Dimeric Proanthocyanidins on the Stability of Dentin and Adhesive Biointerfaces.

A dentin biomodification strategy with selective proanthocyanidin (PAC)-enriched extracts reinforces dentin and dentin-resin interfaces. Enrichment of the extracts according to the degree of polymerization allows exploration of bioactive principles of PACs and structure-activity relationships. This study investigated the sustained dentin matrix biomodification and dentin-resin bioadhesion of 2 fractions consisting exclusively of B-type PAC dimers with or without a single galloyl motif (specifically, DIMERG and DIMERNG) and their precursor material, enriched grape seed extract (e-GSE; Vitis vinifera). The biomodification potential was determined by long-term evaluation of the apparent modulus of elasticity and collagen solubility (hydroxyproline release). Chemical characterization of the dentin matrix was performed by attenuated total reflectance-Fourier-transform infrared spectroscopy. The bioadhesive properties were assessed by a microtensile bond strength test at different time points, and macro-hybrid layers were produced to verify the degree of conversion of the adhesive resin. Fractions consisting of DIMERG, DIMERNG, and their precursor, e-GSE, increased the modulus of elasticity at all time points and reduced collagen degradation. Specimens treated with DIMERNG remained stable throughout 12 mo of storage, whereas a significant drop in the modulus of elasticity was observed for the DIMERG and e-GSE groups at 6 mo. The fractions and precursor did not affect the degree of resin conversion at the hybrid layer. Changes in infrared resonances corresponding to collagen cross-links in the dentin matrix occurred for all treatments. Higher bond strength was observed for dentin treated with e-GSE as compared with DIMERG and DIMERNG; all biointerfaces remained stable after 12 mo. Nongalloylated PACs mediate stable dentin biomodification, which includes protective activity against collagen degradation and reinforcement of the anchoring dentin matrix. Collectively, PACs with a higher degree of oligomerization offer a robust bioadhesion between the hydrophilic dentin matrix and the hydrophobic adhesive.

Biostability of the Proanthocyanidins-Dentin Complex and Adhesion Studies.

Oligomeric proanthocyanidins (OPACs) are potent and renewable natural bioactives possible to be refined into chemically standardized mixtures for biological applications. Herein, we found that multiscale interactions of OPACs with the dentin matrix create tight biointerfaces with hydrophobic methacrylate adhesives on wet surfaces. An enriched mixture of OPACs, with a known phytochemical profile, was produced from grape seed crude extract ( Vitis vinifera; enriched grape seed extract [e-GSE]) and applied to dentin matrices to determine changes to the mechanical properties and biodegradability of the dentin matrix and favorable resin adhesion mechanisms. Methods included a 3-point flexural test, quantification of hydroxyproline (collagen solubilization), static and dynamic nanomechanical analyses, resin-dentin microtensile bond strength, and micropermeability at the adhesive interface. The e-GSE-modified dentin matrix exhibited remarkably low collagen solubilization and sustained the bulk elastic properties over 12 mo. Tan δ findings reveal a more elastic-like behavior of the e-GSE-modified dentin matrix, which was not affected by H-bond destabilization by urea. Dentin-methacrylate biointerfaces with robust and stable adhesion were created on e-GSE-primed dentin surfaces, leading to a dramatic decrease of the interfacial permeability. Standardized OPAC mixtures provide a new mechanism of adhesion to type I collagen-rich tissues that does not rely on hydrophilic monomers. The bioadhesion mechanism involves physicochemical modifications to the dentin matrix, reduced tissue biodegradation, and bridging to methacrylate resins.

Effect of Bioactive Primers on Bacterial-Induced Secondary Caries at the Tooth-Resin Interface.

Secondary caries at the tooth-resin interface is the primary reason for replacement of resin composite restorations. The tooth-resin interface is formed by the interlocking of resin material with hydroxyapatite crystals in enamel and collagen mesh structure in dentin. Efforts to strengthen the tooth-resin interface have identified chemical agents with dentin collagen cross-linking potential and antimicrobial activities. The purpose of the present study was to assess protective effects of bioactive primer against secondary caries development around enamel and dentin margins of class V restorations, using an in vitro bacterial caries model. Class V composite restorations were prepared on 60 bovine teeth (n=15) with pretreatment of the cavity walls with control buffer solution, an enriched fraction of grape seed extract (e-GSE), 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide/N-hydroxysuccinimide, or chlorhexidine digluconate. After incubating specimens in a bacterial model with Streptococcus mutans for four days, dentin and enamel were assessed by fluorescence microscopy. Results revealed that only the naturally occurring product, e-GSE, significantly inhibited the development of secondary caries immediately adjacent to the dentin-resin interface, as indicated by the caries inhibition zone. No inhibitory effects were observed in enamel margins. The results suggest that the incorporation of e-GSE into components of the adhesive system may inhibit secondary caries and potentially contribute to the protection of highly vulnerable dentin-resin margins.

Anaphylactic shock during endodontic treatment due to allergy to formaldehyde in a root canal sealant.

A 41-yr-old patient experienced an anaphylactic shock reaction caused by formaldehyde in a root canal sealant during endodontic treatment. The clinical events, positive skin tests, and a high level of immunoglobin E to formalin RAST (class 4) suggest the involvement of immunoglobin E-dependent mechanisms toward formaldehyde. This very infrequent observation in endodontic therapy focuses attention on the different pathological manifestations related to formalin, their mechanisms, and the prevention possibilities in dentistry.

Oral manifestations of AIDS-associated non-Hodgkin's lymphomas.

While B-cell lymphomas are frequently found in AIDS patients, reports on oral manifestations are rare. Among a group of 465 HIV-infected patients 5 presented with primary oral manifestations of a malignant B-cell lymphoma. The primary site of manifestation was the maxilla in 3 cases and the mandible in 2 cases. Based on the histological and immunohistochemical examination the tumors were differentiated as Burkitt's lymphoma (n = 1), as anaplastic large cell (ALC) lymphoma of the B-cell type (n = 1), as high-grade non-Hodgkin's lymphoma not classifiable according to the Kiel classification (n = 1), as immunoblastic-plasmoblastic lymphoma (n = 1), and as centroblastic lymphoma (n = 1). Serum samples were negative for HTLV-I antibodies in 5/5 cases.

[Asthma, rhinitis and urticaria following occupational exposure to cyanoacrylate glues]. / Asthme, rhinite et urticaire secondaires à l'exposition professionnelle aux colles cyano-acrylates.

Cyanoacrylate glues are more and widely used in the industry because of easy handling and great sticking power. These very volatile and chemically reactive glues may not only cause contact eczema, but also rhinitis and asthma. Nineteen cases of asthma have been reported to date. We report two new cases of occupational asthma as well as one case of urticaria, a clinical symptom not yet described, to our knowledge. In the three cases, diagnosis was made based on a compatible medical history and positive realistic exposure tests. The mechanism is still unknown, due to the physical properties of cyanoacrylate glues; in fact, it is not possible to perform prick tests or specific IgE measurements. Besides the usual preventive measures, maintaining a relative humidity greater than 55% seems to induce polymerization of free monomers of alkyl cyanoacrylate, thereby reducing their volatility. Rhinitis and asthma due to cyanoacrylate glue may receive compensation as occupational diseases in France.

[New aero-allergens]. / Les nouveaux pneumallergènes.

As the number of proteins recognized as causing allergic respiratory diseases increases, new aero allergens have appeared in the animal and vegetable realms, both in home and professional environments. Lepidoglyphus destructor and Blomia tropicalis, two mites found in storage areas, are particularly important in agricultural areas and in homes. Over the last ten years, the frequency of reactions to cockroaches has also increased in several countries. The allergenicity of non-biting insects is a frequent cause of allergy in certain countries including Japan. Chironomides cause respiratory diseases in professional and outdoor environments. The important role of Alternaria, a mold, in producing severe asthma has also been demonstrated. The pathophysiology of pollen-induced asthma has been shown to result from pollen allergens carried by particles less than 5 microns in diameter. Cyprus and ash tree pollen also cause an increasing number of pollinoses and flowers can cause rhinitis and asthma. Respiratory allergy to Ficus benjamina inaugurated a new type of allergies caused airborne allergens from non-pollinating plants. Allergy to latex raises a particular problem for health care workers. The immunochemical structures of the major and minor airborne allergens are now better known and the homologous structures of different allergens largely explains certain cross-reactions. In the future, recombinant allergens will probably be used to better understand the role of allergens in inducing and maintaining the allergic reaction and should help in our approach to diagnosis and therapy.

Dentin biomodification potential depends on polyphenol source.

Although proanthocyanidins (PACs) modify dentin, the effectiveness of different PAC sources and the correlation with their specific chemical composition are still unknown. This study describes the chemical profiling of natural PAC-rich extracts from 7 plants using ultra high pressure/performance liquid chromatography (UHPLC) to determine the overall composition of these extracts and, in parallel, comprehensively evaluate their effect on dentin properties. The total polyphenol content of the extracts was determined (as gallic acid equivalents) using Folin-Ciocalteau assays. Dentin biomodification was assessed by the modulus of elasticity, mass change, and resistance to enzymatic biodegradation. Extracts with a high polyphenol and PAC content from Vitis vinifera, Theobroma cacao, Camellia sinensis, and Pinus massoniana induced a significant increase in modulus of elasticity and mass. The UHPLC analysis showed the presence of multiple types of polyphenols, ranging from simple phenolic acids to oligomeric PACs and highly condensed tannins. Protective effect against enzymatic degradation was observed for all experimental groups; however, statistically significant differences were observed between plant extracts. The findings provide clear evidence that the dentin bioactivities of PACs are source dependent, resulting from a combination of concentration and specific chemical constitution of the complex PAC mixtures.

Polyethylene glycol-mediated infection with avian sarcoma viruses.

In this communication we report that fusion of viral and cellular membranes by polyethylene glycol is a convenient approach to overcoming genetically determined resistance to infection. Using this method, avian sarcoma virus-transformed mammalian cells have been produced which serve as useful model systems for the study of Rous sarcoma virus-specific tumor antigens.

[IgE allergy due to formaldehyde paste during endodontic treatment. Apropos of 4 cases: 2 with anaphylactic shock and 2 with generalized urticaria]. / Allergie IgE dépendante au formol de pâte canalaire lors du traitement endodontique. A propos de 4 cas: 2 chocs anaphylactiques et 2 urticaires généralisées.

We report 4 cases of allergic reaction to formaldehyde-containing root canal sealant after endodontic care: 2 anaphylactic shocks and 2 local reactions with generalized urticaria. Allergic IgE mediated mechanisms were suggested by the clinical presentation, skin tests and high levels of anti-formaldehyde IgE. These infrequent but potentially severe reactions after canal treatment led us to examine the involved mechanisms, the diagnostic procedure and the possibility of prevention in odontostomatology.

Hepatitis B and C among Berlin dental personnel: incidence, risk factors, and effectiveness of barrier prevention measures.

A study of 215 Berlin dentists and 108 dental assistants recruited at the 1997 Berlin Dental Society meeting assessed their occupational risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. HBV vaccine coverage, and barrier prevention methods used. Among dentists, 7% (95% CI 4-11) and 0.5% (95% CI 0-3) had serological evidence of previous HBV and HCV infection, respectively. Similar figures for dental assistants were 1% (95% CI 0-5) and 0% (95% CI 0-4). Only 74% of dentists and 63% of dental assistants reported HBV vaccination. Approximately half always used gloves, eye glasses, or face masks. HBV unvaccinated dentists whose patients had HBV risk factors had a greater risk of HBV infection; those who always wore face masks were at lower risk (OR 0.2, 95% CI 0.02-0.98). These data indicate that among Berlin dentists, the HCV risk was lower than that of HBV and that face masks may have lowered the risk of HBV. The use of eye glasses or gloves did not appear to lower the risk of HBV acquisition in this population.

Sensitivity of HIV antibody detection in saliva.

To assess the sensitivity and specificity of HIV antibody detection in saliva we tested matched serum and saliva samples from HIV-infected and uninfected individuals. Saliva specimens were collected by two different devices of the Salivette system and stored at different temperatures. Samples were tested for HIV antibodies by two commercially available enzyme-linked immunosorbent assays (ELISAs; Wellcome, Biotest). HIV antibodies were detected in 98.5% (Wellcome) and 97.8% (Biotest) of the saliva samples (standard Salivettes) from 135 seropositive individuals. Using the Salivettes flavoured with citric acid the sensitivity was only 22.9%. No reactions in ELISA were found in saliva from HIV-seronegative individuals. Salivary HIV-specific IgA was detected in 90% of seropositive individuals. All positive saliva samples stored at room temperature were still reactive after 20 days; of those stored at 37 degrees C, 23 out of 24 were positive when retested on day 5. Sensitivity of HIV antibody detection in saliva samples dried onto filter paper was 100% when a minimum of 100 microliters of saliva was used. HIV antibody testing in saliva is an efficient tool for large scale epidemiological studies when standard Salivettes are used for sample collection. Saliva samples can be stored in Salivettes or dried onto filter paper for several days at room temperature and under tropical conditions (37 degrees C).

[Quantitative determination of CMV-DNA in saliva of patients with bone marrow and stem cell transplantation using TaqMan-PCR]. / Quantitative Bestimmung humaner CMV-DNA im Speichel von Patienten mit Knochenmark- und Stammzelltransplantation mithilfe der TaqMan(R)-PCR.

BACKGROUND: Human cytomegalovirus (HCMV) infection is associated with severe and life-threatening diseases in immunocompromised patients, especially after bone marrow (BM) and stem cell (SC) transplantation. Prior to transplantation the potential risk of HCMV disease is therefore determined by HCMV-antibody blood testing of transplant donor (D) and recipient (R). Virus carriers are positive for anti-CMV-IgG. Virus patterns are distinguished as follows: group 1 (D+/R+), group 2 (D-/R+), group 3 (D+/R-), and group 4 (D-/R-). AIM: The aim of this study was qualitative and quantitative determination of the HCMV DNA load in saliva of BM and SC transplantation patients. PATIENTS AND METHOD: Unstimulated saliva was collected from 20 patients prior to BM and SC transplantation, during the time of conditioning, and after transplantation. DNA was isolated and analyzed for evidence of HCMV DNA with TaqMan PCR. RESULTS: HCMV DNA was isolated in seven cases. In all group 1 patients (D+/R+) HCMV DNA could be demonstrated. Only three of seven group 2 patients (D-/R+) were positive for HCMV DNA. The only group 3 patient (D+/R-) and all eight group 4 patients (D-/R-) were negative. CONCLUSION: TaqMan PCR is a reliable method for HCMV DNA quantification. In three patients (anti-HCMV-IgG positive) who received an anti-CMV-IgG negative transplant HCMV DNA was isolated. In contrast, no HCMV-DNA was evident in HCMV-negative patients who received an HCMV-negative transplant. Accordingly, the risk of HCMV reactivation is more probable than the risk of reinfection.

Meat wrapper's asthma: identification of the causal agent.

Meat wrapper's asthma is a typical example of occupational asthma due to emissions from chemical products. The authors report three new cases due to the use of the now classic meat packaging techniques in supermarkets. The chemical agents involved were identified. Inhalation tests have been carried out in one patient with the complete wrappings, i.e. the PVC film and the price labels, and separate tests were performed with eight additives of the PVC film, and with phthalic anhydride and di-cyclohexylphthalate emitted from heated price labels. These tests incriminate two products: phthalic anhydride seems to be the principal causal agent and epoxidized soybean oil can be suspected as a secondary agent causing this occupational asthma.

Epithelial uptake and transport of cell-free human immunodeficiency virus type 1 and gp120-coated microparticles.

Cell-free human immunodeficiency virus type 1 (HIV-1) can be taken up and released by a monolayer of primary human gingival cells and remain infectious for CD4+ cells. Virus-sized latex particles covalently coated with purified native HIV-1 envelope glycoprotein gp120 are also transported through the primary epithelial cells. This process is significantly stimulated by increasing the intracellular cyclic AMP (cAMP) concentration. Inhibition experiments with mannan and alpha-methyl-mannopyranoside indicated that mannosyl groups are involved in the interaction between gp120 and gingival cells. An increase of cellular oligomannosyl receptors by incubation with the mannosidase inhibitor deoxymannojirimycin augmented transcellular transport of the gp120-coated particles. The results suggest that infectious HIV can penetrate gingival epithelia by a cAMP-dependent transport mechanism involving interaction of the lectin-like domain of gp120 and mannosyl residues on glycoproteins on the mucosal surface. Penetration of HIV could be inhibited by soluble glycoconjugates present in oral mucins.

Increased immunoglobulin G production by short term cultured duodenal biopsy samples from HIV infected patients.

BACKGROUND: Secretory immunity is a major defence mechanism against infections at mucosal surfaces which are common in HIV infected patients. AIMS: To analyse intestinal immunoglobulin production in HIV infection in comparison with that in saliva and serum. PATIENTS AND METHODS: Immunoglobulin G (IgG), A (IgA), and M (IgM) concentrations were determined in supernatants of short term cultured duodenal biopsy samples, serum, and saliva from HIV infected patients (n = 28) and controls (n = 14) by radial immunodiffusion. RESULTS: IgG was increased in the supernatants of short term cultured biopsy samples and saliva from HIV infected patients compared with controls (p < 0.01), but IgA and IgM levels were normal. In contrast, both IgG and IgA concentrations in serum were higher in HIV infected patients than in controls (p < 0.002). No correlation was found between IgA produced by duodenal biopsy specimens and serum IgA. CONCLUSION: Abnormalities in mucosal immunoglobulin production in HIV infection were surprisingly small, indicating that specific secretory immunity rather than quantitative immunoglobulin production may be impaired. However, increased production of IgG could contribute to mucosal inflammation by complement activation. Our findings of normal mucosal IgA production and the lack of correlation between serum and mucosal IgA argues against an intestinal origin for the increased serum IgA levels in HIV infected patients.

Occupational asthma in France: a 1-yr report of the observatoire National de Asthmes Professionnels project.

Observatoire National des Asthmes Professionnels (ONAP) was created in 1996 by two French professional societies to estimate the incidence of occupational asthma and to promote preventive measures against it. Occupational and chest physicians were asked to report newly diagnosed cases of work-related asthma and reactive airway dysfunction syndrome (RADS), the information collected included age, sex, occupation, suspected causal agents and diagnostic methods. In 1997, 82.3% of 559 cases reported (64% males, mean age 36 +/- 13 yrs) involved occupational asthma, 4.7% RADS and 12.7% atypical asthma syndromes. Incidence rates (expressed as number of cases per million workers) showed a regional variation that ranged from 4 to 73 (national mean: 25.7). The most frequently suspected agents were flour (23.3%), followed by isocyanates (16.6%), latex (7.5%), aldehydes (5.5%), and persulphates (4.1%). Occupations at risk were bakers (23.9%), healthcare workers (12%), painters (9.1%), hairdressers (5.2%), wood industry workers (4.8%) and cleaners (3.5%). These results are compared to those of other systems set up in Europe and North America. Because of the considerable bias inherent in a surveillance system based on voluntary, reporting, the number of occupational asthma cases reported is probably lower than the real incidence. Nevertheless, the French National Observatory for Occupational Asthma encourages physician awareness of occupational asthma and provides an estimate of its incidence and aetiologies in France.

Urticaria and rhinitis to shrubs of Ficus benjamina and breadfruit in a banana-allergic road worker: evidence for a cross-sensitization between Moracea, banana and latex.

BACKGROUND: We report the case of a road worker with a food allergy to banana, who developed urticaria and rhinitis when cutting shrubs of Ficus benjamina and breadfruit. He did not develop an allergy to latex of Hevea brasiliensis. RESULTS: Sensitization to latex of F. benjamina, H. brasiliensis, breadfruit and banana was demonstrated using skin tests and specific IgE measurements. RAST inhibitions procedures showed that specific IgE to breadfruit latex cross-reacted more strongly with latex of H. brasiliensis and banana than with latex of F. benjamina with the same extract. CONCLUSION: Given the wide distribution of Moracea trees in tropical regions, sensitization to latex of H. brasiliensis and banana could be a consequence of sensitization to Moracea members; F. benjamina does not seem to be the only Moracea responsible for cross-allergy with latex and fruit. Consequently, it seems interesting to test other members of the Moracea family in patients sensitized to latex of H. brasiliensis and banana. Sensitization to breadfruit could be a risk factor for sensitization to latex of H. brasiliensis.