Gloria Denotti

Alterations of the salivary secretory peptidome profile in children affected by type 1 diabetes

The acidic soluble fraction of whole saliva of type 1 diabetic children was analyzed by reversed phase (RP)1–HPLC-ESI-MS and compared with that of sex- and age-matched control subjects. Salivary acidic proline-rich phosphoproteins (aPRP), histatins, α-defensins, salivary cystatins, statherin, proline-rich peptide P-B (P-B), beta-thymosins, S100A8 and S100A9*(S100A9* corresponds to S100A9 vairant lacking the first four amino acids), as well some naturally occurring peptides derived from salivary acidic proline-rich phosphoproteins, histatins, statherin, and P-B peptide, were detected and quantified on the basis of the extracted ion current peak area. The level of phosphorylation of salivary acidic proline-rich phosphoproteins, histatin-1 (Hst-1), statherin and S100A9* and the percentage of truncated forms of salivary acidic proline-rich phosphoproteins was also determined in the two groups. The study revealed that statherin, proline-rich peptide P-B, P-C peptide, and histatins, were significantly less concentrated in saliva of diabetic subjects than in controls, while concentration of α-defensins 1, 2 and 4 and S100A9* was higher. The low concentration of P-C peptide was paralleled by high levels of some of its fragments. On the whole, the study highlighted the severe impairment of the repertoire of peptides involved in the safeguard of the oral cavity in children who have diabetes, as well as an higher concentration of the proinflammatory mediator S100A9* with respect to healthy children.

Microbial biofilm modulation by ultrasound: Current concepts and controversies

Biofilm elimination is often necessary during antimicrobial therapy or industrial medical manufacturing decontamination. In this context, ultrasound treatment has been frequently described in the literature for its antibiofilm effectiveness, but at the same time, various authors have described ultrasound as a formidable enhancer of bacterial viability. This discrepancy has found no solution in the current literature for around 9 years; some works have shown that every time bacteria are exposed to an ultrasonic field, both destruction and stimulation phenomena co-exist. This co-existence proves to have different final effects based on various factors such as: ultrasound frequency and intensity, the bacterial species involved, the material used for ultrasound diffusion, the presence of cavitation effects and the forms of bacterial planktonic or biofilm. The aim of this work is to analyze current concepts regarding ultrasound effect on prokaryotic cells, and in particular ultrasound activity on bacterial biofilm.

Circadian rhythms of histatin 1 histatin 3, histatin 5, statherin and uric acid in whole human saliva secretion

The circadian rhythms of histatins 1, 3, 5, of statherin and uric acid were investigated in whole human saliva. Histatins showed a rhythm approximately synchronous with salivary flow rate (acrophase around 5 pm), the higher amplitude pertaining to histatin 1 (about 50% of the mesor). Uric acid showed a large rhythm asynchronous with flow rate and histatin concentrations (4.4 ± 1.4 am). Statherin did not show a significant circadian rhythm on five of six volunteers. This finding confirms that the secretion route of statherin is different from that of histatins.

Determination of the human salivary peptides, histatins 1, 3, 5 and statherin by high-performance liquid chromatography and by diode-array detection

A reversed-phase high-performance liquid chromatography (HPLC) method with diode-array detection for the quantification of several human salivary peptides is described. Sample pretreatment consisted of the acidification of whole saliva by phosphate buffer. This treatment produced precipitation of mucins, alpha-amylases and other high-molecular-mass salivary proteins, simultaneous inhibition of intrinsic protease activities and reduction of sample viscosity. Direct HPLC analysis by diode-array detection of the resulting acidic sample allowed one to quantify histatin 1, histatin 3, histatin 5, statherin, as well as uric acid, in normal subjects. Moreover, the groups of peaks pertaining to proline-rich proteins and cystatins were tentatively identified. The method can be useful in assessing the concentration of salivary peptides from normal subjects and from patients suffering oral and/or periodontal diseases.

In Vitro evaluation of Enterococcus faecalis adhesion on various endodontic medicaments.

E. faecalis in endodontic infection represents a biofilm type of disease, which explains the bacteria’s resistance to various antimicrobial compounds and the subsequent failure after endodontic treatment. The purpose of this study was to compare antimicrobial activities and bacteria kinetic adhesion in vitro for three endodontic medicaments with a clinical isolate of E. faecalis. We devised a shake culture which contained the following intracanalar preparations: CPD, Endoidrox (EIX), PulpCanalSealer (PCS); these were immersed in a liquid culture medium inoculated with the microorganism. The shake system velocity was able to prevent non-specific bacteria adhesion and simulated the salivary flow. Specimens were collected daily (from both the medium and medicaments) for 10 days; the viable cells were counted by plate count, while the adhesion index AI° [E. faecalis fg DNA] /mm2 was evaluated in the pastes after DNA extraction, by quantitative real time PCR for the 16S rRNA gene. A partial growth inhibition, during the first 24 hours, was observed in the liquid medium and on the medicaments for EIX and subsequently for CPD (six logs). EIX showed the lowest adhesion coefficient (5*102 [fg DNA]/mm2) for nine days and was similar to the control. PCS showed no antimicrobial/antibiofilm properties. This showed that “calcium oxide” base compounds could be active against biofilm progression and at least in the short term (2-4 days) on E. faecalis cells growing in planktonic cultures.

Evaluation of Antimicrobial-Antibiofilm Activity of a Hydrogen Peroxide Decontaminating System Used in Dental Unit Water Lines

A dental unit water line (DUWL) equipped with a device designed to automatically and continually flush a bacteriostatic solution of hydrogen peroxide (WHE) and a discontinuous disinfecting system (BIOSTER) was evaluated. In the first instance a preliminary sensitivity test on a large number of microorganisms (bacteria and fungi) was tried with a H2O2 range from 100 to 800 ppm. The bacteria frequently reported in DUWL (including Pseudomonas spp, Streptococcus spp., Staphylococcus spp., E. coli) and some periodontal pathogens showed a minimum inhibitory concentration from 100 to 300 H2O2 ppm (also including M. marinum and C. albicans). However, H2O2 did not show any inhibitory effects against: A. actinomycetemcomitans, C. glabrata C. parapsilos, F. nucleatum, M. micros. In a second step, the DUWL was experimentally infected with S. faecalis, E. coli, P. aeruginosa, S. aureus. After disinfection steps with 3% H2O2, the inhibitory effect on planktonic forms and on sessile biofilm was measured. In a third step, the count of 16S rRNA gene copies by real time PCR at different points of the DUWL described an accrue of bacterial slime in “hot spot” regions characterized by irregular/slow water flux (valves, elbows). However these results suggest that hydrogen peroxide is not only able to inhibit bursts of planktonic bacteria inside the DUWL, but that it could also be effective against sessile biofilm containing heterotrophic microorganisms derived from domestic water line contamination. In addition some oral pathogens could be contaminating and surviving in DUWL.

Oil Essential Mouthwashes Antibacterial Activity against Aggregatibacter actinomycetemcomitans: A Comparison between Antibiofilm and Antiplanktonic Effects

The aim of this work is to determine the antibacterial activity of three marketed mouthwashes on suspended and sessile states of Aggregatibacter actinomycetemcomitans. The efficacy of two commonly used products in clinical practice, containing essential oils as active ingredients (menthol, thymol, methyl salicylate, and eucalyptol) in association with or without alcohol, has been evaluated in comparison with a chlorhexidine-based mouthwash. The microtiter plate assay, in order to obtain a spectrophotometric measurement of bacterial responses at growing dilutions of each antiseptic, was used for the study. The analysis revealed that a good antibacterial activity is reached when the abovementioned mouthwashes were used at concentration over a 1/24 dilution and after an exposure time of 30 seconds at least. In conclusion, the alcoholic mouthwash appears to have a better biofilm inhibition than its antiplanktonic activity while the nonalcoholic product demonstrates an opposite effect with a better antiplanktonic behavior.

Use of Ultrasonic Bone Surgery (Piezosurgery) to Surgically Treat Bisphosphonate-Related Osteonecrosis of the Jaws (BRONJ). A Case Series Report with at Least 1 Year of Follow-Up

This preliminary work documents the use of a powerful piezosurgery device to treat biphosphonate-related osteonecrosis of the jaw (BRONJ) in combination with classical medication therapy. Eight patients presenting 9 BRONJ sites were treated, 2 in the maxilla and 7 in the mandible. Reason for biphosphonate (BiP) intake was treatment of an oncologic disease for 5 patients and osteoporosis for 3. The oncologic and osteoporosis patients were diagnosed with BRONJ after 35-110 months and 80-183 months of BiP treatment, respectively. BRONJ 2 and 3 was found in 4 patients. Resection of the bone sequestrae was performed with a high power ultrasonic (piezo) surgery and antibiotics were administrated for 2 weeks. Soft tissue healing was incomplete at the 2-week control but it was achieved within 1 month. At the 1-year control, soft tissue healing was maintained at all patients, without symptom recurrence. One patient with paraesthesia had abated; of the 2 pa-tients with trismus, one was healed, severity of the second trismus abated. This case report series suggests that bone resection performed with a high power ultrasonic surgery device combined with antibiotics might lead to BRONJ healing. More patients are warranted to confirm the present findings and assess this treatment approach.

A Modified Intraoral Resin Mouthguard to Prevent Self-Mutilations in Lesch-Nyhan Patients

Lesch-Nyhan syndrome, described in 1964 by Lesch and Nyhan, is a X-linked recessive disorder, occurring in 1 : 100000 to 1 : 380000 live births. LNS is characterized by a decrease in activity of hypoxanthine guanine phosphoribosyl transferase, an enzyme involved in purine metabolism, resulting in overproduction of uric acid. Hyperuricemia and neurological features including choreoathetoid spasticity, self-mutilation, and mental retardation clinically characterize this syndrome. In LNS patients the typical feature is loss of tissue from biting themselves with partial or complete amputation of fingers, lips, and tongue. The self-mutilation compares with the eruption of the deciduous teeth. Several drugs trials have been administered to improve self-destructive behavior and invasive treatment approaches, such as extractions of teeth and orthognathic surgery, have been suggested with variable effectiveness. Nowadays prevention is, therefore, the standard of care. The role of dentistry is essential in the management of the self-mutilating behavior, because the teeth represent the main self-injury instrument. This report presents a revision of various therapeutic approaches to manage self-destruction, highlighting the effectiveness of a preventive treatment. It describes a new technique: a resin mouthguard, realized at Gaslini Hospital, to obtain immediate healing of the oral lesions, confirmed in the follow-up period.

Distribution of Human Papillomavirus Genotypes in Sardinian Patients with Oral Squamous Cell Carcinoma

Human papillomaviruses (HPVs) seem to play an important role in the pathogenesis of gynecological carcinomas and in head and neck carcinomas. The aim of this study was to detect and genotype HPVs in fresh oral squamous cell carcinoma (OSCC) from a Sardinian population, and to determine whether HPV presence was significantly associated with the development of OSCC. The oral mucosa tissues were obtained from 120 samples (68 OSCC and 52 control samples) taken from a Sardinian population seen at the Dental Clinic of the Department of Surgery and Odontostomatological Sciences, University of Cagliari (Italy) and the “ Ospedale SS Trinità”, Cagliari (A.S.L. 8) between 2007 and 2008. PCR was used for the detection of HPV DNA and the genotype was determined by DNA sequencing. The frequency of HPV infection was evaluated in relation to age, sex, smoking and alcohol use. Statistical analysis was performed using the SPSS 11.5 software. The results showed the presence of HPV-DNA in 60.3% of OSCC with HPV-16 (51.2%) being the most frequent genotype. In these Sardinian OSCC patients, HPV-DNA was detected more in males (65.8%) than in females (34.1%) while controls show a 0% of HPV presence. HPV positive was highly associated with OSCC among subjects with a history of heavy tobacco and alcohol use and among those with no such history. A greater frequency of high risk HPV presence was observed in patients with OSCC compared to health control patients. In addition these results suggested that oral HPV presence could be associated in OSCC subjects. Our results need more analyses to detect the HPV-DNA integration into tumoral cells.