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1.
Microbiol Spectr ; 11(3): e0479322, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37199657

RESUMO

The Amazon River basin sustains dramatic hydrochemical gradients defined by three water types: white, clear, and black waters. In black water, important loads of allochthonous humic dissolved organic matter (DOM) result from the bacterioplankton degradation of plant lignin. However, the bacterial taxa involved in this process remain unknown, since Amazonian bacterioplankton has been poorly studied. Its characterization could lead to a better understanding of the carbon cycle in one of the Earth's most productive hydrological systems. Our study characterized the taxonomic structure and functions of Amazonian bacterioplankton to better understand the interplay between this community and humic DOM. We conducted a field sampling campaign comprising 15 sites distributed across the three main Amazonian water types (representing a gradient of humic DOM), and a 16S rRNA metabarcoding analysis based on bacterioplankton DNA and RNA extracts. Bacterioplankton functions were inferred using 16S rRNA data in combination with a tailored functional database from 90 Amazonian basin shotgun metagenomes from the literature. We discovered that the relative abundances of fluorescent DOM fractions (humic-, fulvic-, and protein-like) were major drivers of bacterioplankton structure. We identified 36 genera for which the relative abundance was significantly correlated with humic DOM. The strongest correlations were found in the Polynucleobacter, Methylobacterium, and Acinetobacter genera, three low abundant but omnipresent taxa that possessed several genes involved in the main steps of the ß-aryl ether enzymatic degradation pathway of diaryl humic DOM residues. Overall, this study identified key taxa with DOM degradation genomic potential, the involvement of which in allochthonous Amazonian carbon transformation and sequestration merits further investigation. IMPORTANCE The Amazon basin discharge carries an important load of terrestrially derived dissolved organic matter (DOM) to the ocean. The bacterioplankton from this basin potentially plays important roles in transforming this allochthonous carbon, which has consequences on marine primary productivity and global carbon sequestration. However, the structure and function of Amazonian bacterioplanktonic communities remain poorly studied, and their interactions with DOM are unresolved. In this study, we (i) sampled bacterioplankton in all the main Amazon tributaries, (ii) combined information from the taxonomic structure and functional repertory of Amazonian bacterioplankton communities to understand their dynamics, (iii) identified the main physicochemical parameters shaping bacterioplanktonic communities among a set of >30 measured environmental parameters, and (iv) characterized how bacterioplankton structure varies according to the relative abundance of humic compounds, a by-product from the bacterial degradation process of allochthonous DOM.


Assuntos
Matéria Orgânica Dissolvida , Água , RNA Ribossômico 16S/genética , Organismos Aquáticos , Carbono/análise
2.
Food Chem ; 421: 136217, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37121018

RESUMO

Cassava landraces are impacted by post-harvest physiological deterioration (PPD). 34 primary/secondary metabolites (carotenes, flavonols, indols, phenolic, hydroxycinnamic, and organic acids) were analysed using HPLC/GC-MS in 72 landraces harvested 8 months after planting (MAP) to clarify whether these compounds may play a role in PPD tolerance. Cluster analysis differentiated a first group with high organic acids contents, citric acid being dominant, a second group with landraces high in tryptophan, a third group including landraces with high phenolic and hydroxycinnamic acids content, and a fourth group characterised by 8 carotenoids. PPD tolerant and susceptible landraces were present in each group. To determine if PPD is related to age of harvest, 174 landraces were harvested at 6, 8, 10 and 12 MAP. Scopoletin, sucrose and glucose were analysed. PPD was positively correlated with DMC and negatively correlated with scopoletin at all ages of harvest. Scopoletin is a useful biomarker to characterize landraces.


Assuntos
Manihot , Escopoletina , Escopoletina/metabolismo , Manihot/metabolismo , Carotenoides/metabolismo , Verduras/metabolismo , Raízes de Plantas/metabolismo
3.
Int J Mol Sci ; 23(21)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36361736

RESUMO

How specific interactions between plant and pathogenic, commensal, or mutualistic microorganisms are mediated and how bacteria are selected by a plant are important questions to address. Here, an Arabidopsis thaliana mutant called chs5 partially deficient in the biogenesis of isoprenoid precursors was shown to extend its metabolic remodeling to phenylpropanoids and lipids in addition to carotenoids, chlorophylls, and terpenoids. Such a metabolic profile was concomitant to increased colonization of the phyllosphere by the pathogenic strain Pseudomonas syringae pv. tomato DC3000. A thorough microbiome analysis by 16S sequencing revealed that Streptomyces had a reduced colonization potential in chs5. This study revealed that the bacteria-Arabidopsis interaction implies molecular processes impaired in the chs5 mutant. Interestingly, our results revealed that the metabolic status of A. thaliana was crucial for the specific recruitment of Streptomyces into the microbiota. More generally, this study highlights specific as well as complex molecular interactions that shape the plant microbiota.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Streptomyces , Arabidopsis/metabolismo , Streptomyces/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Pseudomonas syringae/metabolismo , Proteínas de Arabidopsis/metabolismo
4.
Microbiol Spectr ; 10(6): e0206422, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36445161

RESUMO

Fish bacterial communities provide functions critical for their host's survival in contrasting environments. These communities are sensitive to environmental-specific factors (i.e., physicochemical parameters, bacterioplankton), and host-specific factors (i.e., host genetic background). The relative contribution of these factors shaping Amazonian fish bacterial communities is largely unknown. Here, we investigated this topic by analyzing the gill bacterial communities of 240 wild flag cichlids (Mesonauta festivus) from 4 different populations (genetic clusters) distributed across 12 sites in 2 contrasting water types (ion-poor/acidic black water and ion-rich/circumneutral white water). Transcriptionally active gill bacterial communities were characterized by a 16S rRNA metabarcoding approach carried on RNA extractions. They were analyzed using comprehensive data sets from the hosts genetic background (Genotyping-By-Sequencing), the bacterioplankton (16S rRNA) and a set of 34 environmental parameters. Results show that the taxonomic structure of 16S rRNA gene transcripts libraries were significantly different between the 4 genetic clusters and also between the 2 water types. However, results suggest that the contribution of the host's genetic background was relatively weak in comparison to the environment-related factors in structuring the relative abundance of different active gill bacteria species. This finding was also confirmed by a mixed-effects modeling analysis, which indicated that the dissimilarity between the taxonomic structure of bacterioplanktonic communities possessed the best explicative power regarding the dissimilarity between gill bacterial communities' structure, while pairwise fixation indexes (FST) from the hosts' genetic data only had a weak explicative power. We discuss these results in terms of bacterial community assembly processes and flag cichlid fish ecology. IMPORTANCE Host-associated microbial communities respond to factors specific to the host physiology, genetic backgrounds, and life history. However, these communities also show different degrees of sensitivity to environment-dependent factors, such as abiotic physico-chemical parameters and ecological interactions. The relative importance of host- versus environment-associated factors in shaping teleost bacterial communities is still understudied and is paramount for their conservation and aquaculture. Here, we studied the relative importance of host- and environment-associated factors structuring teleost bacterial communities using gill samples from a wild Amazonian teleost model (Mesonauta festivus) sampled in contrasting habitats along a 1500 km section of the Amazonian basin, thus ensuring high genetic diversity. Results showed that the contribution of the host's genetic background was weak compared to environment-related bacterioplanktonic communities in shaping gill bacterial assemblages, thereby suggesting that our understanding of teleost microbiome assembly could benefit from further studies focused on the ecological interplay between host-associated and free-living communities.


Assuntos
Brânquias , Microbiota , Animais , RNA Ribossômico 16S/genética , Brânquias/química , Brânquias/microbiologia , Peixes/genética , Peixes/microbiologia , Microbiota/fisiologia , Água , Genômica , Bactérias/genética
5.
Clin Neurophysiol ; 138: 38-51, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35364464

RESUMO

OBJECTIVE: Although adolescent idiopathic scoliosis is thought to be an orthopedic disorder, sensorimotor deficits resulting in asymmetric neural drive to the axial musculature have been proposed as contributing factors. Asymmetry in the vestibular control of spinal motoneurons can cause spine deformation reminiscent of idiopathic scoliosis in animal models. METHODS: To examine the neural control of axial muscles, we compared common oscillatory drive to bilateral lumbar muscles between 19 participants with adolescent idiopathic scoliosis and 19 healthy adolescents. We measured right and left paraspinal muscle activity during steady isometric back extensions at 15% or 30% of their maximum voluntary contraction. RESULTS: The variance in exerted force and symmetry in bilateral muscle activation were similar between groups. We estimated the strength of common oscillations between muscle motoneuron pools using intermuscular coherence. Compared to controls, participants with adolescent idiopathic scoliosis exhibited smaller intermuscular coherence between paraspinal muscles in the alpha and beta bands. To identify the cause of the observed decreased in intermuscular coherence, we quantified variability of electromyography power ratio and relative activation timing between the paraspinal muscle. Intermuscular phase between muscle oscillations across the alpha band demonstrated larger variability in adolescent with idiopathic scoliosis. The variability of the ratio of lumbar muscles power was similar between groups in the alpha and beta bands. CONCLUSION: Our results suggest that altered bilateral control of axial muscles characterized by increased variability in the timing of alpha oscillations may be linked to spine deformation in adolescents. SIGNIFICANCE: Our findings provide a new perspective on neural factors associated with a common spine deformation, adolescent idiopathic scoliosis.


Assuntos
Escoliose , Adolescente , Eletromiografia , Humanos , Região Lombossacral , Músculo Esquelético , Músculos Paraespinais , Coluna Vertebral
6.
Endocrinology ; 163(2)2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34967898

RESUMO

Leydig cells produce androgens that are essential for male sex differentiation and reproductive function. Leydig cell function is regulated by several hormones and signaling molecules, including growth hormone (GH). Although GH is known to upregulate Star gene expression in Leydig cells, its molecular mechanism of action remains unknown. The STAT5B transcription factor is a downstream effector of GH signaling in other systems. While STAT5B is present in both primary and Leydig cell lines, its function in these cells has yet to be ascertained. Here we report that treatment of MA-10 Leydig cells with GH or overexpression of STAT5B induces Star messenger RNA levels and increases steroid hormone output. The mouse Star promoter contains a consensus STAT5B element (TTCnnnGAA) at -756 bp to which STAT5B binds in vitro (electrophoretic mobility shift assay and supershift) and in vivo (chromatin immunoprecipitation) in a GH-induced manner. In functional promoter assays, STAT5B was found to activate a -980 bp mouse Star reporter. Mutating the -756 bp element prevented STAT5B binding but did not abrogate STAT5B-responsiveness. STAT5B was found to functionally cooperate with DNA-bound cJUN. The STAT5B/cJUN cooperation was only observed in Leydig cells and not in Sertoli or fibroblast cells, indicating that additional Leydig cell-enriched transcription factors are required. The STAT5B/cJUN cooperation was lost only when both STAT5B and cJUN elements were mutated. In addition to identifying the Star gene as a novel target for STAT5B in Leydig cells, our data provide important new insights into the mechanism of GH and STAT5B action in the regulation of Leydig cell function.


Assuntos
Hormônio do Crescimento/farmacologia , Células Intersticiais do Testículo/metabolismo , Fosfoproteínas/genética , Proteínas Proto-Oncogênicas c-jun/fisiologia , Fator de Transcrição STAT5/genética , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , DNA/química , DNA/metabolismo , Expressão Gênica/efeitos dos fármacos , Células Intersticiais do Testículo/classificação , Masculino , Camundongos , Fosfoproteínas/análise , Fosfoproteínas/fisiologia , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Fator de Transcrição STAT5/análise , Fator de Transcrição STAT5/fisiologia , Regulação para Cima/efeitos dos fármacos
7.
Anim Microbiome ; 3(1): 3, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33499999

RESUMO

BACKGROUND: Disentangling the dynamics of microbial interactions within communities improves our comprehension of metacommunity assembly of microbiota during host development and under perturbations. To assess the impact of stochastic variation of neutral processes on microbiota structure and composition under disturbance, two types of microbial habitats, free-living (water), and host-associated (skin and gut) were experimentally exposed to either a constant or gradual selection regime exerted by two sublethal cadmium chloride dosages (CdCl2). Yellow Perch (Perca flavescens) was used as a piscivorous ecotoxicological model. Using 16S rDNA gene based metataxonomics, quantitative diversity metrics of water, skin and gut microbial communities were characterized along with development and across experimental conditions. RESULTS: After 30 days, constant and gradual selection regimes drove a significant alpha diversity increase for both skin and gut microbiota. In the skin, pervasive negative correlations between taxa in both selection regimes in addition to the taxonomic convergence with the environmental bacterial community, suggest a loss of colonisation resistance resulting in the dysbiosis of yellow perch microbiota. Furthermore, the network connectivity in gut microbiome was exclusively maintained by rare (low abundance) OTUs, while most abundant OTUs were mainly composed of opportunistic invaders such as Mycoplasma and other genera related to fish pathogens such as Flavobacterium. Finally, the mathematical modelling of community assembly using both non-linear least squares models (NLS) based estimates of migration rates and normalized stochasticity ratios (NST) based beta-diversity distances suggested neutral processes drove by taxonomic drift in host and water communities for almost all treatments. The NLS models predicted higher demographic stochasticity in the cadmium-free host and water microbiomes, however, NST models suggested higher ecological stochasticity under perturbations. CONCLUSIONS: Neutral models agree that water and host-microbiota assembly promoted by rare taxa have evolved predominantly under neutral processes with potential involvement of deterministic forces sourced from host filtering and cadmium selection. The early signals of perturbations in the skin microbiome revealed antagonistic interactions by a preponderance of negative correlations in the co-abundance networks. Our findings enhance our understanding of community assembly host-associated and free-living under anthropogenic selective pressure.

8.
Molecules ; 25(5)2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32131509

RESUMO

Inhibitors of enzymes in essential cellular pathways are potent probes to decipher intricate physiological functions of biomolecules. The analysis of Arabidopsis thaliana sterol profiles upon treatment with a series of azasterols reveals a specific in vivo inhibition of SMT2, a plant sterol-C-methyltransferase acting as a branch point between the campesterol and sitosterol biosynthetic segments in the pathway. Side chain azasteroids that modify sitosterol homeostasis help to refine its particular function in plant development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis/metabolismo , Azasteroides/farmacologia , Inibidores Enzimáticos/farmacologia , Metiltransferases , Fitosteróis/biossíntese , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/metabolismo , Azasteroides/química , Inibidores Enzimáticos/química , Metiltransferases/antagonistas & inibidores , Metiltransferases/metabolismo
9.
Front Microbiol ; 9: 869, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29774016

RESUMO

Adaptation of microbial communities to anthropogenic stressors can lead to reductions in microbial diversity and disequilibrium of ecosystem services. Such adaptation can change the molecular signatures of communities with differences in taxonomic and functional composition. Understanding the relationship between taxonomic and functional variation remains a critical issue in microbial ecology. Here, we assessed the taxonomic and functional diversity of a lake metacommunity system along a polymetallic pollution gradient caused by 60 years of chronic exposure to acid mine drainage (AMD). Our results highlight three adaptive signatures. First, a signature of taxon-function decoupling was detected in the microbial communities of moderately and highly polluted lakes. Second, parallel shifts in taxonomic composition occurred between polluted and unpolluted lakes. Third, variation in the abundance of functional modules suggested a gradual deterioration of ecosystem services (i.e., photosynthesis) and secondary metabolism in highly polluted lakes. Overall, changes in the abundance of taxa, function, and more importantly the polymetallic resistance genes such as copA, copB, czcA, cadR, cCusA, were correlated with trace metal content (mainly Cadmium) and acidity. Our findings highlight the impact of polymetallic pollution gradient at the lowest trophic levels.

10.
Gait Posture ; 57: 124-129, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28605674

RESUMO

This work identifies, among adolescents with idiopathic scoliosis, those demonstrating impaired sensorimotor control through a classification procedure comparing the amplitude of their vestibular-evoked postural responses. The sensorimotor control of healthy adolescents (n=17) and adolescents with idiopathic scoliosis (n=52) with either mild (Cobb angle≥15° and ≤30°) or severe (Cobb angle >30°) spine deformation was assessed through galvanic vestibular stimulation. A classification procedure sorted out adolescents with idiopathic scoliosis whether the amplitude of their vestibular-evoked postural response was dissimilar or similar to controls. Compared to controls, galvanic vestibular stimulation evoked larger postural response in adolescents with idiopathic scoliosis. Nonetheless, the classification procedure revealed that only 42.5% of all patients showed impaired sensorimotor control. Consequently, identifying patients with sensorimotor control impairment would allow to apply personalized treatments, help clinicians to establish prognosis and hopefully improve the condition of patients with adolescent idiopathic scoliosis.


Assuntos
Retroalimentação Sensorial , Equilíbrio Postural/fisiologia , Postura/fisiologia , Escoliose/diagnóstico , Potenciais Evocados Miogênicos Vestibulares/fisiologia , Vestíbulo do Labirinto/fisiopatologia , Adolescente , Fenômenos Biomecânicos , Criança , Estimulação Elétrica , Feminino , Seguimentos , Humanos , Masculino , Escoliose/fisiopatologia , Escoliose/terapia , Índice de Gravidade de Doença
11.
J Manipulative Physiol Ther ; 39(7): 473-479, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27544925

RESUMO

OBJECTIVE: It has been hypothesized that the impaired sensorimotor control observed in adolescents with idiopathic scoliosis (IS) may be related more to the onset of scoliosis than to the maturation of sensory systems or sensorimotor control mechanisms. The objective of this study was to assess sensorimotor control in adults diagnosed with IS in adolescence versus healthy controls. METHODS: The study included 20 young adults 20 to 24 years of age (10 healthy controls and 10 diagnosed with adolescent IS but not treated for it). Binaural bipolar galvanic vestibular stimulation (GVS) was delivered to assess sensorimotor control. Vertical forces under each foot and upper body kinematics along the frontal plane were measured before GVS (2-second window), during GVS (2-second window), immediately after the cessation of GVS (1-second window), and during the following 2 seconds. Balance control was assessed by calculating the root mean square values of vertical forces and upper body kinematics. RESULTS: Compared with healthy controls, the IS group showed greater body sway upon GVS; the amplitude of this sway was even greater immediately after the cessation of GVS-an outcome requiring sensorimotor control. CONCLUSION: Compared with normal controls, adults who had been diagnosed with IS in adolescence showed altered balance control immediately following GVS. This finding suggests that dysfunctional sensorimotor control may be related to the onset of scoliosis rather than to a transient suboptimal development of the sensory systems or sensorimotor control mechanisms.


Assuntos
Retroalimentação Sensorial , Escoliose/fisiopatologia , Feminino , Humanos , Masculino , Adulto Jovem
12.
Cell Rep ; 14(11): 2707-17, 2016 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-26972004

RESUMO

Uridylation emerges as a key modification promoting mRNA degradation in eukaryotes. In addition, uridylation by URT1 prevents the accumulation of excessively deadenylated mRNAs in Arabidopsis. Here, we show that the extent of mRNA deadenylation is controlled by URT1. By using TAIL-seq analysis, we demonstrate the prevalence of mRNA uridylation and the existence, at lower frequencies, of mRNA cytidylation and guanylation in Arabidopsis. Both URT1-dependent and URT1-independent types of uridylation co-exist but only URT1-mediated uridylation prevents the accumulation of excessively deadenylated mRNAs. Importantly, uridylation repairs deadenylated extremities to restore the size distribution observed for non-uridylated oligo(A) tails. In vivo and in vitro data indicate that Poly(A) Binding Protein (PABP) binds to uridylated oligo(A) tails and determines the length of U-extensions added by URT1. Taken together, our results uncover a role for uridylation and PABP in repairing mRNA deadenylated ends and reveal that uridylation plays diverse roles in eukaryotic mRNA metabolism.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Ligação a Poli(A)/metabolismo , RNA Nucleotidiltransferases/metabolismo , RNA Mensageiro/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/genética , Sítios de Ligação , Western Blotting , Imunoprecipitação , MicroRNAs/metabolismo , Poli A/metabolismo , Poli U/metabolismo , Proteínas de Ligação a Poli(A)/genética , Interferência de RNA , RNA Nucleotidiltransferases/genética , Estabilidade de RNA , RNA Interferente Pequeno/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação
13.
Eur Spine J ; 25(10): 3347-3352, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26846230

RESUMO

PURPOSE: This study aims at verifying if impaired sensorimotor control observed in adolescents and young adults with scoliosis is also present in adult patients who underwent surgery to reduce their spine deformation. METHODS: The study included ten healthy adults and ten adults with idiopathic scoliosis who underwent surgery to reduce their spine deformation. Galvanic vestibular stimulation was delivered to assess sensorimotor control. Vertical forces under each foot and horizontal displacement of the upper body were measured before, during and after stimulation. Balance control was assessed by calculating the root mean square values of kinematic and kinetic variables. RESULTS: The amplitude of the vestibular-evoked postural response was 3.4 % (0.8-6.0 %) and 4.5 % (-0.4 to 9.5 %) of the maximal range of motion. Therefore, spine surgery did not limit the postural response. Patients with idiopathic scoliosis exhibited larger body sway than the healthy controls during and immediately after vestibular stimulation. The maximal normalized lateral displacement of the body was 0.85 and 0.40 cm/m and maximal normalized vertical force was 0.78 vs. 0.39 N/kg, for idiopathic scoliosis and healthy groups, respectively. CONCLUSIONS: This result suggests that dysfunctional sensorimotor integration is still present even in adult idiopathic scoliosis that underwent spine deformation correction.


Assuntos
Equilíbrio Postural/fisiologia , Desempenho Psicomotor , Escoliose/cirurgia , Adulto , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Período Pós-Operatório , Escoliose/fisiopatologia , Resultado do Tratamento
14.
PLoS One ; 10(11): e0143124, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26580068

RESUMO

Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20) or severe (n = 16) spine deformation were compared to those of healthy control adolescents (n = 16). Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes.


Assuntos
Retroalimentação Sensorial , Equilíbrio Postural , Escoliose/fisiopatologia , Coluna Vertebral/fisiopatologia , Vestíbulo do Labirinto/fisiopatologia , Adolescente , Fenômenos Biomecânicos , Estudos de Casos e Controles , Criança , Estimulação Elétrica , Potencial Evocado Motor , Feminino , Humanos , Masculino , Postura , Escoliose/patologia , Coluna Vertebral/patologia , Vestíbulo do Labirinto/patologia
15.
Gait Posture ; 42(4): 558-63, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26371828

RESUMO

Idiopathic scoliosis is the most frequent spinal deformity in adolescence. While its aetiology remains unclear, impairments in balance control suggest a dysfunction of the sensorimotor control mechanisms. The objective of this paper is to evaluate the ability of patients with idiopathic scoliosis to reweigh sensory information. Using a neuromechanical model, the relative sensory weighting of vestibular and proprioceptive information was assessed. Sixteen healthy adolescents and respectively 20 and 16 adolescents with mild or severe scoliosis were recruited. Binaural bipolar galvanic vestibular stimulation was delivered to elicit postural movement along the coronal plane. The kinematics of the upper body, using normalized horizontal displacement of the 7th cervical vertebra, was recorded 1s before, 2s during, and 1s following vestibular stimulation. The neuromechanical model included active feedback mechanisms that generated corrective torque from the vestibular and proprioceptive error signals. The model successfully predicted the normalized horizontal displacement of the 7th cervical vertebra. All groups showed similar balance control before vestibular stimulation; however, the amplitude (i.e., peak horizontal displacement) of the body sway during and immediately following vestibular stimulation was approximately 3 times larger in patients compared to control adolescents. The outcome of the model revealed that patients assigned a larger weight to vestibular information compared to controls; vestibular weight was 6.03% for controls, whereas it was 13.09% and 13.26% for the mild and severe scoliosis groups, respectively. These results suggest that despite the amplitude of spine deformation, the sensory reweighting mechanism is altered similarly in adolescent patients with scoliosis.


Assuntos
Equilíbrio Postural/fisiologia , Propriocepção/fisiologia , Escoliose/fisiopatologia , Adolescente , Fenômenos Biomecânicos , Estudos de Casos e Controles , Vértebras Cervicais/fisiopatologia , Criança , Feminino , Humanos , Masculino , Modelos Neurológicos , Distribuição Aleatória , Índice de Gravidade de Doença
16.
BMC Genomics ; 16: 500, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26149072

RESUMO

BACKGROUND: Hygienic behavior is a complex, genetically-based quantitative trait that serves as a key defense mechanism against parasites and diseases in Apis mellifera. Yet, the genomic basis and functional pathways involved in the initiation of this behavior are still unclear. Deciphering the genomic basis of hygienic behavior is a prerequisite to developing an extensive repertoire of genetic markers associated to the performance level of this quantitative trait. To fill this knowledge gap, we performed an RNA-seq on brain samples of 25 honeybees per hives from five hygienic and three non-hygienic hives. RESULTS: This analysis revealed that a limited number of functional genes are involved in honeybee hygienic behavior. The genes identified, and especially their location in the honeybee genome, are consistent with previous findings. Indeed, the genomic sequences of most differentially expressed genes were found on the majority of the QTL regions associated to the hygienic behavior described in previous studies. According to the Gene Ontology annotation, 15 genes are linked to the GO-terms DNA or nucleotide binding, indicating a possible role of these genes in transcription regulation. Furthermore, GO-category enrichment analysis revealed that electron carrier activity is over-represented, involving only genes belonging to the cytochrome P450. Cytochrome P450 enzymes' overexpression can be explained by a disturbance in the regulation of expression induced by changes in transcription regulation or sensitivity to xenobiotics. Over-expressed cytochrome P450 enzymes could potentially degrade the odorant pheromones or chemicals that normally signal the presence of a diseased brood before activation of the removal process thereby inhibit hygienic behavior. CONCLUSIONS: These findings improve our understanding on the genetics basis of the hygienic behavior. Our results show that hygienic behavior relies on a limited set of genes linked to different regulation patterns (expression level and biological processes) associated with an over-expression of cytochrome P450 genes.


Assuntos
Abelhas/genética , Regulação da Expressão Gênica/genética , Genoma de Inseto/genética , Animais , Comportamento Animal , Encéfalo/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Ontologia Genética , Marcadores Genéticos/genética , Anotação de Sequência Molecular/métodos , Comportamento Social , Transcrição Gênica/genética
17.
Sci Rep ; 5: 12636, 2015 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-26223214

RESUMO

While honey bee exposure to systemic insecticides has received much attention, impacts on wild pollinators have not been as widely studied. Neonicotinoids have been shown to increase acetylcholinesterase (AChE) activity in honey bees at sublethal doses. High AChE levels may therefore act as a biomarker of exposure to neonicotinoids. This two-year study focused on establishing whether bumble bees living and foraging in agricultural areas using neonicotinoid crop protection show early biochemical signs of intoxication. Bumble bee colonies (Bombus impatiens) were placed in two different agricultural cropping areas: 1) control (≥ 3 km from fields planted with neonicotinoid-treated seeds) or 2) exposed (within 500 m of fields planted with neonicotinoid-treated seeds), and maintained for the duration of corn sowing. As determined by Real Time qPCR, AChE mRNA expression was initially significantly higher in bumble bees from exposed sites, then decreased throughout the planting season to reach a similar endpoint to that of bumble bees from control sites. These findings suggest that exposure to neonicotinoid seed coating particles during the planting season can alter bumble bee neuronal activity. To our knowledge, this is the first study to report in situ that bumble bees living in agricultural areas exhibit signs of neonicotinoid intoxication.


Assuntos
Acetilcolinesterase/biossíntese , Anabasina/farmacologia , Abelhas/enzimologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Proteínas de Insetos/biossíntese , Sementes , Zea mays , Animais
18.
PLoS One ; 10(5): e0125790, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25993642

RESUMO

Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads.


Assuntos
Abelhas/efeitos dos fármacos , Abelhas/virologia , Praguicidas/toxicidade , Zea mays , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Animais , Abelhas/parasitologia , Suscetibilidade a Doenças , Flores/química , Flores/toxicidade , Genes de Insetos/efeitos dos fármacos , Agricultura Orgânica , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/toxicidade , Praguicidas/análise , Pólen/química , Pólen/toxicidade , Sementes/química , Sementes/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Varroidae/patogenicidade , Zea mays/química , Zea mays/toxicidade
19.
Eur J Obstet Gynecol Reprod Biol ; 179: 22-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24965974

RESUMO

OBJECTIVES: To evaluate the rate and circumstances of outborn deliveries within a French perinatal network, and to determine their avoidability. STUDY DESIGN: Cohort study including preterm infants <33 weeks gestation and/or weighing <1500g born outside a level III maternity unit in Lower Normandy region, France, in 2008-2010. In 2008 and 2009, only neonates transferred to the Caen University Teaching Hospital (CHU) were included. In 2010, all outborn neonates in the region were included by means of a medical information system program. A panel of 7 experts was set up to determine the avoidability of each outborn case using a two-stage modified Delphi procedure. Inter-expert agreement was evaluated using the kappa index. RESULTS: Sixty-four cases (71 neonates) were included. The outborn rate in 2010 was 16.1% (40/248, 95% CI (116-207%)). The most common reason for delivery was spontaneous onset of labour (57.8%). In 12 cases, the place of birth (level 2b maternity unit) was considered to be appropriate by the experts (term ≥32WG), but 8 cases involved infants of low birth weight (<1500g). For the 52 cases born in inappropriate sites, 9.6% were considered to be avoidable (kappa index=0.42 (p<10-3)). CONCLUSION: Our outborn rate meets regionalisation targets. Our method of expert evaluation identified a small percentage of avoidable births in inappropriate sites. Regular reassessment of obstetric practices and good coordination between network actors are crucial to improve the management of pregnancies at risk of outborn delivery.


Assuntos
Parto Obstétrico , Hospitais , Unidades de Terapia Intensiva Neonatal , Estudos de Coortes , Feminino , França , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Recém-Nascido de muito Baixo Peso , Gravidez
20.
Paediatr Anaesth ; 23(3): 265-70, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23301926

RESUMO

BACKGROUND: This retrospective cohort study was designed to assess the impact of intrathecal morphine compared with no intrathecal morphine on blood loss and on hemodynamic stability during surgery for pediatric idiopathic scoliosis correction. METHODS: A retrospective review was done of 256 anesthetic charts who underwent scoliosis surgery between January 1993 and February 2012 by the same orthopedic surgeon. 128 patients were operated on before 2003 without intrathecal morphine (NITM group) and 128 were treated later on with intrathecal morphine (ITM group).Primary endpoints were a 20% decrease in blood loss in the ITM group and hemodynamic stability. RESULTS: Both groups were similar for age, girl/boy ratio, weight and duration of surgery. Blood loss was significantly greater in the NITM group: 1793.1 ± 964.3 ml vs 655.8 ± 323.0 ml (P < 0.0001). Overall mean decrease in blood loss was 63.4% between the NITM group and the ITM group. A significantly (P < 0.0001) greater number of patients from the NITM group (122) received blood transfusions as compared to the ITM group (30). The volume of blood transfused per patient was significantly greater in the NITM group (701.4 ± 492.5 ml) than in the ITM group (293.7 ± 170.9 ml) (P < 0.0001). Heart rate was stable intra-operatively in both groups. Variation in blood pressure >20% of baseline occurred more frequently in the NITM group (28.1%) than in the ITM group (14.8%) (P = 0.01). CONCLUSIONS: These data demonstrate that intrathecal morphine in pediatric surgical scoliosis correction significantly decreases intra-operative blood loss and transfusions and enhances blood pressure stability.


Assuntos
Analgésicos Opioides/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Morfina/uso terapêutico , Escoliose/cirurgia , Adolescente , Analgésicos Opioides/administração & dosagem , Anestesia , Criança , Estudos de Coortes , Soluções Cristaloides , Feminino , Hemodinâmica/efeitos dos fármacos , Hemoglobinas/análise , Hemoglobinas/metabolismo , Humanos , Injeções Espinhais , Soluções Isotônicas/uso terapêutico , Masculino , Monitorização Intraoperatória , Morfina/administração & dosagem , Recuperação de Sangue Operatório , Substitutos do Plasma/uso terapêutico , Estudos Retrospectivos , Fusão Vertebral , Resultado do Tratamento
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