Prediction of clinical response to corticosteroid or platelet-rich plasma injection in plantar fasciitis with MRI: A prospective, randomized, double-blinded study.

PURPOSE: The purpose of this study was to identify association between magnetic resonance imaging (MRI) features and clinical data at baseline and six months following platelet-rich plasma (PRP) or corticosteroid (CS; cortivazol) injection in patients with plantar fasciitis, and to identify initial MRI criteria associated with a favorable clinical response to treatment. MATERIAL AND METHODS: The study was registered on ClinicalTrials.gov (NCT03857334). MRI examinations of 36 patients with plantar fasciitis lasting more than 3 months who were randomly assigned to receive ultrasound-guided PRP (PRP group, 20 patients) or CS (CS group, 18 patients) injection were quantitatively and qualitatively analyzed with respect to plantar fascia thickness, plantar fascia hyperintensity on T2-weighted STIR (HSTIR) images, calcaneal bone marrow and surrounding soft tissues. Clinical evaluation including visual analytic scale (VAS) assessment and MRI examinations were obtained before and 6 months after treatment. Good clinical response was defined as pain VAS decrease > 50% at 6 months. ROC curves with AUC measurements were used to determine cut-off points. RESULTS: In the whole study population, an association was found between MRI features (deep soft tissue and calcaneal bone marrow HSTIR) and pain VAS scores for the first steps of the day (P = 0.028 and P = 0.007, respectively). No significant radioclinical associations on post-treatment MRI examinations were found in either group. Initial coronal thickness of plantar fascia was associated with a good clinical response in the CS group (P < 0.01). ROC curve analysis found that 7-mm or thicker plantar aponeurosis at initial MRI was predictive of good clinical response in patients with CS treatment (Youden index = 0.6). PRP infiltrations were effective regardless of fascia thickness (73% of patients with ≤ 7 mm aponeurosis and 67% for thicker ones). CONCLUSION: Initial facia thickness (> 7 mm) is predictive of good clinical response six months after CS injection, whereas PRP injection shows effectiveness regardless of fascia thickness.

MRI of sacroiliac joints for the diagnosis of axial SpA: prevalence of inflammatory and structural lesions in nulliparous, early postpartum and late postpartum women.

OBJECTIVES: To determine the prevalence of bone marrow oedema (BME) at the sacroiliac joint (SIJ) in early postpartum (EPP), nulliparous (NP) and late postpartum (LPP) women, and to identify factors associated with BME presence at the SIJ. METHODS: Three groups were obtained: NP (never given birth), EPP (given birth within 12 months) and LPP (given birth more than 24 months). The primary outcome was the presence of BME and/or structural lesions (erosions, osteophytes, ankylosis and sclerosis) at the SIJ MRI. RESULTS: BME prevalence was greater among EPP (33%) than NP (14%, p=0.001), but was not different to LPP (21%, p=0.071). The Assessment of SpondyloArthritis international Society (ASAS) MRI criteria for sacroiliitis were positive in 75%, 71% and 80%, respectively, of EPP, NP and LPP women with BME. EPP (38%) had similar prevalence of sclerosis than LPP (28%, p=0.135), but greater than NP (18%, p=0.001). Lastly, EPP (28%) had similar prevalence of osteophytes than LPP (42%) and NP (27%), although there was a difference between LPP and NP (p=0.006). CONCLUSIONS: EPP have higher BME prevalence at the SIJ than NP, EPP tend to have higher BME prevalence compared with LPP and BME presence decreases with time from delivery. Three-quarters of women with BME at the SIJ had a positive ASAS MRI criteria for sacroiliitis, indicating that BME presence as the main criterion for a positive diagnosis can lead to false-positive results. SIJ MRIs should not be interpreted in isolation, since age, time from delivery and other factors may outweigh the pertinence of MRI findings. Trial registration number NCT02956824.

Alternative PACS interface devices are well-accepted and may reduce radiologist's musculoskeletal discomfort as compared to keyboard-mouse-recording device.

OBJECTIVE: To evaluate the use of two alternative picture archiving and communication systems (PACS) interface devices (a graphics tablet and a handheld controller) in clinical practice and on task-oriented exercises. MATERIAL AND METHODS: Eleven senior radiologists were prospectively evaluated. The participants used the two tested interface devices for 10 working periods each and answered a questionnaire to evaluate the ergonomics of this experience. The prevalence of work-related musculoskeletal discomfort with the standard PACS interface set (mouse-keyboard-recording device) and these two devices was assessed. Exercises evaluating image scrolling and selection, image zooming and panning, image windowing, performing measurements, and reporting were performed with the standard PACS interface set and with the two tested devices. The sitting posture and hand position were evaluated. RESULTS: The general appreciation of the two alternative interface devices was considered to be similar to that of the standard interface set. The ergonomics of the handheld controller was considered to be slightly better than that of the standard interface set. The prevalence of musculoskeletal discomfort was 81%, 45%, and 18% for the standard interface set, graphics tablet, and handheld controller, respectively. With the graphics tablet and the handheld controller in 45% and 60%, respectively, there was a working posture change with respect to the standard interface set. The mean total exercise completion times of both tested devices were 27% higher than that of the standard interface set. CONCLUSION: Despite the increase in completion time of the task-oriented exercises, the tested devices were well accepted and considered to be more comfortable than the standard set. KEY POINTS: • Alternative PACS interface devices can be used as a substitute for the standard mouse-keyboard-recording device set with a potential improvement in work ergonomics and a reduction in work-related musculoskeletal discomfort.

Contrast-Enhanced 3-T Perfusion MRI With Quantitative Analysis for the Characterization of Musculoskeletal Tumors: Is It Worth the Trouble?

OBJECTIVE: The purpose of this study was to evaluate the diagnostic performance of quantitative perfusion parameters in 3-T MRI for benign-malignant differentiation in musculoskeletal tumors. SUBJECTS AND METHODS: Ninety-five patients with histologically proven musculoskeletal tumors were prospectively included in this study. All patients underwent 3-T contrast-enhanced perfusion MRI with T1 mapping. The extended Tofts pharmacokinetic model was used to obtain four semiquantitative and four quantitative perfusion parameters for each tumor. Two radiologists evaluated all images and manually placed the ROIs in consensus. RESULTS: The 95 patients had 57 (59%) benign and 38 (41%) malignant tumors. Thirty-seven (39%) were bone and 58 (61%) were soft-tissue tumors. No significant differences were found in the perfusion parameters of benign and malignant tumors (p = 0.105-0.609). The best performance for benign-malignant differentiation was found for fractional volume of the extravascular extracellular space, which yielded 79% and 38% sensitivity and specificity. When soft-tissue tumors were considered, the transfer constant from plasma to the extravascular extracellular space exhibited a significant difference (p = 0.028) and had 79% and 27% sensitivity and specificity. CONCLUSION: Quantitative perfusion MRI had fair sensitivity and poor specificity for benign-malignant differentiation, which was similar to that obtained with semiquantitative parameters.

Overexpression screen reveals transcription factors involved in lipid accumulation in Yarrowia lipolytica.

Yarrowia lipolytica is a non-conventional oleaginous yeast that displays high lipid titers and yields; its production capacity holds significant promise for industrial biolipid applications. While its lipid metabolism has been widely studied, little is known about its transcriptional regulatory network. Deciphering the role of transcriptional regulators is crucial for understanding lipid accumulation, a complex phenomenon. To identify the transcription factors involved in lipid metabolism, we developed a systematic overexpression approach for 148 putative transcription factors. Analyses of overexpressing transformants revealed that 38 had an impact on lipid accumulation under at least one of the growth conditions tested. For most of these factors, our results provide the first experimentally determined functional annotation. Our data suggest that the regulation network differs depending on the carbon source, which is critical information when carrying out industrial bioprocesses. These results will therefore help guide further rational metabolic engineering for improving biolipid production by Y. lipolytica. Moreover, this work has created the largest collection of Y. lipolytica overexpressing strains to date, which will be useful in phenotype screening.

Inference and interrogation of a coregulatory network in the context of lipid accumulation in Yarrowia lipolytica.

Complex phenotypes, such as lipid accumulation, result from cooperativity between regulators and the integration of multiscale information. However, the elucidation of such regulatory programs by experimental approaches may be challenging, particularly in context-specific conditions. In particular, we know very little about the regulators of lipid accumulation in the oleaginous yeast of industrial interest Yarrowia lipolytica. This lack of knowledge limits the development of this yeast as an industrial platform, due to the time-consuming and costly laboratory efforts required to design strains with the desired phenotypes. In this study, we aimed to identify context-specific regulators and mechanisms, to guide explorations of the regulation of lipid accumulation in Y. lipolytica. Using gene regulatory network inference, and considering the expression of 6539 genes over 26 time points from GSE35447 for biolipid production and a list of 151 transcription factors, we reconstructed a gene regulatory network comprising 111 transcription factors, 4451 target genes and 17048 regulatory interactions (YL-GRN-1) supported by evidence of protein-protein interactions. This study, based on network interrogation and wet laboratory validation (a) highlights the relevance of our proposed measure, the transcription factors influence, for identifying phases corresponding to changes in physiological state without prior knowledge (b) suggests new potential regulators and drivers of lipid accumulation and

Contrast-enhanced 3T MR Perfusion of Musculoskeletal Tumours: T1 Value Heterogeneity Assessment and Evaluation of the Influence of T1 Estimation Methods on Quantitative Parameters.

OBJECTIVE: To evaluate intra-tumour and striated muscle T1 value heterogeneity and the influence of different methods of T1 estimation on the variability of quantitative perfusion parameters. MATERIAL AND METHODS: Eighty-two patients with a histologically confirmed musculoskeletal tumour were prospectively included in this study and, with ethics committee approval, underwent contrast-enhanced MR perfusion and T1 mapping. T1 value variations in viable tumour areas and in normal-appearing striated muscle were assessed. In 20 cases, normal muscle perfusion parameters were calculated using three different methods: signal based and gadolinium concentration based on fixed and variable T1 values. RESULTS: Tumour and normal muscle T1 values were significantly different (p = 0.0008). T1 value heterogeneity was higher in tumours than in normal muscle (variation of 19.8% versus 13%). The T1 estimation method had a considerable influence on the variability of perfusion parameters. Fixed T1 values yielded higher coefficients of variation than variable T1 values (mean 109.6 ± 41.8% and 58.3 ± 14.1% respectively). Area under the curve was the least variable parameter (36%). CONCLUSION: T1 values in musculoskeletal tumours are significantly different and more heterogeneous than normal muscle. Patient-specific T1 estimation is needed for direct inter-patient comparison of perfusion parameters. KEY POINTS: • T1 value variation in musculoskeletal tumours is considerable. • T1 values in muscle and tumours are significantly different. • Patient-specific T1 estimation is needed for comparison of inter-patient perfusion parameters. • Technical variation is higher in permeability than semiquantitative perfusion parameters.

Using a vector pool containing variable-strength promoters to optimize protein production in Yarrowia lipolytica.

BACKGROUND: The yeast Yarrowia lipolytica is an increasingly common biofactory. To enhance protein expression, several promoters have been developed, including the constitutive TEF promoter, the inducible POX2 promotor, and the hybrid hp4d promoter. Recently, new hp4d-inspired promoters have been created that couple various numbers of UAS1 tandem elements with the minimal LEU2 promoter or the TEF promoter. Three different protein-secretion signaling sequences can be used: preLip2, preXpr2, and preSuc2. RESULTS: To our knowledge, our study is the first to use a set of vectors with promoters of variable strength to produce proteins of industrial interest. We used the more conventional TEF and hp4d promoters along with five new hybrid promoters: 2UAS1-pTEF, 3UAS1-pTEF, 4UAS1-pTEF, 8UAS1-pTEF, and hp8d. We compared the production of RedStar2, glucoamylase, and xylanase C when strains were grown on three media. As expected, levels of RedStar2 and glucoamylase were greatest in the strain with the 8UAS1-pTEF promoter, which was stronger. However, surprisingly, the 2UAS1-pTEF promoter was associated with the greatest xylanase C production and activity. This finding underscored that stronger promoters are not always better when it comes to protein production. We therefore developed a method for easily identifying the best promoter for a given protein of interest. In this gateway method, genes for YFP and α-amylase were transferred into a pool of vectors containing different promoters and gene expression was then analyzed. We observed that, in most cases, protein production and activity were correlated with promoter strength, although this pattern was protein dependent. CONCLUSIONS: Protein expression depends on more than just promoter strength. Indeed, promoter suitability appears to be protein dependent; in some cases, optimal expression and activity was obtained using a weaker promoter. We showed that using a vector pool containing promoters of variable strength can be a powerful tool for rapidly identifying the best producer for a given protein of interest.

Radiology resident MR and CT image analysis skill assessment using an interactive volumetric simulation tool - the RadioLOG project.

OBJECTIVE: Assess the use of a volumetric simulation tool for the evaluation of radiology resident MR and CT interpretation skills. MATERIAL AND METHODS: Forty-three participants were evaluated with a software allowing the visualisation of multiple volumetric image series. There were 7 medical students, 28 residents and 8 senior radiologists among the participants. Residents were divided into two sub-groups (novice and advanced). The test was composed of 15 exercises on general radiology and lasted 45 min. Participants answered a questionnaire on their experience with the test using a 5-point Likert scale. This study was approved by the dean of the medical school and did not require ethics committee approval. RESULTS: The reliability of the test was good with a Cronbach alpha value of 0.9. Test scores were significantly different in all sub-groups studies (p < 0.0225). The relation between test scores and the year of residency was logarithmic (R2 = 0.974). Participants agreed that the test reflected their radiological practice (3.9 ± 0.9 on a 5-point scale) and was better than the conventional evaluation methods (4.6 ± 0.5 on a 5-point scale). CONCLUSION: This software provides a high quality evaluation tool for the assessment of the interpretation skills in radiology residents. KEY POINTS: • This tool allows volumetric image analysis of MR and CT studies. • A high reliability test could be created with this tool. • Test scores were strongly associated with the examinee expertise level. • Examinees positively evaluated the authenticity and usability of this tool.

High-throughput transformation method for Yarrowia lipolytica mutant library screening.

As a microorganism of major biotechnological importance, the oleaginous yeast Yarrowia lipolytica is subjected to intensive genetic engineering and functional genomic analysis. Future advancements in this area, however, require a system that will generate a large collection of mutants for high-throughput screening. Here, we report a rapid and efficient method for high-throughput transformation of Y. lipolytica in 96-well plates. We developed plasmids and strains for the large-scale screening of overexpression mutant strains, using Gateway® vectors that were adapted for specific locus integration in Y. lipolytica. As an example, a collection of mutants that overexpressed the alkaline extracellular protease (AEP) was obtained in a single transformation experiment. The platform strain that we developed to receive the overexpression cassette was designed to constitutively express a fluorescent protein as a convenient growth reporter for screening in non-translucid media. An example of growth comparison in skim milk-based medium between AEP overexpression and deletion mutants is provided.

The AbrB2 autorepressor, expressed from an atypical promoter, represses the hydrogenase operon to regulate hydrogen production in Synechocystis strain PCC6803.

We have thoroughly investigated the abrB2 gene (sll0822) encoding an AbrB-like regulator in the wild-type strain of the model cyanobacterium Synechocystis strain PCC6803. We report that abrB2 is expressed from an active but atypical promoter that possesses an extended -10 element (TGTAATAT) that compensates for the absence of a -35 box. Strengthening the biological significance of these data, we found that the occurrence of an extended -10 promoter box and the absence of a -35 element are two well-conserved features in abrB2 genes from other cyanobacteria. We also show that AbrB2 is an autorepressor that is dispensable to cell growth under standard laboratory conditions. Furthermore, we demonstrate that AbrB2 also represses the hox operon, which encodes the Ni-Fe hydrogenase of biotechnological interest, and that the hox operon is weakly expressed even though it possesses the two sequences resembling canonical -10 and -35 promoter boxes. In both the AbrB2-repressed promoters of the abrB2 gene and the hox operon, we found a repeated DNA motif [TT-(N(5))-AAC], which could be involved in AbrB2 repression. Supporting this hypothesis, we found that a TT-to-GG mutation of one of these elements increased the activity of the abrB2 promoter. We think that our abrB2-deleted mutant with increased expression of the hox operon and hydrogenase activity, together with the reporter plasmids we constructed to analyze the abrB2 gene and the hox operon, will serve as useful tools to decipher the function and the regulation of hydrogen production in Synechocystis.

Genome analysis and genome-wide proteomics of Thermococcus gammatolerans, the most radioresistant organism known amongst the Archaea.

BACKGROUND: Thermococcus gammatolerans was isolated from samples collected from hydrothermal chimneys. It is one of the most radioresistant organisms known amongst the Archaea. We report the determination and annotation of its complete genome sequence, its comparison with other Thermococcales genomes, and a proteomic analysis. RESULTS: T. gammatolerans has a circular chromosome of 2.045 Mbp without any extra-chromosomal elements, coding for 2,157 proteins. A thorough comparative genomics analysis revealed important but unsuspected genome plasticity differences between sequenced Thermococcus and Pyrococcus species that could not be attributed to the presence of specific mobile elements. Two virus-related regions, tgv1 and tgv2, are the only mobile elements identified in this genome. A proteogenome analysis was performed by a shotgun liquid chromatography-tandem mass spectrometry approach, allowing the identification of 10,931 unique peptides corresponding to 951 proteins. This information concurrently validates the accuracy of the genome annotation. Semi-quantification of proteins by spectral count was done on exponential- and stationary-phase cells. Insights into general catabolism, hydrogenase complexes, detoxification systems, and the DNA repair toolbox of this archaeon are revealed through this genome and proteome analysis. CONCLUSIONS: This work is the first archaeal proteome investigation done at the stage of primary genome annotation. This archaeon is shown to use a large variety of metabolic pathways even under a rich medium growth condition. This proteogenomic study also indicates that the high radiotolerance of T. gammatolerans is probably due to proteins that remain to be characterized rather than a larger arsenal of known DNA repair enzymes.

Recovery of ionizing-radiation damage after high doses of gamma ray in the hyperthermophilic archaeon Thermococcus gammatolerans.

The recently discovered hyperthermophilic and radioresistant archaeon Thermococcus gammatolerans is of great interest to compare and contrast the impact of its physiology on radioresistance and its ability to repair damaged chromosomes after exposure to gamma irradiation with radioresistant bacteria. We showed that, in contrast to other organisms, cell survival was not modified by the cellular growth phase under optimal growth conditions but nutrient-limited conditions did affect the T. gammatolerans radioresistance. We determined the first kinetics of damaged DNA recovery in an archaeon after exposure to massive doses of gamma irradiation and compared the efficiency of chromosomal DNA repair according to the cellular growth phase, nutrient availability and culture conditions. Chromosomal DNA repair kinetics showed that stationary phase cells reconstitute disrupted chromosomes more rapidly than exponential phase cells. Our data also revealed that this radioresistant archaeon was proficient to reconstitute shattered chromosomes either slowly or rapidly without any loss of viability. These results suggest that rapid DNA repair is not required for the extreme radioresistance of T. gammatolerans.