Insulin Mimetic Effect of Tungsten Compounds on Isolated Rat Adipocytes

Investigations of effective, orally active, and safe antidiabetic metallopharmaceuticals have been carried out during the last two decades. It has been reported that tungsten compounds mimic the action of insulin in intact cell systems. As insulin mimetics, the most investigated tungsten compound was sodium tungstate (ST), rarely investigated was tungstophosphoric acid (WPA), but never alanine complex of tungstophosphoric acid (WPA-A). In this study, the insulin mimetic activity of three different tungsten compounds, ST, WPA, and WPA-A, was evaluated by means of in vitro measurements of the glucose uptake and inhibition of free fatty acids release from epinephrine-treated isolated rat white adipocytes. We investigated the influence of concentration (lower and higher, 0.1 and 1.0 mM, respectively) and solvent: isotonic salt solution—saline (0.9% w/v of NaCl) and dimethyl sulfoxide (DMSO; 2% v/v), on the biological effect of tested compounds. Our experimental data showed that all of the three investigated tungsten compounds possess insulin mimetic activity in vitro on the isolated adipocytes. Influence of concentration and solvents on insulin mimetic effect for the certain tungsten compounds were: WPA was shown effect independently of concentration and solvents; higher concentration and DMSO were significant decreasing insulin mimetic effect of ST; lower concentration and saline led to decreasing effect of WPA-A. Generally, there were no differences in insulin mimetic effect of three tungsten compounds in lower concentration and dissolved in DMSO. When saline was used as solvent, it was needed higher concentration of investigated compounds to accomplish the same effect. In conclusion, our results suggest that low concentration (0.1 mM) of ST, WPA, and WPA-A dissolved in 2% DMSO could be the good candidates for in vivo investigation of their antidiabetic properties.     

Applications of self-organizing map for patterning macrofungal diversity of xerothermic swards

Macrofungal communities were investigated in four associations of xerothermic swards: Festucetum pallentis, Origano-Brachypodietum, Adonido-Brachypodietum pinnati and Diantho-Armerietum elongatae in a Jurassic area of the Częstochowa Upland (southern Poland). A total of 47 species were recorded. The self-organising map (SOM)—an unsupervised algorithm for artificial neural networks—was used to recognise patterns in the macrofungal communities of diverse xerothermic swards. Only two associations were mycologically similar: Origano-Brachypodietum and Adonido-Brachypodietum pinnati. Species with high and significant IndVal (the species indicator value) for each investigated phytocoenoses are presented. The presence of macrofungal species and the participation of indicator species were connected with habitat factors of plant associations, as documented by the IndVal application. In the least fertile phytocoenoses, macrofungal communities were poor with few indicator species. The more fertile phytocoenoses had richer and more varied communities of macrofungi with higher numbers of indicator species. The ordering methods applied in this study were very effective for analyzing the macrofungal communities existing in plant associations.     

Giant viruses,giant chimeras: The multiple evolutionary histories of Mimivirus genes

Background  

Although capable to evolve, viruses are generally considered non-living entities because they are acellular and devoid of metabolism. However, the recent publication of the genome sequence of the Mimivirus, a giant virus that parasitises amoebas, strengthened the idea that viruses should be included in the tree of life. In fact, the first phylogenetic analyses of a few Mimivirus genes that are also present in cellular lineages suggested that it could define an independent branch in the tree of life in addition to the three domains, Bacteria, Archaea and Eucarya.     

The origin of a novel gene through overprinting in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Background  

Overlapped genes originate by a) loss of a stop codon among contiguous genes coded in different frames; b) shift to an upstream initiation codon of one of the contiguous genes; or c) by overprinting, whereby a novel open reading frame originates through point mutation inside an existing gene. Although overlapped genes are common in viruses, it is not clear whether overprinting has led to new genes in prokaryotes.     

Chromatin in diapause of the silkworm <Emphasis Type="Italic">Bombyx mori</Emphasis> L.: Thermal parthenogenesis and normal development

By using hematoxylin staining, peculiarities of chromatin of diapausing silkworm embryos were studied in normal and parthenogenetic development. A direct correlation was revealed between the number of interphase chromatin grains and the number of chromosomes in the nucleus; polyploidization of cells in embryo was studied at the stage of diapause. The polyploidization in parthenogenesis is not restricted to endomitotic chromosome set doubling, as it includes 6n-nuclei. To explain the more diverse spectrum of polyploid cells in parthenogenesis (as compared with the norm), it is necessary to take into account fusion of cleavage nuclei, which is realized by the cytoplasmic mechanism of karyogamy in the absence of fertilization. On squash preparations, for the first time, we identified primordial germ cells of the diapausing embryo, which are characterized by less compact chromatin, especially in the zygotic variant of development; by larger nuclei and cytoplasm; and by an irregular number and size of nucleoli. Estimation of ploidy of the primary germ cells in parthenogenesis by counting “loose” chromatin grains in diapause is possible and indicates polyploidization in the primordial germ cells. This explains an inevitable admixture of tetraploid eggs in the grain of diploid parthenoclones and its absence in normal development. The cytological method used has revealed a spiral arrangement of chromatin grains on the internal nuclear surface at different ploidy levels.     

Recovery rates of chlorophyll-fluorescence parameters in desiccation-tolerant plants: fitted logistic curves as a versatile and robust source of comparative data

Desiccation-tolerant plants vary greatly in the rate of recovery of chlorophyll-fluorescence parameters on re-wetting. This paper seeks general curves that will adequately describe the course of recovery, and quantify the variations in rate within and between species. Recovery of F _v /F _m is closely fitted in many species by a logistic curve, starting from zero, on a logarithmic time-scale (seconds to days). Such curves have three parameters, an asymptote at maximum F _v /F _m, a half-recovery time (T _0.5), and a slope constant (S). If F _v /F _m in dry material differs substantially from zero, four-parameter logistic curves can give a better fit. In either case, T _0.5 and S show wide ecologically-significant variation. Some species show anomalously high values of F _v /F _m in the early minutes of recovery, alongside low absolute values of F _m; these invite further investigation. Logistic curves give good fits to the recovery in light of Φ _PSII, q _P, and photosynthetic CO₂ fixation. The results provide the means to quantify ‘high-inertia’ versus ‘low-inertia’ strategies of desiccation tolerance, and to explore the factors influencing recovery time and rate, and the reasons for some discrepancies from the common course of recovery. There is substantial overlap in all parameters between the bryophytes and pteridophytes studied.     

Parallel evolution of character displacement driven by competitive selection in terrestrial salamanders

Background  

Parallel evolution can occur when common environmental factors exert similar selective forces on morphological variation in populations in different geographic localities. Competition can also generate morphological shifts, and if competing species co-occur in multiple geographic regions, then repeated instances of competitively-driven morphological divergence (character displacement) can occur. Despite the importance of character displacement for inferring the role of selection in morphological evolution however, replicated instances of sympatric morphological divergence are understudied.     

The development of policy approaches for reducing nitrogen pollution to coastal waters of the USA

Two-thirds of the coastal rivers and bays in the United States are degraded from nutrient pollution, and nitrogen inputs these waters continue to increase. The nitrogen comes from a variety of sources, including runoff from agricultural fields, concentrated animal feeding operations, atmospheric deposition from fossil fuel combustion, and sewage and septic wastes. Technical solutions for nitrogen pollution exist at reasonable cost. That most of these solutions have not yet been implemented to any significant extent across the United States suggests that new policy approaches are necessary. The best solution may involve a combination of voluntary and mandatory approaches, applying different approaches to different sources of nitrogen pollution. A watershed-based approach that relies heavily on voluntary mechanisms (such as crop-yield insurance to reduce over-fertilization) is likely to be the most effective for some sources of nitrogen (such as runoff from agricultural fields), while a uniform national regulatory approach may be better for others (such as NO_x emissions from fossil fuel combustion). Implementation of management strategies should be carefully coupled to monitoring programs to assess the effectiveness of these strategies. While both nitrogen and phosphorus are important to control, the focus should be on nitrogen management, in part because nitrogen is more generally the causal agent of coastal eutrophication. Also, while nitrogen-control practices tend to also reduce phosphorus pollution, phosphorus-control practices often have little effect on nitrogen. Although current scientific and technical knowledge is sufficient to begin to make substantial progress toward solving coastal nitrogen pollution, progress will be made more quickly and more cost effectively with increased investment in appropriate scientific research.     

Lectin Binding Assays for In-Process Monitoring of Sialylation in Protein Production

Many therapeutic proteins require appropriate glycosylation for their biological activities and plasma half life. Coagulation factor VIII (FVIII) is a glycoprotein which has extensive post-translational modification by N-linked glycosylation. The terminal sialic acid in the N-linked glycans of FVIII is required for maximal circulatory half life. The extent of FVIII sialylation can be determined by high pH anion-exchange chromatography coupled with a pulse electrochemical detector (HPAEC-PED), but this requires a large amount of purified protein. Using FVIII as a model, the objective of the present study was to develop assays that enable detection and prediction of sialylation deficiency at an early stage in the process and thus prevent downstream product quality excursions. Lectin ECA (Erythrina Cristagalli) binds to unsialylated Galβ1-4 GlcNAc and the ECA-binding level (i.e., terminal Gal(β1-4) exposure) is inversely proportional to the level of sialylation. By using ECA, a cell-based assay was developed to measure the global sialylation profile in FVIII producing cells. To examine the Galβ1-4 exposure on the FVIII molecule in bioreactor tissue culture fluid (TCF), an ELISA-based ECA-FVIII binding assay was developed. The ECA-binding specificity in both assays was assessed by ECA-specific sugar inhibitors and neuraminidase digestion. The ECA-binding specificity was also independently confirmed by a ST3GAL4 siRNA knockdown experiment. To establish the correlation between Galβ1-4 exposure and the HPAEC-PED determined FVIII sialylation value, the FVIII containing bioreactor TCF and the purified FVIII samples were tested with ECA ELISA binding assay. The results indicated an inverse correlation between ECA binding and the corresponding HPAEC-PED sialylation value. The ECA-binding assays are cost effective and can be rapidly performed, thereby making them effective for in-process monitoring of protein sialylation.