Detection of Horizontal Root Fracture with Small-volume Cone-Beam Computed Tomography in the Presence and Absence of Intracanal Metallic Post

Introduction: The aim of the present study was to test the accuracy of small-volume cone-beam computed tomography (CBCT) scanning in the detection of horizontal root fractures and to assess the influence of a metallic post. Methods: Forty teeth were divided into four groups based on the presence of metallic posts and horizontal root fracture. The teeth were examined by small-volume CBCT scanning at 0.2-mm voxel resolution. Three observers analyzed the samples for the presence of a horizontal root fracture. Sensitivity and specificity were calculated. Results: High values for accuracy (73%-88%) were obtained in the groups without a metallic post, and statistically significant differences were found when the group with a metallic post has been observed (55%-70%). Intraobserver agreement also showed statistically significant differences in the groups with a metallic post. Conclusions: Small-volume CBCT scanning showed high accuracy in detecting horizontal root fracture without a metallic post. However, the presence of a metallic post significantly reduced the specificity and sensitivity of this examination. (J Endod 2011;37:1456-1459)

Detection of Herpesviruses and Periodontal Pathogens in Subgingival Plaque of Patients With Chronic Periodontitis, Generalized Aggressive Periodontitis, or Gingivitis

Background: Herpesviruses may be related to the etiology of aggressive periodontitis (AgP) and chronic periodontitis (CP) by triggering periodontal destruction or by increasing the risk for bacterial infection. This case-control study evaluated the presence of herpes simplex virus type 1 (HSV-1), Epstein-Barr virus type 1 (EBV-1), human cytomegalovirus (HCMV), Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia (previously T. forsythensis) in patients with generalized AgP (AgP group), CP (CP group), or gingivitis (G group) and in healthy individuals (C group). Methods: Subgingival plaque samples were collected with paper points from 30 patients in each group. The nested polymerase chain reaction (PCR) method was used to detect HSV-1, EBV-1, and HCMV. Bacteria were identified by 16S rRNA-based PCR. Results: HSV-1, HCMV, and EBV-1 were detected in 86.7%, 46.7%, and 33.3% of the AgP group, respectively; in 40.0%, 50.0%, and 46.7% of the CP group, respectively; in 53.3%, 40.0%, and 20.0% of the G group, respectively; and in 20.0%, 56.7%, and 0.0% of the C group, respectively. A. actinomycetemcomitans was detected significantly more often in the AgP group compared to the other groups (P<0.005). P. gingivalis and T. forsythia were identified more frequently in AgP and CP groups, and AgP, CP, and G groups had higher frequencies of P. intermedia compared to the C group. Conclusion: In Brazilian patients, HSV-1 and EBV-1, rather than HCMV, were more frequently associated with CP and AgP. J Periodontol 2008;79:2313-2321.

Correlation between c-Jun and human papillomavirus in oral premalignant and malignant lesions

c-Jun, one of the components of the transcription factor activating protein-1 (AP-1), is suggested as a factor in malignant progression of oral lesions. c-Jun and other AP-1 components relationships with human papillomavirus (HPV) infection have been investigated, but not yet focusing on oral carcinogenesis. The aim of this study was to verify whether c-Jun immunohistochemical expression is related to HPV DNA detection in oral premalignant and malignant lesions. Fifty cases diagnosed as oral leukoplakias, with different degrees of epithelial dysplasia, and as oral squamous cell carcinomas (OSCC) were submitted to immunohistochemistry to detect c-Jun and to in situ hybridization with signal amplification to assess HPV DNA. It was verified that c-Jun nuclear expression increased according to the degree of dysplasia within the lesion, with the greatest expression in OSCC. The same did not happen concerning HPV infection - a discrete proportional relation was observed in indexes found in leukoplakia with no dysplasia, leukoplakia with dysplasia and OSCC, but statistically insignificant. When separating the group of leukoplakia by degrees of dysplasia, this relation of proportion was not observed. Nevertheless, the overall prevalence of HPV infection was 24% and the high-risk HPV types were the most frequently identified, which does not allow excluding HPV as a risk factor in oral carcinogenesis. When relating c-Jun expression and HPV infection, no statistically significant relationship is observed. Results suggest then that malignant progression mediated by c-Jun is independent of the presence of HPV in oral carcinogenesis. (C) 2007 Elsevier Ltd. All rights reserved.

Immunocytochemical detection of dentine matrix protein 1 in experimentally induced reactionary and reparative dentine in rat incisors

Objective: Although the general mechanisms of dentinogenesis are understood, several aspects regarding tertiary dentine formation still deserve investigation, especially regarding the presence and distribution of some noncollagenous matrix proteins. As dentine matrix protein 1 (DMP 1) is present in primary dentine, it is possible that this protein may also be present in the dentine matrix secreted after injury, but there are no immunocytochemical studies attempting its detection in tertiary dentine. The aim of this study was to examine the ultrastructural immunolocalization of DMP 1 in the tertiary dentine after extrusion of the rat incisor. Study design: Upper incisors were extruded 3 mm and then repositioned into their sockets. After several periods, the incisors were fixed and processed for transmission electron microscopy and for immunocytochemistry for DMP 1. Results: Extrusion yielded both types of tertiary dentine, which varied in aspect and related cells. DMP 1 was found in the mineralized matrix of all types of dentine, presenting high affinity for collagen, but rare colloidal gold particles over predentine. DMP 1 was evident in the supranuclear region and inside the nucleus of some odontoblast-like cells. Conclusion: The observed association between DMP 1 and collagen seem to be essential for reactionary and reparative dentine formation. (C) 2010 Elsevier Ltd. All rights reserved.

Resource entitlements of indigenous minorities, their poverty and conservation of nature: Status of Australian Aborigines, comparisons with India's tribals, theory and changing policies globally

Considers the relevance of A.K. Sen’s theory of entitlements to the situation facing indigenous tribal people, its relationship to institutionalism, and to theories of property rights. Changing world views about the resource entitlements that should be given to local communities are outlined concentrating on the views expressed by the World Conservation Union (IUCN). These changing views have relevance for the resource entitlements of indigenous tribal communities and are reflected in differences in the policy approaches inherent in the Convention on International Trade in Endangered Species (CITES) and the more recent Convention on Biological Diversity. The latter embodies the view that provision of greater resource entitlements to local communities can provide economic incentives for nature conservation. There is a case for Indigenous Australians to be given greater rights to market the natural produce from their lands. Despite progress with land rights, they are not entitled to market much of the natural produce from their land. The socioeconomic status of Australian Aborigines is outlined. Their standard of living and their life expectancy are low by world standards and in comparison to other Australians. This is partly a result of historical events that have restricted their rights. These events are outlined briefly. Views differ about the appropriate development paths for Indigenous Australians and these are assessed. Concern on environmental and economic grounds is expressed about the view that the economic development of Australian Aboriginal communities would be accelerated by replacing their communal land titles by private land titles and encouraging Western-style agriculture and commercial development of their lands. Some comparisons are also made with the situation of India’s Tribals.

Detection of cytokines and nitric oxide synthase in skin lesions of Jorge Lobo`s disease patients

Studies investigating the immunopathological aspects of Jorge Lobo`s disease have shown that the inflammatory infiltrate consists mainly of histiocytes and multinucleated giant cells involving numerous yeast-like cells of Lacazia loboi, with the T lymphocytes more common than B lymphocytes and plasma cells. The quantification of cytokines in peripheral blood mononuclear cells culture supernatant has revealed alterations in the cytokines profile, characterized by predominance of a Th2 profile. In view of these findings and of the role of cytokines in cell interactions, the objective of the present study was to investigate the presence of the cytokines IL-10, TGF-ss 1 and TNF-alpha, as well as iNOS enzyme in granulomas induced by L. loboi. Histological sections obtained from skin lesions of 16 patients were analyzed by immunohistochemistry for the presence of these cytokines and iNOS. The results showed that TGF-ss 1 was the cytokine most frequently expressed by cells present in the inflammatory infiltrate, followed by IL-10. There was a minimum to discrete positivity of cells expressing TNF-alpha and iNOS. The results suggest that the presence of immunosuppressive cytokines in skin lesions of patients with the mycosis might be responsible for the lack of containment of the pathogen as demonstrated by the presence of numerous fungi in the granuloma.

Differential inclusions and robust control theory

Uncontrolled systems (x) over dot is an element of Ax, where A is a non-empty compact set of matrices, and controlled systems (x) over dot is an element of Ax + Bu are considered. Higher-order systems 0 is an element of Px - Du, where and are sets of differential polynomials, are also studied. It is shown that, under natural conditions commonly occurring in robust control theory, with some mild additional restrictions, asymptotic stability of differential inclusions is guaranteed. The main results are variants of small-gain theorems and the principal technique used is the Krasnosel'skii-Pokrovskii principle of absence of bounded solutions.

Should optional properties be used in conceptual modelling? A theory and three empirical tests

An important feature of some conceptual modelling grammars is the features they provide to allow database designers to show real-world things may or may not possess a particular attribute or relationship. In the entity-relationship model, for example, the fact that a thing may not possess an attribute can be represented by using a special symbol to indicate that the attribute is optional. Similarly, the fact that a thing may or may not be involved in a relationship can be represented by showing the minimum cardinality of the relationship as zero. Whether these practices should be followed, however, is a contentious issue. An alternative approach is to eliminate optional attributes and relationships from conceptual schema diagrams by using subtypes that have only mandatory attributes and relationships. In this paper, we first present a theory that led us to predict that optional attributes and relationships should be used in conceptual schema diagrams only when users of the diagrams require a surface-level understanding of the domain being represented by the diagrams. When users require a deep-level understanding, however, optional attributes and relationships should not be used because they undermine users' abilities to grasp important domain semantics. We describe three experiments which we then undertook to test our predictions. The results of the experiments support our predictions.

Radiographic Signals Detection of Systemic Disease. Orthopantomographic Radiography

For the purposes of this report, ""systemic disease"" will be interpreted as conditions that are spread out within the body rather than localized strictly to the tissues of the oral cavity. Since it would take many volumes to review all such conditions, the intent of the authors is to review a few examples of conditions where initial panoramic radiographic findings suggested widespread disease of significance enough to affect the quality of life and longevity of the patient.

Standardization of the Electromyographic Signal Through the Maximum Isometric Voluntary Contraction

The objective of this study was to analyze the electromyographic (EMG) data, before and after normalization. One hundred (100) normal subjects (with no signs and symptoms of temporomandibular disorders) participated in this study. A surface EMG of the masticatory muscles was performed. Two different tests were performed: maximum voluntary clench (MVC) on cotton rolls and MVC in intercuspal position. The normalization was done using the mean value of the EMG signal of the first examination. The coefficient of variation CV showed lower values for the standardized data. The standardization was effective in reducing the differences between records from the same subject and in different subjects.

Patch dynamics and metapopulation theory: the case of successional species

We present a mathematical framework that combines extinction-colonization dynamics with the dynamics of patch succession. We draw an analogy between the epidemiological categorization of individuals (infected, susceptible, latent and resistant) and the patch structure of a spatially heterogeneous landscape (occupied-suitable, empty-suitable, occupied-unsuitable and empty-unsuitable). This approach allows one to consider life-history attributes that influence persistence in patchy environments (e.g., longevity, colonization ability) in concert with extrinsic processes (e.g., disturbances, succession) that lead to spatial heterogeneity in patch suitability. It also allows the incorporation of seed banks and other dormant life forms, thus broadening patch occupancy dynamics to include sink habitats. We use the model to investigate how equilibrium patch occupancy is influenced by four critical parameters: colonization rate? extinction rate, disturbance frequency and the rate of habitat succession. This analysis leads to general predictions about how the temporal scaling of patch succession and extinction-colonization dynamics influences long-term persistence. We apply the model to herbaceous, early-successional species that inhabit open patches created by periodic disturbances. We predict the minimum disturbance frequency required far viable management of such species in the Florida scrub ecosystem. (C) 2001 Academic Press.