Herbarium collections and field data-based plant diversity maps for Burkina Faso

A map of plant species diversity in Burkina Faso is presented based on field observations and specimen data from the Ouagadougou University Herbarium (OUA) and the Herbarium Senckenbergianum (FR). A map of collecting intensity and field observations illustrates centres of botanical research activities in Burkina Faso. To overcome problems associated with biased sampling intensity, distributions of species have been modelled and extrapolated to maps of vascular plant diversity, life forms and diversity of four selected families (Poaceae, Cyperaceae, Dioscoreaceae and Rubiaceae). The area of most intensive collection and observation is around Gorom‐Gorom and Fada N’Gourma. Modelled diversity generally increases towards the south, as does the proportion of phanerophytes, lianas and hemicryptophytes, while the opposite trend is observed for therophytes. Poaceae diversity is highly correlated with total vascular plant diversity, making the family especially suitable as an indicator for overall plant diversity. Cyperaceae are rather evenly distributed throughout the country, Dioscoreaceae are restricted to the Sudanian Zone. Rubiaceae have their highest diversities in the very south. Our approach can be transferred to areas with a similar database, certainly to other areas within West Africa. Future research should focus on distribution data for rare species, enabling our approach to evaluate the West African system of protected areas.     

Physical Activity Levels and Domains Assessed by Accelerometry in German Adolescents from GINIplus and LISAplus

Background

Physical activity (PA) is a well-known and underused protective factor for numerous health outcomes, and interventions are hampered by lack of objective data. We combined accelerometers with diaries to estimate the contributions to total activity from different domains throughout the day and week in adolescents.

Methods

Accelerometric and diary data from 1403 adolescents (45% male, mean age 15.6 ± 0.5 years) were combined to evaluate daily levels and domains of sedentary, light, and moderate-to-vigorous activity (MVPA) during a typical week. Freedson’s cutoff points were applied to determine levels of activity. Total activity was broken down into school physical education (PE), school outside PE, transportation to school, sport, and other time.

Results

About 2/3 of adolescents’ time was spent sedentary, 1/3 in light activity, and about 5% in MVPA. Boys and girls averaged 46 (SD 22) and 38 (23) minutes MVPA per day. Adolescents were most active during leisure sport, spending about 30% of it in MVPA, followed by PE (about 20%) transport to school (14%) and either school class time or other time (3%). PE provided 5% of total MVPA, while leisure sport provided 16% and transportation to school 8%. School was the most sedentary part of the day with over 75% of time outside PE spent sedentary.

Conclusions

These German adolescents were typical of Europeans in showing low levels of physical activity, with significant contributions from leisure sport, transportation and school PE. Leisure sport was the most active part of the day, and participation did not vary significantly by sex, study center (region of Germany) or BMI. Transportation to school was frequent and thus accounted for a significant fraction of total MVPA. This indicates that even in a population with good access to dedicated sporting activities, frequent active transportation can add significantly to total MVPA.     

Fluorescent non-imidazole histamine H3 receptor ligands with nanomolar affinities

Omega-piperidinoalkanamine derivatives with fluorescent moieties (2-cyanoisoindol-1-yl, 7-nitrobenzofurazan-4-yl) have been synthesized starting from piperidine in three steps. The compounds display moderate to good histamine hH(3) receptor affinities with K(i) values ranging from 178 to 11nM. The new compounds may act as tools for identification and understanding of the binding site on the histamine H(3) receptor.     

New Approaches for Absolute Quantification of Stable‐Isotope‐Labeled Peptide Standards for Targeted Proteomics Based on a UV Active Tag

Targeted proteomics depends on the availability of stable isotope labeled (SIL) peptide standards, which for absolute protein quantification need to be absolutely quantified. In the present study, three new approaches for absolute quantification of SIL peptides are developed. All approaches rely on a quantification tag (Qtag) with a specific UV absorption. The Qtag is attached to the peptide during synthesis and is removed by tryptic digestion under standard proteomics workflow conditions. While one quantification method (method A) is designed to allow the fast and economic production of absolutely quantified SIL peptides, two other methods (methods B and C) are developed to enable the straightforward re‐quantification of SIL peptides after reconstitution to control and monitor known problems related to peptide solubility, precipitation, and adhesion to vials. All methods yield consistent results when compared to each other and when compared to quantification by amino acid analysis. The precise quantitation methods are used to characterize the in vivo specificity of the H3 specific histone methyltransferase EZH2.     

Syntheses of branched-chain sugars with push-pull functionality

The reaction of methyl 4,6-O-benzylidene-3(2)-deoxy-- -erythro-hexopyranosid-2(3)-ulose with carbon disulfide, alkyl iodide, and sodium hydride gave methyl 4,6-O-benzylidene-3(2)-[bis(alkylthio)methylene]-3(2)-deoxy-- -erythro-hexopyranosid-2(3)-uloses. Methyl 4,6-O-benzylidene-2-[bis(methylthio)methylene]-2-deoxy-- -erythro-hexopyranosid-3-ulose (5) reacted with aromatic amines to give, in a rearrangement process, N-aryl-2-aryliminomethyl-4,6-O-benzylidene-2-deoxy-- -erythro-hex-1-enopyranosylamin-3-uloses. The reaction of 5 which hydrazine hydrate afforded 5-methylthio-(methyl-4,6-O-benzylidene-2,3-dideoxy-- -erythro-hexopyranosido)[3,2-c]pyrazole.     

Actin filaments are involved in the maintenance of Golgi cisternae morphology and intra-Golgi pH

Here we examine the contribution of actin dynamics to the architecture and pH of the Golgi complex. To this end, we have used toxins that depolymerize (cytochalasin D, latrunculin B, mycalolide B, and Clostridium botulinum C2 toxin) or stabilize (jasplakinolide) filamentous actin. When various clonal cell lines were examined by epifluorescence microscopy, all of these actin toxins induced compaction of the Golgi complex. However, ultrastructural analysis by transmission electron microscopy and electron tomography/three-dimensional modelling of the Golgi complex showed that F-actin depolymerization first induces perforation/fragmentation and severe swelling of Golgi cisternae, which leads to a completely disorganized structure. In contrast, F-actin stabilization results only in cisternae perforation/fragmentation. Concomitantly to actin depolymerization-induced cisternae swelling and disorganization, the intra-Golgi pH significantly increased. Similar ultrastructural and Golgi pH alkalinization were observed in cells treated with the vacuolar H+ -ATPases inhibitors bafilomycin A1 and concanamycin A. Overall, these results suggest that actin filaments are implicated in the preservation of the flattened shape of Golgi cisternae. This maintenance seems to be mediated by the regulation of the state of F-actin assembly on the Golgi pH homeostasis.     

Relationship between the structure of amphiphilic copolymers and their ability to disturb lipid bilayers

Nonionic amphiphiles and particularly block copolymers of ethylene oxide and propylene oxide (Pluronics) cause pronounced chemosensitization of tumor cells that exhibit multiple resistance to antineoplastic drugs. This effect is due to inhibition of P-glycoprotein (P-gp) responsible for drug efflux. It was suggested that the inhibition of P-gp might be due to changes in its lipid surrounding. Indeed, high dependence of P-gp activity on the membrane microviscosity was demonstrated [Regev et al. (1999) Eur. J. Biochem. 259, 18-24], suggesting that the ability of Pluronics to affect the P-gp activity is mediated by their effect on the membrane structure. We have found recently that adsorption of Pluronics on lipid bilayers induced considerable disturbance of the lipid packing [Krylova et al. (2003) Chemistry 9, 3930-3936]. In the present paper, we studied 19 amphiphilic copolymers, including newly synthesized hyperbranched polyglycerols, Pluronic and Brij surfactants, for their ability to accelerate flip-flop and permeation of antitumor drug doxorubicin (DOX) in liposomes. It was found that not only bulk hydrophobicity but also the chemical microstructure of the copolymer determines its membrane disturbing ability. Copolymers containing polypropylene oxide caused higher acceleration of flip-flop and DOX permeation than polysurfactants containing aliphatic chains. The effects of copolymers containing hyperbranched polyglycerol "corona" were more pronounced, as compared to the copolymers with linear poly(ethylene oxide) chains, indicating that a bulky hydrophilic block induces additional disturbances in the lipid bilayer. A good correlation between the copolymer flippase activity and a linear combination of copolymer bulk hydrophobicity and the van der Waals volume of its hydrophobic block was found. The relationship between the structure of a copolymer and its ability to disturb lipid membranes presented in this paper may be useful for the design of novel amphiphilic copolymers capable of affecting the activity of membrane transporters in living cells.     

Synergistic antitumor effect of bispecific CD19 x CD3 and CD19 x CD16 diabodies in a preclinical model of non-Hodgkin's lymphoma

To target NK cells against non-Hodgkin's lymphoma, we constructed a bispecific diabody (BsDb) with reactivity against both human CD19 and FcgammaRIII (CD16). Bacterially produced CD19 x CD16 BsDb specifically interacted with both CD19(+) and CD16(+) cells and exhibited significantly higher apparent affinity and slower dissociation from the tumor cells than from effector cells. It was able to induce specific lysis of tumor cells in the presence of isolated human NK cells or nonfractionated PBLs. The combination of the CD19 x CD16 BsDb with a previously described CD19 x CD3 BsDb and CD28 costimulation significantly increased the lytic potential of human PBLs. Treatment of SCID mice bearing an established Burkitt's lymphoma (5 mm in diameter) with human PBLs, CD19 x CD16 BsDb, CD19 x CD3 BsDb, and anti-CD28 mAb resulted in the complete elimination of tumors in 80% of animals. In contrast, mice receiving human PBLs in combination with either diabody alone showed only partial tumor regression. These data clearly demonstrate the synergistic effect of small recombinant bispecific molecules recruiting different populations of human effector cells to the same tumor target.