Dental management considerations for the patient with an acquired coagulopathy. Part 1: Coagulopathies from systemic disease

Current teaching suggests that many patients are at risk for prolonged bleeding during and following invasive dental procedures, due to an acquired coagulopathy from systemic disease and/or from medications. However, treatment standards for these patients often are the result of long-standing dogma with little or no scientific basis. The medical history is critical for the identification of patients potentially at risk for prolonged bleeding from dental treatment. Some time-honoured laboratory tests have little or no use in community dental practice. Loss of functioning hepatic, renal, or bone marrow tissue predisposes to acquired coagulopathies through different mechanisms, but the relationship to oral haemostasis is poorly understood. Given the lack of established, science-based standards, proper dental management requires an understanding of certain principles of pathophysiology for these medical conditions and a few standard laboratory tests. Making changes in anticoagulant drug regimens are often unwarranted and/or expensive, and can put patients at far greater risk for morbidity and mortality than the unlikely outcome of postoperative bleeding. It should be recognised that prolonged bleeding is a rare event following invasive dental procedures, and therefore the vast majority of patients with suspected acquired coagulopathies are best managed in the community practice setting

Current concepts of the management of dental extractions for patients taking warfarin

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Controversy has surrounded the correct management of patients therapeutically anticoagulated with warfarin who require dental extractions. The risk of bleeding must be weighed up against the risk of thromboembolism when deciding whether to interfere with a patient's warfarin regimen. An improved understanding of the importance of fibrinolytic mechanisms in the oral cavity has resulted in the development of various local measures to enable these patients to be treated on an outpatient basis. Methods: A review of the literature was undertaken. This was supplemented by the authors' clinical trials and extensive clinical experience with anticoagulated patients. Results: Various protocols for treating patients taking warfarin have been reviewed and summarized and an overview of the haemostatic and fibrinolytic systems is presented. A protocol for management of warfarinized patients requiring dental extractions in the outpatient setting is proposed. Conclusions: Patients therapeutically anticoagulated with warfarin can be treated on an ambulatory basis, without interruption of their warfarin regimen provided appropriate local measures are used.G Carter, AN Goss, JV Lloyd, R Tocchett

Lettere a una distinta e cara signora. Giovanni Maver, Evel Gasparini e Olga Resnevic Signorelli

L'articolo ricostruisce i rapporti tra un'esponente di spicco della comunità russa in Italia nella prima metà del Novecento e due protagonisti degli studi di slavistica, disciplina allora nascente. Il contributo comprende la pubblicazione e il commento di materiale epistolare inedito

Using Surficial Reflectance Properties to Analyze Carbonaceous-Like Asteroid Subclasses

In our research we applied AutoClass, a data mining technique based upon Bayesian Classification, to the reflectance properties of asteroids most similar to carbonaceous meteorites. Previous reflectance studies relied mostly on Principal Component Analysis (PCA) to differentiate subgroups of asteroids within the carbonaceous-like group (e.g. B, G, F, Ch, Cg and Cb). The advantage of AutoClass is that it calculates the most probable classification automatically, removing the human factor from this part of the analysis. Using the Sloan Digital Sky Survey (SDSS) surficial reflectance data, AutoClass divided the carbonaceous-like asteroids into two large classes and six smaller classes. The two large classes (n=4974 and 2033, respectively) displayed distinct regions with some overlap in color-vs-color plots. Each cluster\u27s average spectrum was compared to \u27typical\u27 spectra of the carbonaceous-like group subtypes as defined by Tholen (1989) and each cluster\u27s members were evaluated for consistency with previous taxonomies. Of the 117 asteroids classified as B-subtype in previous taxonomies, only 12 were found with SDSS colors that matched our criteria of having less than 0.1 magnitude error in u(wavelength 0.35 microns) and 0.05 magnitude error in wavelengths 0.48, 0.62, 0.76, and 0.91 microns. Although this was a relatively small group, 11 of the 12 B-types were placed by AutoClass in the same cluster. By determining the carbonaceous-like group sub-classifications in the large SDSS database, this research furthers our understanding of asteroid surficial composition variability

On Identifying Clusters Within the C-type Asteroids of the Sloan Digital Sky Survey

We applied AutoClass, a data mining technique based upon Bayesian Classification, to C-group asteroid colors in the Sloan Digital Sky Survey (SDSS). Previous taxonomic studies relied mostly on Principal Component Analysis (PCA) to differentiate asteroids within the C-group (e.g. B, G, F, Ch, Cg and Cb). AutoClass\u27s advantage is that it calculates the most probable classification for us, removing the human factor from this part of the analysis. In our results, AutoClass divided the C-groups into two large classes and six smaller classes. The two large classes (n=4974 and 2033, respectively) display distinct regions with some overlap in color-vs-color plots. Each cluster\u27s average spectrum is compared to \u27typical\u27 spectra of the C-group subtypes as defined by Tholen (1989) and each cluster\u27s members are evaluated for consistency with previous taxonomies. Of the 117 asteroids classified as B-type in previous taxonomies, only 12 were found with SDSS colors that matched our criteria of having less than 0.1 magnitude error in u and 0.05 magnitude error in g, r, i, and z colors. Although this is a relatively small group, 11 of the 12 B-types were placed by AutoClass in the same cluster. By determining the C-group sub-classifications in the large SDSS database, this research furthers our understanding of the stratigraphy and composition of the main-belt