148 research outputs found
Chikungunya Virus Glycoproteins Mediate Viral Entry and Cellular Fusion
The Chikungunya virus (CHIKV) has currently been identified in over 40 countries and in 2008 was listed as a US National Institute of Allergy and Infectious Diseases (NIAID) category C priority pathogen. Outbreaks of the virus have been documented as early as 1779 and frequent outbreaks have been reported through 1960-2003, most notably in Reunion Island, a French overseas department in the Indian Ocean. Out of a total population of 785,000 in Reunion Island, 300,000 cases were reported including a total of 237 deaths. Numerous aspects of the viral life cycle are unknown, with no current vaccine the implementation of more research and dissemination of more knowledge is of great public health importance. A CHIKV construct was synthesized by Genewiz, containing CHIKV structural proteins in pcDNA 3.1. This construct was used to create CHIKV pseudo-viral particles with a luciferase based reporter. The pseudo-virus was used to survey many cell lines for permissivity to infection. This construct was also used to create 3 other constructs containing CHIKV E1, E2, and E3 individually. These constructs were used individually and in combination with each other to create pseudo-viruses for cellular infection. The cell-cell fusion capabilities of the full CHIKV construct along with the individual envelope proteins were also tested in a Cre-Lox system
Evaluación de dos técnicas para el registro de relación céntrica mandibular: arco gótico versus céntrica de poder
ResumenLa búsqueda de la verdadera posición mandibular con respecto a la cavidad glenoidea y la relación de los otros componentes que constituyen la articulación temporomandibular conocida como rela-ción céntrica (RC) son esenciales para el diagnóstico, tratamiento y estabilidad del mismo. El propósito del estudio fue evaluar dos técnicas para el registro de RC (técnica céntrica de poder y técni-ca del arco gótico) con objeto de determinar el método más eficaz para brindar mayor veracidad en el registro, dado que, en nuestra institución, se han experimentado algunas inconsistencias durante la obtención de registros en pacientes con malformaciones o discre-pancias esqueléticas considerables. Se evaluaron quince pacien-tes sistémicamente sanos, clase ósea II, de entre 13 y 17 años de edad, ocho del sexo femenino (53.4%) y siete del sexo masculino (46.6%). Se realizaron treinta montajes en un articulador semiajus-table utilizando ambas técnicas, se monitorearon los cambios a ni-vel condilar utilizando el indicador de posición axial condilar (IPAC). Los resultados mostraron que no hubo diferencias significativas; sin embargo, los cambios sagitales, verticales y transversales fueron mayores con la técnica del arco gótico.AbstractThe search for the true mandibular position with respect to the glenoid fossa and the relationship of the other components which constitute the temporomandibular joint known as centric relation (CR) are essential factors for its diagnosis, treatment and stability. The aim of the present study was to assess two techniques used for recording CR: power centric technique and gothic arch technique, with the purpose of determining the most effective method to confer greater accuracy to the recording. This was triggered by the fact that in our institution some inconsistencies had been detected when taking records of patients afflicted with considerable skeletal discrepancies or malformations. Fifteen healthy skeletal class II patients were assessed. Patients’ ages ranged from 13 to 17 years. Eight patients were female (53.4%) and seven male (46.6%). Using both techniques, thirty mountings were performed in a semi-adjustable articulator, condylar changes were monitored using axial condylar position indicator (API). Results revealed no significant differences, nevertheless, observed transversal, vertical and saggital changes were greater with the gothic arch technique
Sagittal joint spaces of the temporomandibular joint: Systematic review and meta-analysis
Introduction: The joint space measurements of the temporomandibular joint have been used to determine the condyle position variation. Therefore, the aim of this study is to perform a systematic review and meta-analysis on the
coronal joint spaces measurements of the temporomandibular joint.
Materials and Methods: An electronic database search was performed with the terms “condylar position”; “joint
space”AND”TMJ”. Inclusionary criteria included: tomographic 3D imaging of the TMJ, presentation of at least
two joint space measurements on the coronal plane. Exclusionary criteria were: mandibular fractures, animal studies, surgery, presence of genetic or chronic diseases, case reports, opinion or debate articles or unpublished material. The risk of bias of each study was judged as high, moderate or low according to the “Cochrane risk of bias
tool”. The values used in the meta-analysis were the medial, superior and lateral joint space measurements and their
differences between the right and left joint.
Results: From the initial search 2706 articles were retrieved. After excluding the duplicates and all the studies that
did not match the eligibility criteria 4 articles classified for final review. All the retrieved articles were judged as low
level of evidence. All of the reviewed studies were included in the meta-analysis concluding that the mean coronal
joint space values were: medial joint space 2.94 mm, superior 2.55 mm and lateral 2.16 mm.
Conclusions: the analysis also showed high levels of heterogeneity. Right and left comparison did not show statistically significant differences
Opening and closure forces of sliding mechanisms of different self-ligating brackets
Self-ligating brackets engage the wire by means of a slide mechanism. Forces that have to be applied to open and close the sliding mechanism of brackets are still unknown. OBJECTIVE: The aim of this study was to measure and compare the opening and closure forces of different self-ligating brackets. MATERIAL AND METHODS: Three different stainless steel self-ligating brackets (Carriere LX, Ortho Organizers; F1000, Leone; Damon Q, Ormco) were tested. For each different bracket, 20 maxillary right central incisors and 20 mandibular right central incisors were used. Opening and closure forces were measured using an Instron Universal Testing Machine. Statistical analysis was performed and ANOVA and Tukey tests were carried out. RESULTS: Opening forces were registered between 1.1 N and 5.6 N, whereas closure forces were recorded between 1.57 N and 4.87 N. Significant differences were detected among the different brackets and between the two prescriptions tested. CONCLUSION: The knowledge of different opening and closure forces of self-ligating brackets can help the orthodontist in the clinical management of these devices
Effect of prosthodontic planning on lateral occlusion scheme: a comparison between conventional and digital planning
Recently, digital wax-up is proposed as a tool to aid prosthodontic planning. However, there are no data about the effect of prosthodontic planning on lateral occlusion scheme. Objective : This study aims to evaluate the impact of conventional and digital prosthodontic planning on lateral occlusion scheme. Material and Methods : Dental models of 10 patients were collected. All models had Angle Class I occlusion and were undergoing prosthodontic treatment that would influence the lateral occlusion scheme. Each set of models had received both conventional wax-up and digital wax-up. In relation to the lateral occlusion scheme, the following variables were evaluated: the prevalence of the different lateral occlusion scheme, number of contacting teeth and percentage of each contacting tooth. Four excursive positions on the working side were included: 0.5, 1.0, 2.0 and 3.0 mm from the maximal intercuspation position. Results : The lateral occlusion scheme of the two wax-up models was subjected to alterations following excursion. There was a tendency for the prevalence of canine-guided occlusion to increase and for the prevalence of group function occlusion to decrease with increasing excursion. The number of contacting teeth was decreasing with the increasing magnitude of excursion. For the 0.5 mm and 1.0 mm positions, the two wax-ups had significantly greater contacts than the pre-treatment models, while at the 2.0 mm and 3.0 mm positions, all the models were similar. For all models, canines were the most commonly contacting teeth, followed by the teeth adjacent to them. No difference was observed between the two wax-ups in relation to the number of contacting teeth. Conclusion : Although the prosthodontic planning had influenced the pattern of the lateral occlusion scheme and contacts, there was no difference between the conventional and digital prosthodontic planning
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