Pyrophosphate-stimulated uptake of calcium into the germlings of Phytophthora infestans.

The uptake of 1 micrometer calcium into 6-h-old germination tubes of the fungus Phytophthora infestans follows Michaelis-Menten kinetics with a Km of 33 +/- 4 micrometer and a V of 0.3 nmol.min-1.(5 x 10(4) cells)-1.Uptake is inhibited by ruthenium red and lanthanum (both at 1 micrometer) and by the proton conductors 2,4-dinitrophenol (1 mM) and carbonylcyanide m-chlorophenylhydrazone and carbonylcyanide p-trifluoromethoxyphenylhydrazone (1--10 micrometer) and also by sodium azide. These data suggest that calcium uptake is dependent on energy and on a carrier. Calcium uptake is stimulated by pyrophosphate but not by ATP, orthophosphate, or polyphosphate. This stimulation is prevented by proton conductors or by incubation at 0 degrees C.     

Intestinal endotoxin as a trigger of type 1 diabetes mellitus

The blood serum level of intestinal flora endotoxin was studied in 45 children and adolescents aged 3–17 years with type 1 diabetes mellitus. In all the patients the endotoxin levels 2.89 ± 0.33 EU/ml) were significantly elevated compared to the control group (0.4 ± 0.03 EU/ml). A higher level of endotoxin at the disease onset (3.93 ± 0.79 EU/ml) compared to that in children afflicted with diabetes for more than two years (2.37 ± 0.27 EU/ml) gives evidence of the involvement of endotoxin in the initiation of the disease.     

Coupling of M3 Acetylcholine Receptor to Gq16 Activates a Natriuretic Peptide Receptor Guanylyl Cyclase

Muscarinic activation of tracheal smooth muscle (TSM) involves a M₃AChR/heterotrimeric-G protein/NPR-GC coupling mechanism. G protein activators Mastoparan (MAS) and Mastoparan-7 stimulated 4- and 10-fold the NPR-GC respectively, being insensitive to PTX and antibodies against Gα_i/o subfamily. Muscarinic and MAS stimulation of NPR-GC was blocked by antibodies against C-terminal of Gα_q16, whose expression was confirmed by RT-PCR. However, synthetic peptides from C-terminal of Gα_q15/16 stimulated the NPR-GC. Coupling of α_q16 to M₃AChR is supported by MAS decreased [³H]QNB binding, being abolished after M₃AChR-4-DAMP-alkylation. Anti-i₃M₃AChR antibodies blocked the muscarinic activation of NPR-GC, and synthetic peptide from i₃M₃AChR (M₃P) was more potent than MAS increasing GTPγ [³⁵S] and decreasing the [³H]QNB activities. Coupling between NPR-GC and Gα_q16 was evaluated by using trypsin-solubilized-fraction from TSM membranes, which displayed a MAS-sensitive-NPR-GC activity, being immunoprecipitated with anti-Gα_q16, also showing an immunoreactive heterotrimeric-G-β -subunit. These data support the existence of a novel transducing cascade, involving Gα_q16β γ coupling M₃AChR to NPR-GC.     

A cryptic invasion within an invasion and widespread introgression in the European water frog complex: consequences of uncontrolled commercial trade and weak international legislation

In Western Europe, many pond owners introduce amphibians for ornamental purposes. Although indigenous amphibians are legally protected in most European countries, retailers are circumventing national and international legislation by selling exotic nonprotected sibling species. We investigated to what extent non‐native species of the European water frog complex (genus Pelophylax) have become established in Belgium, using morphological, mitochondrial and nuclear genetic markers. A survey of 87 sampling sites showed the presence of non‐native water frogs at 47 locations, mostly Marsh frogs (Pelophylax ridibundus). Surprisingly, at least 19% of all these locations also harboured individuals with mitochondrial haplotypes characteristic of Anatolian water frogs (Pelophylax cf. bedriagae). Nuclear genotyping indicated widespread hybridization and introgression between P. ridibundus and P. cf. bedriagae. In addition, water frogs of Turkish origin obtained through a licensed retailer, also contained P. ridibundus and P. cf. bedriagae, with identical haplotypes to the wild Belgian populations. Although P. ridibundus might have invaded Belgium by natural range expansion from neighbouring countries, our results suggest that its invasion was at least partly enhanced by commercial trade, with origins as far as the Middle East. Also the invasion and rapid spread of Anatolian lineages, masked by their high morphological similarity to P. ridibundus, is likely the result of unregulated commercial trade. We expect that Anatolian frogs will further invade the exotic as well as the native range of P. ridibundus and other Pelophylax species elsewhere in Western and Central Europe, with risks of large‐scale hybridization and introgression.     

A holistic high-throughput screening framework for biofuel feedstock assessment that characterises variations in soluble sugars and cell wall composition in <Emphasis Type="Italic">Sorghum bicolor</Emphasis>

Background

A major hindrance to the development of high yielding biofuel feedstocks is the ability to rapidly assess large populations for fermentable sugar yields. Whilst recent advances have outlined methods for the rapid assessment of biomass saccharification efficiency, none take into account the total biomass, or the soluble sugar fraction of the plant. Here we present a holistic high-throughput methodology for assessing sweet Sorghum bicolor feedstocks at 10 days post-anthesis for total fermentable sugar yields including stalk biomass, soluble sugar concentrations, and cell wall saccharification efficiency.

Results

A mathematical method for assessing whole S. bicolor stalks using the fourth internode from the base of the plant proved to be an effective high-throughput strategy for assessing stalk biomass, soluble sugar concentrations, and cell wall composition and allowed calculation of total stalk fermentable sugars. A high-throughput method for measuring soluble sucrose, glucose, and fructose using partial least squares (PLS) modelling of juice Fourier transform infrared (FTIR) spectra was developed. The PLS prediction was shown to be highly accurate with each sugar attaining a coefficient of determination (R ² ) of 0.99 with a root mean squared error of prediction (RMSEP) of 11.93, 5.52, and 3.23 mM for sucrose, glucose, and fructose, respectively, which constitutes an error of <4% in each case. The sugar PLS model correlated well with gas chromatography–mass spectrometry (GC-MS) and brix measures. Similarly, a high-throughput method for predicting enzymatic cell wall digestibility using PLS modelling of FTIR spectra obtained from S. bicolor bagasse was developed. The PLS prediction was shown to be accurate with an R ² of 0.94 and RMSEP of 0.64 μg.mgDW^-1.h^-1.

Conclusions

This methodology has been demonstrated as an efficient and effective way to screen large biofuel feedstock populations for biomass, soluble sugar concentrations, and cell wall digestibility simultaneously allowing a total fermentable yield calculation. It unifies and simplifies previous screening methodologies to produce a holistic assessment of biofuel feedstock potential.

     

Vacuoles: main compartments of potassium, magnesium, and phosphate ions in Saccharomyces carlsbergenis cells.

The uneven distribution of Mg2+, K+, and phosphate in Saccharomyces carlsbergensis was demonstrated by the differential extraction of ions. Their concentrations were 5, 60, and 1 mM in the cytoplasm and 73, 470, and 110 mM in vacuoles, respectively. The intracellular gradients of these ions were 1:15, 1:8, and 1:110, respectively, across the tonoplast. The determination of free Mg2+ (1.35 mM in the cytosol and 20 mM in vacuoles) showed that the ion accumulation in vacuoles could not be explained by the higher degree of ion complexing in these organelles.     

Intestinal endotoxin in induction of type 1 diabetes

We studied serum level of intestinal flora endotoxin (LPS) in 45 children and adolescents aged 3-17 years old with diabetes mellitus type 1. Levels of endotoxin, were significantly elevated in type 1 diabetic patients (2.89 +/- 0.33 Eu/ml) compared with control (0.4 +/- 0.03 Eu/ml). There was significant difference in serum LPS levels in patients with type 1 diabetes onset (3.93 +/- 0.79 Eu/ml) compared with children and adolescent with old time diabetes (2.37 +/- 0.27 Eu/ml). These results have a major implication on our understanding of the role of gut flora endotoxin in pathogenesis of type 1 diabetes.