48 research outputs found
Amselle, Jean-Loup. – L’art de la friche. Essai sur l’art africain contemporain
There has been a remarkable increase in exhibitions and scholarly publications on African contemporary art in recent years. Although the concept and term had been introduced in the 1960 , it was not until the “famous-infamous” blockbuster show Magiciens de la terre 1989 in Paris, that we saw the emergence of a true discourse with an expanding textual network slowly being moulded. Two major journals, Nka–Contemporary African Art and Revue noire, came into being as a direct response to the crit..
Amselle, Jean-Loup. – L’art de la friche. Essai sur l’art africain contemporain
There has been a remarkable increase in exhibitions and scholarly publications on African contemporary art in recent years. Although the concept and term had been introduced in the 1960 , it was not until the “famous-infamous” blockbuster show Magiciens de la terre 1989 in Paris, that we saw the emergence of a true discourse with an expanding textual network slowly being moulded. Two major journals, Nka–Contemporary African Art and Revue noire, came into being as a direct response to the crit..
Attenuation of the BOLD fMRI Signal and Changes in Functional Connectivity Affecting the Whole Brain in Presence of Brain Metastasis
To date, there are almost no investigations addressing functional connectivity (FC) in
patients with brain metastases (BM). In this retrospective study, we investigate the influence of BM
on hemodynamic brain signals derived from functional magnetic resonance imaging (fMRI) and FC.
Motor-fMRI data of 29 patients with BM and 29 matched healthy controls were analyzed to assess
percent signal changes (PSC) in the ROIs motor cortex, premotor cortex, and supplementary motor
cortex and FC in the sensorimotor, default mode, and salience networks using Statistical Parametric
Mapping (SPM12) and marsbar and CONN toolboxes. In the PSC analysis, an attenuation of the
BOLD signal in the metastases-affected hemisphere compared to the contralateral hemisphere was
significant only in the supplementary motor cortex during hand movement. In the FC analysis,
we found alterations in patients’ FC compared to controls in all examined networks, also in the
hemisphere contralateral to the metastasis. This indicates a qualitative attenuation of the BOLD signal
in the affected hemisphere and also that FC is altered by the presence of BM, similarly to what is
known for primary brain tumors. This transformation is not only visible in the infiltrated hemisphere,
but also in the contralateral one, suggesting an influence of BM beyond local damage
Gemcitabine Maintenance Therapy in Patients With Metastasized Soft Tissue Sarcomas
Background:
Metastasized soft-tissue sarcomas still pose a significant therapeutic challenge given the limited efficacy of currently available multimodal treatment strategies. Recent progress in molecular characterization of sarcoma subtypes has enabled successful personalized therapy approaches in a minority of selected patients with targetable mutations. However, in the majority of patients with refractory soft tissue sarcomas, long-term survival remains poor.
Methods:
We report on three adult patients with various soft tissue sarcomas subjected to Gemcitabine maintenance therapy. Tumor entities included leiomyosarcoma of the pancreas (patient 1), undifferentiated pleomorphic sarcoma of the right femur (patient 2), and peri-aortic leiomyosarcoma (patient 3). Metastatic sites encompassed liver, lung, and bones. All patients received Gemcitabine maintenance therapy until disease progression following prior salvage chemotherapy with Docetaxel and Gemcitabine. Patients were treated outside of clinical trials. Response assessment was based on radiological imaging.
Results:
In response to salvage chemotherapy with Docetaxel and Gemcitabine, one patient exhibited a partial remission, and two patients showed stable disease. Patient 1 exhibited stable disease for 6 months during Gemcitabine maintenance therapy before suffering rapid progression of hepatic metastases. Patient 2 underwent 21 months of Gemcitabine maintenance therapy, which was discontinued after progressive pulmonary metastases were detected. Patient 3 is still being treated with Gemcitabine maintenance therapy. Remarkably, owing to significant chemotherapy-associated hematotoxicity, the dose of Gemcitabine dose was reduced by two-thirds. Nevertheless, stable disease with constant pulmonary metastases has been maintained in this patient for 14 months.
Conclusions:
Gemcitabine maintenance therapy following prior Docetaxel and Gemcitabine chemotherapy is manageable and reveals potential benefits for patients with aggressive metastasized soft tissue sarcomas. Prospective trials evaluating Gemcitabine maintenance therapy are encouraged
Amelioration of Parkinsonian tremor evoked by DBS: which role play cerebello-(sub)thalamic fiber tracts?
Background
Current pathophysiological models of Parkinson’s disease (PD) assume a malfunctioning network being adjusted by the DBS signal. As various authors showed a main involvement of the cerebellum within this network, cerebello-cerebral fiber tracts are gaining special interest regarding the mediation of DBS effects.
Objectives
The crossing and non-decussating fibers of the dentato-rubro-thalamic tract (c-DRTT/nd-DRTT) and the subthalamo-ponto-cerebellar tract (SPCT) are thought to build up an integrated network enabling a bidimensional communication between the cerebellum and the basal ganglia. The aim of this study was to investigate the influence of these tracts on clinical control of Parkinsonian tremor evoked by DBS.
Methods
We analyzed 120 electrode contacts from a cohort of 14 patients with tremor-dominant or equivalence-type PD having received bilateral STN-DBS. Probabilistic tractography was performed to depict the c-DRTT, nd-DRTT, and SPCT. Distance maps were calculated for the tracts and correlated to clinical tremor control for each electrode pole.
Results
A significant difference between “effective” and “less-effective” contacts was only found for the c-DRTT (p = 0.039), but not for the SPCT, nor the nd-DRTT. In logistic and linear regressions, significant results were also found for the c-DRTT only (pmodel logistic = 0.035, ptract logistic = 0,044; plinear = 0.027).
Conclusions
We found a significant correlation between the distance of the DBS electrode pole to the c-DRTT and the clinical efficacy regarding tremor reduction. The c-DRTT might therefore play a major role in the mechanisms of alleviation of Parkinsonian tremor and could eventually serve as a possible DBS target for tremor-dominant PD in future
Limited capability of MRI radiomics to predict primary tumor histology of brain metastases in external validation
Background
Growing research demonstrates the ability to predict histology or genetic information of various malignancies using radiomic features extracted from imaging data. This study aimed to investigate MRI-based radiomics in predicting the primary tumor of brain metastases through internal and external validation, using oversampling techniques to address the class imbalance.
Methods
This IRB-approved retrospective multicenter study included brain metastases from lung cancer, melanoma, breast cancer, colorectal cancer, and a combined heterogenous group of other primary entities (5-class classification). Local data were acquired between 2003 and 2021 from 231 patients (545 metastases). External validation was performed with 82 patients (280 metastases) and 258 patients (809 metastases) from the publicly available Stanford BrainMetShare and the University of California San Francisco Brain Metastases Stereotactic Radiosurgery datasets, respectively. Preprocessing included brain extraction, bias correction, coregistration, intensity normalization, and semi-manual binary tumor segmentation. Two-thousand five hundred and twenty-eight radiomic features were extracted from T1w (± contrast), fluid-attenuated inversion recovery (FLAIR), and wavelet transforms for each sequence (8 decompositions). Random forest classifiers were trained with selected features on original and oversampled data (5-fold cross-validation) and evaluated on internal/external holdout test sets using accuracy, precision, recall, F1 score, and area under the receiver-operating characteristic curve (AUC).
Results
Oversampling did not improve the overall unsatisfactory performance on the internal and external test sets. Incorrect data partitioning (oversampling before train/validation/test split) leads to a massive overestimation of model performance.
Conclusions
Radiomics models’ capability to predict histologic or genomic data from imaging should be critically assessed; external validation is essential
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
Cultural Diasporas
This study examines the contribution that artists from a non-EU background maketowards cultural life and cultural industries in Europe and beyond. In particular, it looksat how such artists form "diasporas" which in turn create networks of cultural exchangeinside the EU and with third countries. It provides examples of these activities in threebroad diaspora groups of African, Balkan and Turkish backgroun