Mechanism of action of tin-containing fluoride solutions as anti-erosive agents in dentine - an in vitro tin-uptake, tissue loss, and scanning electron microscopy study

Solutions containing tin and fluoride exhibit remarkable anti-erosive properties with tin ions as a major agent. To elucidate its mechanism of action in dentine, the tin uptake on and in the tissue was investigated and related to histological findings and substance loss. Samples were treated twice daily, each treatment lasting for 2 min, with fluoride solutions [pH 4.5; 1,500 parts per million (p.p.m.) F] containing 2,100, 1,400, or 400 p.p.m. Sn as SnCl(2). In experiments 1 and 2, samples were eroded with citric acid (pH 2.3) six times each day, each treatment lasting for 5 min; in experiment 2, the demineralized organic matrix was continuously digested by collagenase; in experiment 3, no erosive challenges were performed. Sample surfaces and cross-sections were investigated using energy dispersive X-ray spectroscopy, scanning electron microscopy, and profilometry. Surface retention of tin was found in almost all treatment groups and was highest in experiment 2. On cross-sections, tin was retained within the organic matrix; in mineralized areas, tin was found mainly within a depth of 10 mum. Test solutions inhibited substance loss significantly; in experiment 2, the effect was dose-dependent. Erosion inhibition seemed to depend mainly on the incorporation of tin in the mineralized dentine when the organic portion was preserved, but on surface precipitation when the organic portion was continuously digested.

β-Caryophyllene ameliorates cisplatin-induced nephrotoxicity in a cannabinoid 2 receptor-dependent manner

(E)-β-caryophyllene (BCP) is a natural sesquiterpene found in many essential oils of spice (best known for contributing to the spiciness of black pepper) and food plants with recognized anti-inflammatory properties. Recently it was shown that BCP is a natural agonist of endogenous cannabinoid 2 (CB(2)) receptors, which are expressed in immune cells and mediate anti-inflammatory effects. In this study we aimed to test the effects of BCP in a clinically relevant murine model of nephropathy (induced by the widely used antineoplastic drug cisplatin) in which the tubular injury is largely dependent on inflammation and oxidative/nitrative stress. β-caryophyllene dose-dependently ameliorated cisplatin-induced kidney dysfunction, morphological damage, and renal inflammatory response (chemokines MCP-1 and MIP-2, cytokines TNF-α and IL-1β, adhesion molecule ICAM-1, and neutrophil and macrophage infiltration). It also markedly mitigated oxidative/nitrative stress (NOX-2 and NOX-4 expression, 4-HNE and 3-NT content) and cell death. The protective effects of BCP against biochemical and histological markers of nephropathy were absent in CB(2) knockout mice. Thus, BCP may be an excellent therapeutic agent to prevent cisplatin-induced nephrotoxicity through a CB(2) receptor-dependent pathway. Given the excellent safety profile of BCP in humans it has tremendous therapeutic potential in a multitude of diseases associated with inflammation and oxidative stress.

Erosive tooth wear: diagnosis, risk factors and prevention

PURPOSE: To provide an overview on diagnosis, risk factors and prevention of erosive tooth wear, which is becoming an increasingly important factor when considering the long- term health of the dentition. RESULTS: Awareness of dental erosion by the public is still not widespread due to the cryptic nature of this slowly progressing condition. Smooth silky-glazed appearance with the absence of perikymata and intact enamel along the gingival margin, with cupping and grooving on occlusal surfaces are some typical signs of enamel erosion. In later stages, it is sometimes difficult to distinguish between the influences of erosion, attrition or abrasion during a clinical examination. Biological, behavioral and chemical factors all come into play, which over time, may either wear away the tooth surface, or potentially protect it. In order to assess the risk factors, patient should record their dietary intake for a distinct period of time. Based on these analyses, an individually tailored preventive program may be suggested to patients. It may comprise dietary advice, optimization of fluoride regimes, stimulation of salivary flow rate, use of buffering medicaments and particular motivation for non-destructive tooth brushing habits. The frequent use of fluoride gel and fluoride mouthrinse in addition to fluoride toothpaste offers the opportunity to minimize abrasion of tooth substance.

Periapical surgery and the maxillary sinus: radiographic parameters for clinical outcome

OBJECTIVE: To find out whether conventional periapical radiographs can be used to determine the risk of creating an oroantral communication (OAC) while performing periapical surgery on maxillary premolars and molars. STUDY DESIGN: One hundred thirteen periapical radiographs of maxillary premolars and molars with periapical radiolucencies indicating chronic apical periodontitis were retrospectively analyzed and classified. The surgery reports were evaluated for occurrence of perforation of the maxillary sinus and postoperative complications. RESULTS: Perforation of the sinus membrane (also referred to as the Schneiderian membrane) occurred in 12 cases (9.6%). Exposure of the membrane without rupture occurred in 15 cases (12%). It was found that the distance between the apex or the periapical lesion and the sinus floor did not serve as a predictor of a possible sinus membrane rupture. On the other hand, if the radiograph showed a distinct distance between the lesion and the sinus floor, there was an 82.5% probability that OAC would not occur. Additionally, a blurred radiographic outline of the periapical lesion did not indicate an increased risk of sinus membrane rupture. CONCLUSION: Conventional periapical radiographs cannot be used as predictors for perforation of the maxillary sinus during periapical surgery. However, radiographs with a specific distance between the periapical lesion and the sinus floor point toward a very low risk of accidental sinus perforation during periapical surgery.

CO2 laser-irradiation through topically applied fluoride increases acid resistance of demineralised human enamel in vitro

PURPOSE: To evaluate the effect of CO2 laser treatment through topically applied amine fluoride solution on demineralised enamel. MATERIALS AND METHODS: Sixty extracted human molar crowns were selected and cut longitudinally into half. One half was subjected to a 10-day pH-cycling procedure to create caries-like lesions, whereas the other was left non-demineralised. The following treatments were randomly assigned (one treatment per tooth, on respective non-demineralised and demineralised matched specimens): exposure to a 1% amine fluoride solution for 15 s without irradiation (group I), irradiation for 15 s with a continuous-wave CO2 laser (group II), or laser-treatment for 15 s through the amine fluoride solution applied immediately beforehand (group III). Fluoride uptake (n = 30) and acid resistance (n = 30) were determined after treatment. Enamel surface alterations after laser irradiation were monitored using scanning electron microscopy. RESULTS: In groups I and III, an increased fluoride uptake was detected (p < or = 0.05). Laser irradiation through topical fluoride resulted in an increased acid resistance of sound and demineralised enamel specimens in deeper layers (p < or = 0.05). In addition, less surface alterations were observed in SEM examination of specimens irradiated through the amine fluoride solution compared with counterparts treated with laser only. CONCLUSIONS: CO2 laser light application through an amine fluoride solution may be instrumental in enhancing acid resistance of sound and demineralised enamel.

Pulp and periodontal healing of laterally luxated permanent teeth: results after 4 years

AIM: To evaluate the pulp and periodontal healing of laterally luxated permanent teeth. MATERIAL AND METHODS: Patients presenting with lateral luxation of permanent teeth during 2001-2002 were enrolled in this clinical study. Laterally luxated teeth were repositioned and splinted with a TTS/composite resin splint for 4 weeks. Immediate (prophylactic) root-canal treatment was performed in severely luxated teeth with radiographically closed apices. All patients received tetracycline for 10 days. Re-examinations were performed after 1, 2, 3, 6, 12 and 48 months. RESULTS: All 47 laterally luxated permanent teeth that could be followed over the entire study period survived. In 10 teeth (21.3%), a prophylactic root-canal treatment was performed within 2 weeks following injury. The remaining 37 teeth showed the following characteristics at the 4-year re-examination: 19 teeth (51.4%) had pulp survival (no clinical or radiographic signs or symptoms), nine teeth (24.3%) presented with pulp canal calcification, and pulp necrosis was seen in another nine teeth (24.3%), within the first year after trauma. None of the teeth with a radiographically open apex at the time of lateral luxation showed complications. External root resorption was only seen in one tooth. CONCLUSIONS: Laterally luxated permanent teeth with incomplete root formation have a good prognosis, with all teeth surviving in this study. The most frequent complication was pulp necrosis that was only seen in teeth with closed apices.

Structural model of the CopA copper ATPase of Enterococcus hirae based on chemical cross-linking

The CopA copper ATPase of Enterococcus hirae belongs to the family of heavy metal pumping CPx-type ATPases and shares 43% sequence similarity with the human Menkes and Wilson copper ATPases. Due to a lack of suitable protein crystals, only partial three-dimensional structures have so far been obtained for this family of ion pumps. We present a structural model of CopA derived by combining topological information obtained by intramolecular cross-linking with molecular modeling. Purified CopA was cross-linked with different bivalent reagents, followed by tryptic digestion and identification of cross-linked peptides by mass spectrometry. The structural proximity of tryptic fragments provided information about the structural arrangement of the hydrophilic protein domains, which was integrated into a three-dimensional model of CopA. Comparative modeling of CopA was guided by the sequence similarity to the calcium ATPase of the sarcoplasmic reticulum, Serca1, for which detailed structures are available. In addition, known partial structures of CPx-ATPase homologous to CopA were used as modeling templates. A docking approach was used to predict the orientation of the heavy metal binding domain of CopA relative to the core structure, which was verified by distance constraints derived from cross-links. The overall structural model of CopA resembles the Serca1 structure, but reveals distinctive features of CPx-type ATPases. A prominent feature is the positioning of the heavy metal binding domain. It features an orientation of the Cu binding ligands which is appropriate for the interaction with Cu-loaded metallochaperones in solution. Moreover, a novel model of the architecture of the intramembranous Cu binding sites could be derived.

Age and gender differences in health-related quality of life of children and adolescents in Europe: a multilevel analysis

OBJECTIVES: To determine age and gender differences in health-related quality of life (HRQOL) in children and adolescents across 12 European countries using a newly developed HRQOL measure (KIDSCREEN). METHODS: The KIDSCREEN-52 questionnaire was filled in by 21,590 children and adolescents aged 8-18 from 12 countries. We used multilevel regression analyses to model the hierarchical structure of the data. In addition, effect sizes were computed to test for gender differences within each age group. RESULTS: Children generally showed better HRQOL than adolescents (P < 0.001). While boys and girls had similar HRQOL at young age, girls' HRQOL declined more than boys' (P < 0.001) with increasing age, depending on the HRQOL scale. There was significant variation between countries both at the youngest age and for age trajectories. CONCLUSIONS: For the first time, gender and age differences in children's and adolescents' HRQOL across Europe were assessed using a comprehensive and standardised instrument. Gender and age differences exist for most HRQOL scales. Differences in HRQOL across Europe point to the importance of national contexts for youth's well-being.

Comparison of intraoral radiography and limited cone beam computed tomography for the assessment of root-fractured permanent teeth

AIM: To compare intraoral occlusal (OC) and periapical (PA) radiographs vs. limited cone beam computed tomography (CBCT) in diagnosing root-fractured permanent teeth. MATERIAL AND METHODS: In 38 patients (mean age 24 years, range 8-52 years) with 44 permanent teeth with horizontal root fractures, intraoral radiographs (PA and OC) and limited CBCT were used to evaluate the location (apical, middle, cervical third of the root) and angulation of the fracture line. Furthermore, the conventional radiographs and CBCT images were compared for concordance of fracture location. RESULTS: In the PA and OC radiographs, 28 fractures (63.6%) were located in the middle third of the root, 11 (25.0%) in the apical third and 5 (11.4%) in the cervical third. The PA/OC radiographs and the sagittal CBCT images (facial aspect) yielded the same level of root fracture in 70.5% of cases (31 teeth; 95% CI: 54.1-82.7%). The PA/OC radiographs and sagittal CBCT images (palatal aspect) showed the same level of root fracture in 31.8% of cases. There was a statistically significant association between the angle at which the root fracture line intersected the axis of the tooth and the level of root fracture in the facial aspect of the sagittal CBCT images. CONCLUSIONS: The diagnosis of the location and angulation of root fractures based on limited CBCT imaging differs significantly from diagnostic procedures based on intraoral radiographs (PA/OC) alone. The clinical significance for treatment strategies and for the prognosis of root-fractured teeth has to be addressed in future studies.

Intravaginal and intracervical application of seminal plasma in in vitro fertilization or intracytoplasmic sperm injection treatment cycles--a double-blind, placebo-controlled, randomized pilot study

OBJECTIVE: To evaluate whether intravaginal application of seminal plasma at the time of follicle aspiration in IVF or intracytoplasmic sperm injection treatment cycles has the potential to increase pregnancy rate. To calculate the number of patients needed to achieve significance in a multicenter trial. DESIGN: Double-blind, placebo-controlled randomized pilot study. SETTING: University department of gynecological endocrinology and reproductive medicine. PATIENT(S): One hundred sixty-eight patients undergoing IVF or intracytoplasmic sperm injection treatment. INTERVENTION(S): Cryopreserved seminal plasma from the patient's partner or sodium chloride (placebo) was injected into the cervix and the posterior fornix of the vagina just after follicle aspiration. MAIN OUTCOME MEASURE(S): Clinical-pregnancy rate. RESULT(S): One hundred sixty-eight patients agreed to participate in the study. Participation was limited to one treatment cycle. Thirty-one patients (18%) were excluded from the study, mainly as a result of canceled embryo transfers. Seventy patients received placebo, and 67 received seminal plasma. The clinical-pregnancy rate was 25.7% (18/70) in the placebo group. The clinical-pregnancy rate in the seminal plasma group reached 37.3% (25/67), corresponding to a relative increase of 45%. CONCLUSION(S): Even though significance was not reached in this pilot study, the data suggest that seminal plasma has the potential to improve pregnancy rate. It is estimated that around 450 patients need to be recruited to reach significance in a multicenter study.

Two new flavonol glycosides and a metabolite profile of Bryophyllum pinnatum, a phytotherapeutic used in obstetrics and gynaecology

Bryophyllum pinnatum is a succulent perennial plant native to Madagascar which is used in anthroposophical medicine to treat psychiatric disorders and as a tocolytic agent to prevent premature labour. We performed a metabolite profiling study in order to obtain a comprehensive picture of the constituents in B. pinnatum leaves and to identify chromatographic markers for quality control and safety assessment of medicinal preparations. Preliminary HPLC-PDA-ESIMS analyses revealed that flavonoid glycosides were the main UV-absorbing constituents in the MeOH extract of B. pinnatum. Two phenolic glucosides, syringic acid β-D-glucopyranosyl ester (1) and 4'-O-β-D-glucopyranosyl-cis-p-coumaric acid (2), as well as nine flavonoids (3-11) including kaempferol, quercetin, myricetin, acacetin, and diosmetin glycosides were unambiguously identified by 1H and 2D NMR analysis after isolation from a MeOH extract. The flavonol glycosides quercetin 3-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside 7-O-β-D-glucopyranoside (3) and myricetin 3-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside (4) were new natural products. With the aid of HPLC-PDA-APCIMS and authentic references isolated from the related species B. daigremontianum, the presence of four bufadienolides, bersaldegenin-1-acetate (12), bryophyllin A (13), bersaldegenin-3-acetate (14), and bersaldegenin-1,3,5-orthoacetate (15) was detected in B. pinnatum.

Pulmonary Echinococcus multilocularis metastasis in a dog.

A young adult Labrador retriever dog was presented for surgical debulking of hepatic alveolar echinococcosis. Computed tomography detected hepatomegaly with multiple large cavitary masses with extension of tissue from a lesion wall into the caudal vena cava and numerous nodules in all lung lobes. Following euthanasia, histology confirmed parasitic vesicles with granulomatous reaction in all lesions, and polymerase chain reaction (PCR) established the causative agent to be Echinococcus multilocularis. This report is the first to present imaging features of pulmonary E. multilocularis granulomata in a dog.

Decision Support Models for Composing and Navigating through e-Learning Objects

Libraries of learning objects may serve as basis for deriving course offerings that are customized to the needs of different learning communities or even individuals. Several ways of organizing this course composition process are discussed. Course composition needs a clear understanding of the dependencies between the learning objects. Therefore we discuss the metadata for object relationships proposed in different standardization projects and especially those suggested in the Dublin Core Metadata Initiative. Based on these metadata we construct adjacency matrices and graphs. We show how Gozinto-type computations can be used to determine direct and indirect prerequisites for certain learning objects. The metadata may also be used to define integer programming models which can be applied to support the instructor in formulating his specifications for selecting objects or which allow a computer agent to automatically select learning objects. Such decision models could also be helpful for a learner navigating through a library of learning objects. We also sketch a graph-based procedure for manual or automatic sequencing of the learning objects.