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Cyanobacteria are well known for their production of a multitude of highly toxic and / or allelopathic compounds. Among the photosynthetic microorganisms, cyanobacteria, belonging to the genus Nostoc are regarded as good candidate for producing biologically active secondary metabolites which are highly toxic to humans and other animals. Since so many reports have been published on the poisoning of different animals from drinking water contaminated with cyanobacteria toxins, it might be assumed that bioactive compounds are found only in aquatic species causes toxicity. However, the discovery of several dead dogs, mice, ducks, and fish around paddy fields, prompted us to study the toxic compounds in a strain of Nostoc which is most abundant in the paddy fields of Iran, using polymerase chain reaction and liquid chromatography coupled with a diode array detector and mass spectrophotometer. Results of molecular analysis demonstrated that the ASN_M strain contains the nosF gene. Also, the result of ion chromatograms and MS 2 fragmentation patterns showed that while there were three different peptidic compound classes (anabaenopeptin, cryptophycin, and nostocyclopeptides), there were no signs of the presence of anatoxin-a, homoanatoxin-a, hassallidin or microcystins. Moreover, a remarkable antifungal activity was identified in the methanolic extracts. Based on the results, this study suggests that three diverse groups of potentially bioactive compounds might account for the death of these animals. This case is the first documented incident of toxicity from aquatic cyanobacteria related intoxication in dogs, mice, and aquatic organisms in Iran.Key Words: cyanobacteria; natural bioactive compound; Nostoc; toxicity INTRODUCTIONThe genus Nostoc is an ecologically, morphologically, and physiologically diverse genus of microorganisms inhabiting soils, and represents large reservoir of potentially valuable natural compounds (Dembitsky and Řezanka 2005). The ecological significance of the Nostoc species extends beyond the compounds which they primarily known to produce, as many of these organisms are capable of modifying their habitats through the synthesis of biologically active products (Ehrenreich et al. 2005). These compounds demonstrate a diverse range of biological activities and chemical structures, including novel cyclic and linear lipopeptides, fatty acids, alkaloids, and other organic chemicals (Dittmann et al. 2001). A large number of novel antimicrobial agents have been identiReceived September 16, 2012, Accepted November 20, 2012 *Corresponding Author E-mail: bahare77biol@yahoo.com Tel: +98-91-1371-0956, Fax: +98-21-8884-8940 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 304 1,500-2,000 lux for two weeks (Kaushik 1987). Three small fragments of growing co...

We introduce Twist1 and MAML1 as new molecular markers of advanced tumor, which determine the characteristics and aggressive behavior of ESCC. Along with the emerging evidence of their role in different cellular processes and aberrations in various cancers, they are suggested as potentially interesting therapeutic targets to reverse a broad spectrum of functional aberrations that promote ESCC development.

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Pollen from different tree and grass species represent the greatest inducers of type I allergy worldwide. Oriental plane trees, as Platanus orientalis, are an important source of airborne allergens in cities of the southwest Asia and southeast Europe. This study was aimed to identify relevant allergens of P. orientalis pollen and to ascertain whether P. orientalis allergens have cross-reactivity with related plane trees, such as Platanus acerifolia and Platanus occidentalis pollen components. Nineteen patients with a clinical history of reaction to P. orientalis pollen and a positive skin-prick test (SPT) to P. orientalis pollen extract were included in this study. Identification of IgE-binding proteins in Platanus pollen extracts was elucidated by immunoblotting using sera from P. orientalis pollen-sensitive patients. Cross-reactivity studies among P. orientalis allergens and relevant species was evaluated by immunoblot-inhibition and ELISA inhibition assays. All the patients were polysensitive and exhibited positive SPT to grass and tree pollen allergens. The IgE-binding pattern of P. orientalis pollen extract was well defined. The inhibition experiments showed that the capacity of P. occidentalis was greater than P. acerifolia pollen extract in preventing the reactivity of immobilized P. orientalis pollen extract with the IgE antibodies of patients. The 28-kDa molecule was the most frequent allergen among nine IgE-binding proteins of P. orientalis pollen. The IgE-reactive components of P. orientalis pollen showed a higher level of cross-reactivity with P. occidentalis pollen in comparison with P. acerifolia pollen.