Search

Background and Purpose: In this study we attempt to automatically classify individual patients with different parkinsonian disorders, making use of pattern recognition techniques to distinguish among several forms of parkinsonisms (multi-class classification), based on a set of binary classifiers that discriminate each disorder from all others., Methods: We combine diffusion tensor imaging, proton spectroscopy and morphometric-volumetric data to obtain MR quantitative markers, which are provided to support vector machines with the aim of recognizing the different parkinsonian disorders. Feature selection is used to find the most important features for classification. We also exploit a graph-based technique on the set of quantitative markers to extract additional features from the dataset, and increase classification accuracy., Results: When graph-based features are not used, the MR markers that are most frequently automatically extracted by the feature selection procedure reflect alterations in brain regions that are also usually considered to discriminate parkinsonisms in routine clinical practice. Graph-derived features typically increase the diagnostic accuracy, and reduce the number of features required., Conclusions: The results obtained in the work demonstrate that support vector machines applied to multimodal brain MR imaging and using graph-based features represent a novel and highly accurate approach to discriminate parkinsonisms, and a useful tool to assist the diagnosis., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Aims/hypothesis: We investigated the significance of microangiopathy in the development of foot ulcer, which is still disputed., Methods: We assessed microangiopathy by histological analysis of the capillary ultrastructure using transmission electron microscopy and capillary density and arteriolar morphology in paraffin-embedded sections from the skin of type 2 diabetic patients: 30 neuroischaemic patients (Isc) revascularised with peripheral angioplasty and 30 neuropathic patients (Neu) with foot ulcer, compared with ten non-diabetic volunteers., Results: In the diabetic patients, capillaries in the dermal papillary layer were fewer (-22.2%, 159 ± 43 vs 205 ± 52 mm(2) in non-diabetic volunteers, p < 0.01). They also showed detrimental remodelling, with a 2.2-fold increase in capillary basement membrane thickness (3.44 ± 1.19 vs 1.53 ± 0.34 μm in non-diabetic volunteers, p < 0.001) and a 57.7% decrease in lumen area (14.6 ± 11.1 vs 34.7 ± 27.5 μm(2), p < 0.001). No differences were observed between the diabetic Isc or Neu patients. Isc were more prone to develop arteriolar occlusion than Neu (16.8 ± 6.9% vs 6.7 ± 3.7%, respectively, p < 0.001). No patient had been amputated at 30 days and healing time was significantly longer in Isc (180 ± 120 vs 64 ± 50 days in Neu, p < 0.001)., Conclusions/interpretation: Capillary microangiopathy is present in equal measure in neuroischaemic and neuropathic diabetic foot skin. The predominance of arteriolar occlusions with neuroischaemia indicated the existence of an additional 'small vessel disease' that did not affect an effective revascularisation and did not worsen the prognosis of major amputations but slowed the healing process of the neuroischaemic foot ulcer., Trial Registration: ClinicalTrials.gov NCT02610036.

This paper aims to identify approaches that generate appropriate synthetic data (computer generated) for cardiac phase-resolved blood-oxygen-level-dependent (CP-BOLD) MRI. CP-BOLD MRI is a new contrast agent- and stress-free approach for examining changes in myocardial oxygenation in response to coronary artery disease. However, since signal intensity changes are subtle, rapid visualization is not possible with the naked eye. Quantifying and visualizing the extent of disease relies on myocardial segmentation and registration to isolate the myocardium and establish temporal correspondences and ischemia detection algorithms to identify temporal differences in BOLD signal intensity patterns. If transmurality of the defect is of interest pixel-level analysis is necessary and thus a higher precision in registration is required. Such precision is currently not available affecting the design and performance of the ischemia detection algorithms. In this work, to enable algorithmic developments of ischemia detection irrespective to registration accuracy, we propose an approach that generates synthetic pixel-level myocardial time series. We do this by 1) modeling the temporal changes in BOLD signal intensity based on sparse multi-component dictionary learning, whereby segmentally derived myocardial time series are extracted from canine experimental data to learn the model; and 2) demonstrating the resemblance between real and synthetic time series for validation purposes. We envision that the proposed approach has the capacity to accelerate development of tools for ischemia detection while markedly reducing experimental costs so that cardiac BOLD MRI can be rapidly translated into the clinical arena for the noninvasive assessment of ischemic heart disease.

Context: Notch genes encode receptors for a signaling pathway that regulates cell growth and differentiation in various contexts, but the role of Notch signaling in thyroid follicular cells has never been fully published., Objective: The objective of the study was to characterize the expression of Notch pathway components in thyroid follicular cells and Notch signaling activities in normal and transformed thyrocytes. DESIGN/SETTING AND PATIENTS: Expression of Notch pathway components and key markers of thyrocyte differentiation was analyzed in murine and human thyroid tissues (normal and tumoral) by quantitative RT-PCR and immunohistochemistry. The effects of Notch overexpression in human thyroid cancer cells and FTRL-5 cells were explored with analysis of gene expression, proliferation assays, and experiments involving transfection of a luciferase reporter construct containing human NIS promoter regions., Results: Notch receptors are expressed during the development of murine thyrocytes, and their expression levels parallel those of thyroid differentiation markers. Notch signaling characterized also normal adult thyrocytes and is regulated by TSH. Notch pathway components are variably expressed in human normal thyroid tissue and thyroid tumors, but expression levels are clearly reduced in undifferentiated tumors. Overexpression of Notch-1 in thyroid cancer cells restores differentiation, reduces cell growth rates, and stimulates NIS expression via a direct action on the NIS promoter., Conclusion: Notch signaling is involved in the determination of thyroid cell fate and is a direct regulator of thyroid-specific gene expression. Its deregulation may contribute to the loss of differentiation associated with thyroid tumorigenesis.

There is no effective treatment for recurrent or metastatic medullary thyroid carcinoma (MTC), a tumor arising from thyroid C-cells commonly presenting an inherited or acquired RET mutation. In this study we examined the sensitivity of two human MTC cell lines to novel pyrazolopyrimidine derivates, able to inhibit src-family tyrosine kinase activity. In TT cells [carrying the multiple endocrine neoplasia (MEN)2A Ret mutation Cys 634Trp] and MZ-CRC-1 cells (carrying the MEN2B RET mutation Met891Thr), one of these compounds, namely Si 34, determined a significant growth inhibitory effect (approximately 90% vs control for TT, 80% vs control for MZ-CRC-1) mainly due to enhanced cell mortality after a 6-day incubation. At concentrations that increased cell mortality, neither biochemical or morphological characteristics of apoptosis were detected in TT and MZCRC- 1 cells treated with Si 34. These results, when confirmed in other in vivo preclinical models, suggest that this novel tyrosine kinase inhibitor may be useful for the treatment of MTC.

Context: BRAF mutations are common in papillary thyroid carcinomas (PTCs). By affecting the expression of genes critically related to the development and differentiation of thyroid cancer, they may influence the prognosis of these tumors., Objective: Our objective was to characterize the expression of thyroid-specific genes associated with BRAF mutation in PTCs. DESIGN/SETTING AND PATIENTS: We examined the expression of key markers of thyrocyte differentiation in 56 PTCs with BRAF mutations (BRAF-mut) and 37 with wild-type BRAF (BRAF-wt). Eight samples of normal thyroid tissue were analyzed as controls. Quantitative PCR was used to measure mRNA levels for the sodium/iodide symporter (NIS), apical iodide transporter (AIT-B), thyroglobulin (Tg), thyroperoxidase (TPO), TSH receptor (TSH-R), the transcription factor PAX8, and glucose transporter type 1 (Glut1). NIS protein expression and localization was also analyzed by immunohistochemistry., Results: mRNA levels for all thyroid-specific genes were reduced in all PTCs vs. normal thyroid tissues. NIS, AIT-B, Tg, and TPO expression was significantly lower in BRAF-mut tumors than in the BRAF-wt group. Glut-1 transcript levels were increased in all PTCs, and additional increases were noted in BRAF-mut tumors. In both tumor subsets, the NIS protein that was expressed was abnormally retained in the cytoplasm., Conclusion: BRAF V600E mutation in PTCs is associated with reduced expression of key genes involved in iodine metabolism. This effect may alter the effectiveness of diagnostic and/or therapeutic use of radioiodine in BRAF-mut PTCs.

Nucleotide receptors signaling affects cell proliferation, with possible implications on tumorigenic processes. However, molecular targets and action mechanisms of the extracellular nucleotides are still poorly elucidated. We have previously shown in ARO cells that APE1/Ref-1, a transcriptional coactivator responsible for the maintenance of the cellular proliferative rate, is functionally controlled by P2-mediated signaling. Here, we demonstrate that extracellular ATP has a mitogenic effect on ARO cells, increasing ERK phosphorylation, AP1 activation, and cyclin D1 expression. Using the ATP/ADPase apyrase and the P2 receptor antagonist suramin, we show that the extracellular ATP, physiologically released by ARO cells, exerts mitogenic effects. A differential proteomic approach was used to identify molecular events associated with the ATP-induced cell proliferation. Among other proteins, Hsp90 was found upregulated upon ATP stimulation. Pretreatment with suramin completely blocked the ATP-induced Hsp90 activation, confirming the involvement of cell-surface P2 nucleotide receptors in the ATP-mediated activation of ARO cells. Treatment of proliferating ARO cells with suramin and apyrase significantly reduced the intracellular levels of Hsp90, suggesting an autocrine/paracrine mechanism of control on Hsp90 expression by extracellular ATP. The influence of Hsp90 on ATP-induced cell proliferation was also demonstrated by its specific inhibition with 17-AAG. The molecular pathway by which ATP stimulates cell proliferation was further investigated by siRNA strategies showing that Hsp90 is a target of APE1/Ref-1 functional activation. Stimulation of ARO cells with specific nucleotide receptors agonists evidenced a major involvement of P2Y1 and P2Y2 receptors in controlling the Hsp90 activation. Accordingly, these two receptors resulted significantly upregulated in sample biopsies from different thyroid tumors., (Copyright 2006 Wiley-Liss, Inc.)

Context: Evidence from in vitro studies or animal models has shown that TSH affects thyrocytes by thyroid-specific expression modulation., Objective: The objective of our study was to analyze the role of TSH in human thyroid gene expression in vivo., Design/setting: Thirty-nine normal thyroid tissues were collected at the same center., Study Subjects: Patients were divided into two groups based on serum TSH levels: 17 with normal TSH levels (1-4 mU/liter; group 1) and 22 with TSH levels below 0.5 mU/liter (group 2)., Intervention: Group 2 underwent thyroidectomy after suppressive L-T4 therapy., Main Outcome Measures: mRNA levels of thyroid genes such as sodium/iodide symporter (NIS), apical iodide transporter, pendrin, thyroglobulin, thyroperoxidase, TSH receptor, paired box transcription factor 8, and thyroid transcription factor-1 were evaluated by quantitative PCR., Results: The reduction of TSH stimulation causes decreases in NIS and apical iodide transporter gene expression in normal tissues and more limited reductions in thyroglobulin, thyroperoxidase, and paired box transcription factor 8, but it has no significant effect on TSH receptor, pendrin, or thyroid transcription factor-1. Comparison of NIS levels in normal and nodular tissues from the same patient confirmed that it is differentially expressed in nodules only in the presence of normal TSH (P < 0.01). In patients with suppressed TSH, nodular NIS levels were similar to those in normal tissues., Conclusions: Our data represent the first demonstration in human thyroid tissues that TSH contributes to the regulation of thyrocyte differentiation by modulating thyroid gene levels. It exerts a particularly important effect on the transcription of NIS, which becomes very low after prolonged TSH suppression.

Pax proteins are transcriptional regulators that control a variety of developmental decisions in vertebrates. During development, the paired-box gene 8 (PAX8) is expressed in the thyroid, kidney, and several areas of the central nervous system. It is also expressed in the adult thyroid gland, in which it mediates TSH-induced modulation of the expression of important genes, such as those encoding thyroglobulin, thyroperoxidase, and the sodium/iodide symporter (NIS). Thus far, placental expression of PAX8 has been described only in mice. In the present study, we show that PAX8 is also expressed in the human placenta at term. In an in vitro model of placental cancer, the JAR choriocarcinoma cell line, human chorionic gonadotropin (hCG) increased levels of PAX8 mRNA and protein, and gel retardation assays indicated that the up-regulation of PAX8 protein expression is associated with an increase in its DNA-binding activity. The effects of hCG were mimicked by forskolin, indicating that they are cAMP dependent. Levels of mRNA for the Wilms' tumor 1 (WT1) and NIS genes were increased in JAR cells by hCG treatment, whereas overexpression of PAX8 increased only levels of WT1 mRNA. In cells transfected with PAX8-specific small interfering RNA, the stimulatory effects of hCG on WT1 mRNA levels were abolished, but hormonal enhancement of NIS mRNA levels was unchanged. These findings indicate that, in JAR cells, hCG activates a cAMP-dependent pathway that can up-regulate WT1 expression through PAX8.