Toxicity of waters from the St. Lawrence River at Massena Area-of-Concern to the plankton species Selenastrum capricornutum and Ceriodaphnia dubia

In 1972, the US and Canada committed to restore the chemical, physical, and biological integrity of the Great Lakes Ecosystem under the first Great Lakes Water Quality Agreement. During subsequent amendments, part of the St. Lawrence River at Massena NY, and segments of three tributaries, were designated as one Area of Concern (AOC) due to various beneficial use impairments (BUIs). Plankton beneficial use was designated impaired within this AOC because phytoplankton and zooplankton population data were unavailable or needed “further assessment”. Contaminated sediments from industrial waste disposal have been largely remediated, thus, the plankton BUI may currently be obsolete. The St. Lawrence River at Massena AOC remedial action plan established two criteria which may be used to assess the plankton BUI; the second states that, “in the absence of community structure data, plankton bioassays confirm no toxicity impact in ambient waters”. This study was implemented during 2011 to determine whether this criterion was achieved. Acute toxicity and chronic toxicity of local waters were quantified seasonally using standardized bioassays with green alga Selenastrum capricornutum and water flea Ceriodaphnia dubia to test the hypothesis that waters from sites within the AOC were no more toxic than were waters from adjacent reference sites. The results of univariate and multivariate analyses confirm that ambient waters from most AOC sites (and seasons) were not toxic to both species. Assuming both test species represent natural plankton assemblages, the quality of surface waters throughout most of this AOC should not seriously impair the health of resident plankton communities.     

Protective effect of nanosilica on irradiated dates against saw toothed grain beetle,Oryzaephilus surinamensis (Coleoptera: Silvanidae) adults

The insecticidal activity of nanosilica particles (NSPs) [20 ± 4 nm] was determined using the saw-toothed grain beetle, Oryzaephilus surinamensis (L) adults as the experimental insect. When the unsexed adults were exposed to different doses of nanosilica (0.2, 0.4, 0.6, 0.8 and 1.0 mg/Petri dish) for different periods (1, 2 and 3 days), it was found that NSPs had more insecticidal activity against O. surinamensis. Moreover, it was found that as the exposure time and dose increased, the mortality percentages of the adults increased. When the adult fed on irradiated dates which treated with different doses of nanosilica (0.5, 1,2 and 4 mg/1date) the mortality was higher than in nanosilica alone. The LD₅₀ of the bioassay tests showed that the calculated LD₅₀ values of each treatment were 0.468, 1.201 and 0.572 mg/1date. The adult of O. surinamensis (untreated, treated with LD₅₀ of nanosilica and fed on unirradiated or irradiated dates) examined by a scanning electron microscope. The examination showed the same malformations in all treatments which caused abrasion and damage on the outer surface. Nanosilica can be effectively replacing chemical insecticides to protect stored products.     

Diagnostischer Zellkulturtest (MTT-Test) für den Nachweis von zytotoxischen Kontaminanten und Rückständen

Zusammenfassung. Im Unterschied zu physikalisch-chemischen und immun-chemischen Methoden, die den Nachweis und die Identifizierung einzelner Toxine in unterschiedlichen Probenmaterialien erm?glichen, k?nnen mit Hilfe von biologischen Testverfahren Hinweise zur Toxizit?t als Summenparameter erfasst werden. Der Einsatz von Bioassays ist insbesondere dann sinnvoll, wenn mehrere Toxine, m?glicherweise auch bislang unbekannte, in einer Probe erwartet werden k?nnen. Zu diesem Zweck wurde ein wirkungsbezogener Zytotoxizit?tstest entwickelt und bei Vergleichsuntersuchungen von Mykotoxinen, Pestiziden, Mikroorganismenkulturen und für die überprüfung der Qualit?t von Nahrungsmitteln, Futtermitteln sowie Umweltproben angewendet. Das Prinzip des Assays basiert auf dem Vergleich der zytotoxischen Effekte von Rohextrakten aus Verdachtsproben mit denen entsprechender Kontrollen gegenüber der als Zielorganismus eingesetzten SK (Swine Kidney) – Zelllinie, die sich gegenüber Matrixeffekten der unterschiedlichen Proben in Bereichen zwischen 50–1.000 mg Probenaliquot/ml Zellkulturmedium als unempfindlich erwiesen hat. Um eine m?glichst komplette Information über die Gesamtbelastung von Probenmaterialien mit zytotoxischen Kontaminanten und Rückst?nden zu erhalten, werden zun?chst Rohextrakte mit organischen L?sungsmitteln hergestellt und die in Mikrotiterplatten einges?ten SK-Zielzellen mit Verdünnungen der Extrakte belastet. Nach Inkubation bis zu 20 Stunden bei 37°C wird der Grad der Zellsch?digung über die MTT-Formazan Farbreaktion gemessen. Jede Sch?digung der Zielzellen durch zytotoxische Substanzen reduziert dabei die Spaltung des gelbgef?rbten Tetrazoliumsalzes MTT zu violetten Formazanen und erlaubt durch photometrische Messung der Extinktionen bei 510 nm einen objektiven Nachweis. In diesem übersichtsbeitrag werden das Testprinzip und die Ergebnisse verschiedener Applikationsbereiche (Mykotoxine, Pestizide, Schimmelpilzisolate, Bakterienisolate, Lebens- und Futtermittel, Organ- und Darminhaltsproben, Umweltproben) des vielseitig einsetzbaren Zytotoxizit?tstests beschrieben. Eingegangen: 27. Juli 2006     

Development and Analysis of Three Diesel Particulate-Related Standard Reference Materials for the Determination of Chemical,Physical, and Biological Characteristics

The National Institute of Standards and Technology (NIST) has recently issued three Standard Reference Materials (SRMs) related to diesel particulate matter: SRM 1650a, Diesel Particulate Matter; SRM 2975, Diesel Particulate Matter (Industrial Forklift); and SRM 1975, Diesel Particulate Extract. These three materials have certified and reference concentrations for selected polycyclic aromatic hydrocarbons (PAHs) including many alkyl-substituted compounds. SRM 1650a is the reissue of an existing material and SRMs 2975 and 1975 represent new materials. The characterization of the PAH content of these three diesel particulate-related SRMs is presented with a discussion of the approach for the certification of PAH concentrations. In addition, the physical and biological characterization of these materials is discussed. A review of customer reported uses of these SRMs in the chemical, physical, and biological sciences is also provided.     

High‐throughput microbial bioassays to screen potential New Zealand functional food ingredients intended to manage the growth of probiotic and pathogenic gut bacteria

A spectrophotometric bioassay was used to screen selected food ingredients intended for development of functional foods designed to influence the growth of gut bacteria. Dose–response profiles displaying Δ_growth, the magnitude of deviation from growth of controls, were generated for probiotics Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium lactis and pathogens Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus. Ingredients were manuka honey UMF?20+(dose‐dependently increased probiotics and decreased pathogens); bee pollen (biphasic growth effects against all); Rosehips and BroccoSprouts^® (increased all dose‐dependently); blackcurrant oil (little effect) and propolis (inhibited all strains). Ingredients were also bioassayed in pairs to assess desirable or undesirable synergistic interactions. Observed synergies included manuka honey (predominantly desirable); rosehips or BroccoSprouts® (desirable and undesirable); blackcurrant oil (desirable) and propolis (tended towards synergies reinforcing its antimicrobial effects), collectively revealing a complex web of interactions which varied by ingredient and bacterial strain. Manuka honey was particularly effective at influencing gut bacteria. The surprising frequency of undesirable synergistic interactions illustrates the importance of pre‐testing potential ingredient combinations intended for use in functional foods.     

Tid基因对水稻的转化及转基因植株的抗虫性

利用基因枪转化法将大豆Kunitz型胰蛋白酶抑制剂(SKTI)基因Ti^d转入北方推广的水稻(Oryza sativa L)品种丰优301和通887，所获得的潮霉素抗性植株通过GUS组织化学分析、PCR检测、Southern blot分子检测，证实Ti^d基因已经转入水稻基因组中，为转基因植株。用转基因水稻植株叶片进行了室内饲喂水稻二化螟(Chilo suppressalis)实验，抗虫性分析结果表明，与对照比较，部分转基因水稻植株明显地增强了对水稻二化螟虫的抗性。对转基因R1代植株进行PCR和PCR Southern分析，表明外源基因在转基因植株后代今稳定遗传。     

重组人CTAL4-Ig活性测定参考品的制备及标定

目的　建立用于效价测定的重组人CTAL4 Ig参考品。方法　按WHO标准品有关要求制备参考品 ,分装、冻干后进行检测 ,采用Raji细胞体外活性测定法进行标定。结果　冻干重组人CTAL4 Ig参考品经检测外观、无菌实验合格 ,水分为 2 2 % ,经 10次标定活性值位于 336～ 4 6 3U/支 ,平均值为 4 19U/支 ,10次结果的标准差为36 0 3U/支 ,变异系数为 8 6 1% ,加速热稳定实验表明其生物学活性在 - 2 0℃、4℃和 2 5℃下 12个月保持稳定。结论　该批重组人CTAL4 Ig活性参考品各项指标均符合标准品的要求 ,效价定为 4 0 0AU/支 ,编号为 2 0 0 2 /0 1。     

生物测定法和重量法用于分析阿特拉津除草膜药效的评价

本文介绍了生物测定法和重法用于分析阿特拉津除昌地膜药效的研究结果。浮萍生测法对阿特拉津浓度的分辨力较低，只可作为除草膜药效定性分析的方法，柯氏藻生测法灵敏度高，对除草膜含药量差异的分辨力较高试验周期较短，是除草膜药效分析的较好方法；田间除草效果试验一般来验证其它方法的可靠性，其试验周期长，只能用于评价少量样本的除草效果；重不操作简便，可作为分析工艺条件对除划剂在膜面的分布关况影响的简便方法。     

Antifeedants in the Feces of the Pine Weevil Hylobius abietis: Identification and Biological Activity

Egg-laying females of the pine weevil, Hylobius abietis (L.), regularly deposit feces adjacent to each egg. Egg cavities are gnawed in the bark of roots of recently dead conifer trees. After egg deposition, the cavity is sealed by feces and a plug of bark fragments. Root bark containing egg cavities with feces is avoided as food by pine weevils, which indicates the presence of natural antifeedants. Here we present the first results of the isolation and chemical analyses of antifeedant compounds in the feces of H. abietis. In feeding bioassays, methanol extracts of the feces revealed strong antifeedant properties. Methanol extracts were fractionated by medium-pressure liquid chromatography and the antifeedant effects were mainly found in the fractions of highest polarity. Volatile compounds in the active fractions were identified by gas chromatography–mass spectrometry (GC–MS) and the nonvolatile compounds were characterized by pyrolysis–GC–MS. Based on mass spectra, a number of compounds with various chemical structures were selected to be tested for their antifeedant properties. Antifeedant effects were found among compounds apparently originating from lignin: e.g., a methylanisol, guaiacol, veratrol, dihydroxybenzenes, and dihydroconiferyl alcohol. A weak effect by fatty acid derivatives was found. The types of naturally occurring antifeedant compounds identified in this study may become useful for the protection of planted conifer seedlings against damage by H. abietis.