395 research outputs found

    Comparison of Histogram-based Textural Features between Cancerous and Normal Prostatic Tissue in Multiparametric Magnetic Resonance Images

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    In the last decade, multiparametric magnetic resonance imaging (mpMRI) has been expanding its role in prostate cancer detection and characterization. In this work, 19 patients with clinically significant peripheral zone (PZ) tumours were studied. Tumour masks annotated on the whole-mount histology sections were mapped on T2-weighted (T2w) and diffusion-weighted (DW) sequences. Gray-level histograms of tumoral and normal tissue were compared using six first-order texture features. Multivariate analysis of variance (MANOVA) was used to compare group means. Mean intensity signal of ADC showed the highest showed the highest area under the receiver operator characteristics curve (AUC) equal to 0.85. MANOVA analysis revealed that ADC features allows a better separation between normal and cancerous tissue with respect to T2w features (ADC: P = 0.0003, AUC = 0.86; T2w: P = 0.03, AUC = 0.74). MANOVA proved that the combination of T2-weighted and apparent diffusion coefficient (ADC) map features increased the AUC to 0.88. Histogram-based features extracted from invivo mpMRI can help discriminating significant PZ PCa

    Automatic segmentation of ultrasound images of gastrocnemius medialis with different echogenicity levels using convolutional neural networks

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    The purpose of this study was to develop an automatic method for the segmentation of muscle cross-sectional area on transverse B-mode ultrasound images of gastrocnemius medialis using a convolutional neural network(CNN). In the provided dataset images with both normal and increased echogenicity are present. The manually annotated dataset consisted of 591 images, from 200 subjects, 400 relative to subjects with normal echogenicity and 191 to subjects with augmented echogenicity. From the DICOM files, the image has been extracted and processed using the CNN, then the output has been post-processed to obtain a finer segmentation. Final results have been compared to the manual segmentations. Precision and Recall scores as mean ± standard deviation for training, validation, and test sets are 0.96 ± 0.05, 0.90 ± 0.18, 0.89 ± 0.15 and 0.97 ±0.03, 0.89± 0.17, 0.90 ± 0.14 respectively. The CNN approach has also been compared to another automatic algorithm, showing better performances. The proposed automatic method provides an accurate estimation of muscle cross-sectional area in muscles with different echogenicity levels

    Polymer-coated superparamagnetic iron oxide nanoparticles as T-2 contrast agent for MRI and their uptake in liver

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    Aim: To study the efficiency of multifunctional polymer-based superparamagnetic iron oxide nanoparticles (bioferrofluids) as a T-2 magnetic resonance contrast agent and their uptake and toxicity in liver. Materials & methods: Mice were intravenously injected with bioferrofluids and Endorem (R). The magnetic resonance efficiency, uptake and in vivo toxicity were investigated by means of magnetic resonance imaging (MRI) and histological techniques. Results: Bioferrofluids are a good T-2 contrast agent with a higher r(2)/r(1) ratio than Endorem. Bioferrofluids have a shorter blood circulation time and persist in liver for longer time period compared with Endorem. Both bioferrofluids and Endorem do not generate any noticeable histological lesions in liver over a period of 60 days post-injection. Conclusion: Our bioferrofluids are powerful diagnostic tool without any observed toxicity over a period of 60 days post-injection. Lay abstract: Several superparamagnetic iron oxide nanoparticles (SPIONs) preparations have been approved by US FDA for clinical use as MRI contrast agents. In recent years, we have been developing a synthetic multifunctional platform for SPIONs based on the use of polymers. In this report, we explored the diagnostic potential of these nanoparticles (herein called bioferrofluids) as an MRI contrast agent and their uptake in liver, without neglecting their toxicological effects. Results show that our bioferrofluids are a good T-2 contrast agent without any observed toxicity in liver

    Hippocampal FGF-2 and BDNF overexpression attenuates epileptogenesis-associated neuroinflammation and reduces spontaneous recurrent seizures

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    Under certain experimental conditions, neurotrophic factors may reduce epileptogenesis. We have previously reported that local, intrahippocampal supplementation of fibroblast growth factor-2 (FGF-2) and brain-derived neurotrophic factor (BDNF) increases neurogenesis, reduces neuronal loss, and reduces the occurrence of spontaneous seizures in a model of damage-associated epilepsy. Here, we asked if these possibly anti-epileptogenic effects might involve anti-inflammatory mechanisms. Thus, we used a Herpes-based vector to supplement FGF-2 and BDNF in rat hippocampus after pilocarpine-induced status epilepticus that established an epileptogenic lesion. This model causes intense neuroinflammation, especially in the phase that precedes the occurrence of spontaneous seizures. The supplementation of FGF-2 and BDNF attenuated various parameters of inflammation, including astrocytosis, microcytosis and IL-1β expression. The effect appeared to be most prominent on IL-1β, whose expression was almost completely prevented. Further studies will be needed to elucidate the molecular mechanism(s) for these effects, and for that on IL-1β in particular. Nonetheless, the concept that neurotrophic factors affect neuroinflammation in vivo may be highly relevant for the understanding of the epileptogenic process

    Esophageal dysmotility in scleroderma patients with different disease forms and ANA patterns: a scintigraphic study in 100 cases

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    Objective: To define the prevalence and severity of esophageal involvement in systemic sclerosis (SSc) and its relationship with the different clinical forms and ANA specificities of the disease. Methods: A hundred consecutive patients with SSc, 48 with cutaneous limited, 26 with intermediate and 26 with diffuse form of disease, 49 with anti-centromere and 37 with anti-Scl70 ANA pattern, were submitted to scintigraphy using a semisolid orally ingested bolus to detect esophageal hypomotility. Results: An impairment of esophageal function has been observed in 68% of SSc patients. Esophageal dysmotility was significantly more frequent and severe in patients with cutaneous diffuse and intermediate forms of SSc and with anti- Scl70 ANA pattern. Conclusions: Esophageal involvement is very common in SSc. The scintigraphy confirms to be a useful and non invasive diagnostic method; moreover it permits to quantify the severity of the esophageal dysmotility by analyzing both global and segmental function

    Inhibition of tyrosine kinase receptors by SU6668 promotes abnormal stromal development at the periphery of carcinomas

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    Dynamic contrast-enhanced (albumin-Gd-DTPA) magnetic resonance imaging, performed during 2 weeks of daily administration of an inhibitor of tyrosine kinase receptors (SU6668) in an HT-29 colon carcinoma model, revealed the onset of a hyper-enhancing rim, not observed in untreated tumours. To account for tissue heterogeneity in the quantitative analysis, we segmented tumours into three subunits automatically identified by cluster analysis of the enhancement curves using a k-means algorithm. Transendothelial permeability (Kps) and fractional plasma volume (fPV) were calculated in each subunit. An avascular and necrotic region, an intermediate zone and a well-vascularised periphery were reliably identified. During untreated tumour growth, the identified sub-regions did not substantially change their enhancement pattern. Treatment with SU6668 induced major changes at tumour periphery where a significant increase of Kps and fPV was observed with respect to control tumours. Histology revealed a sub-capsular layer composed of hyper-dense viable tumour cells in the periphery of untreated tumours. The rim of viable neoplastic cells was reduced in treated tumours, and replaced by loose connective tissue characterised by numerous vessels, which explains the observed hyper-enhancement. The present data show a peripheral abnormal development of cancer-associated stroma, indicative of an adaptive response to anti-angiogenic treatment

    Pre-operative micronutrient deficiencies in patients with severe obesity candidates for bariatric surgery

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    PURPOSE: In patients with obesity, micronutrient deficiencies have been reported both before and after bariatric surgery (BS). Obesity is a chronic pro-inflammatory status, and inflammation increases the risk of micronutrient malnutrition. Our objective was to assess in pre-BS patients the prevalence of micronutrient deficiencies and their correlation with blood values of C-reactive protein (CRP). METHODS: Anthropometric data, instrumental examinations, and blood variables were centrally measured in the first 200 patients undergoing a pre-BS evaluation at the “Città della Salute e della Scienza” Hospital of Torino, starting from January 2018. RESULTS: At least one micronutrient deficiency was present in 85.5% of pre-BS patients. Vitamin D deficiency was the most prevalent (74.5%), followed by folate (33.5%), iron (32%), calcium (13%), vitamin B12 (10%), and albumin (5.5%) deficiency. CRP values were high (> 5 mg/L) in 65% of the patients. These individuals showed increased rate of iron, folate, vitamin B12 deficiency, and a higher number of micronutrient deficiencies. In a multiple logistic regression model, increased CRP levels were significantly associated with deficiencies of vitamin B12 (OR = 5.84; 95% CI 1.25–27.2; p = 0.024), folate (OR = 4.02; 1.87–8.66; p < 0.001), and with the presence of ≥ 2 micronutrient deficiencies (OR = 2.31; 1.21–4.42; p = 0.01). CONCLUSIONS: Micronutrient deficiencies are common in patients with severe obesity undergoing BS, especially when inflammation is present. In the presence of increased CRP values before surgery, it might be advisable to search for possible multiple micronutrient deficiencies
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