Evolutionary relationships among the protostrongylidae (Nematoda: Metastrongyloidea) as inferred from morphological characters, with consideration of parasite-host coevolution.

The phylogeny of nematodes in the family Protostrongylidae (Nematoda: Metastrongyloidea) was reconstructed by cladistic analysis of 28 binary and multistate characters derived from comparative morphology. Analyses were hierarchical, and examined (1) relationships among genera, including 13 ingroup taxa and Metastrongylidae as an outgroup (single tree, 78 steps, consistency index [CI] = 0.705); and (2) relationships among genera and species groups, including 21 ingroup taxa and Metastrongylus apri as an outgroup (single tree, 76 steps, CI = 0.582). In the species-level tree, Protostrongylidae was divided into 2 major clades, 1 containing the subfamilies Muelleriinae (including the recently described Umingmtakstrangylus pallikuukensis), Elaphostrongylinae, and the Varestrongylinae (excluding Pneumocaulus kadenazii). Varestrongylus was paraphyletic as it included Pneumostrongylus calcaratus. The second major clade consisted of a paraphyletic group containing Protostrongylus spp. and Spiculocaulus leuckarti and, basal to this subclade, several other individual protostrongylid lineages. The various subclades generally correspond to the subfamilial divisions of the Protostrongylidae. The Neostrongylinae, however, is not supported as Neostrongylus and Orthostrongylus are not sister groups. Based on a large number of hypothesized synapomorphies, the elaphostrongylines appear to be a highly derived group of protostrongylids, a feature potentially correlated with their habitat localization in muscular and nervous tissues. The generic-level tree retained most of the primary structure revealed among the species but excluded the varestrongylines from the Muelleriinae + Elaphostrongylinae subclade. Artiodactyles of the family Cervidae are considered basal hosts for protostrongylids; secondary colonization in Caprini, Rupicaprini, and among lagomorphs is postulated.     

Climate Change Promotes the Emergence of Serious Disease Outbreaks of Filarioid Nematodes

Filarioid parasites represent major health hazards with important medical, veterinary, and economic implications, and considerable potential to affect the everyday lives of tens of millions of people globally (World Health Organization, 2007). Scenarios for climate change vary latitudinally and regionally and involve direct and indirect linkages for increasing temperature and the dissemination, amplification, and invasiveness of vector-borne parasites. High latitude regions are especially influenced by global climate change and thus may be prone to altered associations and dynamics for complex host-pathogen assemblages and emergence of disease with cascading effects on ecosystem structure. Although the potential for substantial ecological perturbation has been identified, few empirical observations have emanated from systems across the Holarctic. Coincidental with decades of warming, and anomalies of high temperature and humidity in the sub-Arctic region of Fennoscandia, the mosquito-borne filarioid nematode Setaria tundra is now associated with emerging epidemic disease resulting in substantial morbidity and mortality for reindeer and moose. We describe a host-parasite system that involves reindeer, arthropods, and nematodes, which may contribute as a factor to ongoing declines documented for this ungulate species across northern ecosystems. We demonstrate that mean summer temperatures exceeding 14°C drive the emergence of disease due to S. tundra. An association between climate and emergence of filarioid parasites is a challenge to ecosystem services with direct effects on public health, sustainability of free-ranging and domestic ungulates, and ultimately food security for subsistence cultures at high latitudes.     

Improved synthesis of dicyclohexylidene protected quebrachitol and its use in the synthesis of L-chiro-inositol derivatives

A modified synthesis of 1L-1,2:3,4-di-O-cyclohexylidene-5-O-methyl-chiro-inositol has been accomplished that improves the overall procedure, yield, and environmental aspects of its formation. Several inositol analogues have been prepared from this intermediate for testing as biosynthetic inhibitors of glycosyl-phosphatidylinositol (GPI) anchor formation.     

Systematics and emerging infectious diseases: from management to solution

The crisis of emerging infectious disease stems from the absence of comprehensive taxonomic inventories of the world's parasites, which includes the world's pathogens. Recent technological developments raise hopes that the global inventory of species, including potential pathogens, can be accomplished in a timely and cost-effective manner. The phylogenetics revolution initiated by systematists provides a means by which information about pathogen transmission dynamics can be placed in a predictive framework. Increasingly, that information is widely available in digital form on the Internet. Systematic biology is well positioned to play a crucial role in efforts to be proactive in the arena of emerging parasitic and infectious diseases.     

Low incidence of polyploids and high uniformity of karyotypes displayed by Delphinium (Ranunculaceae) in the Hengduan Mountains region of south‐west China

The chromosome numbers and morphology in 92 populations belonging to 49 species and three varieties in the genus Delphinium L. (Ranunculaceae), mostly from the Hengduan Mountains region of south‐west China, were studied. Forty seven species and three varieties were diploid, with 2n = 16, one species was tetraploid, with 2n = 32, and one species had diploid and tetraploid cytotypes. Three species had B chromosomes, representing the first time the occurrence of B chromosomes has been reported in the genus. The karyotypes of all the diploid species were quite uniform, commonly bimodal, and usually consisted of one pair of large median‐centromeric (m), one pair of large submedian‐centromeric (sm), five pairs of medium‐sized subterminal‐centromeric (st), and one pair of smaller sm (rarely st) chromosomes. The low incidence of polyploids in Delphinium from the Hengduan Mountains region indicates that polyploidy has played a minor role in the speciation of this highly diversified genus in the region. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 172–188.     

Pharmacological activities of Vitex agnus-castus extracts in vitro.

The pharmacological effects of ethanolic Vitex agnus-castus fruit-extracts (especially Ze 440) and various extract fractions of different polarities were evaluated both by radioligand binding studies and by superfusion experiments. A relative potent binding inhibition was observed for dopamine D2 and opioid (micro and kappa subtype) receptors with IC50 values of the native extract between 20 and 70 mg/mL. Binding, neither to the histamine H1, benzodiazepine and OFQ receptor, nor to the binding-site of the serotonin (5-HT) transporter, was significantly inhibited. The lipophilic fractions contained the diterpenes rotun-difuran and 6beta,7beta-diacetoxy-13-hydroxy-labda-8,14-dien . They exhibited inhibitory actions on dopamine D2 receptor binding. While binding inhibition to mu and kappa opioid receptors was most pronounced in lipophilic fractions, binding to delta opioid receptors was inhibited mainly by a aqueous fraction. Standardised Ze 440 extracts of different batches were of constant pharmacological quality according to their potential to inhibit the binding to D2 receptors. In superfusion experiments, the aqueous fraction of a methanolic extract inhibited the release of acetylcholine in a concentration-dependent manner. In addition, the potent D2 receptor antagonist spiperone antagonised the effect of the extract suggesting a dopaminergic action mediated by D2 receptor activation. Our results indicate a dopaminergic effect of Vitex agnus-castus extracts and suggest additional pharmacological actions via opioid receptors.     

Promoter hypermethylation using 24-gene array in early head and neck cancer: Better outcome in oral than in oropharyngeal cancer

Silencing of tumor suppressor genes (TSGs) by DNA promoter hypermethylation is an early event in carcinogenesis and a potential target for personalized cancer treatment. In head and neck cancer, little is known about the role of promoter hypermethylation in survival. Using methylation specific multiplex ligation-dependent probe amplification (MS-MLPA) we investigated the role of promoter hypermethylation of 24 well-described genes (some of which are classic TSGs), which are frequently methylated in different cancer types, in 166 HPV-negative early oral squamous cell carcinomas (OSCC), and 51 HPV-negative early oropharyngeal squamous cell carcinomas (OPSCC) in relation to clinicopathological features and survival. Early OSCC showed frequent promoter hypermethylation in RARB (31% of cases), CHFR (20%), CDH13 (13%), DAPK1 (12%), and APC (10%). More hypermethylation (≥ 2 genes) independently correlated with improved disease specific survival (hazard ratio 0.17, P = 0.014) in early OSCC and could therefore be used as prognostic biomarker. Early OPSCCs showed more hypermethylation of CDH13 (58%), TP73 (14%), and total hypermethylated genes. Hypermethylation of two or more genes has a significantly different effect on survival in OPSCC compared with OSCC, with a trend toward worse instead of better survival. This could have a biological explanation, which deserves further investigation and could possibly lead to more stratified treatment in the future.     

Emended description and redetermination of Sarwaria caballeroi n. comb. (nematoda: Ostertagiinae) with details of the synlophe and esophageal characters

Among genera of the ostertagiine nematodes, structural attributes of Spiculopteragia caballeroi are consistent with criteria that diagnose the genus Sarwaria. Specifically, the following characters are compatible with referral to this genus: (1) species characterized by monomorphic males; (2) tapering lateral synlophe in the cervical zone; (3) minuscule, thornlike cervical papillae; (4) length of Ray "4" < Ray "5"; (5) relatively thick or robust Ray "4"; (6) a substantially reduced dorsal lobe and dorsal ray that are disposed or curved ventrally relative to Rays "8"; and (7) a broad, laterally inflated dorsal lobe. Consequently, we propose Sarwaria caballeroi n. comb., and we provide further validation for the genus Sarwaria. Additionally, we propose that the ostertagiines are represented by 12 valid genera, including those characterized by a bursal formula of 2-2-1 (Cervicaprastrongylus, Hyostrongylus, Mazamastrongylus, Spiculopteragia, and Teladorsagia in addition to Sarwaria), and those in which the lateral rays describe a 2-1-2 pattern (Camelostrongylus, Longistrongylus, Marshallagia, Orloffia, Ostertagia, and Pseudomarshallagia).     

Understanding Host-Switching by Ecological Fitting

Despite the fact that parasites are highly specialized with respect to their hosts, empirical evidence demonstrates that host switching rather than co-speciation is the dominant factor influencing the diversification of host-parasite associations. Ecological fitting in sloppy fitness space has been proposed as a mechanism allowing ecological specialists to host-switch readily. That proposal is tested herein using an individual-based model of host switching. The model considers a parasite species exposed to multiple host resources. Through time host range expansion can occur readily without the prior evolution of novel genetic capacities. It also produces non-linear variation in the size of the fitness space. The capacity for host colonization is strongly influenced by propagule pressure early in the process and by the size of the fitness space later. The simulations suggest that co-adaptation may be initiated by the temporary loss of less fit phenotypes. Further, parasites can persist for extended periods in sub-optimal hosts, and thus may colonize distantly related hosts by a "stepping-stone" process.     

Relative accuracy of spatial predictive models for lynx Lynx canadensis derived using logistic regression-AIC,multiple criteria evaluation and Bayesian approaches

We compared probability surfaces derived using one set of environmental variables in three Geographic Information Systems (GIS) -based approaches: logistic regression and Akaike's Information Criterion (AIC),Multiple Criteria Evaluation (MCE),and Bayesian Analysis (specifically Dempster-Shafer theory). We used lynx Lynx canadensis as our focal species,and developed our environment relationship model using track data collected in Banff National Park,Alberta,Canada,during winters from 1997 to 2000. The accuracy of the three spatial models were compared using a contingency table method. We determined the percentage of cases in which both presence and absence points were correctly classified (overall accuracy),the failure to predict a species where it occurred (omission error) and the prediction of presence where there was absence (commission error). Our overall accuracy showed the logistic regression approach was the most accurate (74.51% ). The multiple criteria evaluation was intermediate (39.22%),while the Dempster-Shafer (D-S) theory model was the poorest (29.90%). However,omission and commission error tell us a different story: logistic regression had the lowest commission error,while D-S theory produced the lowest omission error. Our results provide evidence that habitat modellers should evaluate all three error measures when ascribing confidence in their model. We suggest that for our study area at least,the logistic regression model is optimal. However,where sample size is small or the species is very rare,it may also be useful to explore and/or use a more ecologically cautious modelling approach (e.g. Dempster-Shafer) that would over-predict,protect more sites,and thereby minimize the risk of missing critical habitat in conservation plans.