303,953 research outputs found
Study of Acute Toxicity of a New Veterinary Drug for Inttrammary Introduction
Preclinical studies of veterinary medicinal products are important and compulsory studies in the development of new dosage forms. The aim of preclinical research is to determine the toxic effect and therapeutic efficacy of the test substance-the future dosage form, its effect on the body\u27s basic systems, as well as the identification of possible side effects.This work is part of the research on the development of the composition and technology of the veterinary drug - a solution for intramammary application, conventionally called "Argocide", intended for the treatment of mastitis in cattle.A study of the acute toxicity of the intramammary veterinary drug was carried out in experiments on white rats of both sexes, according to the requirements for potential medicines. The establishment of the value of the average lethal dose (LD50) of the veterinary drug "Argocide" with intramuscular single administration to white mature rats is impossible due to the absence of animal death even when the drug is administered at doses exceeding 5.0 ml/kg. This experiment allows the veterinary preparation "Argocide" to be classified as practically non-toxic compounds (V class).The analysis of the results of the conducted studies indicates the relative harmlessness of the potential drug for veterinary medicine and allows us to foresee that the "Argocide" preparation can be classified as low-risk substances, which justifies the expediency of its further study and introduction into practice
High dose rate brachytherapy as monotherapy for localised prostate cancer : a hypofractionated two-implant approach in 351 consecutive patients
BACKGROUND: To report the clinical outcome of high dose rate brachytherapy as sole treatment for clinically localised prostate cancer.
METHODS: Between March 2004 and January 2008, a total of 351 consecutive patients with clinically localised prostate cancer were treated with transrectal ultrasound guided high dose rate brachytherapy. The prescribed dose was 38.0 Gy in four fractions (two implants of two fractions each of 9.5 Gy with an interval of 14 days between the implants) delivered to an intraoperative transrectal ultrasound real-time defined planning treatment volume. Biochemical failure was defined according to the Phoenix Consensus and toxicity evaluated using the Common Toxicity Criteria for Adverse Events version 3.
RESULTS: The median follow-up time was 59.3 months. The 36 and 60 month biochemical control and metastasis-free survival rates were respectively 98%, 94% and 99%, 98%. Toxicity was scored per event with 4.8% acute Grade 3 genitourinary and no acute Grade 3 gastrointestinal toxicity. Late Grade 3 genitourinary and gastrointestinal toxicity were respectively 3.4% and 1.4%. No instances of Grade 4 or greater acute or late adverse events were reported.
CONCLUSIONS: Our results confirm high dose rate brachytherapy as safe and effective monotherapy for clinically organ-confined prostate cancer
The microbiotest battery as an important component in the assessment of snowmelt toxicity in urban watercourses—preliminary studies
The aim of the study was to use a battery of
biotests composed of producers (Selenastrum
capricornutum, Sorghum saccharatum, Lepidium
sativum, and Sinapis alba), consumers (Thamnocephalus
platyurus), and decomposers (Tetrahymena thermophila)
to evaluate the toxicity of snowmelt and winter storm
water samples. The toxicity of the samples collected in
the winter period December to February (2010–2011), in
one of the largest agglomerations in Poland, the city of
Lodz, was compared to that of storm water samples taken
under similar conditions in June. The most toxic snowmelt
samples were found to be high acute hazard (class IV),
while the remaining samples were rated as slight acute
hazard (class II). L. sativum (in the Phytotox test) was the
most sensitive test organism, giving 27 % of all toxic
responses, followed by S. capricornutum with 23 % of
all responses. T. thermophila was the least sensitive, with
only 2 % of all toxic responses. The greatest range of
toxicity was demonstrated by samples from the single
family house catchment: no acute hazard (class I) to high
acute hazard (class IV
Comparison Between Acute Toxicity And Chemical Analysis Of Natural Gas Drilling Effluent Samples Using Penaeus Monodon
The regulation of point source discharges usually based on specific chemicals which describe thresholds below which no adverse impact on the receiving water. The limitation of this technique includes the fact that it does not take into account interactions among toxicants (e.g. additivity, synergism, antagonism). Therefore, toxicity testing is recommended as integrated approach for identifying toxic pollutants to complement chemical-specific analysis by assessing the sum toxicity of all components in the mixture. The objective of this research was the assessment of Penaeus monodon (PM) as an indicator species for toxicity testing through comparisons between results from 48-h LC50 and chemical analysis of the natural gas drilling effluent. Chemical analysis of effluent samples was performed in order to determine concentrations of BTEX (benzene, toluene, ethyl benzene, xylene) and heavy metals (Cr, Ni, Cu, As, Pb, Cd). Average 48-h LC50\u27s for PM was 2,94 % for effluent and 0.68 g/l for KCl. Comparison between acute toxicity and chemical analysis showed a significant correlation between toluene concentrations and 48-h LC50 in PM (p<0.05). No significant correlation was found between the detectable heavy metal concentrations and acute toxicity data in PM. Results suggest that the lack of correlation between toxicity and almost all chemical parameters indicates that toxicity testing is much more useful for monitoring toxicity of effluents than chemical analysis. Additional studies are needed to identify alternative toxicity endpoints as sensitive indicators of impacts on the environment
Toxic Hazards Research Unit
The activities of the Toxic Hazards Research Unit (THRU) for the period of June 1970 through May 1971 reviewed. Modification of the animal exposure facilities primarily for improved human safety but also for experimental integrity and continuity are discussed. Acute toxicity experiments were conducted on hydrogen fluoride (HF), hydrogen chloride (HCl), nitrogen dioxide (NO2), and hydrogen cyanide (HCN) both singly and in combination with carbon dioxide (CO). Additional acute toxicity experiments were conducted on oxygen difluoride (OF2) and chlorine pentafluoride (ClF5). Subacute toxicity studies were conducted on methylisobutylketone and dichloromethane (methylene dichloride). The interim results of further chronic toxicity experiments on monomethylhydrazine (MMH) are also described
Acute Toxicity of Perfluorooctane Sulfonic Acid on Early Life Stages of Daphnia Magna, Siriella Armata, Paracentrotus Lividus Sea Urchin, and Turbot (Scophthalmus Maximus L.).
Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant whose potential toxicity is causing great concern. In the present study, we used two crustaceans (_Daphnia magna_, _Siriella armata_), echinoid embryos (_Paracentrotus lividus_) and turbot (_Scophthalmus maximus L._) embryos and larvae to investigate the acute toxicity of this compound. The marine species _S. armata_ exhibited greater sensitivity than the freshwater species _D. magna_. In the 48-h acute toxicity test the median lethal concentration was 10.96 mg/L for _S. armata_ and 87.46 mg/L for _D. magna_. In the 96h toxicity test, turbot showed the lowest EC50 (0.155 mgL-1), whilst the EC50 for _S. armata_ was 7.92 mgL-1 which was approximately three times lower than that for sea urchin (24.12 mgL-1). The EC10 values were estimated as 0.032 mgL-1, 4.23 mgL-1 and 45.21 mgL-1 for turbot, Siriella and daphnia, respectively. The LOEC values were 75 µgL-1, 2.5 mgL-1 and 75 mgL-1 (p< 0.05) for turbot, daphnia, and Siriella, respectively. The NOEC values were estimated at 37.5 µgL-1, 1.25 mgL-1 and 50 mgL-1 (p< 0.05) for turbot, Siriella and daphnia, respectively. The order of acute toxicity was: turbot > _S. armata_ > sea urchin > _Daphnia magna_. This result highlights the importance of including a marine fish in the battery of species to describe the toxicity of these compounds. Considering the persistent nature of PFOS, more research is required to determine potential consequences of long-term exposure to these compounds in aquatic ecosystems
TOXICITY OF PREDNISOLONE, DEXAMETHASONE AND THEIR PHOTOCHEMICAL DERIVATIVES ON AQUATIC ORGANISMS
Light exposure of aqueous suspensions of prednisolone and dexamethasone causes their partial phototransformation.
The photoproducts, isolated by chromatographic techniques, have been identified by spectroscopic means.
Prednisolone, dexamethasone and their photoproducts have been tested to evaluate their acute and chronic toxic effects
on some freshwater chain organisms. The rotifer Brachionus calyciflorus and the crustaceans Thamnocephalus platyurus
and Daphnia magna were chosen to perform acute toxicity tests, while the alga Pseudokircheneriella subcapitata (formerly
known as Selenastrum capricornutum) and the crustacean Ceriodaphnia dubia to perform chronic tests. The
photochemical derivatives are more toxic than the parent compounds. Generally low acute toxicity was found. Chronic
exposure to this class of pharmaceuticals caused inhibition of growth population on the freshwater crustacean C. dubia
while the alga P. subcapitata seems to be less affected by the presence of these drugs
Acute Toxicity Test of Carbamate Insecticide on Common Carp, Cyprinus Carpio Linnaeus, 1758
Pestisida golongan karbamat merupakan sumber pencemar yang sangat toksik bagi hewan, meskipun insektisida go-longan karbamat ini mudah terurai di alam baik pada media air maupun pada organisme dalam rantai makanan. Tujuan penelitian ini ialah mengukur nilai LC50-96 insektisida karbamat (Marshal 200 EC) terhadap hewan uji. Hewan uji yang digunakan pada penelitian ini adalah ikan mas (Cyprinus carpio L.) dengan panjang 6-8 cm dan bobot 5,5-9 g. Metode yang digunakan pada penelitian ini ialah metode eksperimental dengan dua tahapan penelitian, yaitu uji pendahuluan dan uji toksisitas akut (LC50-96). Uji pendahuluan dilakukan tanpa ulangan dan uji toksisitas akut dilakukan ulangan sebanyak dua kali. Data uji toksisitas akut dianalisis dengan analisis probit. Hasil penelitian menunjukkan bahwa nilai LC50-96 insektisida karbamat (Marshal 200 EC) terhadap ikan mas adalah 1,68 mgL-1
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