9 research outputs found
The evolution of CT diagnosed papillae tip microcalcifications: can we predict the development of stones?
OBJECTIVES: To determine the incidence of computed tomography (CT) identifiable Randall plaques in a CT explored population; to determine the clinical relevance of this radiological finding by a 7-year follow-up; to determine a cut point to identify a population with high risk of developing calcium stone disease (SD). MATERIALS AND METHODS: Retrospective study of all patients explored by abdominal CT in our center between January and March 2005. INCLUSION CRITERIA: age 30-60 years and no SD. Papillae attenuation was measured on nonenhanced CT in Hounsfield units (HU) and the mean of all papillae was calculated. Patients were re-evaluated after 7 years to identify calcium stone formers. Anamnesis and already available CT, ultrasound, kidney, ureter, and bladder radiograph (KUB) or intravenous urography (IVU) images performed as part of their follow-up were used. In patients with no follow-up, ultrasound and KUB were to be performed. Pearson correlation, Student t-test, and the receiver operator curve were used for statistical analysis. RESULTS: A total of 362 patients fulfilled the inclusion criteria and were analyzed; 12 developed calcium SD after 7 years. A significant difference was encountered between the papillae attenuation of stone formers (SF) versus non-SF (47.2HU vs. 35.5HU, p=0.001). There was good correlation between papillae attenuation and the possibility of developing SD (R=0.87). An optimal cut point of 43HU with a sensitivity of 81% and specificity of 97%, area under the curve 0.91, separated SF and non-SF. CONCLUSION: Patients with high papillae density have a higher risk of developing SD. A cut point of 43HU could accurately be used to identify a high-risk population
Comparative Study Using CAD Optimization Tools for the Workspace of a 6DOF Parallel Kinematics Machine
This paper deals with an up-to-date topic among robotic industrial applications that require a high degree of speed, rigidity, and orientation. Currently, when technology and software applications reach a high level of performance, in various robotic industrial applications that start from certain concepts, the implementation of efficient structures has proven to be challenging. New structures such as the parallel kinematic machine (PKM) category has proven its efficiency through its structure in terms of high inertia rigidity and high speeds during processes. This paper deals with the subject of PKM-type structures in terms of the optimal design workspace of such a structure. The calculation of the workspace is considered the premise from which it starts in terms of its implementation in a robotic production line. The entire process of calculating the workspace for a given PKM structure is carried out through modern CAD applications that have specific modules in place in this direction. CATIA V5 offers the possibility through the product engineering optimizer module, simulation and calculation of different scenarios aimed at identifying the volume of the workspace for a PKM structure. In the article, we demonstrate the relations between the robot workspace and the design parameters, a method that can also be applied for other parallel structures. The method is useful for robot designers in the optimization of parallel robots with regard to the workspace by using CAD tools. Previous research in the field refers of the usage of CAD tools only for visual representation and not for optimizing the workspace, while this study and test results show that CAD tools are suitable for analyzing and optimizing the robot workspace of the 6DOF parallel robot, due to its easiness in application and fast implementation time
The evolution of CT diagnosed papillae tip microcalcifications: can we predict the development of stones?
OBJECTIVES: To determine the incidence of computed tomography (CT) identifiable Randall plaques in a CT explored population; to determine the clinical relevance of this radiological finding by a 7-year follow-up; to determine a cut point to identify a population with high risk of developing calcium stone disease (SD). MATERIALS AND METHODS: Retrospective study of all patients explored by abdominal CT in our center between January and March 2005. INCLUSION CRITERIA: age 30-60 years and no SD. Papillae attenuation was measured on nonenhanced CT in Hounsfield units (HU) and the mean of all papillae was calculated. Patients were re-evaluated after 7 years to identify calcium stone formers. Anamnesis and already available CT, ultrasound, kidney, ureter, and bladder radiograph (KUB) or intravenous urography (IVU) images performed as part of their follow-up were used. In patients with no follow-up, ultrasound and KUB were to be performed. Pearson correlation, Student t-test, and the receiver operator curve were used for statistical analysis. RESULTS: A total of 362 patients fulfilled the inclusion criteria and were analyzed; 12 developed calcium SD after 7 years. A significant difference was encountered between the papillae attenuation of stone formers (SF) versus non-SF (47.2HU vs. 35.5HU, p=0.001). There was good correlation between papillae attenuation and the possibility of developing SD (R=0.87). An optimal cut point of 43HU with a sensitivity of 81% and specificity of 97%, area under the curve 0.91, separated SF and non-SF. CONCLUSION: Patients with high papillae density have a higher risk of developing SD. A cut point of 43HU could accurately be used to identify a high-risk population
Efficacy and Safety of the Hexanic Extract of Serenoa repens vs. Watchful Waiting in Men with Moderate to Severe LUTS-BPH: Results of a Paired Matched Clinical Study
We investigated changes in symptoms and quality of life (QoL) in men with moderate-to-severe lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH) receiving the hexanic extract of Serenoa repens (HESr) and compared results with a matched group on watchful waiting (WW). Data was from a real-world, open-label, prospective, multicenter study. This sub-group analysis included patients with moderate-to-severe symptoms receiving either the HESr 320 mg/daily for six months (HESr) or who remained untreated for LUTS/BPH (WW). Changes in urinary symptoms and QoL were measured by IPSS and BII questionnaires. Two statistical approaches (iterative matching and propensity score pairing) were used to maximize between-group comparability at baseline. Tolerability was assessed in the HESr group. After iterative matching, data for analysis was available for 783 patients (102 WW, 681 HESr). IPSS scores improved by a mean (SD) of 3.8 (4.4) points in the HESr group and by 2.2 (4.5) points in the WW group (p = 0.002). Changes in BII score were 1.8 (2.4) points and 1.0 (2.2) points, respectively (p < 0.001). Three patients (0.9%) treated with the HESr reported mild adverse effects. Moderate-severe LUTS/BPH patients treated for six months with the HESr showed greater improvements in symptoms and QoL than matched patients on WW, with a very low rate of adverse effects