly significant increase in AT levels, thus confirming the hypothesis that interferon was probably responsible for the observed effect. These results suggest a link between the immune response and DNA repair mechanisms.

[Long-term results of surgical therapy of hemifacial spasm and blepharospasm (author's transl)]

Between 1965 and 1976, 95 patients with hemifacial spasm and blepharospasm have been operated according to the method developed by Fisch at the ENT-Clinic of the University of Zurich. 69 of the patients were followed over an interval of 1 to 12 years. 80% of the patients with hemifacial spasm and 65% of the patients with blepharospasm were free of symptoms or significantly improved. These results remained unvaried over an observation period of 6 to 12 years. The motility of the face was preserved to a very high degree in spite of extensive resection of peripheral facial nerve branches.