On-column epimerization of dihydroartemisinin: an effective analytical approach to overcome the shortcomings of the International Pharmacopoeia monograph

We developed a cryo-HPLC/UV method for the simultaneous determination of artemisinin (1), alpha-dihydroartemisinin (2alpha), beta-dihydroartemisinin (2beta), and a ubiquitous thermal decomposition product of 2 (designated as diketoaldehyde, 3), starting from the International Pharmacopoeia monograph on dihydroartemisinin. The method takes for the first time the on-column epimerization process of 2 into consideration. Chromatographic separation was obtained under reversed-phase conditions on a Symmetry C18 column (3.5 microm particle size) with a mobile phase consisting of acetonitrile-water 60:40 (v/v), delivered at 0.60-1.00 ml/min flow-rates, with ultraviolet detection at low wavelength (lambda = 210 nm). Low temperatures (T = 0-10 degrees C) were selected on the grounds of a diastereoselective dynamic HPLC (DHPLC) study performed at different temperatures, aimed at identifying the best experimental conditions capable of minimizing the on-column interconversion process.     

Antinociceptive effect of the C-terminus of murine S100A9 protein on experimental neuropathic pain

The synthetic peptide identical to the C-terminus of murine S100A9 protein (mS100A9p) has antinociceptive effect on different acute inflammatory pain models. In this study, the effect of mS100A9p was investigated on neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve in rats. Hyperalgesia, allodynia, and spontaneous pain were assessed to evaluate nociception. These three signs were detected as early as 2 days after sciatic nerve constriction and lasted for over 14 days after CCI. Rats were treated with different doses of mS100A9p by intraplantar, oral, or intrathecal routes on day 14 after CCI, and nociception was evaluated 1h later. These three routes of administration blocked hyperalgesia, allodynia and spontaneous pain. The duration of the effect of mS100A9p depends on the route used and phenomenon analyzed. Moreover, intraplantar injection of mS100A9p in the contralateral paw inhibited the hyperalgesia on day 14 days after CCI. The results obtained herein demonstrate the antinociceptive effect of the C-terminus of murine S100A9 protein on experimental neuropathic pain, suggesting a potential therapeutic use for it in persistent pain syndromes, assuming that tolerance does not develop to mS100A9p.     

Thinking about RNA? MicroRNAs in the brain

MicroRNAs (miRNAs) are a recently discovered class of small RNA molecules implicated in a wide range of diverse gene regulatory mechanisms. Interestingly, numerous miRNAs are expressed in a spatially and temporally controlled manner in the nervous system. This suggests that gene regulation networks based on miRNA activities may be particularly relevant in neurons. Recent studies show the involvement of RNA-mediated gene silencing in neurogenesis, neural differentiation, synaptic plasticity, and neurologic and psychiatric diseases. This review focuses on the roles of miRNAs in the gene regulation of the nervous system.     

A survey of modern pollen and vegetation along an altitudinal transect in southern Georgia, Caucasus region

This paper describes the pollen representation of vegetation patterns along an altitudinal transect in the South Caucasus region. Surface sediments from eight small- to medium-sized lakes and wetlands were analysed for modern pollen, and the results analysed numerically using detrended correspondence analysis (DCA) and dichotomised ordination (TWINSPAN). Pollen spectra from the semidesert region have a clear palynological signal characterised by an abundance of Chenopodiaceae. Differentiation of oak forest, upper tree-line and subalpine communities is more difficult: all are dominated by arboreal pollen (AP) types. The authors propose a number of indicator pollen types and pollen threshold values that may assist in detecting tree-line variations and deforestation events in Holocene pollen diagrams.     

Isolation and characterization of S genome specific sequences from Aegilops sect. sitopsis species.

Three S genome specific sequences were isolated from Aegilops sect. sitopsis species using different experimental approaches. Two clones, UTV86 and UTV39, were isolated from a partial genomic library obtained from DNA of Aegilops sharonensis, whereas a third clone, UTV5, was isolated from Aegilops speltoides. The three clones were characterized by sequencing, analysis of methylation, and sequence organization and abundance in some Aegilops and Triticum species. The clones UTV39 and UTV5 belong to the same family of tandem repeated sequences and showed high homology with a sequence already present in nucleotide databases. The UTV86 clone from Ae. sharonensis corresponded to an interspersed low frequency repeated sequence and did not show any significant homology with reported sequences. Southern hybridization experiments, using the cloned sequences as probes, detected polymorphism in the restriction patterns of all the five Aegilops species in section sitopsis. Aegilops speltoides showed the most divergent hybridization pattern. A close relationship was detected between the S genome of Ae. speltoides and the G genome of the wild Triticum timopheevii. In situ hybridization revealed a telomeric and (or) subtelomeric location of the sequences UTV39 and UTV5.     

Angiocardiography in the diagnosis of interventricular septum defects in a double displacement of great vessels from the right ventricle]

The paper is devoted to analysis of the results of angiocardiographic investigation of 237 patients with a double deflection of great vessels (DDGV) from the right ventricle (RV) (the patients ranged in age from 3 months to 23.5 years) to study the potentialities of the method in the diagnosis of a defect position of the interventricular septum (DIVS). Angiographic investigation permitted a sufficiently accurate determination of a DIVS position in DDGV from the RV. Of paramount importance for determining a DIVS position is the establishment of the interrelationships of the latter with the infundibular septum and the openings of major arteries. For diagnosis of a DIVS position one should necessarily use left and right ventriculography both in standard and axial projections.     

Climate-based model of spatial pattern of the species richness of ants in Georgia

For optimal planning of conservation and monitoring measures, it is important to know the spatial pattern of species richness and especially areas with high species richness. A spatial pattern of the species richness of ants in Georgia (Caucasus) was modeled, areas with the highest number of ant’s species were inferred, and climatic factors that influence the pattern of ant diversity were identified. A database was created by accumulating occurrences for 63 ant species, including 256 localities and 2,018 species/occurrences. Species richness was positively correlated with variables associated with temperature and negatively correlated with variables associated with precipitation. Species richness reaches a maximum at the elevations 800–1,200?m a.s.l. and declines at both lower and higher altitudes. The role of climatic variables and geography of the study area in determining the observed pattern of species richness is discussed.     

Serosa membrane plays a key role in transferring vitellin polypeptides to the perivitelline fluid in insect embryos

In mid-embryogenesis, the stick insect Carausius morosus comes to be comprised of three distinct districts: the embryo proper, the yolk sac and the perivitelline fluid. A monolayered epithelium, the so-called serosa membrane, encloses the yolk sac and its content of vitellophages and large yolk granules. During embryonic development, the yolk sac declines gradually in protein concentration due to Vt polypeptides undergoing limited proteolysis to yield a number of Vt cleavage products of lower molecular weights. mAbs 1D1 and 5H11 are monoclonal antibodies raised against some of the Vt cleavage products generated by this process in the yolk sac. At the confocal microscope, antibody fluorescence is initially associated with a few yolk granules, while it is gradually displaced in the cytosolic spaces of the vitellophages. With the proceeding of embryonic development, label appears also in the serosa membrane in the form of clustered dots. At the ultrastructural level, gold particles are initially associated with the vitellophages that are labeled on a few yolk granules and in the cytosolic space flanking the yolk granules. Subsequently, the serosa cells become labeled on vesicles close to the yolk granules or just underneath the plasma membrane. Inside the serosa cells, label is also associated with granules budding from the Golgi apparatus, but never with the intercellular channels percolating the serosa membrane. These observations are interpreted as indicating that Vt cleavage products leak out from the yolk granules into the cytosolic spaces of the vitellophages and are eventually transferred to the perivitelline fluid via transcytosis through the serosa cells.     

Hsp40 is involved in cilia regeneration in sea urchin embryos.

In a previous paper we demonstrated that, in Paracentrotus lividus embryos, deciliation represents a specific kind of stress that induces an increase in the levels of an acidic protein of about 40 kD (p40). Here we report that deciliation also induces an increase in Hsp40 chaperone levels and enhancement of its ectodermal localization. We suggest that Hsp40 might play a chaperoning role in cilia regeneration.