Search results for " TOXICITY"
showing 10 items of 346 documents
An approach to the diazinon toxicity in the European eel: bioaccumulation studies
1993
Abstract The acute toxicity effects of diazinon on European eel ( Anguilla anguilla ) were examined using short-term exposures in static conditions. In these conditions the 96-h median lethal concentration (LC 50 ) was 0.086 mg/1. In addition, the eels were exposed to two sublethal diazinon concentrations, 0.042 and 0.056 mg/1 (1/2 and 2/3 LC 50 96-h, respectively) for different exposure times, till a maximum of 96 h, and bioaccumulation and clearance of this insecticide in liver, muscle, gill and blood tissues were studied. BCF values of diazinon after 96 h exposure to 0.042 mg/l were 1850 in liver, 875 in gill and 775 in eel muscle. BCF values of diazinon over a 48-h exposure period to 0.…
Teratogenicity and Developmental Toxicity of Herbal Products
2017
Developmental toxicology and research in teratogenicity focus on xenobiotic substances that damage embryos and fetuses and lead to death, growth retardation, and/or malformation of offspring. While considerable information has been acquired about synthetic drugs and environmental xenobiotics, much less is known about the teratogenicity of herbal products. In this chapter we report on some major topics of developmental toxicity and teratogenicity, and discuss the safety of a few selected medicinal herbs in this context, i.e., Artemisia annua L., Caulophyllum thalictroides (L.) Michx., Echinacea spec,. Glycyrrhiza spec., herbs derived from Chinese medicine, Hypericum perforatum L., Panax gins…
Iron-Catalyzed C−O Bond Activation: Opportunity for Sustainable Catalysis
2017
Oxygen-based electrophiles have emerged as some of the most valuable cross-coupling partners in organic synthesis due to several major strategic and environmental benefits, such as abundance and potential to avoid toxic halide waste. In this context, iron-catalyzed C-O activation/cross-coupling holds particular promise to achieve sustainable catalytic protocols due to its natural abundance, inherent low toxicity, and excellent economic and ecological profile. Recently, tremendous progress has been achieved in the development of new methods for functional-group-tolerant iron-catalyzed cross-coupling reactions by selective C-O cleavage. These methods establish highly attractive alternatives t…
Ernährungsphysiologie erhitzter Fette: Langfristige Tierversuche
1974
Das Fette, die bei intensiver Beruhrung mit dem Luftsauerstoff langere Zeit auf hohere Temperaturen erhitzt worden sind, toxische Eigenschaften entwickeln, ist in vielen Laboratorien ubereinstimmend gezeigt worden. Je nach Schwere des Eingriffs reichen die bei Futterungsversuchen erhobenen Befunde von einer praktisch symptomenlosen Vertraglichkeit uber mehr oder minder schwere Wachstumsverzogerungen junger Tiere bis zu einer hohen Toxicitat wie starke Erhohung der Letalitatsrate und schweren anatomischen und histologischen Veranderungen der Organe. Fritierfette haben sich beim Einhalten der folgenden Bedingungen: Temperaturen nicht uber 180° C, Vermeiden jeder lokalen Uberhitzung durch einw…
Untersuchungen über die chronische Toxizität der Ascorbinsäure bei der Ratte
1963
Bei einer chronischen Verabreichung (10 Wochen) von 6,5 g Ascorbinsaure je kg Korpergewicht per os wurden bei der Ratte keine schadlichen Wirkungen beobachtet, selbst wenn die Tiere einer Stressituation (4 Wochen dauernde eiweisarme Ernahrung) unterworfen wurden. Tagesdosen von 27,3 g/kg Korpergewicht erwiesen sich als sicher toxisch. Die Mortalitatsrate betrug bei dieser Dosierung 77% innerhalb von 4 Wochen. Auf Grund dieser Versuche kann man als oberste Grenze der Vertraglichkeit bei chronischer Zufuhr 10 g Ascorbinsaure je kg Korpergewicht annehmen. Unter Zugrundelegung dieser Zahl ergibt sich fur die als wunschenswert erachtete Tagesdosis von 75 mg fur den Menschen eine Sicherheitsspann…
¿Es real el riesgo de osteoporosis y riesgo de fracturas con el uso crónico de inhibidores de la bomba de protones?
2011
Proton pump inhibitors (PPI) are one of the most widely used groups of drugs and their potential toxicity is periodically reviewed, emphasizing aspects originally considered secondary. The present review analyzes the physiological and pharmacological bases and the scarce clinical evidence for a potential association between the continued administration of PPI and the development of osteoporosis and bone fractures. Both disorders are clearly related to calcium homeostasis and are highly important in elderly patients due to their poor general prognosis and disabling consequences.
Advanced analytical techniques based on high-resolution mass spectrometry for the detection of micropollutants and their toxicity in aquatic environm…
2020
Abstract An abundance of micropollutants (MPs) in treated wastewater (WW) and occasionally even in drinking water represents a global threat from the environmental and public health risk standpoint. Along with the development of innovative WW treatment technologies, advanced analytical techniques, such as chromatography hyphenated to high-resolution mass spectrometry, are required for ensuring the detectability of target and nontarget MPs. Further studies on the chronic toxicity of MPs are needed to improve the regulation of hazardous substances in WWs. This article provides an up-to-date overview of the latest methodological developments related to the screening and quantification of MPs, …
Effect of soil moisture on pesticide toxicity to an enchytraeid worm, Enchytraeus sp.
1997
The aim of the study was to find out whether soil moisture affects toxicity of organic pesticides to an enchytraeid worm. Laboratory experiments were carried out with dimethoate and benomyl, using a small Enchytraeus sp. as the test species. Substrate was natural agricultural field soil cultivated without pesticides for several years. Experimental design consisted of three soil moistures (40, 55, and 70% of water holding capacity) and five pesticide concentrations, plus controls. Measured parameters were survival, size of the parent worms and number and size of juveniles produced. Dimethoate was relatively non-toxic to this species. Dimethoate did not decrease survival, but sublethal effect…
Acute toxicity of toluene, hexane, xylene, and benzene to the rotifers Brachionus calyciflorus and Brachionus plicatilis.
1992
A large number of studies on the biological effects of oil pollution in the aquatic environment deal with the effects of whole crude or refined oils or their water-soluble fractions. However, low boiling, aromatic hydrocarbons, which are probably the most toxic constituents of oil, have until now not been examined in sufficient detail. Toluene, benzene and xylene, constitute a major component of various oils. They may be readily lost by weathering but are toxic in waters that are relatively stagnant and are chronically polluted. Korn et al. have stated that toluene is more toxic than many other hydrocarbons such as benzene, though the latter are more water-soluble. Report of the effects of …
Acute lethal toxicity of some pesticides toBrachionus calyciflorus andBrachionus plicatilis
1991
Due to their widespread distribution and toxic nattwe pesticides may have a serious impact on the aquatic environment and exert adverse effects on the associated organisms. Acute bioassay tests have been used to determine the actual impact of various pesticides on aquatic life. Static acute toxicity tests provide rapid and reproductible concentration-response curves for estimating toxic effects of chemicals on aquatic organisms. These tests provide a data base for determining relative toxicity to a variety of species.