Metabolic and molecular action of <Emphasis Type="Italic">Trigonella foenum-graecum</Emphasis> (fenugreek) and trace metals in experimental diabetic tissues

Diabetes mellitus is a heterogeneous metabolic disorder characterized by hyperglycaemia resulting in defective insulin secretion, resistance to insulin action or both. The use of biguanides, sulphonylurea and other drugs are valuable in the treatment of diabetes mellitus; their use, however, is restricted by their limited action, pharmaco-kinetic properties, secondary failure rates and side effects. Trigonella foenum-graecum, commonly known as fenugreek, is a plant that has been extensively used as a source of antidiabetic compounds from its seeds and leaf extracts. Preliminary human trials and animal experiments suggest possible hypoglycaemic and anti-hyperlipedemic properties of fenugreek seed powder taken orally. Our results show that the action of fenugreek in lowering blood glucose levels is almost comparable to the effect of insulin. Combination with trace metal showed that vanadium had additive effects and manganese had additive effects with insulin on in vitro system in control and diabetic animals of young and old ages using adipose tissue. The Trigonella and vanadium effects were studied in a number of tissues including liver, kidney, brain peripheral nerve, heart, red blood cells and skeletal muscle. Addition of Trigonella to vanadium significantly removed the toxicity of vanadium when used to reduce blood glucose levels. Administration of the various combinations of the antidiabetic compounds to diabetic animals was found to reverse most of the diabetic effects studied at physiological, biochemical, histochemical and molecular levels. Results of the key enzymes of metabolic pathways have been summarized together with glucose transporter, Glut-4 and insulin levels. Our findings illustrate and elucidate the antidiabetic/insulin mimetic effects of Trigonella, manganese and vanadium.     

Assessment of gut bacteria for a paratransgenic approach to control Dermolepida albohirtum larvae

Bacteria from the hindguts of Dermolepida albohirtum larvae were assessed for their potential to be used in paratransgenic strategies that target scarab pests of sugarcane. Bacteria isolated in pure culture from the hindguts of D. albohirtum larvae were from the Proteobacteria, Firmicutes, and Actinobacteria phyla and matched closely with taxa from intestinal and rhizosphere environments. However, these isolates were not the most common gut-associated bacteria identified in denaturing gradient gel electrophoresis (DGGE) hindgut profiles. Subsequently, eight species of gut bacteria were fed to larvae, and RNA-based DGGE analysis of 16S rRNA was used to detect the persistence of these isolates in the hindgut environment. One of these isolates (Da-11) remained metabolically active in the hindgut for 19 days postconsumption. Da-11 most likely forms a new genus within the Burkholderiales order, along with taxa independently identified from larvae of the European scarab pest, Melolontha melolontha. Using the EZ::Tn5 transposon system, a kanamycin resistance gene was inserted into the chromosome of Da-11, thus establishing a stable transformation technique for this species. A second feeding trial that included inoculating approximately 400 transgenic Da-11 cells onto a food source resulted in a density of 1 x 10(6) transgenic Da-11 cells/ml in the hindguts of larvae at 9 days postconsumption. These populations were maintained in the hindgut for at least another 12 days. The successful isolation, genetic transformation, and establishment of transgenic Da-11 cells in the hindguts of D. albohirtum larvae fulfill fundamental requirements for the future development of a paratransgenic approach to control scarab pests of sugarcane.     

A comparative genomics study of genetic products potentially encoding ladderane lipid biosynthesis

Background  

The fatty acids of anaerobic ammonium oxidizing (anammox) bacteria contain linearly concatenated cyclobutane moieties, so far unique to biology. These moieties are under high ring strain and are synthesised by a presently unknown biosynthetic pathway.     

Analysis of cardiac signals using spatial filling index and time-frequency domain

Background  

Analysis of heart rate variation (HRV) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS). HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generating the signal is not simply linear, but also involves nonlinear contributions. These signals are essentially non-stationary; may contain indicators of current disease, or even warnings about impending diseases. The indicators may be present at all times or may occur at random in the time scale. However, to study and pinpoint abnormalities in voluminous data collected over several hours is strenuous and time consuming.     

Symmetric cyanine dyes for detecting nucleic acids

A novel approach to the design of sensitive fluorescent probes for nucleic acids detection is proposed. Suitable modifications of tri- and pentamethine cyanine dyes in the polymethine chain and/or in the heterocyclic residues can result in a significant decrease in unbound dye fluorescence intensity and an increase in dye emission intensity in the presence of DNA compared to the unsubstituted dye. The sharp enhancement in the fluorescence intensity upon dye interaction with double-stranded DNA permits the application of the modified tri- and pentamethine dyes as fluorescent probes in double-stranded DNA detection in homogeneous assays.     

Chemical inhibition of acetyl coenzyme A carboxylase as a strategy to increase polyhydroxybutyrate yields in transgenic sugarcane

Polyhydroxybutyrate (PHB) is a naturally occurring bacterial polymer that can be used as a biodegradable replacement for some petrochemical‐derived plastics. Polyhydroxybutyrate is produced commercially by fermentation, but to reduce production costs, efforts are underway to produce it in engineered plants, including sugarcane. However, PHB levels in this high‐biomass crop are not yet commercially viable. Chemical ripening with herbicides is a strategy used to enhance sucrose production in sugarcane and was investigated here as a tool to increase PHB production. Class A herbicides inhibit ACCase activity and thus reduce fatty acid biosynthesis, with which PHB production competes directly for substrate. Treatment of PHB‐producing transgenic sugarcane plants with 100 μm of the class A herbicide fluazifop resulted in a fourfold increase in PHB content in the leaves, which peaked ten days post‐treatment. The minimum effective concentration of herbicide required to maximize PHB production was 30 μm for fluazifop and 70 μm for butroxydim when applied to saturation. Application of a range of class A herbicides from the DIM and FOP groups consistently resulted in increased PHB yields, particularly in immature leaf tissue. Butroxydim or fluazifop treatment of mature transgenic sugarcane grown under glasshouse conditions increased the total leaf biomass yield of PHB by 50%–60%. Application of an ACCase inhibitor in the form of a class A herbicide to mature sugarcane plants prior to harvest is a promising strategy for improving overall PHB yield. Further testing is required on field‐grown transgenic sugarcane to more precisely determine the effectiveness of this strategy.     

Variable infection frequency and high diversity of multiple strains of Wolbachia pipientis in Perkinsiella Planthoppers

This survey of Wolbachia infections in populations of the planthoppers Perkinsiella saccharicida and Perkinsiella vitiensis revealed variable frequencies, low-titer infections, and high phylogenetic diversities of strains. These observations add to the growing realization that Wolbachia infections may be extremely common within invertebrates and yet occur infrequently within populations and at low titer within individuals.