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1.
Front Neurosci ; 16: 911065, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35873825

RESUMO

Radiomics-guided prediction of overall survival (OS) in brain gliomas is seen as a significant problem in Neuro-oncology. The ultimate goal is to develop a robust MRI-based approach (i.e., a radiomics model) that can accurately classify a novel subject as a short-term survivor, a medium-term survivor, or a long-term survivor. The BraTS 2020 challenge provides radiological imaging and clinical data (178 subjects) to develop and validate radiomics-based methods for OS classification in brain gliomas. In this study, we empirically evaluated the efficacy of four multiregional radiomic models, for OS classification, and quantified the robustness of predictions to variations in automatic segmentation of brain tumor volume. More specifically, we evaluated four radiomic models, namely, the Whole Tumor (WT) radiomics model, the 3-subregions radiomics model, the 6-subregions radiomics model, and the 21-subregions radiomics model. The 3-subregions radiomics model is based on a physiological segmentation of whole tumor volume (WT) into three non-overlapping subregions. The 6-subregions and 21-subregions radiomic models are based on an anatomical segmentation of the brain tumor into 6 and 21 anatomical regions, respectively. Moreover, we employed six segmentation schemes - five CNNs and one STAPLE-fusion method - to quantify the robustness of radiomic models. Our experiments revealed that the 3-subregions radiomics model had the best predictive performance (mean AUC = 0.73) but poor robustness (RSD = 1.99) and the 6-subregions and 21-subregions radiomics models were more robust (RSD  1.39) with lower predictive performance (mean AUC  0.71). The poor robustness of the 3-subregions radiomics model was associated with highly variable and inferior segmentation of tumor core and active tumor subregions as quantified by the Hausdorff distance metric (4.4-6.5mm) across six segmentation schemes. Failure analysis revealed that the WT radiomics model, the 6-subregions radiomics model, and the 21-subregions radiomics model failed for the same subjects which is attributed to the common requirement of accurate segmentation of the WT volume. Moreover, short-term survivors were largely misclassified by the radiomic models and had large segmentation errors (average Hausdorff distance of 7.09mm). Lastly, we concluded that while STAPLE-fusion can reduce segmentation errors, it is not a solution to learning accurate and robust radiomic models.

2.
Biomolecules ; 10(12)2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33353010

RESUMO

The impact of heavy metal, i.e., cadmium (Cd), on the growth, photosynthetic pigments, gas exchange characteristics, oxidative stress biomarkers, and antioxidants machinery (enzymatic and non-enzymatic antioxidants), ions uptake, organic acids exudation, and ultra-structure of membranous bounded organelles of two rice (Oryza sativa L.) genotypes (Shan 63 and Lu 9803) were investigated with and without the exogenous application of ferrous sulfate (FeSO4). Two O. sativa genotypes were grown under different levels of CdCl2 [0 (no Cd), 50 and 100 µM] and then treated with exogenously supplemented ferrous sulfate (FeSO4) [0 (no Fe), 50 and 100 µM] for 21 days. The results revealed that Cd stress significantly (p < 0.05) affected plant growth and biomass, photosynthetic pigments, gas exchange characteristics, affected antioxidant machinery, sugar contents, and ions uptake/accumulation, and destroy the ultra-structure of many membranous bounded organelles. The findings also showed that Cd toxicity induces oxidative stress biomarkers, i.e., malondialdehyde (MDA) contents, hydrogen peroxide (H2O2) initiation, and electrolyte leakage (%), which was also manifested by increasing the enzymatic antioxidants, i.e., superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) and non-enzymatic antioxidant compounds (phenolics, flavonoids, ascorbic acid, and anthocyanin) and organic acids exudation pattern in both O. sativa genotypes. At the same time, the results also elucidated that the O. sativa genotypes Lu 9803 are more tolerant to Cd stress than Shan 63. Although, results also illustrated that the exogenous application of ferrous sulfate (FeSO4) also decreased Cd toxicity in both O. sativa genotypes by increasing antioxidant capacity and thus improved the plant growth and biomass, photosynthetic pigments, gas exchange characteristics, and decrease oxidative stress in the roots and shoots of O. sativa genotypes. Here, we conclude that the exogenous supplementation of FeSO4 under short-term exposure of Cd stress significantly improved plant growth and biomass, photosynthetic pigments, gas exchange characteristics, regulate antioxidant defense system, and essential nutrients uptake and maintained the ultra-structure of membranous bounded organelles in O. sativa genotypes.


Assuntos
Cádmio/química , Compostos Ferrosos/química , Oryza/efeitos dos fármacos , Oryza/genética , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Biomassa , Catalase/metabolismo , Genótipo , Malondialdeído , Estresse Oxidativo , Fotossíntese , Raízes de Plantas/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Plântula/efeitos dos fármacos , Especificidade da Espécie
3.
J Ayub Med Coll Abbottabad ; 26(2): 145-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25603664

RESUMO

BACKGROUND: Pipelle is a silastic curette which does not require a tenaculum or straightening of the cervical fundus axis because of its flexibility and does not require general anaesthesia, whereas Dilatation and curettage (D&C) requires hospitalization and general anaesthesia along with the problem of postoperative pain. The objective of the study was to assess the effectiveness of Pipelle sampling in terms of adequate specimen collection and patients' knowledge and perception about Pipelle and compare it D&C. METHODS: In this randomized control trial, 203 women presenting with abnormal uterine bleeding were enrolled. The patients were randomly assigned to one of the two procedures. In group A 102 patients were subjected to Pipelle endometrial sampling and in group B 101 patients were enrolled for D&C. Frequencies of adequacy of histopathology reports and cost effectiveness of both groups were compared. Patient's knowledge, perception, pain and acceptability of the procedure of both groups were also assessed and compared. RESULTS: The mean age of the patients was 46.3 ± 4.45 years. Tissue obtained for histopathology was 100% adequate when the procedure was D&C while it was 98% in Pipelle group. In group-A 92% patients experienced no discomfort, with only 2% experiencing severe pain and 6% mild pain. On the other hand in group-B, 45% patients experienced moderate and 5% experienced severe pain up to 9 on visual analogue scale (VAS) postoperatively arid requiring post-operative analgesia. The acceptability for the Pipelle suction curette was 98% and for the D&C group was 34%. Regarding previous knowledge of procedure none of patients (100%) knew about Pipelle procedure but 98% patients were aware of D&C procedure. Pipelle was eight times more cost effective as compared to D&C. CONCLUSIONS: The results of obtained by endometrial sample by Pipelle and D&C are compareable. Pipelle significantly produced less pain than D&C.


Assuntos
Biópsia/instrumentação , Curetagem/instrumentação , Dilatação e Curetagem , Endométrio/patologia , Hemorragia Uterina/cirurgia , Adulto , Procedimentos Cirúrgicos Ambulatórios , Biópsia/efeitos adversos , Biópsia/métodos , Dilatação e Curetagem/efeitos adversos , Desenho de Equipamento , Feminino , Humanos , Pessoa de Meia-Idade
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