How Subchronic and Chronic Health Effects can be Neglected for GMOs, Pesticides or Chemicals

Chronic health effects are increasing in the world such as cancers, hormonal, reproductive, nervous, or immune diseases, even in young people. During regulatory toxicological subchronic tests to prevent these on mammalian health, prior commercialization of chemicals, including pesticides and drugs, or GMOs, some statistically significant findings may be revealed. This discussion is about the need to investigate the relevant criteria to consider those as biologically significant. The sex differences and the non linear dose or time related effects should be considered in contrast to the claims of a Monsanto-supported expert panel about a GMO, the MON 863 Bt maize, but also for pesticides or drugs, in particular to reveal hormone-dependent diseases and first signs of toxicities.     

Expression of foreign genes, GUS and hygromycin resistance, in the halophyte Kosteletzkya virginica in response to bombardment with the Particle Inflow Gun

A ‘Particle Inflow Gun’ was constructed to introducethe glucuronidase (GUS) and hygromycin resistance genes intohalophytic suspension cells of Kosteletzkya virginica. The transientexpression of the GUS gene was associated with the cell cultureconditions, physical parameters during the use of the ParticleInflow Gun, and different promoters coupled to GUS. When theCaMV35S promoter was used, the cells adapted at 85 mM NaCl hada similar gene transfer efficiency to those of the non-salt-adaptedcontrol, while expression was less in the 170 mM and 255 mMNaCl-adapted cells. Both elevating bombardment pressure to 1.65mPa and shortening the distance between the cells and the particleholder from 21 cm to 9 cm enhanced GUS expression in the cellsgrown in four salinity treatments. An ABA-responsive promoterinduced the expression of the GUS gene either with 10^–4M ABA or with salts in the post-bombardment medium in both controland NaCl-adapted cell tines. Stable transgenic callus lineswere isolated by using hygromycin containing medium after bombardingthe suspension cells with the Particle Inflow Gun. The presenceof the GUS gene in stable transformants was confirmed not onlyby histochemical and fluorimetric assays for the GUS activity,but also by Southern hybridization of RT-PCR amplified mANA. Key words: Transgenic hatophyte, Particle Inflow Gun, bombardment, salt tolerance, transformation     

Crystallization and 1.1-A diffraction of chorismate lyase from Escherichia coli

Chorismate pathway enzymes are important as producers of nonnucleotide aromatic compounds. The enzyme chorismate lyase from Escherichia coli has been crystallized in four distinct forms, three of which have been characterized by X-ray diffraction. Despite widespread screening, all four crystal forms grow from the same chemical conditions. The wild-type enzyme tends to aggregate, even in the presence of reducing agent, and yielded only one crystal form (monoclinic, form 1) that grew in intricate clusters. Chemical modification of the cysteines mitigated problems with aggregation and solubility but did not affect crystal growth behavior. Protein aggregation was largely eliminated by mutating the protein's two cysteines to serines. The double mutant retains full enzymatic activity and crystallizes in three new forms, one of which (triclinic) diffracts to 1.1-A resolution.     

A novel extracellular carbohydrase produced by Lipomyces tetrasporus

Summary The ascosporogenous yeast Lipomyces tetrasporus produced an unusual extracellular carbohydrase. It was purified to homogeneity using ammonium sulphate precipitation and DEAE Bio-gel A ion-exchange chromatography. While retaining highest activity on low-molecular-weight saccharides such as maltose and nigerose, it displays considerable activity towards polymeric substrates including soluble starch. It is particularly unusual in that it also hydrolyses dextran and has a very high affinity for this substrate. The enzyme has an exo-lytic mode of action with the only hydrolysis product, glucose, being released in the -anomeric form. Optimum activity occurs at pH 4.5 and at 50°C. It is a glycoprotein, and has an M _r value of 150 000 (sodium dodecyl sulphate-polyacrylamide gel electrophoresis) — 183 000 (fast protein liquid chromatography) and a pI of 6.0. Offprint requests to: C. T. Kelly     

Pentyl-4-yn-valproic acid enhances both spatial and avoidance learning, and attenuates age-related NCAM-mediated neuroplastic decline within the rat medial temporal lobe

2-N-Pentyl-4-pentynoic acid [pentyl-4-yn-valproic acid (VPA)] is an analogue of valproic acid that induces neuritogenesis and increases neural cell adhesion molecule (NCAM) prevalence in cultured neural cells. As memory consolidation involves synapse growth, aided by cell adhesion molecule function, we determined whether or not pentyl-4-yn-VPA had cognition-enhancing properties. Pentyl-4-yn-VPA (16-85 mg/kg) significantly improved water maze learning and task retention when given prior to each training session. Acute administration of pentyl-4-yn-VPA also influenced memory consolidation processes as, when given at 3 h post-passive avoidance training, the amnesia induced by scopolamine given 6 h post-training was prevented in a dose-dependent manner. Chronic administration of pentyl-4-yn-VPA (16.8 or 50.4 mg/kg) also significantly reduced escape latencies in the water maze task, 24 h following the last drug administration. This improved spatial learning was accompanied by enhanced neuroplasticity as the expression of NCAM polysialylated neurons in the infragranular zone of the dentate gyrus and in layer II of the perirhinal and piriform cortex was increased significantly following chronic drug treatment. The cognition-enhancing qualities of pentyl-4-yn-VPA, combined with its ability to attenuate the age-related loss of the NCAM polysialylation state, suggest that it may effectively slow the onset of cognitive decline.     

Platelet adhesion and degranulation induce pro-survival and pro-angiogenic signalling in ovarian cancer cells

Thrombosis is common in ovarian cancer. However, the interaction of platelets with ovarian cancer cells has not been critically examined. To address this, we investigated platelet interactions in a range of ovarian cancer cell lines with different metastatic potentials [HIO-80, 59M, SK-OV-3, A2780, A2780cis]. Platelets adhered to ovarian cancer cells with the most significant adhesion to the 59M cell line. Ovarian cancer cells induced platelet activation [P-selectin expression] in a dose dependent manner, with the most significant activation seen in response to the 59M cell line. The platelet antagonists [cangrelor, MRS2179, and apyrase] inhibited 59M cell induced activation suggesting a P2Y12 and P2Y1 receptor mediated mechanism of platelet activation dependent on the release of ADP by 59M cells. A2780 and 59M cells potentiated PAR-1, PAR-4, and TxA2 receptor mediated platelet activation, but had no effect on ADP, epinephrine, or collagen induced activation. Analysis of gene expression changes in ovarian cancer cells following treatment with washed platelets or platelet releasate showed a subtle but valid upregulation of anti-apoptotic, anti-autophagy pro-angiogenic, pro-cell cycle and metabolic genes. Thus, ovarian cancer cells with different metastatic potential adhere and activate platelets differentially while both platelets and platelet releasate mediate pro-survival and pro-angiogenic signals in ovarian cancer cells.     

Profiling SARS-CoV-2 HLA-I peptidome reveals T cell epitopes from out-of-frame ORFs

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