Search results for " mr"

Stabilization of hsp70 mRNA on prolonged cell exposure to hypertonicity

2002

AbstractProlonged exposure of 3T3 cells to 0.5 osM hypertonic medium induced the accumulation of hsp70 mRNAs. This increase in mRNA levels required active protein synthesis. A weak and transient activation of heat shock factor 1 (HSF1) was noted, but it was temporally uncoupled to the accumulation of the hsp70 mRNAs. Nuclear run-on assay and transfection experiments showed that hsp70 gene transcription was not affected by hypertonicity. ActD chase experiments showed that during hypertonic treatment, degradation of hsp70 mRNAs was markedly reduced. This effect did not appear to be a general phenomenon since the increase in mRNA level of another gene induced by hypertonicity (ATA2 transporter…

Inducible Co-Stimulator Null MRL-Fas lpr Mice

2005

MRL/MpJ-Tnfrsf6lpr (MRL-Faslpr) mice develop a spontaneous T cell-dependent autoimmune disease that shares features with human lupus, including fatal nephritis, systemic pathology, and autoantibodies (autoAb). The inducible co-stimulator (ICOS) is upregulated on activated T cells and modulates T cell-mediated responses. To investigate whether ICOS has an essential role in regulating autoimmune lupus nephritis and the systemic illness in MRL-Faslpr mice, ICOS null (-/-) MRL Faslpr and ICOS intact (+/+) MRL-Faslpr strains (wild-type [WT]) were generated and compared. It was determined that in ICOS-/- MRL-Faslpr as compared with the WT strain, (1) there is a significant reduction in circulatin…

Fuzzy C-Means Segmentation on Brain MR Slices Corrupted by RF-Inhomogeneity

2007

Brain MR Images corrupted by RF-Inhomogeneity exhibit brightness variations in such a way that a standard Fuzzy C-Means (fcm) segmentation algorithm fails. As a consequence, modified versions of the algorithm can be found in literature, which take into account the artifact. In this work we show that the application of a suitable pre-processing algorithm, already presented by the authors, followed by a standard fcm segmentation achieves good results also. The experimental results ones are compared with those obtained using SPM5, which can be considered the state of the art algorithm oriented to brain segmentation and bias removal.

Illumination Correction on MR Images

2006

Objective. An important artifact corrupting Magnetic Resonance Images is the rf inhomogeneity, also called bias artifact. This anomaly produces an abnormal illumination fluctuation on the image, due to variations of the device magnetic field. This artifact is particularly strong on images acquired with a device specialized on upper and lower limbs due to their coil configuration. A method based on homomorphic filtering aimed to suppress this artifact was proposed by Guillemaud. This filter has two faults: it doesnt provide an indication about the cutoff frequency (cf) and introduces another illumination artifact on the edges of the foreground. This work is an improvement to this method because i…

Volumetric Bias Correction

2007

This paper presents a method to suppress the bias artifact, also known as RF-inhomogeneity, in Magnetic Resonance Imaging (MRI). This artifact produces illumination variations due to magnetic field fluctuations of the device. In the latest years many works have been devoted to face this problem. In this work we present the 3D version of a new approach to bias correction, which is called Exponential Entropy Driven Homomorphic Unsharp Masking (E2D-HUM). This technique has been already presented by some of the authors for the 2D case only. The description of the whole method is detailed, and some experimental results are reported.

Confronto TAC – MRI per lo studio della cinetica di assorbimento dell’acqua in materiali lapidei

2007

Vengono messe a confronto due tecniche, la Risonanza Magnetica (MRI) e la tomografia assiale computerizzata (TAC), per ottenere informazioni quantitative sulla cinetica di assorbimento dell’acqua in sezioni interne di materiali lapidei. Entrambe le tecniche permettono di studiare adeguatamente il fenomeno. Nel caso in cui si formi un fronte di bagnamento, come per la Pietra di Lecce, l’analisi delle immagini consente di determinare in modo quantitativo l’altezza di risalita in funzione del tempo ed i dati possono essere interpretati alla luce del modello di Washburn per l’assorbimento capillare. Nel caso in cui il fronte non si formi, come per campioni di biocalcareite provenienti da una ca…

Musical expertise modulates functional connectivity of limbic regions during continuous music listening.

2015

Music is known to be an important facet of all human cultures (Merriam, 1964). Listening to music in order to influence moods, evoke strong emotions, and derive pleasure is becoming increasingly common, especially in this day and age when access to music is easy and quick. In recent years, exploring the neural correlates of musical emotions has attracted the attention of neuroscientists (Brattico & Pearce, 2013; Koelsch, Fritz, v. Cramon, Muller, & Friederici, 2006). However, the majority of these studies have not accounted for the effect of musical expertise, despite increasing evidence of structural and functional differences between musicians and nonmusicians, particularly in the regions…

Cinetica di assorbimento dell’acqua tramite NMR Imaging per la valutazione della efficacia di trattamenti idrorepellenti

2007

L'efficacia dei trattamenti normalmente impiegati per proteggere e/o consolidare materiali lapidei può essere valutata mediante la tecnica di imaging a risonanza magnetica nucleare (MRI), che consente di studiare in modo quantitativo, non invasivo, non distruttivo, la cinetica di assorbimento capillare dell'acqua. In campioni omogenei (Pietra di Lecce) si forma un fronte piatto (con una discontinuità netta alla scala di misura) e la tecnica MRI permette di seguire la cinetica in quanto consente di misurare, in funzione del tempo, l'altezza raggiunta da tale fronte in qualunque sezione interna del campione. Vengono confrontati i risultati ottenuti sullo stesso litotipo utilizzando due divers…

ASSESSMENT OF BRAIN METASTASES VOLUME CONTROL DURING STEREOTACTIC RADIOSURGERY BY LONGITUDINAL REGION GROWTH MR IMAGE SEGMENTATION ANALYSIS

2015

Evaluation of proton MR spectroscopy at 3 Tesla without endorectal coil in patients with a localized prostate cancer treated with exclusive radiother…

2011

Prostate cancer is the most frequent tumour affecting the male population. When the prostate is not removed and is treated with radiation therapy, PSA slowly decreases over time to reach its nadir, even sometimes 18 to 24 months after the completion of radiation therapy without combined androgen suppression therapy. When combined with hormones, PSA falls abruptely with no possibility to perceive the impact of either hormones or radiation effects on PSA.The optimal value of PSA that should be reached after radiation therapy (nadir) and time to this nadir are still unclear.Even when a satisfactory value of the PSA nadir is reached, on-going variations of the PSA and its “bounce” effects, whic…