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Background: Gliding motility in Plasmodium parasites, the aetiological agents of malaria disease, is mediated by an actomyosin motor anchored in the outer pellicle of the motile cell. Effective motility is dependent on a parasite myosin motor and turnover of dynamic parasite actin filaments. To date, however, the basis for directional motility is not known. Whilst myosin is very likely orientated as a result of its anchorage within the parasite, how actin filaments are orientated to facilitate directional force generation remains unexplained. In addition, recent evidence has questioned the linkage between actin filaments and secreted surface antigens leaving the way by which motor force is transmitted to the extracellular milieu unknown. Malaria parasites possess a markedly reduced repertoire of actin regulators, among which few are predicted to interact with filamentous (F)-actin directly. One of these, PF3D7_1251200, shows strong homology to the coronin family of actin-filament binding proteins, herein referred to as PfCoronin., Methods: Here the N terminal beta propeller domain of PfCoronin (PfCor-N) was expressed to assess its ability to bind and bundle pre-formed actin filaments by sedimentation assay, total internal reflection fluorescence (TIRF) microscopy and confocal imaging as well as to explore its ability to bind phospholipids. In parallel a tagged PfCoronin line in Plasmodium falciparum was generated to determine the cellular localization of the protein during asexual parasite development and blood-stage merozoite invasion., Results: A combination of biochemical approaches demonstrated that the N-terminal beta-propeller domain of PfCoronin is capable of binding F-actin and facilitating formation of parallel filament bundles. In parasites, PfCoronin is expressed late in the asexual lifecycle and localizes to the pellicle region of invasive merozoites before and during erythrocyte entry. PfCoronin also associates strongly with membranes within the cell, likely mediated by interactions with phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) at the plasma membrane., Conclusions: These data suggest PfCoronin may fulfil a key role as the critical determinant of actin filament organization in the Plasmodium cell. This raises the possibility that macro-molecular organization of actin mediates directional motility in gliding parasites.

Recently, it has been greatly appreciated that intense light matter interaction is modified due to the nano- and microstructures in the target by--surface plasmons, laser energy localization scattering etc. Extreme laser intensities produce dense plasmas and collective mechanisms generate energetic electrons, ions and hard x-rays. Recently, it is postulated that the anharmonic electron motion, driven by ultrashort, high-intensity laser pulses, provides a universal mechanism for the laser absorption. Here, we provide the first demonstration of anharmonic-resonance-aided high laser-absorption in a biological system. At intensities of ∼ 10¹⁶⁻¹⁸ W/cm², 40 fs pulses excite a plasma formed with E. coli bacteria. The density-inhomogeneities due to the micro- and nanostructures in the bacterial target increase anharmonic resonance (AHR) heating and result in a 10⁴-fold enhancement in the hard x-ray yield compared to plain solid targets. These observations lead to novel high-energy x-ray sources that have implications to lithography, imaging and medical applications.

This study evaluated the one-year clinical performance of a one-step, self-etch adhesive (Optibond All-in-One, Kerr, CA, USA) combined with a composite (Herculite XRV Ultra, Kerr Hawe, CA, USA) to restore NCCLs with or without prior acid etching. Restorations performed by the same practitioner were evaluated at baseline and after 3, 6, and 12 months using modified USPHS criteria. At 6 months, the recall rate was 100%. The retention rate was 84.2% for restorations with prior acid etching, but statistically significant differences were observed between baseline and 6 months. Without acid etching, the retention rate was 77%, and no statistically significant difference was noted between 3 and 6 months. Marginal integrity (93.7% with and 87.7% without acid etching) and discoloration (95.3% with and 92.9% without acid etching) were scored as Alpha or Bravo, with better results after acid etching. After one year, the recall rate was 58.06%. Loss of pulp vitality, postoperative sensitivity, or secondary caries were not observed. After one year retention rate was of 90.6% and 76.9% with and without acid conditioning. Optibond All-in-One performs at a satisfactory clinical performance level for restoration of NCCLs after 12 months especially after acid etching.

Introduction: The aim of this study was to compare the shaping ability of two single-file systems and conventional rotary instruments in severely curved root canals of extracted human molars., Methods and Materials: Mesiobuccal canals of 120 mandibular molars with angles of curvature ranging between 25(°) and 35(°) and radii of curvature from 5 to 9 mm, were divided into three groups (n=40). In each group the canals were instrumented with either WaveOne (W), Reciproc (R) or ProTaper (P). The time required for canal shaping and the frequency of broken instruments were recorded. The standardized pre and post-instrumentation radiographs were taken to determine changes in working length (WL) and straightening of canal curvature. The presence of blockage or perforation was also evaluated. Data were analyzed using the one-way analysis of variance (ANOVA) and post-hoc Tukey's test. The level of significance was set at 0.05., Results: Both single-instrument systems reduced the canal preparation time by approximately 50% (P<0.05). No incidence of broken instruments from single-file systems was reported; however, two F2 instruments in the P group were broken (P<0.05). Reduction in WL and straightening of canal curvature was observed in all three systems with the highest scores belonging to P system (P<0.05). No case of blockage or perforation was found during shaping in any group., Conclusion: Single-file systems shaped curved canals with substantial saving in time and a significant decrease in incidence of instrument separation, change in WL, and straightening of canal curvature.

Oral diseases are considered as major public health problem. Dental caries restricts the school activities and are the dominant cause of dental morbidity. The aims of this survey were to determine prevalence of dental caries among pupils of Dakar and to study their food habits and oral hygiene. A descriptive transversal study was conducted from February 15th to May 07th, 2011 with respect of WHO directives (protocol of 1997) readjusted to Senegalese context. Our results showed a prevalence of 41.8%; a mean DMF index of 0.644; a proportion of teeth decayed of 65%, 32.2% for missing teeth and 2.7% of filled teeth. The multivariate logistic regression analysis showed that snacking, consumption of sweetened drinks far from meals and brushing teeth before the meals were significantly linked to the presence of dental caries. These results showed that the state of oral health and the prevention level of dental caries among these children were not so good. A new orientation of oral health policy based on messages regarding the main etiologic factors is imperative.

Aim: The aim of the present study was to assess knowledge of, and management attitude of dentists regarding dentin hypersensitivity., Materials and Methods: The study involved all the dentists from private and public sectors, exerting in Senegal. The following data were requested from the surveyed dentists using an anonymous questionnaire; sociodemographics (i.e. age, gender, area of activity, etc.) and knowledge on triggering factor, type of pain, diagnosis, preventive and curative procedures., Results: Out of the 238 dentists who received the questionnaire, 68.9% returned properly filled forms. They were 116 males and 48 females with a mean age of 41.99 ± 8.50 years. Eighty three percent of the participants had a good understanding of the characteristics of pain related to DH and 92% recognized chemical and thermal stimuli as triggering factor while mechanical stimulus was not evoked. Many responders (90.9%) did not have any idea of the mechanism for pain transmission across the dentin. Regarding diagnosis technique, 68% use mechanical stimuli to elicit DH pain. Regarding management procedure, the use of desensitizing tooth paste is the mostly chosen option followed by professional topical application of fluoride. More than 1/3rd of the surveyed dentists confess resorting to root canal to manage DH., Conclusion: We recommend incorporation of basic science knowledge on orofacial pain and competencies to manage painful conditions like dentin hypersensitivity. Also, health regulatory institutions should make continuing dental education a requirement to preserve the dental licensure.

We demonstrate that the interaction of intense femtosecond light on a plain solid substrate can be substantially altered by a few micron layer coating of bacterial cells, live or dead. Using E. Coli cells, we show that at an intensity of 10(16)W cm(-2), the bremsstraahlung hard x-ray emission (up to 300 keV), is increased by more than two orders of magnitude as compared to a plain glass slab. Particle-in-cell simulations carried out by modeling the bacterial cells as ellipsoidal particles show that the hot electron generation is indeed enhanced by the presence of microstructures. This new methodology should pave way for using microbiological systems of varied shapes to control intense laser produced plasmas for EUV/x-ray generation.

The purpose of this study was to determine radiographically the prevalence of periapical periodontitis in teeth restored with crown in a Senegalese population. Full mouth periapical radiographs were obtained from 208 consecutive adult patients (6234 teeth) presenting as new patients to the Dental Service of the University. The presence of crown restorations, the periapical status and technical quality of root fillings associated were evaluated. 7.69% (n = 16) of patients had at least one tooth that was crowned. The total number of crowns assessed was 0.95% (n = 59). The molars were the teeth most crowned 40.67% (n = 24) followed by anterior teeth 30.50% (n = 18) and premolars 28.81% (n = 17). All the crowned teeth had previous root canal treatment of which only 16.94% (n = 10) were acceptable. 53 % (n = 32) of the teeth had apical periodontitis (PAI > 2). Unacceptable root fillings were associated with a higher prevalence of periapical disease (p < 0.05). Crown with a post extending more than 4 millimetres from the apex were associated with more periapical lesions 64.28% (p < 0.05). The results indicate a low prevalence of crowned teeth, an absence of vital preparation, a high prevalence of radiographic periapical disease and unacceptable root fillings associated.

Introduction: Shaping canal is one of the most important steps in endodontic treatment. It allows the cleaning solutions to reach the totality of the canal and to control any infection of the canal system. To achieve this goal is not without difficulty with the steel instruments, because of their rigidity. Recently, the Nickel Titanium instruments were introduced in Endodontics, to allow a setting form technically simplified and faster The aim of this study was to evaluate the duration of the canal shaping with the Pro Taper system., Materials and Methods: This exploratory study was carried out in Conservative Odontology and Endodontics service (OCE) of the department of Odontology of Faculty of Medicine, Pharmacy and Odonto-Stomatology of the University CheikhAnta Diop of Dakar in 2006. Sixty nine root canals (50 teeth) were shaped with ProTaper., Results: The results showed that an average time of 17.35 minutes was necessary for the shaping of the long canals against 15.38 minutes for the middle canals and 14.29 minutes for the short canals. The average duration of canal shaping of the one-root teeth is 13.76 minutes and 17.77 minutes for the plural root teeth., Conclusion: Taking into account the necessity of maintaining the teeth on the arcade during long year; include that we have now to respect imperatively the biological principles during the canal shaping in a restricted duration to realize a dense and hermetic canal obturation of the canal system in the same meeting. The Pro Taper system is so a reliable means.

Aim: The purpose of this study was to assess the canal anatomy of mandiblar premolars in Senegalese population., Materials and Methods: Retroalveolar radiographs of mandibular premolars of 208 patients in Senegal were obtained. Two experienced practitioners using a long cone tube and the parallel plane technique with angulators took the radiographs. The canal morphology of each tooth was determined in terms of the number of canals radiologically visible to the apex. Any anatomic structure emanating from the pulp chamber or the principal canal to the apex and measuring more than 3 millimetres was considered to be a supplementary canal., Results: For the 208 patients studied, 412 first premolars were present and 4 were absent.Among the 412 teeth, 335 (81.3%) had a single canal, 62 (15.1%) 2 canals, and 17 (3.6%) 3 canals. For the second premolars 408 were present. Of the 408 teeth, 352 (86%) had one canal, 49 (12%) 2 canals, and 8 (2%) 3 canals., Conclusion: The prevalence of two or more canals in premolar mandibular from Senegalese patients was similar to that found in the others ethnic population.