European Ancestry Predominates in Neuromyelitis Optica and Multiple Sclerosis Patients from Brazil

Background

Neuromyelitis optica (NMO) is considered relatively more common in non-Whites, whereas multiple sclerosis (MS) presents a high prevalence rate, particularly in Whites from Western countries populations. However, no study has used ancestry informative markers (AIMs) to estimate the genetic ancestry contribution to NMO patients.

Methods

Twelve AIMs were selected based on the large allele frequency differences among European, African, and Amerindian populations, in order to investigate the genetic contribution of each ancestral group in 236 patients with MS and NMO, diagnosed using the McDonald and Wingerchuck criteria, respectively. All 128 MS patients were recruited at the Faculty of Medicine of Ribeirão Preto (MS-RP), Southeastern Brazil, as well as 108 healthy bone marrow donors considered as healthy controls. A total of 108 NMO patients were recruited from five Neurology centers from different Brazilian regions, including Ribeirão Preto (NMO-RP).

Principal Findings

European ancestry contribution was higher in MS-RP than in NMO-RP (78.5% vs. 68.7%) patients. In contrast, African ancestry estimates were higher in NMO-RP than in MS-RP (20.5% vs. 12.5%) patients. Moreover, principal component analyses showed that groups of NMO patients from different Brazilian regions were clustered close to the European ancestral population.

Conclusions

Our findings demonstrate that European genetic contribution predominates in NMO and MS patients from Brazil.     

Polymorphic Sites at the Immunoregulatory CTLA-4 Gene Are Associated with Chronic Chagas Disease and Its Clinical Manifestations

Background

Chagas disease affects approximately 10 million people mainly in Latin America. The immune regulation by the host seems to be an essential factor for disease evolution, and immune system inhibitory molecules such as CTLA-4 and PD-1 favor the maintenance of peripheral tolerance. Considering that polymorphisms at the immunoregulatory CTLA-4 and PDCD1 genes may alter their inhibitory function, we investigated the association of alleles, genotypes and haplotypes of polymorphic sites observed at the CTLA-4 and PDCD1 genes with different clinical manifestations of chronic Chagas disease (indeterminate, cardiac, digestive and mixed).

Methods

The polymorphisms at the CTLA-4 (-1722T/C, -318C/T and +49A/G) and PDCD1 (PD-1.3G/A) genes were typed using TaqMan methodology in 277 chronic Chagas disease patients classified into four groups, according to clinical characteristics, and 326 non-infected controls.

Results

Our results showed that CTLA-4 -1722CC genotype (22%), -1722C allele (27%) and CTLA-4 TCG (8.6%), TCA (26%) and CCA (15%) haplotypes were strongly associated with the indeterminate form, while the CTLA-4 -318CT genotype (82%) and CTLA-4 -318T allele (47%) were found mainly in patients with the mixed form of the disease. The CTLA-4 TCG haplotype (10.2%) was associated with the digestive form. On the other hand, the PD-1.3G/A polymorphism was not associated with chronic Chagas disease and its clinical manifestations.

Conclusions

Here, we showed that alleles, genotypes and haplotypes reported to increase the expression of the regulatory molecule CTLA-4 were associated with the indeterminate form of the disease. Taken together, our data support the idea that polymorphic sites at immunoregulatory genes may influence the development of Chagas disease variants.     

Stereoselective disposition of fenoprofen in plasma and synovial fluid of patients with rheumatoid arthritis

The simultaneous disposition of fenoprofen enantiomers in synovial fluid and plasma was studied in 11 patients with arthritis and chronic knee effusions treated with a single oral dose of 600 mg rac-fenoprofen. A plasma sample and a synovial fluid sample were collected simultaneously from each patient up to 16 h after the administration of fenoprofen. A stereospecific assay for fenoprofen using LC-MS-MS was developed and applied successfully to the analysis of the enantiomers in plasma (LOQ = 10 ng of each enantiomer/ml) and synovial fluid (LOQ = 25 ng of each enantiomer/ml). The values of the area under the curve (AUC) for the S-(+)-fenoprofen eutomer were approximately 2.5 times higher in plasma than in synovial fluid (256 vs 104 microg h/ml), while the values for the R-(-)-fenoprofen distomer were about four times higher in plasma than in synovial fluid (42.5 vs 10.5 microg h/ml). These data demonstrate accumulation of the S-(+)-fenoprofen eutomer in plasma and in synovial fluid, with concentrations versus time AUC (+)/(-) ratios of 6.0 in plasma and 9.9 in synovial fluid, suggesting a greater accumulation of the eutomer at the active site represented by synovial fluid than in plasma. This result demonstrates the importance of enantioselective methods and of analysis of synovial fluid rather than plasma in studies of the pharmacokinetics-pharmacodynamics of fenoprofen.     

Spatially Extended Habitat Modification by Intertidal Reef-Building Bivalves has Implications for Consumer-Resource Interactions

Ecosystem engineers can strongly modify habitat structure and resource availability across space. In theory, this should alter the spatial distributions of trophically interacting species. In this article, we empirically investigated the importance of spatially extended habitat modification by reef-building bivalves in explaining the distribution of four avian predators and their benthic prey in the Wadden Sea—one of the world’s largest intertidal soft-sediment ecosystems. We applied Structural Equation Modeling to identify important direct and indirect interactions between the different components of the system. We found strong spatial gradients in sediment properties into the surrounding area of mixed blue mussel (Mytilus edulis) and Pacific oyster (Crassostrea gigas) reefs, indicating large-scale (100s of m) engineering effects. The benthic community was significantly affected by these gradients, with the abundance of several important invertebrate prey species increasing with sediment organic matter and decreasing with distance to the reefs. Distance from the reef, sediment properties, and benthic food abundance simultaneously explained significant parts of the distribution of oystercatchers (Haematopus ostralegus), Eurasian curlews (Numenius arquata), and bar-tailed godwits (Limosa lapponica). The distribution of black-headed gulls (Chroicocephalus ridibundus)—a versatile species with many diet options—appeared unaffected by the reefs. These results suggest that intertidal reef builders can affect consumer-resource dynamics far beyond their own boundaries, emphasizing their importance in intertidal soft-bottom ecosystems like the Wadden Sea.     

The phylogenetic potential of entire 26S rDNA sequences in plants

18S ribosomal RNA genes are the most widely used nuclear sequences for phylogeny reconstruction at higher taxonomic levels in plants. However, due to a conservative rate of evolution, 18S rDNA alone sometimes provides too few phylogenetically informative characters to resolve relationships adequately. Previous studies using partial sequences have suggested the potential of 26S or large-subunit (LSU) rDNA for phylogeny retrieval at taxonomic levels comparable to those investigated with 18S rDNA. Here we explore the patterns of molecular evolution of entire 26S rDNA sequences and their impact on phylogeny retrieval. We present a protocol for PCR amplification and sequencing of entire (approximately 3.4 kb) 26S rDNA sequences as single amplicons, as well as primers that can be used for amplification and sequencing. These primers proved useful in angiosperms and Gnetales and likely have broader applicability. With these protocols and primers, entire 26S rDNA sequences were generated for a diverse array of 15 seed plants, including basal eudicots, monocots, and higher eudicots, plus two representatives of Gnetales. Comparisons of sequence dissimilarity indicate that expansion segments (or divergence domains) evolve 6.4 to 10.2 times as fast as conserved core regions of 26S rDNA sequences in plants. Additional comparisons indicate that 26S rDNA evolves 1.6 to 2.2 times as fast as and provides 3.3 times as many phylogenetically informative characters as 18S rDNA; compared to the chloroplast gene rbcL, 26S rDNA evolves at 0.44 to 1.0 times its rate and provides 2.0 times as many phylogenetically informative characters. Expansion segment sequences analyzed here evolve 1.2 to 3.0 times faster than rbcL, providing 1.5 times the number of informative characters. Plant expansion segments have a pattern of evolution distinct from that found in animals, exhibiting less cryptic sequence simplicity, a lower frequency of insertion and deletion, and greater phylogenetic potential.      

Synemin and vimentin are components of intermediate filaments in avian erythrocytes

Synemin, a high-molecular-weight protein associated with intermediate filaments in muscle, and vimentin, an intermediate-filament subunit found in many different cell types, have been identified by immunologic and electrophoretic criteria as components of intermediate filaments in mature avian erythrocytes. Desmin, the predominant subunit of intermediate filaments in muscle, has not been detected in these cells. Two dimensional immunoautoradiography of proteolytic fragments of synemin and vimentin demonstates that the erythrocyte proteins are highly homologous, if not identical, to their muscle counterparts. Double immunoflurorescence reaveals that erythrocyte synemin and vimentin co-localize in a cytoplasmic network of sinuous filaments that extends from the nucleus to the plasma membrane and resists aggregation by colcemid. Erythrocytes that are attached to glass cover slips can be sonicated to remove nuclei and nonadherent regions of the plasma membrane; this leaves elliptical patches of adherent membrane that retain mats of vimentin- and synemin-containing intermediate filaments, as seen by immunofluorescence and rotary shadowing. Similarly, mechanical enucleation of erythrocyte ghosts in suspension allows isolation of plasma membranes that retain a significant fraction of the synemin and vimentin, as assayed by electrophoresis, and intermediate filaments, as seen in thin sections. Both synemin and vimentin remain insoluble along with spectrin and actin, in solutions containing nonionic detergent and high salt. However, brief exposure of isolated membrane to distilled water releases the synemin and vimentin together in nearly pure form, before the release of significant amounts of spectrin and actin. These data suggest that avian erythrocyte intermeditate filaments are somehow anchored to the plasma membrane; erythrocytes may thus provide a simple system for the study of intermediate filaments and their mode of interaction with membranes. In addition, these data, in conjunction with previous data from muscle, indicate that synemin is capable of associating with either desmin or vimentin and may thus perform a special role in the structure or function of intermediate filaments in erythrocytes as well as muscle.