A new species of Wellsopsyllus (Copepoda, Harpacticoida, Paramesochridae) from the deep Southern Ocean and remarks on its biogeography

The new deep-sea copepod species of the family Paramesochridae (Copepoda, Harpacticoida) presented here was collected during the scientific ANtarctic benthic DEEP-sea biodiversity cruise II (ANDEEP II) to the Weddell Abyssal Plain and western Weddell Sea and the CROZet natural iron bloom and EXport experiment (CROZEX cruise) to the Crozet Isles in the Indian Ocean. The new species has been allocated to the subgenus Wellsopsyllus within the genus Wellsopsyllus Kunz, 1981, based on the 1-segmented endopods and 3-segmented exopods of swimming legs 2–4. Furthermore, the new species shows a 1-segmented exopod of the antenna. Wellsopsyllus (W.) antarcticus sp. n. can be distinguished from its congeners by its small body size, the presence of two setae on the distal segment of the endopod of the first swimming leg, by the very small furcal rami, the extremely reduced endopods of second and third swimming legs, the reduced mandibular palp and maxillula, as well as by the size and armature of the fifth and sixth swimming legs in both sexes. Difficulties of the placement of the new species into a suitable genus show an insufficiency in the present family classification. In the future, a revision of the genus Wellsopsyllus is essential. With its presence in the western Weddell Sea and the Indian Ocean, the new species may have a wide distribution range. Furthermore, it is the first abyssal species of the genus Wellsopsyllus sampled outside of the Scotia Sea.     

High-performance liquid chromatographic assay of metabolites of thioguanine and mercaptopurine in capillary blood

The main metabolites of the cytotoxic drugs thioguanine (6TG) and mercaptopurine (6MP) can be measured conveniently in red blood cells (RBC). Isolation of RBC, however, is laborious and requires some milliliters of blood. This HPLC assay allows measurements of thiopurine metabolites in very small blood samples obtained from the finger-tip. The metabolites, derivatives of 6TG and methylmercaptopurine (6MeMP), were extracted and hydrolized with perchloric acid to liberate the corresponding base. 6MeMP is completely transformed under these conditions to 4-amino-5-(methylthio)carbonyl imidazole. The chromatographic separation of 6TG and this imidazole was performed in a single run under isocratic conditions within 10 min using a 70 mm column. The quantification limit was 0.5 nmol/ml for 6TG and 3 nmol/ml blood for 6MeMP. The accuracy was 83% for 6TG (CV=3%) over the concentration range of 0.5-20 nmol/ml blood and 102% (CV=4%) for 6MeMP over the range of 3-150 nmol/ml blood. The intra-assay CV ranged from 5.4 to 7.4% for 6TG and from 6.2 to 10.6% for 6MeMP. The inter-assay CV was 7.5 and 9.5% in a pooled blood sample. The levels in RBC in whole blood were nearly coincident with those obtained in separated RBC, isolation of RBC therefore is not necessary for these measurements, if the drugs are given per os in the day before blood sampling. The concentration of 6MeMP nucleotides is more dependent on the given 6MP dose than the concentration of 6TG nucleotides. Intraindividual variations were small at unchanged drug doses, interindividual metabolite concentrations were highly variable.     

Plant Quarantine as a Measure Against Invasive Alien Species: The Framework of the International Plant Protection Convention and the plant health regulations in the European Union

The introduction of several plant pests into Europe in the 19th century with disastrous consequences called for the development of plant quarantine measures to prevent the spread and introduction of pests of plants and plant products. With the purpose of harmonising these measures, and of promoting measures for pest control, the International Plant Protection Convention (IPPC) was developed to address organisms that are both directly and indirectly injurious to plants. It supplies a framework for measures against invasive alien species according to the Convention on Biological Diversity, as far as they are plant pests. Three examples of invasive alien species within the scope of the IPPC are given in the article: the fungus Ceratocystis fagacearum, the pinewood nematode Bursaphelenchus xylophilus and the flatworm Arthurdendyus triangulatus. In its 1997 revision, the IPPC provides for the establishment of International Standards for Phytosanitary Measures, being acknowledged by the Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organisation. Standards most important for invasive alien species are those on pest risk analysis, on requirements for the establishment of pest-free areas, on surveillance, on pest eradication programmes, and on the import and release of exotic biological agents. Phytosanitary regulations in the European Union (EU) have been harmonised and up to now have regulated about 300 plant pests. The requirements also have a protective horizontal effect against the unintentional introduction of many other species, but the existing broader IPPC mandate for alien plant pests is not fully applied by the EU regulations. This revised version was published online in July 2006 with corrections to the Cover Date.     

Apodopsyllus gabesensis n. sp.: a new species of Paramesochridae (Copepoda: Harpacticoida) from the Gulf of Gabès (south-eastern Tunisia)

Several specimens belonging to a new species of Apodopsyllus were collected during a study on the diversity of meiobenthic communities in the Gulf of Gabès, a Mediterranean shallow-water bay at the south-eastern coast of Tunisia in July 2005. The new species Apodopsyllus gabesensis n. sp. shares the characteristics of the genus such as the lack of endopods from P2 to P4 and the soft and slightly cuticularized body. Apodopsyllus gabesensis n. sp. belongs to the few known species of Apodopsyllus that are described to have comparably distinct patterns of dorsal and lateral cuticular plates and pores. Besides a typical combination of characters that clearly distinguishes the new species from its congeners, the new species shows the following unique single characters: female P5 with a hitherto unknown combination of shape of the exopodal part and shape and setation of the baseoendopodal lobe with two small stout spines; male P6 with a particular shape, and a distinct armature of the exopodal spines in P2–P4 in the male that are pinnate with very short spinules contrary to the female where spines are smooth. The genus Apodopsyllus contains 26 species with the inclusion of the new species.     

Interference free and simplyfied liquid chromatography-based determination of thiopurine S-methyltransferase activity in erythrocytes

The determination of the thiopurine S-methyltransferase activity (TPMT; EC 2.1.1.67) has become an important issue during thiopurine therapy due to its known genetic polymorphism resulting in a wide range of TPMT activity. Therefore, the standard thiopurine drug regimen is associated with increased hematopoetic toxicity in patients with low or absent TPMT activity, whereas patients with high activity may be insufficiently treated. However, presently available methods are labour intensive and time consuming and tend towards too high or too low enzyme activity due to their methodological approach. The use of instable substrate solutions (6-MP or 6-TG), organic solvents like dimethyl sulfoxide and too high substrate and co-substrate saturation concentrations contribute to this phenomenon. We therefore, established an optimized and fast isocratic HPLC linked TPMT assay based on the enzymatic methylation of mercaptopurine or thioguanine in RBC lysates with S-adenosyl-l-methionine as methyl donor. Unspecific non-enzymatic methylation was not detectable. The recovery of 6-methyl-mercaptopurine was 97-102%, the intra- and interday variation between 1.0 and 5.0%, respectively. The assay dispenses with a time consuming extraction procedure with organic solvents, a heating step, and a gradient elution and is therefore, favourable for clinical routine application. The TPMT activity was measured in 62 untreated children with acute lymphoblastic leucemia at the time of diagnosis (activity = 34.0+/-10.6 nmol/g Hb/h, range: 11.5-55.4 nmol/g Hb/h) and in 12 adult healthy volunteers (62.8+/-7.7 nmol/g Hb/h, range: 48-82 nmol/g Hb/h) reflecting the wide measurable TPMT activity found in erythrocytes.     

Mextli Is a Novel Eukaryotic Translation Initiation Factor 4E-Binding Protein That Promotes Translation in Drosophila melanogaster

Translation is a fundamental step in gene expression, and translational control is exerted in many developmental processes. Most eukaryotic mRNAs are translated by a cap-dependent mechanism, which requires recognition of the 5′-cap structure of the mRNA by eukaryotic translation initiation factor 4E (eIF4E). eIF4E activity is controlled by eIF4E-binding proteins (4E-BPs), which by competing with eIF4G for eIF4E binding act as translational repressors. Here, we report the discovery of Mextli (Mxt), a novel Drosophila melanogaster 4E-BP that in sharp contrast to other 4E-BPs, has a modular structure, binds RNA, eIF3, and several eIF4Es, and promotes translation. Mxt is expressed at high levels in ovarian germ line stem cells (GSCs) and early-stage cystocytes, as is eIF4E-1, and we demonstrate the two proteins interact in these cells. Phenotypic analysis of mxt mutants indicates a role for Mxt in germ line stem cell (GSC) maintenance and in early embryogenesis. Our results support the idea that Mxt, like eIF4G, coordinates the assembly of translation initiation complexes, rendering Mxt the first example of evolutionary convergence of eIF4G function.     

Community structure and species diversity of Harpacticoida (Crustacea: Copepoda) at two sites in the deep sea of the Angola Basin (Southeast Atlantic)

The aim of this study was to evaluate compositional differences between harpacticoid (Crustacea, Copepoda) assemblages at two widely separated abyssal locations. During the DIVA 1 cruise of RV METEOR (July/August 2000) to the Angola Basin (Southeast Atlantic), two deep-sea stations, approximately 300 nautical miles apart (Stations 325 and 346), were sampled repeatedly by Multicorer (MUC). For quantitative analyses, 5 MUC samples were selected at random from each of 15 deployments at both stations, totalling 75 cores. Across the study, 7,081 Harpacticoida specimens were encountered and of these 31.4 % were adults and could be analysed to species level: 682 species were identified, with 99.3 % new to science. At northern Station 346, a total of 600 species were recorded—the highest harpacticoid species number ever recorded for a single deep-sea locality. Most species (56 %) were represented by singletons. Multivariate tests identified significant differences between community compositions at the two stations. Diversity, species richness and species density were higher at Station 346, whilst taxonomic distinctness, evenness, and rarefaction were similar between stations. Regression and correlation analyses showed that the difference in species diversity was best explained by species densities rather than species richness. Under-sampling due to low densities was an issue at the southern Station 325. Nevertheless, our study demonstrated significant differences in regional-scale harpacticoid community structures within a single deep-sea basin that would usually be considered a uniform and stable habitat. These observed differences are thought to reflect differences in food availability at the two stations.     

Recent advances in the diagnosis and treatment of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disease of severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and macrophages secreting high amounts of inflammatory cytokines. It is a frequent manifestation in patients with predisposing genetic defects, but can occur secondary to various infectious, malignant, and autoimmune triggers in patients without a known genetic predisposition. Clinical hallmarks are prolonged fever, cytopenias, hepatosplenomegaly, and neurological symptoms, but atypical variants presenting with signs of chronic immunodeficiency are increasingly recognized. Impaired secretion of perforin is a key feature in several genetic forms of the disease, but not required for disease pathogenesis. Despite progress in diagnostics and therapy, mortality of patients with severe HLH is still above 40%. Reference treatment is an etoposide-based protocol, but new approaches are currently explored. Key for a favorable prognosis is the rapid identification of an underlying genetic cause, which has been facilitated by recent immunological and genetic advances. In patients with predisposing genetic disease, hematopoietic stem cell transplantation is performed increasingly with reduced intensity conditioning regimes. Current research aims at a better understanding of disease pathogenesis and evaluation of more targeted approaches to therapy, including anti-cytokine antibodies and gene therapy.     

Analysis of interactions between potent inhibitors of ATP sulfurylase via molecular dynamics

The dynamic behaviour of adenosine triphosphate sulfurylase (ATPs) is analysed to investigate its energetic interactions with inhibitors recently studied theoretically and tested experimentally. The interactions between ATPs and three inhibitors namely, 2,2′-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), butylated hydroxytoluene (BHT), and 3-tert-butyl-4-hydroxyanisole (BHA) in aqueous solution were studied via molecular dynamics simulations. The results of the absolute and relative free energies reveal the existence of synergism in the system. Additionally, the system demonstrates strong steric effect between ABTS and BHA that is not only due to the size of these inhibitors but also their surroundings.