Intraspecific variation in the venom of the vermivorous cone snail Conus vexillum

A combination of proteomic and biochemical assays was used to examine variations in the venom of Conus vexillum taken from two locations (Hurgada and Sharm El-Shaikh) in the Red Sea, Egypt. Using MALDI/TOF-MS, a remarkable degree of intra-species variation between venom samples from both locations was identified. To evaluate variability in the cytotoxic effects of Conus venom, mice were injected with the same dose from each location. The oxidative stress biomarkers [malondialdehyde (MDA), protein carbonyl content (PCC)], antioxidants [glutathione (GSH), superoxide dismutase (SOD), catalase (CAT)], total antioxidant capacity (TAC) and nitric oxide (NO), were measured 3, 6, 9 and 12 h post venom injection. The venoms induced a significant increase in the levels of PCC, MDA, NO, GSH and CAT. The venoms significantly inhibited the activity of SOD and reduced the TAC. Toxicological data showed that the venom obtained from Hurgada was more potent than that obtained from Sharm El-Shaikh. It can be concluded that: (1) the venom of the same Conus species from different regions is highly diversified (2) the venoms from different locations reflect clear differences in venom potency and (3) the cytotoxic effects of C. vexillum venom can be attributed to its ability to induce oxidative stress.     

不同耕作措施对冬小麦-夏玉米复种连作系统土壤有机碳和水分利用效率的影响

在连续8年田间定位试验的基础上,分析了关中平原冬小麦 夏玉米复种连作系统2008—2009年连续两个生长季期间不同耕作措施(结合秸秆还田和不还田)对土壤有机碳和水分利用率的影响.结果表明: 相对于传统耕作,保护性耕作有利于土壤有机碳、水分利用效率和作物产量的提高,其中在“深松+秸秆还田”耕作模式下的增幅最高,土壤有机碳含量在0～30 cm土层增幅达到19.5%,水分利用效率和作物产量提高了16.9%和20.5%,而免耕模式则有效提高了0～10 cm土层有机碳含量.在该地区土壤和气候条件下,深松结合秸秆粉碎还田是最理想的耕作模式,最有利于土壤有机碳累积,并提高水分利用效率和作物产量.     

Delivery of cytoplasmic proteins to autophagosomes

Autophagy represents a signaling-dependent regulated process that allows the degradation of some cellular proteins in autophagosomes, and plays a critical role in the management of cellular homeostasis under various stress conditions. In recent years, selective degradation of cytoplasmic proteins during stress has attracted considerable scientific interest. Here we examined the ability of resveratrol to induce autophagy in a variety of human cancer cell lines. We found that resveratrol-induced autophagy is accompanied by colocalization of proline-, glutamic acid-, and leucine-rich protein-1 (PELP1) with the green fluorescent protein-microtubule-associated protein 1 light chain 3 (GFP-LC3) in autophagosomes. In addition, we found that hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), a previously shown PELP1-interacting protein, is co-recruited to autophagosomes in the presence of resveratrol. Although autophagy has been assumed to be a bulk and non-selective degradation process, in recent years, evidence of selective degradation of cytosolic proteins and organelles by autophagy is mounting. These observations suggest that the interaction of the target protein(s) with the delivery protein or proteins such as HRS facilitates the transport of certain cytoplasmic proteins to autophagosomes for their selective degradation, and thus, could influence the cytoplasmic as well as nuclear functions of nuclear receptor coregulators. Since PELP1 and, perhaps, other nuclear receptor coregulators are widely dysregulated in human cancers, these findings highlight the significance of the autophagic selective degradation of PELP1 following resveratrol (or other phytoestrogens) treatment in developing future strategies to use resveratrol under cancer prevention and therapeutic settings.     

Identification of 100 KDa protein in sera of mice-treated with Cu(II) complex with superoxide dismutase-mimetic activity

The protein profile of sera isolated from mice pre-treated with Cu(II) complex of Girard T with superoxide dismutase (SOD)-mimetic activity was analyzed using SDS-PAGE. This complex was intraperitoneally administered (10 mg/Kg body weight) to Swiss albino mice. The resolved polypeptides showed a new sharp band at 100 KDa against which a polyclonal antibody was raised in rabbit. Sera of rabbit anti-100 KDa protein was used as a powerful probe for the detection of 100 KDa protein isolated from sera of treated mice. Western blot assays revealed a strong reactive polypeptide band at 100 KDa in sera of the mice, but no cross reaction was observed with sera of normal mice. The identification of purified polypeptide was confirmed by different characterization experiments.     

Physiology and characterization of a fungal milk-clotting enzyme from Aspergillus flavus.

Aspergillus flavus produced extracellularly an active rennin-like enzyme when grown aerobically in whey media. The enzyme was detected at early stages of growth reaching a maximum after three to four days at 25 degrees. The activity was destroyed by heating to temperatures higher than 50 degrees, whereas the presence of skim milk during heating preserved the enzyme activity, at least, up to 70 degrees. Calcium chloride significantly stimulated the milk-clotting activity up to 1% final concentration. The clotting time was inversely proportional to protein concentration in the range 0.2-0.6 mg/ml and the enzyme exhibited marked stability when stored at 37 degrees at pH 6.     

L<Subscript>2</Subscript>-norm multiple kernel learning and its application to biomedical data fusion

Background  

This paper introduces the notion of optimizing different norms in the dual problem of support vector machines with multiple kernels. The selection of norms yields different extensions of multiple kernel learning (MKL) such as L _∞, L ₁, and L ₂ MKL. In particular, L ₂ MKL is a novel method that leads to non-sparse optimal kernel coefficients, which is different from the sparse kernel coefficients optimized by the existing L _∞ MKL method. In real biomedical applications, L ₂ MKL may have more advantages over sparse integration method for thoroughly combining complementary information in heterogeneous data sources.     

Comparative analysis of DNA polymorphisms and phylogenetic relationships among Syzygium cumini Skeels based on phenotypic characters and RAPD technique

The Indian black berry (Syzygium cumini Skeels) has a great nutraceutical and medicinal properties. As in other fruit crops, the fruit characteristics are important attributes for differentiation were also determined for different accessions of S. cumini. The fruit weight, length, breadth, length: breadth ratio, pulp weight, pulp content, seed weight and pulp: seed ratio significantly varied in different accessions. Molecular characterization was carried out using PCR based RAPD technique. Out of 80 RAPD primers, only 18 primers produced stable polymorphisms that were used to examine the phylogenetic relationship. A sum of 207 loci were generated out of which 201 loci found polymorphic. The average genetic dissimilarity was 97 per cent among jamun accessions. The phylogenetic relationship was also determined by principal coordinates analysis (PCoA) that explained 46.95 per cent cumulative variance. The two-dimensional PCoA analysis showed grouping of the different accessions that were plotted into four sub-plots, representing clustering of accessions. The UPGMA (r = 0.967) and NJ (r = 0.987) dendrogram constructed based on the dissimilarity matrix revealed a good degree of fit with the cophenetic correlation value. The dendrogram grouped the accessions into three main clusters according to their eco-geographical regions which given useful insight into their phylogenetic relationships.     

Synthesis of some 3-hydroxynaphthalene-2-carbonylamino acid and dipeptide derivatives

Synthesis of a series of 3-hydroxynaphthalene-2-carbonylamino acid methyl esters (II-XI) and some of their corresponding hydrazides (XII-XXI), dipeptide methyl esters (XXII-XXXV) and dipeptide hydrazides (XXXVI-XXXIX) is described. 3-Hydroxynaphthalene-2-CO-L-Tyr-N2H3 (XX) and the corresponding L-Val-L-Ala-N2H3 (XXXVI) were found to be active against a number of micro-organisms.