Phenetic comparison of sevenEchinacea species based on immunomodulatory characteristics

The purpose of the present investigation was to compare similarities and differences in immune response among Echinacea species, which are commonly used to treat upper respiratory infections. The investigation involved two components: acquisition of immunomodulatory data reported here for the first time, and combined phenetic analysis of these data along with previous reports. Experimental data were obtained by stimulating human PBMC in vitro with extracts from Echinacea spp. and assaying production of three cytokines (interleukin-1β [IL-1β] interleukin-2 [IL-2], and tumor necrosis factor α [TNF-α]). Phenetic analyses were employed to compare responses across the entire data set, including UPGMA (Unweighted Pair Group Method with Arithmetic Mean) and neighbor-joining methods. In the immune experiments conducted for this investigation, E. angustifolia,E. paradoxa, E. purpurea, E. simulata, andE. tennesseensis extracts significantly augmented IL-1 β and TNF-α production, whereas no extracts significantly modulated IL-2. All phenetic methods produced similar dendrograms, revealing two species pairs (E. angustifolia + E. simulata and E. pallida + E.sanguinea) where both species cluster tightly and have similar immune-response profiles. These two species-pairs are maximally dissimilar from each other. The remaining species (E. paradoxa, E. purpurea, and E. tennesseensis) occupy intermediate positions in the dendrogram. Our results suggest that Echinacea spp. act heterogeneously on immune function. The utility of these data for science and industry is discussed.     

Aptamer-based capture molecules as a novel coating strategy to promote cell adhesion

The improvement of the cytocompatibility of medical implants is a major goal in biomaterials research. During the last years many researchers worked on the fascinating approach to seed the respective cell types on various artificial substrates before implantation. For instance, cell-seeded implants are supposed to be better candidates for transplantable bone substitutes than conventional artificial bone grafts. To improve cell seeding efficiency and cytocompatibility, we designed a new coating material for medical implants. We used aptamers, highly specific cell binding nucleic acids generated by combinatorial chemistry with an in vitro selection called systematic evolution of exponential enrichment (SELEX). Aptamers do have high binding affinity and selectivity to their target. In our study, human osteoblasts from osteosarcoma tissue were used as a target to create the aptamer. Single aptamer mediated cell sorting assays showed the binding affinity with osteoblasts. Additionally, the aptamers immobilized on tissue culture plates could capture osteoblasts directly and rapidly from the cell solution. This model proves that aptamer coated artificial surfaces can greatly enhance cell adhesion. We assume that this strategy is capable to improve the clinical application of tissue engineered implants.     

Does a modified gamma-glutamyl cycle exist in human erythrocytes (author's transl)]

The first step in the biosynthesis of glutathione is the formation of gamma-glutamyl-cysteine by the enzyme glutamyl-cysteine synthetase. Since this enzyme is not specific for cysteine, different gamma-glutamylamino acids may be formed in vivo which represent potential substrates for the enzymes gamma-glutamylcyclotransferase; in this way 5-oxo-L-proline and free amino acid are formed. We investigated in membrane-free hemolysate the competition between the biosynthesis of glutathione or ophthalmic acid and the degradation of gamma-glutamyl peptides by measuring the formation of 5-oxoproline. The endogenous rate of 5-oxoproline production was 0.13 muM/min. This increased to 2muM/min after addition of 2-aminobutyrate, and to 10muM/min after addition of glutamate and 2-aminobutyrate to hemolysate. Addition of cysteine resulted in an increased oxoproline production only under conditions where glutamyl-cysteine accumulated. In addition, it was shown that for glutamyl-2-aminobutyrate the degradation to 5-oxoproline is faster than the utilization for the tripeptide synthesis. This was not the case for glutamyl-cysteine. Since membrane-free hemolysate (which lacks gamma-glutamyltransferase) is able to produce 5-oxoproline starting from glutamate, it is concluded that this 5-oxoprolinent amino acid transport via a modified gamma-glutamyl cycle.     

Phylogeny of the New World diploid cottons (Gossypium L., Malvaceae) based on sequences of three low-copy nuclear genes

American diploid cottons (Gossypium L., subgenus Houzingenia Fryxell) form a monophyletic group of 13 species distributed mainly in western Mexico, extending into Arizona, Baja California, and with one disjunct species each in the Galapagos Islands and Peru. Prior phylogenetic analyses based on an alcohol dehydrogenase gene (AdhA) and nuclear ribosomal DNA indicated the need for additional data from other molecular markers to resolve phylogenetic relationships within this subgenus. Toward this end, we sequenced three nuclear genes, the anonymous locus A1341, an alcohol dehydrogenase gene (AdhC), and a cellulose synthase gene (CesA1b). Independent and combined analyses resolved clades that are congruent with current taxonomy and previous phylogenies. Our analyses diagnose at least two long distance dispersal events from the Mexican mainland to Baja California, following a rapid radiation of the primary lineages early in the diversification of the subgenus. Molecular data support the proposed recognition of a new species closely related to Gossypium laxum that was recently collected in Mexico.     

Alterations in the intermediary metabolism of selenium-deficient mice

Male albino mice were pair-fed a torula yeast-based selenium-deficient (Se-) diet containing 10 ppb selenium for 4 months, while a control group (Se+) received a similar diet supplemented with 330 ppb selenium as Na2SeO3. In addition to previously observed modulations of drug-metabolizing enzymes (Reiter, R. and Wendel, A. (1985) Biochem. Pharmacol. 34, 2287-2290), an increase of 6-phosphogluconate dehydrogenase activity and succinate dehydrogenase activity in liver by about 60% was found. In vivo, an increased 14CO2 exhalation from a tracer dose of glucose either labeled in the C-1- or C-6 position was observed in selenium-deficient mice. However, no difference in the total CO2 exhalation of Se(-)- as compared to Se+-mice was detectable. In line with the assumption that Se(-)-mice have an increased glucose turnover, Se(-)-mice exhibited a greater glucose tolerance when treated with an oral glucose load of 2.5 mg glucose/kg body weight. Also, the Se(-)-mice had a lower blood glucose level as compared to Se+-controls (89 +/- 3 versus 110 +/- 12 mg glucose/100 ml blood). Further in vitro experiments with red blood cells from Se(-)-mice showed that erythrocytes did not contribute to an increased CO2 formation from glucose via the pentose phosphate shunt. No significant differences between Se(-)- and Se+-animals were found in the profile of urinary metabolites, including ketone bodies and nitrogen excretion. These findings suggest a hitherto unknown involvement of selenium in specific regulatory sites of intermediary metabolism.     

Evaluation of the prevalence and economic burden of adverse drug reactions presenting to the medical emergency department of a tertiary referral centre: a prospective study

Background  

Adverse drug reactions (ADRs) are now recognized as an important cause of hospital admissions, with a proportion ranging from 0.9–7.9%. They also constitute a significant economic burden. We thus aimed at determining the prevalence and the economic burden of ADRs presenting to Medical Emergency Department (ED) of a tertiary referral center in India     

A novel mechanism of autophagic cell death in dystrophic muscle regulated by P2RX7 receptor large-pore formation and HSP90

P2RX7 is an ATP-gated ion channel, which can also exhibit an open state with a considerably wider permeation. However, the functional significance of the movement of molecules through the large pore (LP) and the intracellular signaling events involved are not known. Here, analyzing the consequences of P2RX7 activation in primary myoblasts and myotubes from the Dmd^mdx mouse model of Duchenne muscular dystrophy, we found ATP-induced P2RX7-dependent autophagic flux, leading to CASP3-CASP7-independent cell death. P2RX7-evoked autophagy was triggered by LP formation but not Ca²⁺ influx or MAPK1-MAPK3 phosphorylation, 2 canonical P2RX7-evoked signals. Phosphoproteomics, protein expression inference and signaling pathway prediction analysis of P2RX7 signaling mediators pointed to HSPA2 and HSP90 proteins. Indeed, specific HSP90 inhibitors prevented LP formation, LC3-II accumulation, and cell death in myoblasts and myotubes but not in macrophages. Pharmacological blockade or genetic ablation of p2rx7 also proved protective against ATP-induced death of muscle cells, as did inhibition of autophagy with 3-MA. The functional significance of the P2RX7 LP is one of the great unknowns of purinergic signaling. Our data demonstrate a novel outcome—autophagy—and show that molecules entering through the LP can be targeted to phagophores. Moreover, we show that in muscles but not in macrophages, autophagy is needed for the formation of this LP. Given that P2RX7-dependent LP and HSP90 are critically interacting in the ATP-evoked autophagic death of dystrophic muscles, treatments targeting this axis could be of therapeutic benefit in this debilitating and incurable form of muscular dystrophy.