16 research outputs found

    Silicate calculi, a rare cause of kidney stones in children

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    Urinary silicate calculi in humans are extremely rare. Reported cases of silicate calculi are mostly documented in adults and are commonly related to an excessive intake of magnesium trisilicate in food or drugs. Published studies on the presence of silicate calculi in children are scarce

    Can Laws Be a Potential PET Image Texture Analysis Approach for Evaluation of Tumor Heterogeneity and Histopathological Characteristics in NSCLC?

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    We investigated the association between the textural features obtained from F-18-FDG images, metabolic parameters (SUVmax(,) SUVmean, MTV, TLG), and tumor histopathological characteristics (stage and Ki-67 proliferation index) in non-small cell lung cancer (NSCLC). The FDG-PET images of 67 patients with NSCLC were evaluated. MATLAB technical computing language was employed in the extraction of 137 features by using first order statistics (FOS), gray-level co-occurrence matrix (GLCM), gray-level run length matrix (GLRLM), and Laws' texture filters. Textural features and metabolic parameters were statistically analyzed in terms of good discrimination power between tumor stages, and selected features/parameters were used in the automatic classification by k-nearest neighbors (k-NN) and support vector machines (SVM). We showed that one textural feature (gray-level nonuniformity, GLN) obtained using GLRLM approach and nine textural features using Laws' approach were successful in discriminating all tumor stages, unlike metabolic parameters. There were significant correlations between Ki-67 index and some of the textural features computed using Laws' method (r = 0.6, p = 0.013). In terms of automatic classification of tumor stage, the accuracy was approximately 84% with k-NN classifier (k = 3) and SVM, using selected five features. Texture analysis of FDG-PET images has a potential to be an objective tool to assess tumor histopathological characteristics. The textural features obtained using Laws' approach could be useful in the discrimination of tumor stage

    Lung cancer subtype differentiation from positron emission tomography images

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    Lung cancer is one of the deadly cancer types, and almost 85% of lung cancers are nonsmall cell lung cancer (NSCLC). In the present study we investigated classification and feature selection methods for the differentiation of two subtypes of NSCLC, namely adenocarcinoma (ADC) and squamous cell carcinoma (SqCC). The major advances in understanding the effects of therapy agents suggest that future targeted therapies will be increasingly subtype specific. We obtained positron emission tomography (PET) images of 93 patients with NSCLC, 39 of which had ADC while the rest had SqCC. Random walk segmentation was applied to delineate three-dimensional tumor volume, and 39 texture features were extracted to grade the tumor subtypes. We examined 11 classifiers with two different feature selection methods and the effect of normalization on accuracy. The classifiers we used were the k-nearest-neighbor, logistic regression, support vector machine, Bayesian network, decision tree, radial basis function network, random forest, AdaBoostM1, and three stacking methods. To evaluate the prediction accuracy we performed a leave-one-out cross-validation experiment on the dataset. We also considered optimizing certain hyperparameters of these models by performing 10-fold cross-validation separately on each training set. We found that the stacking ensemble classifier, which combines a decision tree, AdaBoostM1, and logistic regression methods by a metalearner, was the most accurate method for detecting subtypes of NSCLC, and normalization of feature sets improved the accuracy of the classification method

    Antiprotozoal Linear Furanosesterterpenoids from the Marine Sponge Ircinia oros

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    Chemical investigation of the marine sponge Ircinia oros yielded four linear furanosesterterpenoids, including the known metabolites ircinin-1 (1) and ircinin-2 (2) and two new compounds, ircinialactam E (3) and ircinialactam F (4). Their chemical structures were elucidated by using a combination of [α]D, NMR, HRMS, and FT-IR spectroscopy. The absolute configuration of C-18 in compounds 1–3 was identified as R by electronic circular dichroism (ECD) spectroscopy coupled with time-dependent density functional theory calculations. Compounds 1–4 showed moderate leishmanicidal, trypanocidal, and antiplasmodial activities (IC50 values 28–130 μM). This is the second report of rare glycinyl lactam derivatives 3 and 4 from the genus Ircinia

    Does Arterio-Venous Fistula Creation Affects Development of Pulmonary Hypertension in Hemodialysis Patients?

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    Background: Pulmonary arterial hypertension (PAH) is a common complication in hemodialysis (HD) patients and its pathogenesis is not explained clearly. Arterio-venous fistulas (AVFs) creation may contribute to the development of PAH because of increased pulmonary artery blood flow. However, it was not prospectively evaluated that effect of AVF on the development of PAH. Aim: We aimed to evaluate the effects of AVF on PAH and the relationship between blood flow rate of AVF and pulmonary artery pressure (PAP) in HD patients. Patients and Method: The prospective study included 50 patients with end-stage renal disease. Before an AVF was surgically created for hemodialysis, the patients were evaluated by echocardiography. Then, an AVF was surgically created in the patients. After mean 76.14 +/- 11.37 days, the second evaluation was performed by echocardiography. Results: Before AVF creation, 17 (34%) out of 50 patients had PAH. The systolic PAP was significantly higher in the patients with PAH compared with patients without PAH (47.82 +/- 9.82 mmHg vs. 30.15 +/- 5.70 mmHg, respectively, p = 0.001). In the second evaluation, 19 (38%) out of 50 patients had PAH. The systolic PAP values were significantly higher in the patients with PAH compared with patients without PAH (47.63 +/- 8.92 mmHg vs. 25.03 +/- 7.69 mmHg, P = 0.001, respectively). There was no relationship between the blood flow rate of AVF and PAP. Conclusion: PAH is a common problem in HD patients. AVF has no significant effect on the development of PAH within a short period. Similarly, blood flow rate of AVF also did not affect remarkably the systolic PAP
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