Toxic and genotoxic activity of river waters of the Kazakhstan

IntroductionIn this study, physicochemical, genotoxic, and mutagenic properties of water samples from 10 rivers of the Almaty region (Kazakhstan) were evaluated.ResultsThe results of the study demonstrated an increased level  of mineralization and electrical conductivity that might be caused by the high concentration of dissolved mineral salts and ions such as Na⁺, K⁺, Ca^{2 +}, Cl⁻, SO₄²⁻, HCO₃⁻. The excess of Maximum Allowable Concentrations (MACs) for various heavy metals was revealed. The results of tests using the pXen7-lux biosensor showed toxic effects of river waters. At the same time, the studies involved lux biosensors pRecA-lux, pColD-lux, pSoxS-lux, pKatG-lux did not find any genotoxic and oxidative effects. However, toxicity and mutagenicity of the studied water samples was detected by using plant test (Allium cepa and Hordeum vulgare). Phytotoxic, cytotoxic (decrease in the mitotic index) and mutagenic (increase in the frequency of chromosomal aberrations) activity of the water samples was observed. The data of in vivo tests (Danio rerio) showed the high toxicity and teratogenicity of river waters for fish embryos at all stages of development.ConclusionsThe results of this comprehensive study indicate that the contamination of the surface natural waters poses a threat to rivers dwellers and the human population in the rivers areas.     

Toxic cyanobacteria (blue-green algae) in Finnish fresh and coastal waters

A survey of the occurrence of toxic blooms of cyanobacteria in Finnish fresh and coastal waters was made during 1985 and 1986. Toxicity of the freeze-dried water bloom samples was tested by mouse-bioassay (i.p.). Forty-four per cent (83/188) of the bloom samples were found to be lethally toxic. Hepatotoxic blooms (54) were almost twice as common as neurotoxic ones (29). Anabaena was the most frequently found genus in toxic and non-toxic blooms and it was present in all neurotoxic samples. Statistical associations were found between hepatotoxicity and incidence of Microcystis aeruginosa, M. viridis, M. wesenbergii, Anabaena flos-aquae and Anabaena spiroides. Neurotoxicity was statistically associated with Anabaena lemmermannii, Anabaena flos-aquae and Gomphosphaeria naegeliana. Isolation of strains of cyanobacteria confirmed the occurrence of hepatotoxic and neurotoxic strains of Anabaena, as well as hepatotoxic strains of Microcystis and Oscillatoria species.Toxic blooms caused cattle poisonings at three different lakes during the study period. Toxic blooms also occurred in drinking water sources. Our study shows that toxic cyanobacteria are more common in Finnish lakes than would be expected on the basis of animal poisonings. The results of this study show the existence of toxic cyanobacteria in Finnish water supplies and the need for their continued study as agents of water based disease.     

Urushiols of poisonous anacardiaceae

GC-MS has been used to analyze and characterize the mixture of bis-trimethylsilyl derivatives of 3-n-alk(en)ylcatechols (urushiol) obtained from certain poisonous members of the Anacardiaceae. Analyses revealed a variation in composition of urushiol obtained from the same species. Furthermore, urushiols from poison ivy and poison wood, while consisting largely of n-C₁₅-substituted catechols, also contain varying amounts of the homologous n-C₁₇-substituted catechols. Similarly, the 3-alk(en)ylcatechol mixtures from poison oak, while containing mainly n-C₁₇-species, also contain varying amounts of the _n-C₁₅ species. The analysis of a single poison sumac sample revealed that it contained predominantly 3-_n-pentadec(en)ylcatechols.     

Trigger or file-fish (Balistes carolinensis) in Irish waters

Until the year 1947 only two specimens of B. carolinensis had been recorded from Irish waters but from 1947 to 1976 no less than 81 specimens were examined, a large number of which, 32 or 39.5% of the total, in the year 1975 (Table I). The geographical distribution of the specimens shown in Fig. 1 indicates that from the Mayo coast northwards and around to Wexford trigger-fish are rarely taken. The distributions by month (Table II) and length groups (Table III) are also given, together with the relationship between fork lengths and weights (Fig. 2).     

Iron Supplementation During Pregnancy- A Necessary or Toxic Supplement?

The effects of a single intramuscular iron dose, 10mg, to pregnant rats on Day of pregnancy, on the outcome of pregnancy, with respect to foetal weight and mother’s immune function has been investigated. Despite significantly elevated hepatic iron stores after iron supplementation in pregnant rats this had no significant effect upon blood haemoglobin or transferrin saturation levels. However the mean weight of the foetuses at Day 20-21 was significantly lower than that of the non-supplemented pregnant rats. Iron supplements significantly increased the activity of NADPH oxidase in the maternal alveolar macrophages, the primary event in the formation of the phagolysosome to combat invading organisms. However inducible nitric oxide synthase activity was significantly reduced in these macrophages as shown by decreases in LPSinduced and LPS+IFNγ-induced NOS activation. Iron supplementation to rats of normal iron status at the commencement of pregnancy did not show any beneficial effects to either the foetus or the mother.     

一种有毒的游蛇——虎斑颈槽蛇

虎斑颈槽蛇是中国数量较多、分布最广的蛇类之一,但一直被当作无毒蛇而忽视。为了使人们对虎斑颈槽蛇有一个全面、正确的认识,也为以后的相关研究奠定一定的理论基础,从虎斑颈槽蛇的分布,形态,生活习性以及毒腺的研究等方面加以综述。     

Intimate details of the most poisonous poison

Crystal structures of type B botulinum neurotoxin, determined under conditions relevant to the extracellular binding and intracellular substrate cleavage steps of its toxic action, reveal that minimal structural changes occur upon binding a ganglioside or after substrate cleavage. The unique structure of this toxin provides information for developing preventive measures against botulism.