An Automated Pipeline for the Analysis of PET Data on the Cortical Surface

We present a fully automatic pipeline for the analysis of PET data on the cortical surface. Our pipeline combines tools from FreeSurfer and PETPVC, and consists of (i) co-registration of PET and T1-w MRI (T1) images, (ii) intensity normalization, (iii) partial volume correction, (iv) robust projection of the PET signal onto the subject's cortical surface, (v) spatial normalization to a template, and (vi) atlas statistics. We evaluated the performance of the proposed workflow by performing group comparisons and showed that the approach was able to identify the areas of hypometabolism characteristic of different dementia syndromes: Alzheimer's disease (AD) and both the semantic and logopenic variants of primary progressive aphasia. We also showed that these results were comparable to those obtained with a standard volume-based approach. We then performed individual classifications and showed that vertices can be used as features to differentiate cognitively normal and AD subjects. This pipeline is integrated into Clinica, an open-source software platform for neuroscience studies available at www.clinica.run

A pipeline for the analysis of 18F-FDG PET data on the cortical surface and its evaluation on ADNI

International audienc

New advances in the Clinica software platform for clinical neuroimaging studies

International audienc

Deciphering the progression of PET alterations using surface-based spatiotemporal modeling

International audienc

Influence of hemodialysis on pramipexole pharmacokinetics: lessons from two cases and literature review

BACKGROUND: Restless legs syndrome (RLS) is not a rare condition in patients on long-term dialysis. Pramipexole is a small molecule used in the treatment of idiopathic and uremic RLS. Although some information concerning the efficacy and safety of pramipexole in uremic patients is available, data concerning the pharmacokinetics of pramipexole in hemodialysis (HD) are lacking. Following the occurrence of accidental pramipexole intoxication in a chronic HD patient, we were concerned about the efficacy of HD in removing pramipexole. Our aim was thus to assess plasma pramipexole concentrations and pramipexole clearance in a stable chronic HD patient without any residual kidney function. MATERIALS AND METHODS: Our patient was a 63-year-old man on chronic HD for 5 years who had been treated uneventfully with oral pramipexole for uremic RLS since then. During a routine 4-hour high-flux HD session, blood, ultrafiltrate, and dialysate samples were collected every hour to determine pramipexole concentrations over time. RESULTS: Pramipexole blood concentrations ranged from 12.1 to 23.9 µg/L. Pramipexole reduction ratio was 32.5%. Mean dialytic clearance of pramipexole was 76.8 mL/min. Postdialysis rebound was 5.6%. CONCLUSION: In the absence of any side effect, pramipexole blood concentrations at steady state were 2- to 4-fold higher than those observed in subjects with normal kidney function. Like other drugs with a high volume of distribution, pramipexole was poorly removed by HD. Therefore, HD is not recommended as a treatment option for pramipexole intoxication in patients with a glomerular filtration rate superior to 30 mL/min/1.73m²

A pipeline for the analysis of 18F-FDG PET data on the cortical surface and its evaluation on ADNI

International audienc

The intricate network between the p34 and p44 subunits is central to the activity of the transcription/DNA repair factor TFIIH

The general transcription factor IIH (TFIIH) is a multi-protein complex and its 10 subunits are engaged in an intricate protein–protein interaction network critical for the regulation of its transcription and DNA repair activities that are so far little understood on a molecular level. In this study, we focused on the p44 and the p34 subunits, which are central for the structural integrity of core-TFIIH. We solved crystal structures of a complex formed by the p34 N-terminal vWA and p44 C-terminal zinc binding domains from Chaetomium thermophilum and from Homo sapiens. Intriguingly, our functional analyses clearly revealed the presence of a second interface located in the C-terminal zinc binding region of p34, which can rescue a disrupted interaction between the p34 vWA and the p44 RING domain. In addition, we demonstrate that the C-terminal zinc binding domain of p34 assumes a central role with respect to the stability and function of TFIIH. Our data reveal a redundant interaction network within core-TFIIH, which may serve to minimize the susceptibility to mutational impairment. This provides first insights why so far no mutations in the p34 or p44 TFIIH-core subunits have been identified that would lead to the hallmark nucleotide excision repair syndromes xeroderma pigmentosum or trichothiodystrophy

An Automated Pipeline for the Analysis of PET Data on the Cortical Surface

International audienceWe present a fully automatic pipeline for the analysis of PET data on the cortical surface. Our pipeline combines tools from FreeSurfer and PETPVC, and consists of (i) co-registration of PET and T1-w MRI (T1) images, (ii) intensity normalization, (iii) partial volume correction, (iv) robust projection of the PET signal onto the subject's cortical surface, (v) spatial normalization to a template, and (vi) atlas statistics. We evaluated the performance of the proposed workflow by performing group comparisons and showed that the approach was able to identify the areas of hypometabolism characteristic of different dementia syndromes: Alzheimer's disease (AD) and both the semantic and logopenic variants of primary progressive aphasia. We also showed that these results were comparable to those obtained with a standard volume-based approach. We then performed individual classifications and showed that vertices can be used as features to differentiate cognitively normal and AD subjects. This pipeline is integrated into Clinica, an open-source software platform for neuroscience studies available at www.clinica.run