Multivariate statistical characterization of groundwater quality in Ain Azel plain, Algeria

Multivariate statistical techniques, cluster and principal component analysis were applied to the data on groundwater quality of Ain Azel plain (Algeria), to extract principal factors corresponding to the different sources of variation in the hydrochemistry, with the objective of defining the main controls on the hydrochemistry at the plain scale. Q-mode hierarchical cluster analysis grouped 54 groundwater samples into three clusters, that is, relatively less saline water (group 1), mixed water (group 2) and blended water (group 3), based on the similarity of groundwater quality characteristics. Principal component analysis, applied to the data sets of the three different groups obtained from hierarchical cluster analysis, resulted in four, five and three latent factors explaining 83.21, 83.36 and 87.30% of the total variance in groundwater quality data sets of group 1, group 2 and group 3, respectively. The varifactors obtained from PCA indicate that the parameters responsible for groundwater quality variations are mainly related to presence and dissolution of some carbonate, dolomitic and evaporite minerals; natural processes and water-rock interaction in the three water types. The results of this study clearly demonstrate the usefulness of multivariate statistical analysis in hydro chemical.Key words: Cluster analysis, principal component analysis, hydrochemistry, Ain Azel plain, Algeria

Characterization and evaluation of the factors affecting the geochemistry of surface water of Koudiat Medouar Basin, Algeria

Hydrochemistry of surface water in Koudiat Medouar Basin, Algeria was used to assess the quality of surface water for determining its suitability for drinking and agricultural purposes. In the three stations, there is a good correlation between the electrical conductivity and elements Ca, Mg, K, Cl, SO4 and HCO3. In order to determine the geochemical nature of water, the data was interpreted using the Piper diagram wherein the results show the predominance of Ca-Mg-HCO3 or Ca-Mg-HCO3-Cl water type in the Oued Reboa, Ca-Mg-HCO3 or Ca-Mg-Cl-HCO3 water type in the Oued Timgad and Ca-Mg-Cl-HCO3 water type in the Reservoir dam. Principal components analysis results revealed that surface water quality was mainly controlled by geology, agricultural uses and domestic discharges. All the surface water samples in Oued Timgad fall in the field of C3S1, indicating high salinity and low sodium. Most of the surface water samples in Oued Reboa and in the reservoir dam fall in the field of C2S1, indicating medium salinity and low sodium. Based on RSC values, all the samples of the three stations had values less than 1.25 and were safe for irrigation.Key words: Surface water, principal component analysis, drinking and irrigation water quality, Koudiat Medouar Basin, Algeria

Acute Toxicity of Opuntia Ficus Indica and Pistacia Lentiscus Seed Oils in Mice

Opuntia ficus indica and Pistacia lentiscus L. seeds are used in traditional medicine. The objective of this study was to investigate the toxicity of the fixed oil of Opuntia ficus indica and Pistacia lentiscus L. seeds in mice through determination of LD50 values, and also the physicochemical characteristics of the fixed oil of these oils. The acute toxicity of their fixed oil were also investigated in mice using the method of Kabba and Berhens. The fixed oil of Pistacia lentiscus and Opuntia ficus indica seeds were extracted and analyzed for its chemical and physical properties such as acid value, free fatty acid percentage (% FFA), iodine index, and saponification value as well as refractive index and density. LD50 values obtained by single doses, orally and intraperitoneally administered in mice, were respectively 43 ± 0,8 ;[40.7- 45.4 ] ml/kg body wt. p.o. and 2.72 ± 0,1 ;[2.52–2.92] ml/kg body wt. i.p. for Opuntia ficus indica; and 37 ± 1 ;[34.4 – 39.8 ] ml/kg body wt. p.o. and 2.52 ± 0,2 ;[2.22 – 2.81 ] ml/kg body wt. i.p. for Pistacia lentiscus respectively. The yields of seed oil were respectively calculated as 20.25% and 10.41%. The acid and free fatty acid values indicated that the oil has a low acidity

Caspase-2-mediated cell death is required for deleting aneuploid cells

Caspase-2, one of the most evolutionarily conserved of the caspase family, has been implicated in maintenance of chromosomal stability and tumour suppression. Caspase-2 deficient (Casp2-/-) mice develop normally but show premature ageing-related traits and when challenged by certain stressors, succumb to enhanced tumour development and aneuploidy. To test how caspase-2 protects against chromosomal instability, we utilized an ex vivo system for aneuploidy where primary splenocytes from Casp2-/- mice were exposed to anti-mitotic drugs and followed up by live cell imaging. Our data show that caspase-2 is required for deleting mitotically aberrant cells. Acute silencing of caspase-2 in cultured human cells recapitulated these results. We further generated Casp2C320S mutant mice to demonstrate that caspase-2 catalytic activity is essential for its function in limiting aneuploidy. Our results provide direct evidence that the apoptotic activity of caspase-2 is necessary for deleting cells with mitotic aberrations to limit aneuploidy.S Dawar, Y Lim, J Puccini, M White, P Thomas, L Bouchier-Hayes, D R Green, L Dorstyn and S Kuma

In vitro irradiation of basement membrane enhances the invasiveness of breast cancer cells

Following removal of the primary breast tumour by conservative surgery, patients may still have additional malignant foci scattered throughout the breast. Radiation treatments are not designed to eliminate all these residual cancer cells. Rather, the radiation dose is calculated to optimise long-term results with minimal complications. In a tumour, cancer cells are surrounded by a basement membrane, which plays an important role in the regulation of gene expression. Using an invasion chamber, we have shown that irradiation before cell plating of a reconstituted basement membrane (Matrigel; Becton Dickinson, Bedford, MA, USA) increased the invasiveness of the breast cancer cells MDA-MB-231. This radiation enhancement of invasion was associated with the upregulation of the pro-invasive gene matrix metalloproteinase (MMP)-2. The expression of membrane type 1 matrix metalloproteinase (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP), which are required to activate the MMP-2, were also increased. Confirming the role of MMP-2 and MT1-MMP, radiation enhancement of cancer cell invasion was prevented by an MMP-2 inhibitor and an anti-MT1-MMP antibody. This study also demonstrated that radiation can potentially enhance the invasion ability by inducing the release of pro-invasive factors stored in the Matrigel. Conversely, no enhancement of invasiveness was observed with the low metastatic cell line MCF-7. This lack of invasiveness correlated with the absence of the MMP-2 activator MT1-MMP in the MCF-7 cells. Radiotherapy is an efficient modality to treat breast cancer which could be further improved by inhibiting the pro-invasive gene upregulated by radiation

Multifaceted roles of GSK-3 and Wnt/β-catenin in hematopoiesis and leukemogenesis: opportunities for therapeutic intervention

Glycogen synthase kinase-3 (GSK-3) is well documented to participate in a complex array of critical cellular processes. It was initially identified in rat skeletal muscle as a serine/threonine kinase that phosphorylated and inactivated glycogen synthase. This versatile protein is involved in numerous signaling pathways that influence metabolism, embryogenesis, differentiation, migration, cell cycle progression and survival. Recently, GSK-3 has been implicated in leukemia stem cell pathophysiology and may be an appropriate target for its eradication. In this review, we will discuss the roles that GSK-3 plays in hematopoiesis and leukemogenesis as how this pivotal kinase can interact with multiple signaling pathways such as: Wnt/β-catenin, phosphoinositide 3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt/mammalian target of rapamycin (mTOR), Ras/Raf/MEK/extracellular signal-regulated kinase (ERK), Notch and others. Moreover, we will discuss how targeting GSK-3 and these other pathways can improve leukemia therapy and may overcome therapeutic resistance. In summary, GSK-3 is a crucial regulatory kinase interacting with multiple pathways to control various physiological processes, as well as leukemia stem cells, leukemia progression and therapeutic resistance. GSK-3 and Wnt are clearly intriguing therapeutic targets

Checkpoint Signaling, Base Excision Repair, and PARP Promote Survival of Colon Cancer Cells Treated with 5-Fluorodeoxyuridine but Not 5-Fluorouracil

The fluoropyrimidines 5-fluorouracil (5-FU) and FdUrd (5-fluorodeoxyuridine; floxuridine) are the backbone of chemotherapy regimens for colon cancer and other tumors. Despite their widespread use, it remains unclear how these agents kill tumor cells. Here, we have analyzed the checkpoint and DNA repair pathways that affect colon tumor responses to 5-FU and FdUrd. These studies demonstrate that both FdUrd and 5-FU activate the ATR and ATM checkpoint signaling pathways, indicating that they cause genotoxic damage. Notably, however, depletion of ATM or ATR does not sensitize colon cancer cells to 5-FU, whereas these checkpoint pathways promote the survival of cells treated with FdUrd, suggesting that FdUrd exerts cytotoxicity by disrupting DNA replication and/or inducing DNA damage, whereas 5-FU does not. We also found that disabling the base excision (BER) repair pathway by depleting XRCC1 or APE1 sensitized colon cancer cells to FdUrd but not 5-FU. Consistent with a role for the BER pathway, we show that small molecule poly(ADP-ribose) polymerase 1/2 (PARP) inhibitors, AZD2281 and ABT-888, remarkably sensitized both mismatch repair (MMR)-proficient and -deficient colon cancer cell lines to FdUrd but not to 5-FU. Taken together, these studies demonstrate that the roles of genotoxin-induced checkpoint signaling and DNA repair differ significantly for these agents and also suggest a novel approach to colon cancer therapy in which FdUrd is combined with a small molecule PARP inhibitor