Discovery and description of the "davtiani" morphotype for Teladorsagia boreoarcticus (Trichostrongyloidea: Ostertagiinae) abomasal parasites in muskoxen, Ovibos moschatus, and caribou, Rangifer tarandus, from the North American Arctic: implications for parasite faunal diversity

Collections to explore helminth diversity among free-ranging ungulates in the North American Arctic revealed the occurrence of a third male, or " davtiani ," morphotype for Teladorsagia boreoarcticus . Designated as T. boreoarcticus forma (f.) minor B, the males occurred with T. boreoarcticus f. major and T. borearcticus f. minor A in endemic populations of muskoxen (Ovibos moschatus wardi) and barrenground caribou (Rangifer tarandus groenlandicus) on Victoria Island, Nunavut, Canada, and in muskoxen and Peary caribou ( Rangifer tarandus pearyi ) on Banks Island, Northwest Territories, Canada. These specimens differ from conspecific morphotypes in the structure of the genital cone and Sj?berg's organ. Relative to T. boreoarcticus f. minor A, specimens of T. boreoarcticus f. minor B are consistently smaller, and mean dimensions for the bursa and spicules do not overlap. The robust spicules are similar in form, particularly in the relative length of the dorsal and ventral processes, but mean total length is substantially less in specimens of T. boreoarcticus f. minor B. Differences that distinguish the minor morphotypes of T. boreoarcticus parallel those demonstrated for the T. trifurcata and T. davtiani morphotypes in association with T. circumcincta sensu stricto. New host and geographic records include the 3 morphotypes of T. boreoarcticus in muskoxen and Peary caribou from Banks Island and in barrenground caribou from Victoria Island. Recognition of the ubiquitous nature of cryptic species emphasizes the need to effectively develop and use our collections-based resources and museum archives to build a robust understanding of the biosphere. Field inventory should include provisions for integrative approaches that preserve specimens suitable for comparative morphology, multi-faceted molecular investigations, and population genetics.     

Recent advances in the immunogenetics of idiopathic inflammatory myopathy

This review summarizes the previous and current literature on the immunogenetics of idiopathic inflammatory myopathy (IIM) and updates the research progress that has been made over the past decade. A substantial part of the genetic risk for developing adult- and juvenile-onset IIM lies within the major histocompatibility complex (MHC), and a tight relationship exists between individual human leukocyte antigen alleles and specific serological subtypes, which in turn dictate clinical disease phenotypes. Multiple genetic regions outside of the MHC are increasingly being identified in conferring IIM disease susceptibility. We are still challenged with the task of studying a serologically and clinically heterogeneous disorder that is rarer by orders of magnitude than the likes of rheumatoid arthritis. An ongoing and internationally coordinated IIM genome-wide association study may provide further insights into IIM immunogenetics.     

Cloning and expression of an anti-LDL(-) single-chain variable fragment,and its inhibitory effect on experimental atherosclerosis

The in vivo modified forms of low-density lipoprotein (LDL) are important for the formation of foam cells and as mediators of the immuno-inflammatory process involved in the progression of atherosclerosis. Electronegative LDL, LDL(-), is a LDL subfraction with pro-inflammatory properties that is present in human blood. To investigate possible atheroprotective effects, an anti-LDL(-) single-chain variable fragment (scFv) was expressed in the methylotrophic yeast Pichia pastoris and its activity was evaluated in vitro against macrophages and in experimental atherosclerosis in Ldlr^-/- mice. The recombinant 2C7 scFv was produced in a yield of 9.5 mg of protein/L. The specificity and affinity of purified 2C7 scFv against LDL(-) was confirmed by ELISA. To assess the activity of 2C7 scFv on foam cell formation, RAW 264.7 macrophages were exposed to LDL(-) in the presence or absence of 2C7 scFv. The 2C7 scFv inhibited the uptake of LDL(-) by macrophages in a dose-dependent manner, and internalization of LDL(-) by these cells was found to be mediated by the CD36 and CD14 receptor. In addition, compared with untreated cells, lipid accumulation in macrophages was decreased, and the expression of Cd36, Tlr-4 and Cox-2 was downregulated in macrophages treated with 2C7 scFv. Importantly, compared with untreated mice, the treatment of Ldlr^-/- mice with 2C7 scFv decreased the atherosclerotic lesion area at the aortic sinus. In conclusion, our data show that 2C7 scFv inhibits foam cell formation and atherosclerotic plaque development by modulating the expression of genes relevant to atherogenesis. These results encourage further use of this antibody fragment in the development of new therapeutic strategies that neutralize the pro-atherogenic effects of LDL(-).     

Intraclonal variation in RNA viruses: generation, maintenance and consequences

This paper explores the evolutionary implications of the enormous variability that characterizes populations of RNA viruses and retroviruses. It begins by examining the magnitude of genetic variation in both natural and experimental populations. In natural populations, differences arise even within individual infected patients, with the per-site nucleotide diversity at this level ranging from < 1% to 6%. In laboratory populations, two viruses sampled from the same clone differed by ∼0.7% in their fitness. Three different mechanisms that may be important in maintaining viral genetic variability were tested: (1) Fisher's fundamental theorem, to compare the observed rate of fitness change with the extent of fitness-related variation within the same experimental populations; (2) magnitude of genomic mutation rate, to assess whether it correlated with fitness-related variation, as predicted by the mutation-selection balance hypothesis; (3) frequency-dependent selection, which affords rare genotypes an advantage. The paper concludes with a discussion of two evolutionary consequences of variability: the fixation of deleterious mutations by drift in small populations and the role of clonal interference in large ones.  © 2003 The Linnean Society of London. Biological Journal of the Linnean Society , 2003, 79 , 17–26.     

Mountain birch under multiple stressors – heavy metal‐resistant populations co‐resistant to biotic stress but maladapted to abiotic stress

Stress adaptations often include a trade‐off of weakened performance in nonlocal conditions, resulting in divergent selection, and potentially, genetic differentiation and evolutionary adaptation. Results of a two‐phase (greenhouse and field) common garden experiment demonstrated adaptation of mountain birch (Betula pubescens subsp. czerepanovii) populations from industrially polluted areas of the Kola Peninsula, north‐western Russia, to heavy metals (HM), whereas no adaptations to wind or drought stress were detected in populations from wind‐exposed sites. HM‐adapted seedlings were maladapted to drought but less palatable (co‐resistant) to insect herbivores, even under background HM concentrations. The absence of adaptations to harsh microclimate and the generally high adaptive potential of mountain birch, a critical forest forming tree in subarctic Europe, need to be accounted for in models predicting consequences of human‐driven environmental changes, including the projected climate change.     

Direct cord implantation in brachial plexus avulsions: revised technique using a single stage combined anterior (first) posterior (second) approach and end-to-side side-to-side grafting neurorrhaphy

Background

The superiority of a single stage combined anterior (first) posterior (second) approach and end-to-side side-to-side grafting neurorrhaphy in direct cord implantation was investigated as to providing adequate exposure to both the cervical cord and the brachial plexus, as to causing less tissue damage and as to being more extensible than current surgical approaches.

Methods

The front and back of the neck, the front and back of the chest up to the midline and the whole affected upper limb were sterilized while the patient was in the lateral position; the patient was next turned into the supine position, the plexus explored anteriorly and the grafts were placed; the patient was then turned again into the lateral position, and a posterior cervical laminectomy was done. The grafts were retrieved posteriorly and side grafted to the anterior cord. Using this approach, 5 patients suffering from complete traumatic brachial plexus palsy, 4 adults and 1 obstetric case were operated upon and followed up for 2 years. 2 were C5,6 ruptures and C7,8T1 avulsions. 3 were C5,6,7,8T1 avulsions. C5,6 ruptures were grafted and all avulsions were cord implanted.

Results

Surgery in complete avulsions led to Grade 4 improvement in shoulder abduction/flexion and elbow flexion. Cocontractions occurred between the lateral deltoid and biceps on active shoulder abduction. No cocontractions occurred after surgery in C5,6 ruptures and C7,8T1 avulsions, muscle power improvement extended into the forearm and hand; pain disappeared.

Limitations include

spontaneous recovery despite MRI appearance of avulsions, fallacies in determining intraoperative avulsions (wrong diagnosis, wrong level); small sample size; no controls rule out superiority of this technique versus other direct cord reimplantation techniques or other neurotization procedures; intra- and interobserver variability in testing muscle power and cocontractions.

Conclusion

Through providing proper exposure to the brachial plexus and to the cervical cord, the single stage combined anterior (first) and posterior (second) approach might stimulate brachial plexus surgeons to go more for direct cord implantation. In this study, it allowed for placing side grafts along an extensive donor recipient area by end-to-side, side-to-side grafting neurorrhaphy and thus improved results.

Level of evidence

Level IV, prospective case series.     

Observations on the phylogeny of the cestode order Pseudophyllidea Carus, 1863

A preliminary phylogenetic analysis of the Pseudophyllidea, based on the 16 type-genera of putative families, indicates that a division into two suborders is reasonable. The subordinal grouping are, on the whole, congruent with those suggested by earlier workers, but the positions of three genera, Hexagonoporus, Cephalochlamys and Parabothriocephalus, are somewhat anomalous with respect to earlier work.     

Identical ITS-1 and ITS-2 sequences suggest Spiculopteragia asymmetrica and Spiculopteragia quadrispiculata (Nematoda: Trichostrongylidae) constitute morphologically distinct variants of a single species

Sequences of ITS-1 and ITS-2 rDNA for adult males of Spiculopteragia asymmetrica and Spiculopteragia quadrispiculata in red deer (Cervus elaphus) were determined. They were found to be identical, suggesting that S. asymmetrica and S. quadrispiculata represent a single species and do not refute the concept of dimorphic species in the Spiculopteragia.     

Quantification of 1,N6-etheno-2'-deoxyadenosine in human urine by column-switching LC/APCI-MS/MS

1,N6-etheno-2'-deoxyadenosine (epsilondA) is one of several promutagenic DNA modifications arising from cellular oxidative metabolism. It is believed that these background DNA lesions may contribute to various diseases, such as cancer. Therefore, human biomonitoring of epsilondA in urine could be a potential marker for oxidative stress-related DNA damage. Existing methods for quantifying urinary epsilondA use 32P postlabeling. We have developed a nonradioactive, fast, and easier method based on column-switching liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry (LC/APCI-MS/MS) in the positive mode. Differences in column temperatures were used to influence analyte retention and sample focusing. With multiple reaction monitoring (MRM) mode the afforded limit of detection was about 0.7 pM when starting with 3 ml of urine. The urinary excretion rates of epsilondA from 28 nonsmoking and 5 smoking men were 10.0-99.6 pmol/24 h, and did not correlate with body weight, age, or plasma vitamin C concentration. The 5 smokers excreted 30.5 +/-8.5 and the 28 nonsmokers excreted 38.6 +/- 2.4 pmol epsilondA per 24 h, p=.37 (mean +/- SEM). The demonstrated level of performance suggests the future applicability of this method to studies of cancer and other diseases related to oxidative stress in humans.