Lack of influence of GTP cyclohydrolase gene (GCH1) variations on pain sensitivity in humans

OBJECTIVES: To assess the effect of variations in GTP cyclohydrolase gene (GCH1) on pain sensitivity in humans. METHODS: Thermal and cold pain sensitivity were evaluated in a cohort of 735 healthy volunteers. Among this cohort, the clinical pain responses of 221 subjects after the surgical removal of impacted third molars were evaluated. Genotyping was done for 38 single nucleotide polymorphisms (SNPs) whose heterozygosity > 0.2 in GCH1. Influence of the genetic variations including SNPs and haplotypes on pain sensitivity were analyzed. RESULTS: Minor allele frequencies and linkage disequilibrium show significant differences in European Americans, African Americans, Hispanic Americans and Asian Americans. Association analyses in European Americans do not replicate the previously reported important influence of GCH1 variations on pain sensitivity. CONCLUSION: Considering population stratification, previously reported associations between GCH1 genetic variations and pain sensitivity appear weak or negligible in this well characterized model of pain

L’influence de la structure et du vocabulaire du texte sur la compréhension des élèves

Les auteurs étudient l'effet de la structure de texte sur la compréhension, en tenant compte plus particulièrement du niveau scolaire des lecteurs (écoliers de 4e et de 6e année) et du niveau de difficulté du vocabulaire. Les textes utilisés comportent 220 mots. Ils représentent quatre types de structure et deux niveaux de difficulté de vocabulaire. Les contenus sont jugés équivalents en intérêt et en familiarité par un jury d'enseignantes. Les résultats permettent de conclure à une influence de la structure de texte, mais l'analyse des données ne fait pas ressortir d'effet du niveau de difficulté de vocabulaire.This study examines the effect of text structure and vocabulary difficulty level on comprehension for readers in Grades 4 and 6. The 220 word texts represent four types of structure and two levels of vocabulary difficulty. The texts used were judged by a jury of teachers to be equivalent in terms of interest and familiarity. The results obtained permit the authors to conclude that comprehension is influenced by text structure. However, the analysis of data do not show any effect due to vocabulary difficulty level.Los autores estudian el efecto de la estructura de texto sobre la comprension tomando particularmente en cuenta el nivel escalor de los lectores (escolares de 4° ano y 6° ano) y el nivel de dificultad en vocabulario. Los textos utilizados comprenden 220 palabras. Representan cuatro tipos de estructuras y dos nivelés de dificultad de vocabulario. Un jurado de profesores evalûan los contenidos respecto a la equivalencia en interés y en familiaridad. Los resultados permiten concluir sobre una influencia de la estructura de texto, pero el analisis de los datos no destaca efecto alguno del nivel de dificultad.Die Verfasser studieren den Effekt der Textstruktur auf das Verständnis, unter besonderer Beriicksichtigung des Schulniveaus der Lëser (Schiller des 4. und 6. Jahrgangs), und des Schwierigkeitsgrades des Wortschatzes. Die beniitzten Texte bestehen aus zweihundertzwanzig (220) Wôrtern. Sie stellen vier Strukturtypen und zwei Schwierigkeitsstufen des Wortschatzes dar. Die Inhalte sind von einer Jury aus Lehrerinnen beziiglich des Interesses und der Vertrautheit fur gleichwertig erklärt worden. Die Ergebnisse lassen auf einen Einfluss der Textstruktur schlieben, aber die Datenanalyse zeigt keine Wirkung des Schwierigkeitsgrades des Wortschatzes

Genetic polymorphisms in monoamine neurotransmitter systems show only weak association with acute post-surgical pain in humans

BACKGROUND: Candidate gene studies on the basis of biological hypotheses have been a practical approach to identify relevant genetic variation in complex traits. Based on previous reports and the roles in pain pathways, we have examined the effects of variations of loci in the genes of monoamine neurotransmitter systems including metabolizing enzymes, receptors and transporters on acute clinical pain responses in humans. RESULTS: Variations in the catecholamine metabolizing enzyme genes (MAOA and COMT) showed significant associations with the maximum post-operative pain rating while the serotonin transporter gene (SLC6A4) showed association with the onset time of post-operative pain. Analgesic onset time after medication was significantly associated with the norepinephrine transporter gene (SLC6A2). However, the association between COMT genetic variation and pain sensitivity in our study differ from previous studies with small sample sizes, population stratification and pain phenotype derived from combining different types of pain stimuli. Correcting for multiple comparisons did not sustain these genetic associations between monoamine neurotransmitter systems and pain sensitivity even in this large and homogeneous sample. CONCLUSION: These results suggest that the previously reported associations between genetic polymorphisms in the monoamine neurotransmitter systems and the interindividual variability in pain responses cannot be replicated in a clinically relevant pain phenotype

Kinin B1 receptors contributes to acute pain following minor surgery in humans

<p>Abstract</p> <p>Background</p> <p>Kinins play an important role in regulation of pain and hyperalgesia after tissue injury and inflammation by activating two types of G-protein-coupled receptors, the kinin B₁and B₂receptors. It is generally accepted that the B₂receptor is constitutively expressed, whereas the B₁receptor is induced in response to inflammation. However, little is known about the regulatory effects of kinin receptors on the onset of acute inflammation and inflammatory pain in humans. The present study investigated the changes in gene expression of kinin receptors and the levels of their endogenous ligands at an early time point following tissue injury and their relation to clinical pain, as well as the effect of COX-inhibition on their expression levels.</p> <p>Results</p> <p>Tissue injury resulted in a significant up-regulation in the gene expression of B₁and B₂receptors at 3 hours post-surgery, the onset of acute inflammatory pain. Interestingly, the up-regulation in the gene expression of B₁and B₂receptors was positively correlated to pain intensity only after ketorolac treatment, signifying an interaction between prostaglandins and kinins in the inflammatory pain process. Further, the gene expression of both B₁and B₂receptors were correlated. Following tissue injury, B₁ligands des-Arg⁹-BK and des-Arg¹⁰-KD were significantly lower at the third hour compared to the first 2 hours in both the placebo and the ketorolac treatment groups but did not differ significantly between groups. Tissue injury also resulted in the down-regulation of TRPV1 gene expression at 3 hours post-surgery with no significant effect by ketorolac treatment. Interestingly, the change in gene expression of TRPV1 was correlated to the change in gene expression of B₁receptor but not B₂receptor.</p> <p>Conclusions</p> <p>These results provide evidence at the transcriptional level in a clinical model of tissue injury that up-regulation of kinin receptors are involved in the development of the early phase of inflammation and inflammatory pain. The up-regulation of B₁receptors may contribute to acute inflammatory pain through TRPV1 activation.</p

Le Forum, Vol. 44 #3

https://digitalcommons.library.umaine.edu/francoamericain_forum/1105/thumbnail.jp

Investigating patterns of straying and mixed stock exploitation of sea trout, Salmo trutta, in rivers sharing an estuary in south-west England

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.For effective management, information on the stock composition of a fishery is essential. Here, the utility of a resident trout, Salmon trutta L, microsatellite baseline to determine the origins of sea trout entering the rivers Tamar, Tavy and Lynher in south-west England is highlighted – all share a common estuary and have major runs of sea trout. There is a high degree of geographical structuring of the genetic variation in the baseline rivers. Testing with simulated and real data sets showed fish can be assigned to reporting group with a high degree of accuracy. Mixed stock analysis of >1000 sea trout showed that fish entering the Tamar and Tavy constituted mixed stocks. Significantly, in the Tamar, non-natal origin sea trout are restricted to the lower catchment. As well as providing insight into sea trout behaviour, this study also has important implications for the management of recreational rod and line fisheries.This research forms part of the Atlantic AquaticResource Conservation (AARC) project and was funded via the European Union 2007–2013 Atlantic Area Pro-gramme, an INTERREG III B initiat ive; additional funding for this project was provided by the Atlantic SalmonTrust

The role of anthropogenic vs. natural in-stream structures in determining connectivity and genetic diversity in an endangered freshwater fish, Macquarie perch (Macquaria australasica)

Habitat fragmentation is one of the leading causes of population declines, threatening ecosystems worldwide. Freshwater taxa may be particularly sensitive to habitat loss as connectivity between suitable patches of habitat is restricted not only by the natural stream network but also by anthropogenic factors. Using a landscape genetics approach, we assessed the impact of habitat availability on population genetic diversity and connectivity of an endangered Australian freshwater fish Macquarie perch, Macquaria australasica (Percichthyidae). The relative contribution of anthropogenic versus natural in-stream habitat structures in shaping genetic structure and diversity in M. australasica was quite striking. Genetic diversity was significantly higher in locations with a higher river slope, a correlate of the species preferred habitat – riffles. On the other hand, barriers degrade preferred habitat and impede dispersal, contributing to the degree of genetic differentiation among populations. Our results highlight the importance of landscape genetics to understanding the environmental factors affecting freshwater fish populations and the potential practical application of this approach to conservation management of other freshwater organisms

Melioidosis diagnostic workshop, 2013.

Melioidosis is a severe disease that can be difficult to diagnose because of its diverse clinical manifestations and a lack of adequate diagnostic capabilities for suspected cases. There is broad interest in improving detection and diagnosis of this disease not only in melioidosis-endemic regions but also outside these regions because melioidosis may be underreported and poses a potential bioterrorism challenge for public health authorities. Therefore, a workshop of academic, government, and private sector personnel from around the world was convened to discuss the current state of melioidosis diagnostics, diagnostic needs, and future directions