Validation of a diagnostic probability function for estimating probabilities of acute coronary syndrome

BACKGROUND We recently reported about the derivation of a diagnostic probability function for acute coronary syndrome (ACS). The present study aims to validate the probability function as a rule-out criterion in a new sample of patients. METHODS 186 patients presenting with chest pain and/or dyspnea at one of the three participating hospitals' emergency rooms in Switzerland were included in the study. In these patients, information on a set of pre-specified variables was collected and a predicted probability of ACS was calculated for each patient. Approximately two weeks after the initial visit in the emergency room, patients were contacted by phone to assess whether a diagnosis of ACS was established. RESULTS Of the 186 patients included in the study, 31 (17%) had an acute coronary syndrome. A risk probability for ACS below 2% was considered a rule-out criterion for ACS, leading to a sensitivity of 87% and a specificity of 17% of the rule. The characteristics of the study patients were compared to the cases from which the probability function was derived, and considerable deviations were found in some of the variables. CONCLUSIONS The proposed probability function, with a 2% cut-off for ruling out ACS works quite well if the patient data lie within the ranges of values of the original vignettes. If the observations deviate too much from these ranges, the predicted probabilities for ACS should be seen with caution

Computed tomography to quantify tooth abrasion

Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes

Role of arterial hypertension as a predictive marker for bevacizumab efficacy in recurrent glioblastoma - a prospective analysis

Role of arterial hypertension as a predictive marker for bevacizumab efficacy in recurrent glioblastoma – a prospective analysi