Analysis of ECs and related compounds in plasma: artifactual isomerization and ex vivo enzymatic generation of 2-MGs

The analysis of peripheral endocannabinoids (ECs) is a good biomarker of the EC system. Their concentrations, from clinical studies, strongly depend on sample collection and time processing conditions taking place in clinical and laboratory settings. The analysis of 2-monoacylglycerols (MGs) (i.e., 2-arachidonoylglycerol or 2-oleoylglycerol) is a particularly challenging issue because of their ex vivo formation and chemical isomerization that occur after blood sample collection. We provide evidence that their ex vivo formation can be minimized by adding Orlistat, an enzymatic lipase inhibitor, to plasma. Taking into consideration the low cost of Orlistat, we recommend its addition to plasma collecting tubes while maintaining sample cold chain until storage. We have validated a method for the determination of the EC profile of a range of MGs and N-acylethanolamides in plasma that preserves the original isomer ratio of MGs. Nevertheless, the chemical isomerization of 2-MGs can only be avoided by an immediate processing and analysis of samples due to their instability during conservation. We believe that this new methodology can aid in the harmonization of the measurement of ECs and related compounds in clinical samples.     

Reconfigurable Boolean Logic Using Magnetic Single-Electron Transistors

We propose a novel hybrid single-electron device for reprogrammable low-power logic operations, the magnetic single-electron transistor (MSET). The device consists of an aluminium single-electron transistor with a GaMnAs magnetic back-gate. Changing between different logic gate functions is realized by reorienting the magnetic moments of the magnetic layer, which induces a voltage shift on the Coulomb blockade oscillations of the MSET. We show that we can arbitrarily reprogram the function of the device from an n-type SET for in-plane magnetization of the GaMnAs layer to p-type SET for out-of-plane magnetization orientation. Moreover, we demonstrate a set of reprogrammable Boolean gates and its logical complement at the single device level. Finally, we propose two sets of reconfigurable binary gates using combinations of two MSETs in a pull-down network.     

Exploring the Factor Structure of Neurocognitive Measures in Older Individuals

Here we focus on factor analysis from a best practices point of view, by investigating the factor structure of neuropsychological tests and using the results obtained to illustrate on choosing a reasonable solution. The sample (n=1051 individuals) was randomly divided into two groups: one for exploratory factor analysis (EFA) and principal component analysis (PCA), to investigate the number of factors underlying the neurocognitive variables; the second to test the “best fit” model via confirmatory factor analysis (CFA). For the exploratory step, three extraction (maximum likelihood, principal axis factoring and principal components) and two rotation (orthogonal and oblique) methods were used. The analysis methodology allowed exploring how different cognitive/psychological tests correlated/discriminated between dimensions, indicating that to capture latent structures in similar sample sizes and measures, with approximately normal data distribution, reflective models with oblimin rotation might prove the most adequate.     

Evidence for kinetic and immunologic heterogeneity of dihydrofolate reductase in L1210 leukemia cells.

Two species of DHFR were identified in wild-type L1210 murine leukemia cells by analysis of the kinetics of the binding of MTX and dissociation of the MTX-enzyme complex at pH 5.0 and pH 7.2. The two forms of DHFR were also distinguished by immunoinhibition of the binding of MTX and the catalytic reduction of FH2 to FH4 using an antiserum raised to the purified high affinity form of DHFR. The Ka for the binding of MTX by the low affinity form of the enzyme is 4.5 x 10(7) M-1, substantially lower than the reported Ka for the binding of this drug by the high affinity enzyme. The low affinity form of the enzyme catalyzed the reduction of FH2 to FH4 at a rate slower than the high affinity form of DHFR.     

malvolio, the Drosophila homologue of mouse NRAMP-1 (Bcg), is expressed in macrophages and in the nervous system and is required for normal taste behaviour.

We report the sequence, expression pattern and mutant phenotype of malvolio (mvl), the Drosophila homologue of mammalian natural resistance-associated macrophage proteins (NRAMPs). In the mouse, this novel transporter is encoded by Bcg, a dominant gene that confers natural resistance to intracellular parasites. mvl was identified in a screen for mutants that affect taste behaviour. We show that loss-of-function as well as insertional mutants in mvl display defects in taste behaviour with no alterations in the physiology of the sensory neurons. Activity of the reporter enzyme beta-galactosidase, that reflects the expression pattern of mvl, is seen in mature sensory neurons and in macrophages. The conceptual translation of the mvl cDNA shows a striking similarity (65% identity) with human NRAMP with almost complete identity in a conserved consensus motif found in a number of ATP-coupled transporters. Based on its phenotype and expression pattern as well as its structural similarities to NRAMPs and a nitrate transporter in Aspergillus nidulans, we discuss a possible role for MVL in nitrite/nitrate transport and its implications.     

Photosynthesis and water relations of almond tree cultivars grafted on two rootstocks

Five cultivars of Prunus amygdalus Batsch (Ferragnes, Ferrastar, Marcona, Garrigues, and Non Pareil) grafted on two different rootstocks (Garrigues and GF677), and two cultivars (Ferraduel and Casa Nova) grafted on GF677, were grown for three years under rainfed conditions in an orchard in northeast Portugal. Net photosynthetic rate (PN), leaf conductance for water vapour (gs), leaf water potential (Ψ), instantaneous water use efficiency (WUE), and internal CO2 concentration (Ci) were measured at three periods of the growing season: spring, summer (June or July) and late summer (September) over two years. Ferraduel, Ferrastar, and Marcona presented the best performance in the periods when environmental conditions were not very hard (May or September). Casa Nova and Non Pareil were well adapted to high air evaporative demand, preventing the increase of leaf temperature (T1). Ferrastar, although having a good performance in May and September, did well adapt to hard climatic conditions in June 1994. In the following year, although it presented the highest T1, the values were not limiting (30.6 ± 2.1 °C), and PN was only decreased from May to July. Marcona was highly dependent on T1, but prevented its increasing. Garrigues showed lower PN in most measurement periods. GF677 frequently induced the highest PN, WUE, and Ψ. PN was mainly dependent on T1, radiation, Ci, month, and year. WUE depended on the same factors. Ψ depended mainly on gs, air temperature, month, and year. This revised version was published online in June 2006 with corrections to the Cover Date.     

Occurrence of grapevine chrome mosaic nepovirus in Austria

A virus recovered by inoculation of sap from Austrian vines with yellow mosaic symptoms was compared with, and found virtually indistinguishable from, an authentic Hungarian isolate of grapevine chrome mosaic nepovirus. This seems to be the first record of the virus in Austria.     

Translocation from the chloroplast stroma into the thylakoid lumen allows expression of recombinant epidermal growth factor in transplastomic tobacco plants

Transgenic Research - Chloroplast transformation has many potential advantages for the production of recombinant proteins in plants. However, it has been reported that chloroplast expression of...     

Origin of the cultivated passion fruit Passiflora edulis f. flavicarpa and genomic relationships among species of the subgenera Decaloba and Passiflora

• Passiflora edulis f. flavicarpa is the most economically important species in the genus Passiflora. However, the origin of this yellow form of passion fruit remains unclear, being suggested as a hybrid (P. edulis f. edulis × P. ligularis) or wild mutant.
• Here, the origin and genomic relationships of P. edulis f. flavicarpa with some related species in the genus Passiflora (subgenera Decaloba and Passiflora) were investigated using genomic in situ hybridization (GISH). Genomic DNA of 18 species was used as probe, which was hybridized onto chromosomes of P. edulis f. flavicarpa.
• Of all genomic DNA probes tested, none allowed us to identify a specific chromosome set in P. edulis f. flavicarpa. Conversely, probes from the subgenus Passiflora, P. edulis f. edulis, P. alata, P. cincinnata, P. coccinea, P. nitida and P. vitifolia, produced intense and uniform hybridizations on all chromosomes of P. edulis f. flavicarpa. Moreover, probes from P. ligularis, P. foetida and P. sublanceolata produced more intense hybridizations in the terminal region of four chromosomes, corresponding to the DNAr 45S locus, and also dispersed, less intense, hybridization across all chromosomes. Probes from the subgenus Decaloba, P. biflora, P. capsularis, P. cervii, P. coriacea, P. micropetala, P. morifolia, P. rubra and P. suberosa, produced hybridizations restricted to the DNAr 45S sites.
• The hybrid origin of P. edulis f. flavicarpa could not be supported based on the GISH results, and it is suggested that this species is conspecific with P. edulis f. edulis, because the probe with DNA of this form hybridized strongly throughout the target genome. The other putative parent species, P. ligularis, showed only a distant relationship with the target genome. The results also suggest that species of the subgenus Passiflora share many repetitive sequences and that the relationship between subgenera Decaloba and Passiflora is very distant.