Synthesis and biological evaluation of potential modulators of malarial glutathione-S-transferase(s)

Glutathione-S-transferase(s) (E.C.2.5.1.18, GSTs) have been investigated in parasitic protozoans with respect to their biochemistry and they have been identified as potential vaccine candidates in protozoan parasites and as a target in the synthesis of new antiparasitic agents. In a search towards the identification of novel biochemical targets for antimalarial drug design, the area of Plasmodium glutathione metabolism provides a number of promising chemotherapeutic targets. GST activity was determined in various subcellular fractions of malarial parasites Plasmodium yoelii and was found to be localized mainly in the cytosolic fraction (specific activity, c. 0.058 ± 0.016 μmol/min/mg protein). Hemin, a known inhibitor of mammalian GST(s), maximally inhibited this enzyme from P. yoelii to nearly 86%. In a search towards synthetic modulators of malarial GST(s), 575 compounds belonging to various chemical classes were screened for their effect on crude GST from P. yoelii and 92 compounds belonging to various chemical classes were studied on recombinant GST from P. falciparum. Among all the compounds screened, 83 compounds inhibited/stimulated the enzyme from P. yoelii/P. falciparum to the extent of 40% or more.     

Phosphate solubilizing bacteria enhanced growth,oil yield,antioxidant properties and biodiesel quality of Kasumbha

Biodiesel is considered as a potential alternative energy source, but problem exists with the quantity and quality of feedstock used for it. To improve the feedstock quality of biodiesel, a field experiment was conducted under natural conditions. Cultivar Thori of kasumbha was used in the experiment. Commercialized biofertilizers were applied at the rate of 20 kg per acre and chemical fertilizer (diammonium phosphate) was applied as half dose (15 kg/ha). Results indicated that number of leaf plant⁻¹, leaf area, number of seeds capitulum⁻¹ was significantly increased by biofertilizer treatment alone (BF) and combine treatment of biofertilizer and chemical fertilizer (BFCF). Agronomic traits such as plant height, no. of branches of a plant, no. of capitulum/plant was improved significantly by BF treatment over the control. Maximum 1000 seed weight (41%) and seed yield (23%) were recorded in half dose of chemical fertilizers treatment (CFH). Seed oil content and seed phenolics were significantly improved by BF and CF treatments while maximum biodiesel yield was recorded by BF treatment. Maximum oleic acid was recorded by BF treatment while other fatty acids being maximum in control except linoleic acid in BFCF treatment. Results for specific gravity were non-significant while acid value and free fatty acid contents were substantially reduced by BF treatment as compared to other treatments. Maximum value of iodine number was recorded in BFCF treatment while tocopherol contents were improved by BF treatment. It is inferred that biofertilizer treatment alone perform better as compared to other treatments and 50% chemical fertilizer can be replaced using biofertilizer which is a good approach for sustainable environmental-friendly agriculture.Keyword: Green energy, Biofuel, Biodiesel, Kasumbha, Biofertilizers, Fatty acid, NMR     

Imaging and therapy of malignant pleural mesothelioma using replication-competent herpes simplex viruses

BACKGROUND: Malignant pleural mesothelioma (MPM) is an aggressive cancer that is refractory to current treatment modalities. Oncolytic herpes simplex viruses (HSV) used for gene therapy are genetically engineered, replication-competent viruses that selectively target tumor cells while sparing normal host tissue. The localized nature, the potential accessibility and the relative lack of distant metastasis make MPM a particularly suitable disease for oncolytic viral therapy. METHODS: The infectivity, selective replication, vector spread and cytotoxic ability of three oncolytic HSV: G207, NV1020 and NV1066, were tested against eleven pathological types of MPM cell lines including those that are resistant to radiation therapy, gemcitabine or cisplatin. The therapeutic efficacy and the effect on survival of NV1066 were confirmed in a murine MPM model. RESULTS: All three oncolytic HSV were highly effective against all the MPM cell lines tested. Even at very low concentrations of MOI 0.01 (MOI: multiplicity of viral infection, ratio of viral particles per cancer cell), HSV were highly effective against MPM cells that are resistant to radiation, gemcitabine and cisplatin. NV1066, an oncolytic HSV that expresses green fluorescent protein (GFP), was able to delineate the extent of the disease in a murine model of MPM due to selective infection and expression of GFP in tumor cells. Furthermore, NV1066 was able to reduce the tumor burden and prolong survival even when treatment was at an advanced stage of the disease. CONCLUSION: These findings support the continued investigation of oncolytic HSV as potential therapy for patients with therapy-resistant MPM.     

Modelling multivariate outcomes in hierarchical data, with application to cluster randomised trials

In the cluster randomised study design, the data collected have a hierarchical structure and often include multivariate outcomes. We present a flexible modelling strategy that permits several normally distributed outcomes to be analysed simultaneously, in which intervention effects as well as individual-level and cluster-level between-outcome correlations are estimated. This is implemented in a Bayesian framework which has several advantages over a classical approach, for example in providing credible intervals for functions of model parameters and in allowing informative priors for the intracluster correlation coefficients. In order to declare such informative prior distributions, and fit models in which the between-outcome covariance matrices are constrained, priors on parameters within the covariance matrices are required. Careful specification is necessary however, in order to maintain non-negative definiteness and symmetry between the different outcomes. We propose a novel solution in the case of three multivariate outcomes, and present a modified existing approach and novel alternative for four or more outcomes. The methods are applied to an example of a cluster randomised trial in the prevention of coronary heart disease. The modelling strategy presented would also be useful in other situations involving hierarchical multivariate outcomes.     

Crystal structure of a Cbf5-Nop10-Gar1 complex and implications in RNA-guided pseudouridylation and dyskeratosis congenita

H/ACA RNA-protein complexes, comprised of four proteins and an H/ACA guide RNA, modify ribosomal and small nuclear RNAs. The H/ACA proteins are also essential components of telomerase in mammals. Cbf5 is the H/ACA protein that catalyzes isomerization of uridine to pseudouridine in target RNAs. Mutations in human Cbf5 (dyskerin) lead to dyskeratosis congenita. Here, we describe the 2.1 A crystal structure of a specific complex of three archaeal H/ACA proteins, Cbf5, Nop10, and Gar1. Cbf5 displays structural properties that are unique among known pseudouridine synthases and are consistent with its distinct function in RNA-guided pseudouridylation. We also describe the previously unknown structures of both Nop10 and Gar1 and the structural basis for their essential roles in pseudouridylation. By using information from related structures, we have modeled the entire ribonucleoprotein complex including both guide and substrate RNAs. We have also identified a dyskeratosis congenita mutation cluster site within a modeled dyskerin structure.     

Influence of initial cellulose concentration on the carbon flow distribution during batch fermentation by Clostridium thermocellum ATCC 27405

The objective of this research was to understand how carbon loading influences hydrogen (H₂) synthesis and metabolic flow patterns in the thermophilic, cellulolytic bacterium, Clostridium thermocellum. C. thermocellum was cultivated in batch cultures with high (5 g L⁻¹) and low (1 g L⁻¹) initial concentrations of α-cellulose at 60°C. The growth rate of C. thermocellum was 22% lower (0.15 h⁻¹) in cultures with low-cellulose concentration compared with cultures with high-cellulose concentrations. Although substrate depletion coincided with the end of log-growth in low-cellulose cultures, the prime reason for growth arrest in high-cellulose cultures was not identified. Ethanol, acetate, and formate were the major soluble end-products with concomitant release of H₂ and CO₂ under both conditions. Lactate appeared during the late log phase in high-carbon cultures when pH dropped below 6.4 and became the major end-product in stationary phase. During the exponential phase of cell growth, significantly higher yields for H₂ and acetate (1.90 ± 0.14 and 1.11 ± 0.04 mol/mol glucose equivalent, respectively) were obtained from low-cellulose cultures compared to those from high-cellulose cultures. The maximum specific rate of H₂ production, 6.41 ± 0.13 mmol H₂/g dry cell/h, obtained during the exponential phase from low-carbon cultures was about 37% higher than that obtained from high-carbon cultures.     

Proteomic analysis of increased Parkin expression and its interactants provides evidence for a role in modulation of mitochondrial function

Parkin is an ubiquitin‐protein ligase (E3), mutations of which cause juvenile onset – autosomal recessive Parkinson's disease, and result in reduced enzymic activity. In contrast, increased levels are protective against mitochondrial dysfunction and neurodegeneration, the mechanism of which is largely unknown. In this study, 2‐DE and MS proteomic techniques were utilised to investigate the effects of increased Parkin levels on protein expression in whole cell lysates using in an inducible Parkin expression system in HEK293 cells, and also to isolate potential interactants of Parkin using tandem affinity purification and MS. Nine proteins were significantly differentially expressed (±2‐fold change; p<0.05) using 2‐DE analysis. MS revealed the identity of these proteins to be ACAT2, HNRNPK, HSPD1, PGK1, PRDX6, VCL, VIM, TPI1, and IMPDH2. The first seven of these were reduced in expression. Western blot analysis confirmed the reduction in one of these proteins (HNRNPK), and that its levels were dependent on 26S proteasomal activity. Tandem affinity purification/MS revealed 14 potential interactants of Parkin; CKB, DBT, HSPD1, HSPA9, LRPPRC, NDUFS2, PRDX6, SLC25A5, TPI1, UCHL1, UQCRC1, VCL, YWHAZ, YWHAE. Nine of these are directly involved in mitochondrial energy metabolism and glycolysis; four were also identified in the 2‐DE study (HSP60, PRDX6, TPI1, and VCL). This study provides further evidence for a role for Parkin in regulating mitochondrial activity within cells.     

Toxic Effect of Nickel (Ni) on Growth and Metabolism in Germinating Seeds of Sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.)

To assess the toxic effect of nickel (Ni) on the growth and some key metabolic processes in sunflower, varying levels of Ni as Ni(NO₃)₂ up to 60 mg L⁻¹ were applied once to sunflower cultivars SF-187 and Hysun-33 at sowing time in sand culture. An increase in Ni in the growth medium adversely affected growth parameters, sugar concentration (both reducing and non-reducing), as well as the activities of α-amylase and protease. It also slowed down mobilization of stored proteins and amino acids in the germinating seeds. However, an increase in the activities of α-amylase and protease was observed over time from 24 to 120 h after sowing. Cultivar Hysun-33 showed better performance than SF-187 in the presence of excess Ni. Overall, Ni-induced reduction in germination of sunflower seed appeared to be due to disturbance in biochemical metabolism as the availability of sugars for the synthesis of metabolic energy as well as necessary amino acids for the synthesis of proteins and enzymes essential for the growing embryo are generally reduced due to suppression in α-amylase and protease activities.     

Leptin Production by Encapsulated Adipocytes Increases Brown Fat,Decreases Resistin,and Improves Glucose Intolerance in Obese Mice

The neuroendocrine effects of leptin on metabolism hold promise to be translated into a complementary therapy to traditional insulin therapy for diabetes and obesity. However, injections of leptin can provoke inflammation. We tested the effects of leptin, produced in the physiological adipocyte location, on metabolism in mouse models of genetic and dietary obesity. We generated 3T3-L1 adipocytes constitutively secreting leptin and encapsulated them in a poly-L-lysine membrane, which protects the cells from immune rejection. Ob/ob mice (OB) were injected with capsules containing no cells (empty, OB^[Emp]), adipocytes (OB^[3T3]), or adipocytes overexpressing leptin (OB^[Lep]) into both visceral fat depots. Leptin was found in the plasma of OB^[Lep], but not OB^[Emp] and OB^[3T3] mice at the end of treatment (72 days). The OB^[Lep] and OB^[3T3] mice have transiently suppressed appetite and weight loss compared to OB^[Emp]. Only OB^[Lep] mice have greater brown fat mass, metabolic rate, and reduced resistin plasma levels compared to OB^[Emp]. Glucose tolerance was markedly better in OB^[Lep] vs. OB^[Emp] and OB^[3T3] mice as well as in wild type mice with high-fat diet-induced obesity and insulin resistance treated with encapsulated leptin-producing adipocytes. Our proof-of-principle study provides evidence of long-term improvement of glucose tolerance with encapsulated adipocytes producing leptin.     

How dopamine enhances an optimism bias in humans

When predicting financial profits [1], relationship outcomes [2], longevity [3], or professional success [4], people habitually underestimate the likelihood of future negative events (for review see [5]). This well-known bias, termed unrealistic optimism [6], is observed across age [7], culture [8], and species [9] and has a significant societal impact on domains ranging from financial markets to health and well being. However, it is unknown how neuromodulatory systems impact on the generation of optimistically biased beliefs. This question assumes great importance in light of evidence that common neuropsychiatric disorders, such as depression, are characterized by pessimism [10, 11]. Here, we show that administration of a drug that enhances dopaminergic function (dihydroxy-L-phenylalanine; L-DOPA) increases an optimism bias. This effect is due to L-DOPA impairing the ability to update belief in response to undesirable information about the future. These findings provide the?first evidence that the neuromodulator dopamine impacts on belief formation by reducing negative expectations regarding the future.