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863 result(s) for "Martinsen, S."
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Normalization of aberrant resting state functional connectivity in fibromyalgia patients following a three month physical exercise therapy
Physical exercise is one of the most efficient interventions to mitigate chronic pain symptoms in fibromyalgia (FM). However, little is known about the neurophysiological mechanisms mediating these effects. In this study we investigated resting-state connectivity using functional magnetic resonance imaging (fMRI) before and after a 15 week standardized exercise program supervised by physical therapists. Our aim was to gain an understanding of how physical exercise influences previously shown aberrant patterns of intrinsic brain activity in FM. Fourteen FM patients and eleven healthy controls successfully completed the physical exercise treatment. We investigated post- versus pre-treatment changes of brain connectivity, as well as changes in clinical symptoms in the patient group. FM patients reported improvements in symptom severity. Although several brain regions showed a treatment-related change in connectivity, only the connectivity between the right anterior insula and the left primary sensorimotor area was significantly more affected by the physical exercise among the fibromyalgia patients compared to healthy controls. Our results suggest that previously observed aberrant intrinsic brain connectivity patterns in FM are partly normalized by the physical exercise therapy. However, none of the observed normalizations in intrinsic brain connectivity were significantly correlated with symptom changes. Further studies conducted in larger cohorts are warranted to investigate the precise relationship between improvements in fibromyalgia symptoms and changes in intrinsic brain activity. © 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license.
Do molecules matter more than morphology? Promises and pitfalls in parasites
Systematics involves resolving both the taxonomy and phylogenetic placement of organisms. We review the advantages and disadvantages of the two kinds of information commonly used for such inferences – morphological and molecular data – as applied to the systematics of metazoan parasites generally, with special attention to the malaria parasites. The problems that potentially confound the use of morphology in parasites include challenges to consistent specimen preservation, plasticity of features depending on hosts or other environmental factors, and morphological convergence. Molecular characters such as DNA sequences present an alternative data source and are particularly useful when not all the parasite's life stages are present or when parasitaemia is low. Nonetheless, molecular data can bring challenges that include troublesome DNA isolation, paralogous gene copies, difficulty in developing molecular markers, and preferential amplification in mixed species infections. Given the differential benefits and shortcomings of both molecular and morphological characters, both should be implemented in parasite taxonomy and phylogenetics.
Parasitaemia data and molecular characterization of Haemoproteus catharti from New World vultures (Cathartidae) reveals a novel clade of Haemosporida
Background New World vultures (Cathartiformes: Cathartidae) are obligate scavengers comprised of seven species in five genera throughout the Americas. Of these, turkey vultures ( Cathartes aura ) and black vultures ( Coragyps atratus ) are the most widespread and, although ecologically similar, have evolved differences in morphology, physiology, and behaviour. Three species of haemosporidians have been reported in New World vultures to date: Haemoproteus catharti , Leucocytozoon toddi and Plasmodium elongatum , although few studies have investigated haemosporidian parasites in this important group of species. In this study, morphological and molecular methods were used to investigate the epidemiology and molecular biology of haemosporidian parasites of New World vultures in North America. Methods Blood and/or tissue samples were obtained from 162 turkey vultures and 95 black vultures in six states of the USA. Parasites were identified based on their morphology in blood smears, and sequences of the mitochondrial cytochrome b and nuclear adenylosuccinate lyase genes were obtained for molecular characterization. Results No parasites were detected in black vultures, whereas 24% of turkey vultures across all sampling locations were positive for H. catharti by blood smear analysis and/or PCR testing. The phylogenetic analysis of cytochrome b gene sequences revealed that H. catharti is closely related to MYCAMH1, a yet unidentified haemosporidian from wood storks ( Mycteria americana ) in southeastern USA and northern Brazil. Haemoproteus catharti and MYCAMH1 represent a clade that is unmistakably separate from all other Haemoproteus spp., being most closely related to Haemocystidium spp. from reptiles and to Plasmodium spp. from birds and reptiles. Conclusions Haemoproteus catharti is a widely-distributed parasite of turkey vultures in North America that is evolutionarily distinct from other haemosporidian parasites. These results reveal that the genetic diversity and evolutionary relationships of avian haemosporidians are still being uncovered, and future studies combining a comprehensive evaluation of morphological and life cycle characteristics with the analysis of multiple nuclear and mitochondrial genes will be useful to redefine the genus boundaries of these parasites and to re-evaluate the relationships amongst haemosporidians of birds, reptiles and mammals.
Morphological versus molecular identification of avian Haemosporidia: an exploration of three species concepts
More than 200 species of avian Haemosporidia (genera Plasmodium, Haemoproteus, and Leucocytozoon) have been described based primarily on morphological characters seen in blood smears. Recent molecular studies, however, suggest that such methods may mask a substantial cryptic diversity of avian haemosporidians. We surveyed the haemosporidians of birds sampled at 1 site in Israel. Parasites were identified to species based on morphology, and a segment of the parasite's cytochrome b gene was sequenced. We compared 3 species concepts: morphological, genetic, and phylogenetic. Fifteen morphological species were present. Morphological species that occurred once within our dataset were associated with a unique gene sequence, displayed large genetic divergence from other morphological species, and were not contained within clades of morphological species that occurred more than once. With only 1 exception, morphological species that were identified from multiple bird hosts presented identical sequences for all infections, or differed by few synonymous substitutions, and were monophyletic for all phylogenetic analyses. Only the morphological species Haemoproteus belopolskyi did not follow this trend, falling instead into at least 2 genetically distant clades. Thus, except for H. belopolskyi, parasites identified to species by morphology were supported by both the genetic and phylogenetic species concepts.
Disentangling the effects of host relatedness and elevation on haemosporidian parasite turnover in a clade of songbirds
The persistence of a parasite species in an ecological community is determined both by its environmental tolerance and host breadth. The relative contribution of these niche characteristics to parasite community structure is challenging to parse because host persistence is also a consequence of extrinsic environmental factors. We investigated haemosporidian parasites (genera Plasmodium, Leucocytozoon, and Haemoproteus) in a clade of avian hosts in eastern North America. Species in this clade of Catharus thrushes occupy specific elevational bands in a non‐phylogenetically determined manner. This allowed us to tease apart the effects of host relatedness and elevation on parasite community structure, diversity, and infection prevalence. We screened blood and tissue samples from 414 adult birds from four mountain ranges in the Appalachian Highlands for blood parasites using a cytochrome‐b‐nested PCR protocol and identified parasite lineages by sequencing. We found an overall infection prevalence of 88.4% and identified a total of 38 parasite lineages including six novel lineages. Parasite community patterns varied by genus. Host relatedness rather than elevational zone predicted the beta turnover and phylobeta turnover of Leucocytozoon parasites, indicating that closely related rather than geographically proximate host species had more similar parasites. This pattern was not seen in Plasmodium parasites because the diversity of this parasite genus varied considerably in the high elevational zones among mountain ranges, that is, a sky‐island effect. Haemoproteus parasites were rare in this study system. Our study suggests that the mechanisms that underlie community structuring vary between haemosporidian genera due to differences in the degree of host sharing among lineages.
Using Bloodmeal Analysis to Assess Disease Risk to Wildlife at the New Northern Limit of a Mosquito Species
The historically southeastern mosquito species Culex erraticus has over the last 30 years undergone a marked expansion north. We evaluated this species’ potential to participate in local disease cycles in the northeastern USA by identifying the vertebrate sources of blood in Cx. erraticus specimens from New Jersey. We found that the majority of bloodmeals (92.6%) were derived from birds, followed by 6.8% from mammals (of which half were human), and a single amphibian bloodmeal from a spring peeper (0.56%). Medium- and large-sized water birds from the order Pelecaniformes made up 60.4% of the bird species and 55.9% of all identified hosts. This group of birds is known enzootic hosts of arboviruses such as eastern equine encephalitis virus, for which Cx. erraticus is a competent vector. Additionally, we screened blooded mosquitoes for avian malaria parasites and identified three different lineages of Plasmodium, including what may represent a new Plasmodium species (likely a wetland bird specialist) in bloodmeals from Green Herons, a Great Egret, and a Double-Crested Cormorant. Our results support the utility of mosquito bloodmeals as sources of information about circulating wildlife pathogens and reveal the potential of range-expanding species to intensify local zoonoses and bridge enzootic pathogens to humans.
FRI0135 Increased Intrinsic Brain Connectivity between Affective Pain Processing Regions and Bilateral Sensorimotor Cortex in RA Patients Compared To Healthy Controls
BackgroundRheumatoid arthritis (RA) is commonly accompanied by pain that is discordant with the degree of peripheral pathology. Very little is known about the cerebral processes involved in pain processing in RA.ObjectivesTo investigate resting state brain connectivity associated with prolonged pain in RA.Methods24 RA subjects and 19 matched controls were compared with regard to both behavioral measures of pain perception and resting-resting state fMRI data acquired subsequently to fMRI sessions involving pain stimuli. The resting-state fMRI brain connectivity was investigated using 159 seed regions located in cardinal pain processing brain regions. Additional principal component based multivariate pattern analysis of the whole brain connectivity pattern was carried out in a data driven analysis to localize group differences in functional connectivity.ResultsWhen RA patients were compared to controls, we observed significantly lower pain resilience for pressure on the affected finger joints (i.e. P50-joint) and an overall heightened level of perceived global pain in RA patients.Relative to controls, RA patients displayed increased brain connectivity predominately for the supplementary motor areas, mid-cingulate cortex and the primary sensorimotor cortex. Additionally, we observed an increase in brain connectivity between the insula and prefrontal cortex as well as between anterior cingulate cortex and occipital areas for RA patients. None of the group differences in brain connectivity were significantly correlated with behavioral parameters.ConclusionsOur study provides experimental evidence of increased connectivity between frontal midline regions that are implicated in affective pain processing and bilateral sensorimotor regions in RA patients.Disclosure of InterestNone declared
Morphologically defined subgenera of Plasmodium from avian hosts: test of monophyly by phylogenetic analysis of two mitochondrial genes
Malaria parasites in the genus Plasmodium are now placed within 11 subgenera based on morphology under the light microscope, life-history traits, and host taxon. The phylogenetic significance of these characters, however, is problematic because the observed variation could be homoplasious. Using Plasmodium infections found in 2632 birds of many avian families collected in the USA, and several samples from other locations, we compared identifications to subgenus based on morphology in blood smears with a 2-gene molecular phylogeny (the first for avian Plasmodium) to determine if the 5 avian Plasmodium subgenera represent monophyletic groups. Phylogenetic trees recovered by parsimony, likelihood, and Bayesian methods presented nearly identical topologies. The analysis allowed testing the hypothesis of monophyly for the subgenera. Monophyly of the subgenera Haemamoeba, Huffia, and Bennettinia was supported by the analysis. The distinctive morphology of Haemamoeba species appears to have evolved once. Most samples identified to Novyella also fell within a monophyletic clade with the exception of 2 samples that fell basal to all other avian Plasmodium. Samples of the subgenus Giovannolaia did not form a monophyletic group. Thus, the characters used by parasitologists for over a century to define subgenera of Plasmodium vary in their phylogenetic significance.
Fecal samples fail in PCR-based diagnosis of malaria parasite infection in birds
Malaria parasites are common in wild vertebrates on all warm continents and have recently been isolated from wild apes by non-invasive fecal sampling. Here, we examined the utility of fecal samples for malaria parasite detection in wild birds. We collected both blood and fecal samples from 56 birds sampled in the field, extracted DNA from all samples using various methods, and screened all samples using sensitive PCR-based methods. We found 35 birds to be positive for malaria parasite infection (genera Plasmodium and Parahaemoproteus) using blood samples while no fecal samples revealed a positive infection. These results suggest that malaria parasites cannot be efficiently detected from fecal samples of birds and that blood sampling is still necessary for the study of the malaria parasites of wild bird populations.
Documentation of a hybrid Bicknell's Thrush (Catharus bicknelli) X Veery (C. fuscescens) using vocalization and genetic data
We combined data on morphology, behavior, and gene sequences to document the first known case of hybridization within the thrush genus Catharus. During June 2008 at a montane forest site in south-central Vermont, we observed a male bird that repeatedly exhibited song characteristics of both Bicknell's Thrush (C. bicknelli) and Veery (C. fuscescens). Handheld examination determined the bird to be a yearling male with plumage characteristics predominantly of Veery and morphometric traits within the ranges of both Bicknell's Thrush and Veery. While the hybrid vocalized only with Bicknell's Thrush calls, its songs were reminiscent of both Veery and a mixture of Bicknell's Thrush and Veery. Mitochondrial DNA (NADH dehydrogenase 2 and cytochrome b genes) revealed the bird's mother to be a Veery, and nuclear data (ß-fibrinogen 7 and myoglobin 2 introns) revealed DNA of both Veery and Bicknell's Thrush, supporting Bicknell's Thrush as the father of the hybrid. This hybridization is notable given that Bicknell's Thrush and Veery generally breed in different habitat types at different elevations. This discovery is also important in light of the vulnerable conservation status of Bicknell's Thrush and recent declines in Veery populations across much of the species' breeding range. Received 21 April 2016. Accepted 27 January 2017.