Pathways and destination of some male gland secretions in female Locusta migratoria migratorioides (R&F) after insemination

The white secretions (WS) from the tubules of the male accessory glands (AG) of Locusta migratoria are composed of peptides and proteins. The WS are transferred during mating to the female's spermatheca. They have been followed to their destinations with immunological and radioactive marker techniques. In the spermatheca, peptides are split off from WS-protein complexes, permeate the spermathecal epithelium via glandular cells, enter the hemolymph and attach to other proteins in various target organs such as the dorsal fat body, the preterminal/terminal oocytes, and the follicular cells. In developing eggs, they concentrate at the posterior pole where sperm enters the egg, and in early embryogenesis they are found in the germ band. These results extend the functions of the spermatheca and the role of the male during the reproductive process.     

PreBIND and Textomy – mining the biomedical literature for protein-protein interactions using a support vector machine

Background

The majority of experimentally verified molecular interaction and biological pathway data are present in the unstructured text of biomedical journal articles where they are inaccessible to computational methods. The Biomolecular interaction network database (BIND) seeks to capture these data in a machine-readable format. We hypothesized that the formidable task-size of backfilling the database could be reduced by using Support Vector Machine technology to first locate interaction information in the literature. We present an information extraction system that was designed to locate protein-protein interaction data in the literature and present these data to curators and the public for review and entry into BIND.

Results

Cross-validation estimated the support vector machine's test-set precision, accuracy and recall for classifying abstracts describing interaction information was 92%, 90% and 92% respectively. We estimated that the system would be able to recall up to 60% of all non-high throughput interactions present in another yeast-protein interaction database. Finally, this system was applied to a real-world curation problem and its use was found to reduce the task duration by 70% thus saving 176 days.

Conclusions

Machine learning methods are useful as tools to direct interaction and pathway database back-filling; however, this potential can only be realized if these techniques are coupled with human review and entry into a factual database such as BIND. The PreBIND system described here is available to the public at http://bind.ca. Current capabilities allow searching for human, mouse and yeast protein-interaction information.     

Formation of conjugates from ciprofloxacin and norfloxacin in cultures of Trichoderma viride

The formation of conjugates from two antibacterial fluoroquinolone drugs, ciprofloxacin and norfloxacin, was observed in cultures of Trichoderma viride that had been grown in sucrose-peptone broth and extracted 16 d after dosing with the drugs. Both conjugates were purified by high-performance liquid chromatography and found to be optically active. They were identified by mass and proton nuclear magnetic resonance spectra as 4-hydroxy-3-oxo-4-vinylcyclopent-1-enyl ciprofloxacin and 4-hydroxy-3-oxo-4-vinylcyclopent-1-enyl norfloxacin. The transformation of veterinary fluoroquinolones in the presence of fungi may have ecological significance.     

Synthesis of building blocks of human milk oligosaccharides. Fucosylated derivatives of the lacto- and neolacto-series

The synthesis of protected fucosylated derivatives of a Galβ(1→3)GlcNAc and of lactosamine Galβ(1→4)GlcNAc building blocks contained in human milk oligosaccharides is described. Both chemical and enzymatic methods have been exploited for selective protection of the disaccharide. Fucosylation of the appropriate derivatives allowed an easy and relatively short access to different products from common precursors.     

Urinary homovanillic acid (HVA) and vanillymandelic acid (VMA) in workers exposed to manganese dust

The neurotoxicity of manganese (Mn) is well known, however, the neurochemical effect caused by this metal is less well investigated. In this study, urinary homovanillic acid (HVA) and vanillymandelic acid (VMA), two end products of catecholamine metabolism, were measured in 39 workers chronically exposed to Mn in a manganese smelting plant. The average duration of Mn exposure was 17.4 yr. Nineteen nonexposed workers were also studied. Concentrations of Mn in serum (MnS) and in urine (MnU) were measured by Zeeman graphite furnace atomic absorption spectrophotometry (ZAAS), and HVA and VMA determined by high performance liquid chromatography (HPLC). For Mn-exposed workers, the concentration of MnS was nearly 2.8 times (1.61 ± 0.16 mg/L vs 0.56 ± 0.16 mg/L) and MnU about 4.5 times higher (7.62 ± 0.17 mg/L vs 1.69 ± 0.16 mg/L) than the nonexposed. Although the geometric mean concentration of HVA in exposed workers was similar to that of the nonexposed (3.09 ± 1.39 mg/g ere. vs 2.99 ± 1.40 mg/g cre.), the VMA concentration was significantly higher (3.02 ± 1.43 mg/g cre. vs 2.49 ± 1.58 mg/g cre.,p = 0.033). Multiple regression analysis showed that although there were no correlations between any of these parameters with the duration of exposure to Mn, both HVA and VMA showed significant correlations with increase in MnS and MnU. These data provide evidence that exposure to Mn was associated with measurable increase in catecholamine metabolites. This finding is compatible with recent observations in laboratory animals that Mn interferes with neurochemical metabolism.     

A synthetic weak neurotoxin binds with low affinity to Torpedo and chicken alpha7 nicotinic acetylcholine receptors.

Weak neurotoxins from snake venom are small proteins with five disulfide bonds, which have been shown to be poor binders of nicotinic acetylcholine receptors. We report on the cloning and sequencing of four cDNAs encoding weak neurotoxins from Naja sputatrix venom glands. The protein encoded by one of them, Wntx-5, has been synthesized by solid-phase synthesis and characterized. The physicochemical properties of the synthetic toxin (sWntx-5) agree with those anticipated for the natural toxin. We show that this toxin interacts with relatively low affinity (K(d) = 180 nm) with the muscular-type acetylcholine receptor of the electric organ of T. marmorata, and with an even weaker affinity (90 microm) with the neuronal alpha7 receptor of chicken. Electrophysiological recordings using isolated mouse hemidiaphragm and frog cutaneous pectoris nerve-muscle preparations revealed no blocking activity of sWntx-5 at microm concentrations. Our data confirm previous observations that natural weak neurotoxins from cobras have poor affinity for nicotinic acetylcholine receptors.