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Animal-microbe facultative symbioses play a fundamental role in ecosystem and organismal health. Yet, due to the flexible nature of their association, the selection pressures that act on animals and their facultative symbionts remain elusive. Here we apply experimental evolution to Drosophila melanogaster associated with its growth-promoting symbiont Lactobacillus plantarum, representing a well-established model of facultative symbiosis. We find that the diet of the host, rather than the host itself, is a predominant driving force in the evolution of this symbiosis. Furthermore, we identify a mechanism resulting from the bacterium's adaptation to the diet, which confers growth benefits to the colonized host. Our study reveals that bacterial adaptation to the host's diet may be the foremost step in determining the evolutionary course of a facultative animal-microbe symbiosis., (Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: To assess the effect of a history of shoulder problems on the shoulder flexibility and strength in young competitive tennis players., Design: Cross-sectional study., Participants: Ninety-one competitive and asymptomatic tennis players aged between 8 and 15 years old were divided into two groups according to the presence or absence of a history of shoulder problems., Outcome Measures: Glenohumeral joint ranges of motion and the strength of eight shoulder muscles were bilaterally assessed. Five agonist/antagonist muscle strength ratios were also reported. Ranges of motion, strengths and strength ratios were bilaterally compared between the two groups., Results: Players with a history of shoulder problems presented a higher total arc of rotation for both glenohumeral joints (p = 0.02) and a lower external/internal glenohumeral rotator muscle strength ratio (p = 0.02) for both sides. They also presented stronger upper trapezius (p = 0.03) and dominant serratus anterior (p = 0.008) muscles than players without a history of shoulder problems., Conclusion: Having a history of shoulder problems may alter the balance between mobility and stability within the shoulder complex suggesting that particular attention should be given to dominant and non-dominant shoulder functions by coaches and clinicians., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In the past years, the fruit fly Drosophila melanogaster has been extensively used to study the relationship between animals and their associated microbes. Compared to the one of wild populations, the microbiota of laboratory-reared flies is less diverse, and comprises fewer bacterial taxa; nevertheless, the main commensal bacteria found in fly microbiota always belong to the Acetobacteraceae and Lactobacillaceae families. The bacterial communities associated with the fly are environmentally acquired, and the partners engage in a perpetual re-association process. Adult flies constantly ingest and excrete microbes from and onto their feeding substrate, which are then transmitted to the next generation developing within this shared habitat. We wanted to analyze the potential changes in the bacterial community during its reciprocal transfer between the two compartments of the niche (i.e. the fly and the diet). To address this question, we used a diverse, wild-derived microbial community and analyzed its relationship with the fly population and the nutritive substrate in a given habitat. Here we show that the community was overall well maintained upon transmission to a new niche, to a new fly population and to their progeny, illustrating the stable association of a Drosophila-derived microbiota with its fly partner and the nutritional environment. These results highlight the preponderant role of the nutritional substrate in the dynamics of Drosophila/microbiota interactions, and the need to fully integrate this variable when performing such studies., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The microbial environment influences animal physiology. However, the underlying molecular mechanisms of such functional interactions are largely undefined. Previously, we showed that during chronic undernutrition, strains of Lactobacillus plantarum, a major commensal partner of Drosophila, promote host juvenile growth and maturation partly through enhanced expression of intestinal peptidases. By screening a transposon insertion library of Lactobacillus plantarum in gnotobiotic Drosophila larvae, we identify a bacterial cell-wall-modifying machinery encoded by the pbpX2-dlt operon that is critical to enhance host digestive capabilities and promote animal growth and maturation. Deletion of this operon leads to bacterial cell wall alteration with a complete loss of D-alanylation of teichoic acids. We show that L. plantarum cell walls bearing D-alanylated teichoic acids are directly sensed by Drosophila enterocytes to ensure optimal intestinal peptidase expression and activity, juvenile growth and maturation during chronic undernutrition. We thus conclude that besides peptidoglycan, teichoic acid modifications participate in the host-commensal bacteria molecular dialogue occurring in the intestine.

Larval recruitment, the transition of pelagic larvae into reef-associated juveniles, is a critical step for the resilience of marine fish populations but its molecular control is unknown. Here, we investigate whether thyroid-hormones (TH) and their receptors (TR) coordinate the larval recruitment of the coral-reef-fish Acanthurus triostegus . We demonstrate an increase of TH-levels and TR -expressions in pelagic-larvae, followed by a decrease in recruiting juveniles. We generalize these observations in four other coral reef-fish species. Treatments with TH or TR-antagonist, as well as relocation to the open-ocean, disturb A. triostegus larvae transformation and grazing activity. Likewise, chlorpyrifos, a pesticide often encountered in coral-reefs, impairs A. triostegus TH-levels, transformation, and grazing activity, hence diminishing this herbivore's ability to control the spread of reef-algae. Larval recruitment therefore corresponds to a TH-controlled metamorphosis, sensitive to endocrine disruption. This provides a framework to understand how larval recruitment, critical to reef-ecosystems maintenance, is altered by anthropogenic stressors.

Members of the order Thermococcales are common inhabitants of high-temperature hydrothermal vent systems (black smokers) that are represented in clone libraries mostly by isolates from the Thermococcus genus. We report the complete sequence of a novel species from the Pyrococcus genus, P. kukulkanii strain NCB100, which has been isolated from a flange fragment of the Rebecca's Roost hydrothermal vent system in the Guaymas Basin., (Copyright © 2017 Oger et al.)

Context: Playing tennis requires unilateral and intensive movement of the upper limb, which may lead to functional adaptations of the shoulder and an increased injury risk. Identifying which athletes will be future elite tennis players starts at 5 to 6 years of age. Therefore, highly skilled players practice intensively in their childhood. However, whether these functional changes occur during the prepubertal years has not been established., Objectives: To assess changes in glenohumeral-joint-rotation range of motion and strength of the shoulder-complex muscles in prepubertal elite tennis players., Design: Cross-sectional study., Setting: Tennis training sports facilities., Patients or Other Participants: Sixty-seven male tennis players (age range = 7-13 years) selected by a regional tennis center of excellence were divided into 3 biological age groups relative to their predicted age at peak height velocity: greater than 4 (n = 26; age = 8.7 ± 0.7 years, height = 132.4 ± 12.9 cm, mass = 27.8 ± 3.8 kg), 3 to 4 (n = 21; age = 10.3 ± 0.6 years, height = 144.9 ± 5.7 cm, mass = 34.7 ± 4.0 kg), and 2 (n = 20; age = 12.8 ± 1.4 years, height = 158.5 ± 8.7 cm, mass = 43.0 ± 8.2 kg) years before their age at peak height velocity., Main Outcome Measures(s): We measured the internal- and external-rotation ranges of motion of the glenohumeral joint using a goniometer and calculated the total arc of motion. Maximal isometric strength of 8 shoulder muscles was measured using a handheld dynamometer. Strength values were normalized to body weight and used to calculate 4 agonist-to-antagonist strength ratios., Results: The total arc of motion of the glenohumeral joint decreased gradually with biological age (P ≤ .01) due to the decrease in internal-rotation range of motion (P < .001). Absolute strength increased gradually with biological age (P < .001), but the relative strengths and ratios remained similar., Conclusions: Functional adaptations of the shoulder seen in adolescent and adult tennis players were observed in healthy prepubertal players. This knowledge could help clinicians and coaches more effectively monitor shoulder adaptations to tennis practice during the prepubertal years.

The ability of bacteria to adapt to diverse environmental conditions is well-known. The process of bacterial adaptation to a niche has been linked to large changes in the genome content, showing that many bacterial genomes reflect the constraints imposed by their habitat. However, some highly versatile bacteria are found in diverse habitats that almost share nothing in common. Lactobacillus plantarum is a lactic acid bacterium that is found in a large variety of habitat. With the aim of unravelling the link between evolution and ecological versatility of L. plantarum, we analysed the genomes of 54 L. plantarum strains isolated from different environments. Comparative genome analysis identified a high level of genomic diversity and plasticity among the strains analysed. Phylogenomic and functional divergence studies coupled with gene-trait matching analyses revealed a mixed distribution of the strains, which was uncoupled from their environmental origin. Our findings revealed the absence of specific genomic signatures marking adaptations of L. plantarum towards the diverse habitats it is associated with. This suggests fundamentally similar trends of genome evolution in L. plantarum, which occur in a manner that is apparently uncoupled from ecological constraint and reflects the nomadic lifestyle of this species., (© 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.)

Parasites are sometimes able to manipulate the behavior of their hosts. However, the molecular cues underlying this phenomenon are poorly documented. We previously reported that the parasitoid wasp Leptopilina boulardi which develops from Drosophila larvae is often infected by an inherited DNA virus. In addition to being maternally transmitted, the virus benefits from horizontal transmission in superparasitized larvae (Drosophila that have been parasitized several times). Interestingly, the virus forces infected females to lay eggs in already parasitized larvae, thus increasing the chance of being horizontally transmitted. In a first step towards the identification of virus genes responsible for the behavioral manipulation, we present here the genome sequence of the virus, called LbFV. The sequencing revealed that its genome contains an homologous repeat sequence (hrs) found in eight regions in the genome. The presence of this hrs may explain the genomic plasticity that we observed for this genome. The genome of LbFV encodes 108 ORFs, most of them having no homologs in public databases. The virus is however related to Hytrosaviridae, although distantly. LbFV may thus represent a member of a new virus family. Several genes of LbFV were captured from eukaryotes, including two anti-apoptotic genes. More surprisingly, we found that LbFV captured from an ancestral wasp a protein with a Jumonji domain. This gene was afterwards duplicated in the virus genome. We hypothesized that this gene may be involved in manipulating the expression of wasp genes, and possibly in manipulating its behavior.

Thyroid hormones modulate not only multiple functions in vertebrates (energy metabolism, central nervous system function, seasonal changes in physiology, and behavior) but also in some non-vertebrates where they control critical post-embryonic developmental transitions such as metamorphosis. Despite their obvious biological importance, the thyroid hormone precursor protein, thyroglobulin (Tg), has been experimentally investigated only in mammals. This may bias our view of how thyroid hormones are produced in other organisms. In this study we searched genomic databases and found Tg orthologs in all vertebrates including the sea lamprey (Petromyzon marinus). We cloned a full-size Tg coding sequence from western clawed frog (Xenopus tropicalis) and zebrafish (Danio rerio). Comparisons between the representative mammal, amphibian, teleost fish, and basal vertebrate indicate that all of the different domains of Tg, as well as Tg regional structure, are conserved throughout the vertebrates. Indeed, in Xenopus, zebrafish, and lamprey Tgs, key residues, including the hormonogenic tyrosines and the disulfide bond-forming cysteines critical for Tg function, are well conserved despite overall divergence of amino acid sequences. We uncovered upstream sequences that include start codons of zebrafish and Xenopus Tgs and experimentally proved that these are full-length secreted proteins, which are specifically recognized by antibodies against rat Tg. By contrast, we have not been able to find any orthologs of Tg among non-vertebrate species. Thus, Tg appears to be a novel protein elaborated as a single event at the base of vertebrates and virtually unchanged thereafter., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

Purpose: Circulating cell-free DNA (ccfDNA) is a valuable source of tumor material obtained from a simple blood sampling that enables noninvasive analysis of the tumor genome. Our goal was to carry out a multiparametric analysis of ccfDNA and evaluate its prognostic value by investigating the overall survival (OS) of 97 metastatic colorectal cancer patients (mCRC)., Experimental Design: Qualitative parameters (determination of the main KRAS exon2 and BRAF V600E mutations) and quantitative parameters (total ccfDNA concentration, mutant ccfDNA concentration, the proportion of mutant ccfDNA, and ccfDNA integrity index) were determined simultaneously in a single run using a unique Q-PCR multimarker approach (100% success rate)., Results: The median follow-up time was 36 months and median OS was 22 months. Patients showing high ccfDNA levels had significantly shorter OS (18.07 months vs. 28.5 months, P = 0.0087). Moreover, multivariate analysis revealed that a high ccfDNA level is an independent prognostic factor (P = 0.034). All ccfDNA parameters were of prognostic interest: patients with higher levels of mutant ccfDNA and higher mutation loads for the detected mutations had shorter OS (P = 0.0089 and P = 0.05, respectively). In addition, the level of ccfDNA fragmentation correlated positively with decreased OS in the exclusive KRAS/BRAF-mutant cohort of patients (P = 0.0052) and appeared as a strong independent prognostic factor (P = 0.0072), whereas it was not significant in the exclusive KRAS/BRAF WT cohort of patients (P = 0.67)., Conclusions: Our data provide for the first time qualitative and quantitative evidence in favor of multiparametric ccfDNA analysis in mCRC patients for prognostic assessment. Clin Cancer Res; 22(12); 3067-77. ©2016 AACR., (©2016 American Association for Cancer Research.)

The geographic and temporal origins of dogs remain controversial. We generated genetic sequences from 59 ancient dogs and a complete (28x) genome of a late Neolithic dog (dated to ~4800 calendar years before the present) from Ireland. Our analyses revealed a deep split separating modern East Asian and Western Eurasian dogs. Surprisingly, the date of this divergence (~14,000 to 6400 years ago) occurs commensurate with, or several millennia after, the first appearance of dogs in Europe and East Asia. Additional analyses of ancient and modern mitochondrial DNA revealed a sharp discontinuity in haplotype frequencies in Europe. Combined, these results suggest that dogs may have been domesticated independently in Eastern and Western Eurasia from distinct wolf populations. East Eurasian dogs were then possibly transported to Europe with people, where they partially replaced European Paleolithic dogs., (Copyright © 2016, American Association for the Advancement of Science.)

Introduction: In myeloproliferative neoplasms (MPN), aspirin reduces the thrombotic risk. Nevertheless, aspirin resistance may be due to excessive platelet production ("turnover" resistance). Aspirin resistance can also result from a lack of effect of aspirin; this second component is called "intrinsic resistance". Two biological tests are considered reference methods for the assessment of aspirin resistance: TXB2 assay and Light Transmittance Aggregometry (LTA) with arachidonic acid., Materials & Methods: We have compared a third method, the Multiple Electrode Aggregometry (MEA), performed with arachidonic acid on the Multiplate® analyzer, with both reference methods. Thirty-six patients with MPN were assessed for aspirin resistance with all three techniques. 30 patients devoid of MPN were used as controls., Results: The three methods were statistically equivalent: LTA and TXB2 were comparable methods (ROC curve AUC=0.844>0.7; LTA cutoff=67%). At this threshold, LTA had a sensitivity of 73% and a specificity of 96%. MEA (without added aspirin) and TXB2 were also comparable (ROC curve AUC=0.782; MEA cutoff=31U), but at this threshold, 11 patients (30%) were falsely positive with MEA. Last, MEA and LTA were comparable (ROC curve AUC=0.888; MEA cutoff=56U), with a sensitivity of 90% and a specificity of 84.6%. Besides, MEA gave an insight into the mechanism of aspirin resistance (turnover and/or intrinsic)., Conclusion: MEA is both rapid and reliable as compared to reference methods. Clinical correlation with risk of re-thrombosis should definitively validate this method and the best cutoff value., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Introduction: Complex anal fistulas are responsible for pain, faecal incontinence and impaired quality of life. The rectal mucosa advancement flap (RMAF) procedure to cover the internal opening of the fistula remains a strategy of choice. However, a new procedure for closing anal fistulas is now available with the use of a nitinol closure clip (OTSC Proctology, OVESCO), which should ensure a better healing rate. This procedure is currently becoming more widespread, though without robust scientific validation, and it is therefore essential to carry out a prospective evaluation in order to determine the efficacy and safety of this new medical device for complex anal fistulas., Methods and Analysis: The FISCLOSE trial is aimed at evaluating the efficacy and safety of a nitinol closure clip compared to the RMAF procedure for the management of complex anal fistulas. This trial is a prospective, randomised, controlled, single-blind, bicentre and interventional study. Patients (n=46 per group) will be randomly assigned for management with either a closure clip or RMAF. The main objectives are to improve the healing rate of the anal fistula, lessen the postoperative pain and faecal incontinency, enhance the quality of life, and lower the number of reinterventions and therapeutic management costs. The primary outcome is the proportion of patients with a healed fistula at 3 months. The secondary outcomes are anal fistula healing (6 and 12 months), proctological pain (visual analogue scale), the faecal incontinence score (Jorge and Wexner questionnaire), digestive disorders and quality of life (Gastrointestinal Quality of Life Index and Euroqol EQ5D-3 L) up to 1 year., Ethics and Dissemination: The study was approved by an independent medical ethics committee 1 (IRB00008526, CPP Sud-Est 6, Clermont-Ferrand, France) and registered by the competent French authority (ANSM, Saint Denis, France). The results will be disseminated in a peer-reviewed journal and presented at international congresses., Trial Registration Number: NCT02336867; pre-result., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Lactobacillus plantarum strain WJL is a symbiont isolated from the Drosophila melanogaster gut. The genome of L. plantarum WJL, first sequenced in 2013, was resequenced and rescaffolded in this study. A combination of Sanger and Illumina sequencing allowed us to reduce the number of contigs from 102 to 13. This work contributes to a better understanding of the genome and function of this organism., (Copyright © 2015 Martino et al.)

Lactobacillus plantarum is a versatile bacterial species that is isolated mostly from foods. Here, we present the first genome sequence of L. plantarum strain NIZO2877 isolated from a hot dog in Vietnam. Its two contigs represent a nearly complete genome sequence., (Copyright © 2015 Martino et al.)

The analysis of ancient or processed DNA samples is often a great challenge, because traditional Polymerase Chain Reaction - based amplification is impeded by DNA damage. Blocking lesions such as abasic sites are known to block the bypass of DNA polymerases, thus stopping primer elongation. In the present work, we applied the SERRS-hybridization assay, a fully non-enzymatic method, to the detection of DNA refractory to PCR amplification. This method combines specific hybridization with detection by Surface Enhanced Resonant Raman Scattering (SERRS). It allows the detection of a series of double-stranded DNA molecules containing a varying number of abasic sites on both strands, when PCR failed to detect the most degraded sequences. Our SERRS approach can quickly detect DNA molecules without any need for DNA repair. This assay could be applied as a pre-requisite analysis prior to enzymatic reparation or amplification. A whole new set of samples, both forensic and archaeological, could then deliver information that was not yet available due to a high degree of DNA damage.

Brominated flame retardants are suspected to act as disruptors of thyroid hormone signaling. This raises the concern that they might affect children's cognitive functions by influencing thyroid hormone signaling in the developing brain. We present here an in vitro analysis of the ability of the most common compounds, tetrabromobisphenol A (TBBPA) and BDE-209, to alter thyroid hormone response based on a model neural cell line and genome-wide analysis of gene expression., (Copyright © 2014. Published by Elsevier Ireland Ltd.)

The multifactorial causes impacting the risk of developing sporadic forms of Alzheimer's disease (AD) remain to date poorly understood. Epidemiologic studies in humans and research in rodents have suggested that hypothyroidism could participate in the etiology of AD. Recently, we reported that adult-onset hypothyroidism in rats favors β-amyloid peptide production in the hippocampus. Here, using the same hypothyroidism model with the antithyroid molecule propythiouracyl (PTU), we further explored AD-related features, dysfunctional cell-signaling mechanisms and hippocampal-dependent learning and memory. In vivo MRI revealed a progressive decrease in cerebral volume of PTU-treated rats. In the hippocampus, hypothyroidism resulted in tau hyperphosphorylation and increases in several proinflammatory cytokines. These modifications were associated with impaired spatial memory and reduced hippocampal expression of signaling molecules important for synaptic plasticity and memory, including neurogranin, CaMKII, ERK, GSK3β, CREB, and expression of the transcription factor EGR1/Zif268. These data strengthen the idea that hypothyroidism represents an important factor influencing the risk of developing sporadic forms of AD., (Copyright © 2014 Wiley Periodicals, Inc.)

Assessment of KRAS status is mandatory in patients with metastatic colorectal cancer (mCRC) before applying targeted therapy. We describe here a blinded prospective study to compare KRAS and BRAF mutation status data obtained from the analysis of tumor tissue by routine gold-standard methods and of plasma DNA using a quantitative PCR-based method specifically designed to analyze circulating cell-free DNA (cfDNA). The mutation status was determined by both methods from 106 patient samples. cfDNA analysis showed 100% specificity and sensitivity for the BRAF V600E mutation. For the seven tested KRAS point mutations, the method exhibited 98% specificity and 92% sensitivity with a concordance value of 96%. Mutation load, expressed as the proportion of mutant alleles in cfDNA, was highly variable (0.5-64.1%, median 10.5%) among mutated samples. CfDNA was detected in 100% of patients with mCRC. This study shows that liquid biopsy through cfDNA analysis could advantageously replace tumor-section analysis and expand the scope of personalized medicine for patients with cancer.

Retinoic acid (RA) controls many aspects of embryonic development by binding to specific receptors (retinoic acid receptors [RARs]) that regulate complex transcriptional networks. Three different RAR subtypes are present in vertebrates and play both common and specific roles in transducing RA signaling. Specific activities of each receptor subtype can be correlated with its exclusive expression pattern, whereas shared activities between different subtypes are generally assimilated to functional redundancy. However, the question remains whether some subtype-specific activity still exists in regions or organs coexpressing multiple RAR subtypes. We tackled this issue at the transcriptional level using early zebrafish embryo as a model. Using morpholino knockdown, we specifically invalidated the zebrafish endogenous RAR subtypes in an in vivo context. After building up a list of RA-responsive genes in the zebrafish gastrula through a whole-transcriptome analysis, we compared this panel of genes with those that still respond to RA in embryos lacking one or another RAR subtype. Our work reveals that RAR subtypes do not have fully redundant functions at the transcriptional level but can transduce RA signal in a subtype-specific fashion. As a result, we define RAR subtype-specific transcriptotypes that correspond to repertoires of genes activated by different RAR subtypes. Finally, we found genes of the RA pathway (cyp26a1, raraa) the regulation of which by RA is highly robust and can even resist the knockdown of all RARs. This suggests that RA-responsive genes are differentially sensitive to alterations in the RA pathway and, in particular, cyp26a1 and raraa are under a high pressure to maintain signaling integrity.

Unlabelled: Our group has developed a new radiopharmaceutical, (123)I - N-(2-diethylaminoethyl)-2-iodobenzamide ((123)I-BZA2), a benzamide derivative able to bind to melanin pigment in melanoma cells. In a prospective and multicentric phase III clinical study, the value of (18)F-FDG PET/CT and (123)I-BZA2 scintigraphy was compared for melanoma staging., Methods: Patients with a past history of cutaneous or ocular melanoma were included from 8 hospitals. (18)F-FDG imaging was performed according to a standard PET protocol. Whole-body, static planar, and SPECT/CT (if available) images were acquired 4 h after injection of a 2 MBq/kg dose of (123)I-BZA2. (18)F-FDG and (123)I-BZA2 sensitivity and specificity for the diagnosis of melanoma metastasis were calculated and compared on both a lesion basis and a patient basis. True-positive and true-negative lesion status was determined after 6 mo of clinical follow-up or according to lesion biopsies (if available). Melanin content in biopsies was evaluated with the standard Fontana-Masson silver method and was correlated with (123)I-BZA2 uptake. Based on statistical analysis, the number of inclusions was estimated at 186., Results: In all, 87 patients were enrolled from 2008 to 2010. Of these, 45 (52%) had metastases. A total of 338 imaging abnormalities were analyzed; 86 lesions were considered metastases, and 20 of 25 lesion biopsies found melanoma metastases. In a patient-based analysis, the sensitivity of (18)F-FDG for diagnosis of melanoma metastases was higher than that of (123)I-BZA2, at 87% and 39%, respectively (P < 0.05). For specificity, (18)F-FDG and (123)I-BZA2 were not statistically different, at 78% and 94%, respectively. In a lesion-based analysis, the sensitivity of (18)F-FDG was statistically higher than that of (123)I-BZA2 (80% vs. 23%, P < 0.05). The specificity of (18)F-FDG was lower than that of (123)I-BZA2 (54% vs. 86%, P < 0.05). According to biopsy analysis, only 9 of 20 metastatic lesions (45%) were pigmented with high melanin content. (123)I-BZA2 imaging was positive for 6 of 8 melanin-positive lesions, fairly positive for 3 of 10 melanin-negative lesions, and negative for 7 of 10 melanin-negative lesions. The sensitivity and specificity of (123)I-BZA2 for the diagnosis of melanin-positive lesions were 75% and 70%, respectively. Because of a low (123)I-BZA2 sensitivity, this clinical trial was prematurely closed after 87 patients had been included., Conclusion: This study confirms the value of (18)F-FDG PET/CT for melanoma staging and strengthens the high accuracy of (123)I-BZA2 for diagnosis of melanin-positive metastatic melanoma. Moreover, benzamide derivatives radiolabeled with therapeutic radionuclide may offer a new strategy for the treatment of metastatic melanoma patients harboring melanin-positive metastases.

We have used a paleogenetics approach to investigate the genetic landscape of coat color variation in ancient Eurasian dog and wolf populations. We amplified DNA fragments of two genes controlling coat color, Mc1r (Melanocortin 1 Receptor) and CBD103 (canine-β-defensin), in respectively 15 and 19 ancient canids (dogs and wolf morphotypes) from 14 different archeological sites, throughout Asia and Europe spanning from ca. 12 000 B.P. (end of Upper Palaeolithic) to ca. 4000 B.P. (Bronze Age). We provide evidence of a new variant (R301C) of the Melanocortin 1 receptor (Mc1r) and highlight the presence of the beta-defensin melanistic mutation (CDB103-K locus) on ancient DNA from dog-and wolf-morphotype specimens. We show that the dominant K(B) allele (CBD103), which causes melanism, and R301C (Mc1r), the variant that may cause light hair color, are present as early as the beginning of the Holocene, over 10,000 years ago. These results underline the genetic diversity of prehistoric dogs. This diversity may have partly stemmed not only from the wolf gene pool captured by domestication but also from mutations very likely linked to the relaxation of natural selection pressure occurring in-line with this process.

As a strategy to treat Duchenne muscular dystrophy, we used arginine butyrate, which combines two pharmacological activities: nitric oxide pathway activation, and histone deacetylase inhibition. Continuous intraperitoneal administration to dystrophin-deficient mdx mice resulted in a near 2-fold increase in utrophin (protein homologous to dystrophin) in skeletal muscle, heart, and brain, accompanied by an improvement of the dystrophic phenotype in both adult and newborn mice (45 and 70% decrease in creatine kinase level, respectively; 14% increase in tidal volume, 30% decrease in necrotic area in limb and 23% increase in isometric force). Intermittent administration, as performed in clinical trials, was then used to reduce the frequency of injections and to improve safety. This also enhanced utrophin level around 2-fold (EC50=284 mg/ml) and alleviated the dystrophic phenotype (inverted grid and grip test performance near to wild-type values, creatine kinase level decreased by 50%). Skin biopsies were used to monitor treatment efficacy, instead of invasive muscle biopsies, and this could be done a few days after the start of treatment. A 2-fold increase in utrophin expression was also shown in cultured human myotubes. In vivo and in vitro experiments demonstrated that the drug combination acts synergistically. Together, these data constitute a proof of principle of the beneficial effects of arginine butyrate on muscular dystrophy.

Object: To characterize the progression of injured tissue resulting from a permanent focal cerebral ischemia after the acute phase, Magnetic Resonance Imaging (MRI) monitoring was performed on adult male C57BL/6J mice in the subacute stages, and correlated to histological analyses., Material and Methods: Lesions were induced by electrocoagulation of the middle cerebral artery. Serial MRI measurements and weighted-images (T2, T1, T2* and Diffusion Tensor Imaging) were performed on a 9.4T scanner. Histological data (Cresyl-Violet staining and laminin-, Iba1- and GFAP-immunostainings) were obtained 1 and 2 weeks after the stroke., Results: Two days after stroke, tissues assumed to correspond to the infarct core, were detected as a hyperintensity signal area in T2-weighted images. One week later, low-intensity signal areas appeared. Longitudinal MRI study showed that these areas remained present over the following week, and was mainly linked to a drop of the T2 relaxation time value in the corresponding tissues. Correlation with histological data and immuno-histochemistry showed that these areas corresponded to microglial cells., Conclusion: The present data provide, for the first time detailed MRI parameters of microglial cells dynamics, allowing its non-invasive monitoring during the chronic stages of a stroke. This could be particularly interesting in regards to emerging anti-inflammatory stroke therapies.

We have developed a fully enzyme-free SERRS hybridization assay for specific detection of double-stranded DNA sequences. Although all DNA detection methods ranging from PCR to high-throughput sequencing rely on enzymes, this method is unique for being totally non-enzymatic. The efficiency of enzymatic processes is affected by alterations, modifications, and/or quality of DNA. For instance, a limitation of most DNA polymerases is their inability to process DNA damaged by blocking lesions. As a result, enzymatic amplification and sequencing of degraded DNA often fail. In this study we succeeded in detecting and quantifying, within a mixture, relative amounts of closely related double-stranded DNA sequences from Rupicapra rupicapra (chamois) and Capra hircus (goat). The non-enzymatic SERRS assay presented here is the corner stone of a promising approach to overcome the failure of DNA polymerase when DNA is too degraded or when the concentration of polymerase inhibitors is too high. It is the first time double-stranded DNA has been detected with a truly non-enzymatic SERRS-based method. This non-enzymatic, inexpensive, rapid assay is therefore a breakthrough in nucleic acid detection.

This study reports the design of a novel theragnostic nanomedicine which combines (i) the ability to target a prodrug of gemcitabine to an experimental solid tumor under the influence of a magnetic field with (ii) the imaging of the targeted tumoral nodule. This concept is based on the inclusion of magnetite nanocrystals into nanoparticles (NPs) constructed by self-assembling molecules of the squalenoyl gemcitabine (SQgem) bioconjugate. The nanocomposites are characterized by an unusually high drug loading, a significant magnetic susceptibility, and a low burst release. When injected to the L1210 subcutaneous mice tumor model, these magnetite/SQgem NPs were magnetically guided, and they displayed considerably greater anticancer activity than the other anticancer treatments (magnetite/SQgem NPs nonmagnetically guided, SQgem NPs, or gemcitabine free in solution). The histology and immunohistochemistry investigation of the tumor biopsies clearly evidenced the therapeutic superiority of the magnetically guided nanocomposites, while Prussian blue staining confirmed their accumulation at the tumor periphery. The superior therapeutic activity and enhanced tumor accumulation has been successfully visualized using T(2)-weighted imaging in magnetic resonance imaging (MRI). This concept was further enlarged by (i) the design of squalene-based NPs containing the T(1) Gd(3+) contrast agent instead of magnetite and (ii) the application to other anticancer squalenoyls, such as, cisplatin, doxorubicin, and paclitaxel. Thus, by combining different anticancer medicines as well as contrast imaging agents in NPs, we open the door toward generic conceptual framework for cancer treatment and diagnosis. This new theragnostic nanotechnology platform is expected to have important applications in cancer therapy.

In this study, we have applied Surface Enhanced Resonance Raman Scattering (SERRS) technology to the specific detection of DNA. We present an innovative SERRS sandwich-hybridization assay that allows specific DNA detection without any enzymatic amplification, such as is the case with Polymerase Chain Reaction (PCR). In some substrates, such as ancient or processed remains, enzymatic amplification fails due to DNA alteration (degradation, chemical modification) or to the presence of inhibitors. Consequently, the development of a non-enzymatic method, allowing specific DNA detection, could avoid long, expensive and inconclusive amplification trials. Here, we report the proof of concept of a SERRS sandwich-hybridization assay that leads to the detection of a specific chamois DNA. This SERRS assay reveals its potential as a non-enzymatic alternative technology to DNA amplification methods (particularly the PCR method) with several applications for species detection. As the amount and type of damage highly depend on the preservation conditions, the present SERRS assay would enlarge the range of samples suitable for DNA analysis and ultimately would provide exciting new opportunities for the investigation of ancient DNA in the fields of evolutionary biology and molecular ecology, and of altered DNA in food frauds detection and forensics.

Atelopus franciscus is a diurnal bufonid frog that lives in South-American tropical rain forests. As in many other frogs, males produce calls to defend their territories and attract females. However, this species is a so-called "earless" frog lacking an external tympanum and is thus anatomically deaf. Moreover, A. franciscus has no external vocal sac and lives in a sound constraining environment along river banks where it competes with other calling frogs. Despite these constraints, male A. franciscus reply acoustically to the calls of conspecifics in the field. To resolve this apparent paradox, we studied the vocal apparatus and middle-ear, analysed signal content of the calls, examined sound and signal content propagation in its natural habitat, and performed playback experiments. We show that A. franciscus males can produce only low intensity calls that propagate a short distance (<8 m) as a result of the lack of an external vocal sac. The species-specific coding of the signal is based on the pulse duration, providing a simple coding that is efficient as it allows discrimination from calls of sympatric frogs. Moreover, the signal is redundant and consequently adapted to noisy environments. As such a coding system can be efficient only at short-range, territory holders established themselves at short distances from each other. Finally, we show that the middle-ear of A. franciscus does not present any particular adaptations to compensate for the lack of an external tympanum, suggesting the existence of extra-tympanic pathways for sound propagation.

In the heart, the energy supplied by mitochondria to myofibrils is continuously and finely tuned to the contraction requirement over a wide range of cardiac loads. This process is mediated both by the creatine kinase (CK) shuttle and by direct ATP transfer. The aim of this study was to identify the contribution of energy transfer pathways at different cardiac performance levels. For this, five protocols of (31)P NMR inversion and saturation transfer experiments were performed at different performance levels on Langendorff perfused rat hearts. The cardiac performance was changed either through variation of external calcium in the presence or absence of isoprenaline or through variation of LV balloon inflation. The recordings were analyzed by mathematical models composed on the basis of different energy transfer pathway configurations. According to our results, the total CK unidirectional flux was relatively stable when the cardiac performance was changed by increasing the calcium concentration or variation of LV balloon volume. The stability of total CK unidirectional flux is lost at extreme energy demand levels leading to a rise in inorganic phosphate, a drop of ATP and phosphocreatine, a drop of total CK unidirectional flux, and to a bypass of CK shuttle by direct ATP transfer. Our results provide experimental evidence for the existence of two pathways of energy transfer, direct ATP transfer, and PCr transfer through the CK shuttle, whose contribution may vary depending on the metabolic status of the heart.

Recent evidence supports a crucial role for matrix metalloproteinase-9 (MMP-9) in blood-brain barrier (BBB) disruption and vasogenic edema formation after traumatic brain injury (TBI). Although the exact causes of MMP-9 upregulation after TBI are not fully understood, several arguments suggest a contribution of the enzyme poly(ADP-ribose)polymerase (PARP) in the neuroinflammatory response leading to MMP-9 activation. The objectives of this study were to evaluate the effect of PARP inhibition by 3-aminobenzamide (3-AB) (1) on MMP-9 upregulation and BBB integrity, (2) on edema formation as assessed by magnetic resonance imaging (MRI), (3) on neuron survival as assessed by (1)H magnetic resonance spectroscopy ((1)H-MRS), and (4) on neurological deficits at the acute phase of TBI. Western blots and zymograms showed blunting of MMP-9 upregulation 6 h after TBI. BBB permeability was decreased at the same time point in 3-AB-treated rats compared to vehicle-treated rats. Cerebral MRI showed less "free" water in 3-AB-treated than in vehicle-treated rats 6 h after TBI. MRI findings 24 h after TBI indicated predominant cytotoxic edema, and at this time point no significant differences were found between 3-AB- and vehicle-treated rats with regard to MMP-9 upregulation, BBB permeability, or MRI changes. At both 6 and 24 h, neurological function was better in the 3-AB-treated than in the vehicle-treated rats. These data suggest that PARP inhibition by 3-AB protected the BBB against hyperpermeability induced by MMP-9 upregulation, thereby decreasing vasogenic edema formation 6 h after TBI. Furthermore, our data confirm the neuroprotective effect of 3-AB at the very acute phase of TBI.

In the domain of health, one important challenge is the efficient delivery of drugs in the body using non-toxic nanocarriers. Most of the existing carrier materials show poor drug loading (usually less than 5 wt% of the transported drug versus the carrier material) and/or rapid release of the proportion of the drug that is simply adsorbed (or anchored) at the external surface of the nanocarrier. In this context, porous hybrid solids, with the ability to tune their structures and porosities for better drug interactions and high loadings, are well suited to serve as nanocarriers for delivery and imaging applications. Here we show that specific non-toxic porous iron(III)-based metal-organic frameworks with engineered cores and surfaces, as well as imaging properties, function as superior nanocarriers for efficient controlled delivery of challenging antitumoural and retroviral drugs (that is, busulfan, azidothymidine triphosphate, doxorubicin or cidofovir) against cancer and AIDS. In addition to their high loadings, they also potentially associate therapeutics and diagnostics, thus opening the way for theranostics, or personalized patient treatments.

Magnetic resonance imaging (MRI) is widely used to evaluate the consequences of traumatic brain injury (TBI) in both experimental and clinical studies. Improved assessment of experimental TBI using the same methods as those used in clinical investigations would help to translate laboratory research into clinical advances. Here our goal was to characterize lateral fluid percussion-induced TBI, with special emphasis on differentiating the contused cortex from the pericontusional subcortical tissue. We used both in vivo MRI and proton magnetic resonance spectroscopy ((1)H-MRS) to evaluate adult male Sprague-Dawley rats 24 h and 48 h and 7 days after TBI. T2 and apparent diffusion coefficient (ADC) maps were derived from T2-weighted and diffusion-weighted images, respectively. Ratios of N-acetylaspartate (NAA), choline compounds (Cho), and lactate (Lac) over creatine (Cr) were estimated by (1)H-MRS. T2 values were high in the contused cortex 24 h after TBI, suggesting edema development; ADC was low, consistent with cytotoxic edema. At the same site, NAA/Cr was decreased and Lac/Cr elevated during the first week after TBI. In the ipsilateral subcortical area, NAA/Cr was markedly decreased and Lac/Cr was elevated during the first week, although MRI showed no evidence of edema, suggesting that (1)H-MRS detected "invisible" damage. (1)H-MRS combined with MRI may improve the detection of brain injury. Extensive assessments of animal models may increase the chances of developing successful neuroprotective strategies.

Unlabelled: The methionine (MET) dependency of tumor cells opens interesting perspectives for targeting tumor cells and potentiating chemotherapy treatment, like 5-fluorouracil (5-FU) and platinum compound. Since MET deprivation can individually potentiate the different chemotherapeutic agents used in the 48-hour combined regimen of 5-FU, leucovorin and oxaliplatin (FOLFOX) regimen, we initiated a feasibility study associating dietary MET restriction with the FOLFOX regimen in patients with metastatic colorectal cancer., Objectives: (i) To evaluate the depletion in the plasma MET concentration, and (ii) to assess the feasibility of this combination., Methods: Eleven patients were enrolled in this study. They received a median number of 3 two-week cycles of a MET-free diet (3 consecutive days) and FOLFOX6 regimen., Results: The plasma MET concentration was reduced by dietary MET restriction, with a depletion of 58% on the 1st day of MET-free diet. Indeed, we demonstrated the feasibility and good tolerance (nutritional status and toxicity) of the association of a MET-free diet with the FOLFOX regimen. Despite good compliance to the diet, this study revealed the difficulty of administering this combination during further months. Among the 4 patients evaluable for response, 3 experienced a partial response and 1 patient a disease stabilization., (Copyright 2010 S. Karger AG, Basel.)

A mini-compression jig was built to perform in situ tests on bovine trabecular bone monitored by micro-MRI. The MRI antenna provided an isotropic resolution of 78 microm that allows for a volume correlation method to be used. Three-dimensional displacement fields are then evaluated within the bone sample during the compression test. The performances of the correlation method are evaluated and discussed to validate the technique on trabecular bone. By considering correlation residuals and estimates of acquisition noise, the measured results are shown to be trustworthy. By analyzing average strain levels for different interrogation volumes along the loading direction, it is shown that the sample size is less than that of a representative volume element. This study shows the feasibility of the 3D-displacement and strain field analyses from micro-MRI images. Other biological tissues could be considered in future work.

(13)C spectroscopy combined with the injection of (13)C-labeled substrates is a powerful method for the study of brain metabolism in vivo. Since highly localized measurements are required in a heterogeneous organ such as the brain, it is of interest to augment the sensitivity of (13)C spectroscopy by proton acquisition. Furthermore, as focal cerebral lesions are often encountered in animal models of disorders in which the two brain hemispheres are compared, we wished to develop a bi-voxel localized sequence for the simultaneous bilateral investigation of rat brain metabolism, with no need for external additional references. Two sequences were developed at 9.4T: a bi-voxel (1)H-((13)C) STEAM-POCE (Proton Observed Carbon Edited) sequence and a bi-voxel (1)H-((13)C) PRESS-POCE adiabatically decoupled sequence with Hadamard encoding. Hadamard encoding allows both voxels to be recorded simultaneously, with the same acquisition time as that required for a single voxel. The method was validated in a biological investigation into the neuronal damage and the effect on the Tri Carboxylic Acid cycle in localized excitotoxic lesions. Following an excitotoxic quinolinate-induced localized lesion in the rat cortex and the infusion of U-(13)C glucose, two (1)H-((13)C) spectra of distinct (4x4x4mm(3)) voxels, one centred on the injured hemisphere and the other on the contralateral hemisphere, were recorded simultaneously. Two (1)H bi-voxel spectra were also recorded and showed a significant decrease in N-acetyl aspartate, and an accumulation of lactate in the ipsilateral hemisphere. The (1)H-((13)C) spectra could be recorded dynamically as a function of time, and showed a fall in the glutamate/glutamine ratio and the presence of a stable glutamine pool, with a permanent increase of lactate in the ipsilateral hemisphere. This bi-voxel (1)H-((13)C) method can be used to investigate simultaneously both brain hemispheres, and to perform dynamic studies. We report here the neuronal damage and the effect on the Tri Carboxylic Acid cycle in localized excitotoxic lesions.

Individuals with partial HSA21 trisomies and mice with partial MMU16 trisomies containing an extra copy of the DYRK1A gene present various alterations in brain morphogenesis. They present also learning impairments modeling those encountered in Down syndrome. Previous MRI and histological analyses of a transgenic mice generated using a human YAC construct that contains five genes including DYRK1A reveal that DYRK1A is involved, during development, in the control of brain volume and cell density of specific brain regions. Gene dosage correction induces a rescue of the brain volume alterations. DYRK1A is also involved in the control of synaptic plasticity and memory consolidation. Increased gene dosage results in brain morphogenesis defects, low BDNF levels and mnemonic deficits in these mice. Epigallocatechin gallate (EGCG) - a member of a natural polyphenols family, found in great amount in green tea leaves - is a specific and safe DYRK1A inhibitor. We maintained control and transgenic mice overexpressing DYRK1A on two different polyphenol-based diets, from gestation to adulthood. The major features of the transgenic phenotype were rescued in these mice.

A yeast artificial chromosome (YAC) transgenic murine model of partial trisomy 21 overexpressing five human genes -- including DYRK1A, which encodes a serine threonine kinase involved in cell cycle control -- has been shown to present an increase in brain weight. We analyzed this new phenotype by measuring total and regional brain volumes at different ages, using a 7 Tesla magnetic resonance imaging volumetric approach. Volumetric measurements showed a total volume increase of 13.6% in adult mice. Changes in brain morphogenesis were already visible at a very early postnatal stage (postnatal days 2-7). Region-specific changes were characterized from postnatal day 15 to 5 months. These results, made it possible to define region-specific effects of DYRK1A overexpression, with the strongest increase seen in the thalamus-hypothalamus area (24%).

Purpose: To prospectively evaluate in rats whether magnetic cell labeling can be used to noninvasively assess the technical success of endovascular cell therapy for abdominal aortic aneurysms (AAAs)., Materials and Methods: The study was approved by an institutional animal care and use committee. Vascular smooth muscle cells (VSMCs) labeled with iron oxide nanoparticles were seeded endovascularly in already formed AAAs. T2*-weighted gradient-echo and T2-weighted spin-echo magnetic resonance (MR) imaging was performed in vivo at 1.5 T before and 30 minutes after the injection of iron-loaded VSMCs (14 rats), nonlabeled VSMCs (three rats), or iron-free particles (three rats). Ten rats were euthanized shortly after the injection (day 0). Of the 10 remaining rats, which were seeded with iron-loaded cells, three were imaged on day 7 after cell delivery; three, on day 14; and four, on day 28; then they were euthanized. Ex vivo high-field-strength MR imaging of two AAAs was performed 28 days after cell delivery. Histologic examination of cross sections of all AAAs was performed. Statistical evaluations were performed with a nonparametric Wilcoxon correlation test., Results: Magnetic cell labeling did not alter the capability of VSMCs to stabilize the diameter of the aneurysms. T2*-weighted gradient-echo images showed areas of hypointense signal within the aortic wall immediately and up to 1 month after cell therapy. The mean signal intensity decreased significantly after cell delivery (from 2362 +/- 244 [standard deviation] before to 434 +/- 275 after delivery, P < .001). Areas of hypointense signal and iron-loaded VSMCs were colocalized in the area of aortic wall reconstruction at both high-field-strength MR imaging and histologic analysis., Conclusion: MR imaging with magnetic cell labeling can be used to document endovascular cell delivery in already formed AAAs in rats., (RSNA, 2007)

Cerebral hypoxia-ischemia is an important cause of brain injury in the newborn infant. Our purpose was to study magnetic resonance (MR) imaging changes in P7 rat brains submitted to permanent or reversible ischemia. Ischemia was induced by permanent electro-cauterization of the middle cerebral artery combined with a permanent or a transient (50 min) common carotid artery occlusion. The early events during ischemia and reperfusion were investigated by T2-weighted images (T2WI) at 1 and 3 h and by serial diffusion-weighted images (DWI) during 3 h in a 7 T magnet with a standard weighted diffusion sequence (b=1282.04 s mm(-2)) and a SEMS sequence. Within the first hour after MCA occlusion, the T2WI areas of contrast enhancement increased to a mean volume of 12.9+/-6.4%, a steady state still detected at 3 h after the ischemic onset (10.5+/-2.5%). Contrast enhancement in DWI increased as soon as 15 min of ischemia in all animals up to 50 min after CCA occlusion. In permanent ischemia, DWI abnormalities volume then increased more slowly from 50 min to 3 h after CCA occlusion (+25%, n=5). In reversible ischemia, the DWI abnormalities volume either moderately decreased and reached a plateau (-8.4%, n=4) or dramatically decreased (-53.0%, n=3). Both T2WI and DWI evidenced a "patchy" pattern of recovery as also shown on cresyl violet-stained sections. In contrast to the adult, early ischemic injury in P7 rat brains is detected as an increase in hyper-intensities both in T2WI and DWI. Our data indicate that reperfusion is able to block edema evolution after neonatal stroke and that early T2WI and more accurately DWI allow to distinguish between different patterns of injury in reversible ischemia.

Because the question "is AMP-activated protein kinase (AMPK) alpha(2)-isoform a friend or a foe in the protection of the myocardium against ischemia-reperfusion injury?" is still in debate, we studied the functional consequence of its deletion on the contractility, the energetics, and the respiration of the isolated perfused heart and characterized the response to low-flow ischemia and reperfusion with glucose and pyruvate as substrates. alpha(2)-AMPK deletion did not affect basal contractility, respiration, and high-energy phosphate contents but induced a twofold reduction in glycogen content and a threefold reduction in glucose uptake. Low-flow ischemia increased AMPK phosphorylation and stimulated glucose uptake and phosphorylation in both alpha(2)-knockout (alpha(2)-KO) and wild-type (WT) groups. The high sensitivity of alpha(2)-KO to the development of ischemic contracture was attributed to the constitutive impairment in glucose transport and glycogen content and not to a perturbation of the energy transfer by creatine kinase (CK). The functional coupling of MM-CK to myofibrillar ATPase and the CK fluxes were indeed similar in alpha(2)-KO and WT. Low-flow ischemia impaired CK flux by 50% in both strains, showing that alpha(2)-AMPK does not control CK activity. Despite the higher sensitivity to contracture, the postischemic contractility recovered to similar levels in both alpha(2)-KO and WT in the absence of fatty acids. In their presence, alpha(2)-AMPK deletion also accelerated the contracture but delayed postischemic contractile recovery. In conclusion, alpha(2)-AMPK is required for a normal glucose uptake and glycogen content, which protects the heart from the development of the ischemic contracture, but not for contractile recovery in the absence of fatty acids.

Purpose: To assess the role of large b-value diffusion weighted imaging (DWI) in the characterization of the physicochemical properties of the water in brain edema under experimental and clinical conditions., Materials and Methods: Vasogenic brain edema was induced in mice by means of cold injury. A total of 17 patients with extensive peritumoral brain edema were also investigated. The longitudinal relaxation time (T(1)) and apparent diffusion coefficient (D) were measured in the edematous area both in humans and in mice. D was calculated by using both mono- (D(mono)) and biexponential (D(fast) and D(slow)) approaches in the low and overall range of b-values, respectively. The D values were correlated with the T(1) values., Results: A strong linear correlation was found between T(1) and D(mono) in vasogenic brain edema, both in humans and in mice. After breakdown of D(mono) into fast and slow diffusing components, only D(fast) exhibited a strong correlation with T(1); D(slow) was unchanged in vasogenic brain edema., Conclusion: Large b-value DWI can furnish a detailed characterization of vasogenic brain edema, and may provide a quantitative approach for the differentiation of edema types on the basis of the physicochemical properties of the water molecules. Application of the DWI method may permit prediction and follow-up of the effects of antiedematous therapy.

The aim of this study was to demonstrate the feasibility of in vivo cell tracking to monitor anticancer cell therapy by means of a high-resolution noninvasive MRI method. Ovalbumin-specific splenocytes (OT-1) labeled with anionic gamma-Fe2O3 superparamagnetic iron oxide (SPIO) nanoparticles were adoptively transferred into C57BL/6 mice with growing ovalbumin-expressing tumors. OT-1 cells were tracked in vivo by 7 T MRI 24, 48, and 72 hr after they were injected. The results showed significant negative enhancement of the spleen at 24 hr, and of the tumor at 48 and 72 hr, after labeled cell injection. This suggests that the lymphocytes initially homed toward the spleen and were then recruited by the tumor. The presence of labeled cells was confirmed in ex vivo by 9.4 T microimaging of tumors and magnetic sorting of spleen cells. These results confirm that MR tracking of lymphocytes is feasible in vivo. This high-resolution imaging method could be used to improve the monitoring of immune cell therapy., (Copyright (c) 2006 Wiley-Liss, Inc.)

Recent studies have shown that cell migration can be monitored in vivo by magnetic resonance imaging after intracellular contrast agent incorporation. This is due to the dephasing effect on proton magnetization of the local magnetic field created by a labelled cell. Anionic iron oxide nanoparticles (AMNP) are among the most efficient and non-toxic contrast agents to be spontaneously taken up by a wide variety of cells. Here we measured the iron load and magnetization of HeLa tumour cells labelled with AMNP, as a function of the external magnetic field. High-resolution gradient echo 9.4 T MRI detected individual labelled cells, whereas spin echo sequences were poorly sensitive. We then conducted a systematic study in order to determine the gradient echo sequence parameters (echo time, cell magnetization and resolution) most suitable for in vivo identification of single cells., (Copyright 2006 John Wiley & Sons, Ltd.)

We show here, for the first time, that two neutral polymers may completely associate together in water to spontaneously form supramolecular nanoassemblies (nanogels) of spherical shape. The cohesion of these stable structures of about 200 nm is based upon a "lock and key" mechanism: inclusion complexes are formed between the hydrophobic alkyl chains grafted on a polysaccharide (dextran) and the molecular cavities contained in a poly-cyclodextrin polymer. Production yields reached 95%. It was established that all the alkyl chains were included within the cyclodextrins' cavities in these nanoassemblies. The multivalent character of the interactions between the two polymers ensures the stability of the nanoassemblies. Moreover, empty cyclodextrin units remained accessible for the inclusion of compounds of interest such as benzophenon or tamoxifen.

Magnetic resonance spectroscopy studies in animal models of prion disease are very few and concern terminal stages of infection. In order to study earlier stages of the disease, we used in-vivo magnetic resonance spectroscopy in a mouse model of scrapie and, for the first time, in mice infected with a bovine spongiform encephalopathy strain. In bovine spongiform encephalopathy-infected mice, we observed an increase in myo-inositol preceding clinical signs by 20 days, followed by a decrease in N-acetylaspartate at advanced stages. In scrapie-infected mice, changes in N-acetylaspartate and myo-inositol were detected at the beginning of the symptomatic phase. These results show that magnetic resonance spectroscopy is a valuable tool for detecting subtle metabolic changes associated to gliosis and neuronal dysfunction in prion diseases.

A possible treatment for Duchenne muscular dystrophies would be to compensate for dystrophin loss by increasing the expression of utrophin, another cytoskeletal protein of the muscle membrane. We previously found that L-arginine, the substrate for nitric oxide synthase, significantly increased utrophin level in muscle and targeted it to the sarcolemma. Here, we have addressed the expected benefit in the mdx mice. Magnetic resonance imaging of lower limbs revealed a 35% reduction of the necrotic zones, confirmed by histological staining of muscles. This regression of the necrosis was also supported by the drastic reduction of Evans blue incorporation, a cell impermeable dye. The creatine kinase level in the serum decreased by 57%. Utrophin level increased 2- to 3-fold in muscles. Beta-dystroglycan was relocalised with utrophin to the membrane. In the diaphragm, the most affected muscle in mdx mice, the isometric tension increased by 30%, with regression of collagen and of cytoplasmic lipid overloading. Finally, molsidomine, a therapeutic agent that is converted to a NO donor, also attenuated the dystrophic phenotype. Our results suggest that pharmacological activators of the NO pathway may constitute a realistic treatment for Duchenne and Becker muscular dystrophies.

The in vivo spectrum of regenerating muscles shows a specific cross-correlation signal assigned to the (n-3) fatty acyl chain, which peaks during the myoblast fusion phase. In order to identify the origin of this signal and to take all the lipid metabolites into account, we investigated the degeneration-regeneration process by 1H 2D NMR of lipid muscle extracts. We observed an increase in the total amount of lipids during the regeneration process, although the lipid profile did not show any drastic change during this process. The changes in the NMR signal observed in vivo and, in particular, the appearance of the specific (n-3) fatty acyl chain signal appears to arise from mobile lipid compartments located in fusing cells.

Localized in vivo NMR spectroscopy, chemical shift imaging or multi-voxel spectroscopy are potentially useful tools in small animals that are complementary to MRI, adding biochemical information to the mainly anatomical data provided by imaging of water protons. However the contribution of such methods remains hampered by the low spectral resolution of the in vivo 1D spectra. Two-dimensional methods widely developed for in vitro studies have been proposed as suitable approaches to overcome these limitations in resolution. The different homonuclear and heteronuclear sequences adapted to in vivo studies are reviewed. Their specific contributions to the spectral resolution of spectroscopic data and their limitations for in vivo investigations are discussed. The applications to experimental models of pathological processes or pharmacological treatment in mainly brain and muscle are presented. According to their combined sensitivity, acquisition duration and spatial resolution, the heteronuclear 2D experiments, which are mainly used for 1H detected-13C spectroscopy after administration of 13C-labeled compounds, appear to be less efficient than 1H detected-13C 1D methods at high field. However, the applications of 2D proton homonuclear methods show that they remain the best tools for in vivo studies when an improved resolution is required.