lethal dosage
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2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Amjed Najem Alatrushi ◽  
Ahmed Salah Naser

Abstract The objective of our research was to estimate the therapeutic index and assess the interaction of alfaxalone (IP) with ketamine or xylazine (IM) in chicks by using isobolographic analysis. The up-and-down technique was involved to calculate the median effective anesthetic dosages (ED50) of alfaxalone, xylazine, and ketamine given separately or at the same time in young chicks. Then the up-and-down technique was involved to estimate the median lethal dosage (LD50) of alfaxalone (IP) to determine the safety profile. The ED50 of all anesthetics was evaluated isobolographically to assess the type of interaction between alfaxalone and xylazine or alfaxalone and ketamine. The alfaxalone ED50 was 32.88 mg/kg (IP), whereas the LD50 was 102.40 mg/kg (IP). The ED50 values for alfaxalone, ketamine, and xylazine were 32.88, 12.24, and 2.45 mg/kg, respectively. The ED50 values of alfaxalone with ketamine or xylazine (25:25 ED50 values) were: 7.39+2.35, and 8.61+0.63 mg/kg, respectively. ED50 values were decreased when the combinations of alfaxalone/ketamine or alfaxalone/xylazine were administered by 22-21% and 26-25%, respectively. The anesthesia of chicks with alfaxalone is safe, produces a surgical stage of anesthesia, and can be used for minor surgical procedures. The use of alfaxalone with ketamine or xylazine has been shown to have a synergistic effect and these findings may be of clinical relevance in poultry or may be extended to mammals following further clinical trials.


2021 ◽  
Vol 8 (1) ◽  
pp. 6-10
Author(s):  
Siti Hartati Yusida Saragih

Legume cover crop (Mucuna bracteata L.) is a creeper which is currently often used to increase soil fertility in plantation areas. This plant is a leguminous plant that can fix nitrogen nutrients in the soil. One of the M.bracteata plant breeding programs to increase diversity is mutation using gamma ray radiation. The research objective was to determine the level of radiosensitivity of legume cover crop using gamma ray irradiation. The research was conducted at PAIR BATAN using a Gamma Chamber 4000A irradiator and in agricultural experiment, Labuhanbatu University. The plant material used was M.bracteata seeds with irradiation doses of 0, 200, 250, 300, 350 and 400 Gy. This study uses a curve fit analysis program to calculate the LD50 value (Lethal dose 50). The results showed that the plant radiosensitivity by calculating the LD50 value of M.bracteata at the age of 2 Weeks After Planting) was 348.737 Gy. The higher the radiation dose given, the lower the percentage of growth.  Key words: diversity; leguminous; lethal dosage; mutation; gamma rays


2021 ◽  
Vol 1 (1) ◽  
pp. 23-28
Author(s):  
Agung Astuti ◽  
Darmawan Suryo Sudarsono ◽  
Agus Prabowo

The research objectives were to observe the growth and spore production of Metarhizium anisopliae grown at wheat-pollard and wheat-brand and to test the M. anisopliae pathogenicity on instar III rhinoceros beetle larva of coconut pest (Oryctes rhinoceros, L.). The research were executed in 3 phases : (1) Regeneration phase of  M. anisopliae, the experiment was arranged in single factor CRD with 3 kinds of wheat and 3  replications. The influences of the treatments on biomass, spore number and spore viability were observed then; (2) lethal dosage (LD50) determination phase; and (3) phatogenicity test of M. anisopliae, the experiment was arranged in 3 x 3 factorial CRD, where the first factor was the kinds of wheat (i.e. Pollard, Brand and Pollard Brand) and the second factor was the dosage of biopesticide (i.e. 0,5 LD50 LD50  and 2 LD50). The phatogenicity testing was conducted to evaluate the effects on toxicity, mortality speed, and effication percentage. The result indicated that the wheat-brand was the better medium for M. Anisopliae than the pollard and the pollard-brand ones. The average spore number (1021,67 x 1014  spora/ml), biomass (95,94 g) and the viability (127,00 x 108 spora/ml) were significantly higher than the others.  The lethal dosage obtained was 6,70g to gave the mortality percentage (73,33 %) and the effication percentage (73,33 %) significantly higher than the other treatments.


2021 ◽  
Author(s):  
Nnamdi S. Ekesi ◽  
Amer Hasan ◽  
Alia Parveen ◽  
Abdulkarim Shwani ◽  
Douglas D. Rhoads

AbstractWe used an embryo lethality assay (ELA) to assess virulence for different isolates from cases of bacterial chondronecrosis with osteomyelitis (BCO) in broilers. ELA has been used to measure virulence and lethal dosage of Enterococcus faecalis and Enterococcus cecorum. We hypothesized that ELA could substitute for more laborious and costly assessments of BCO isolate pathogenicity using live birds. We evaluated two different levels of bacteria injected into eggs from layer and commercial broiler embryos. Significant findings include a) Escherichia coli from neighboring farms operated by the same integrator had very different embryo lethality, b) isolate Staphylococcus agnetis 908 had low virulence in ELA, even though this isolate can induce more than 50% BCO lameness, c) Enterococcus cecorum 1415 also had low pathogenicity; even though it was recovered from severe bilateral tibial dyschondroplasia, d) human and chicken isolates of S. aureus had significant pathogenicity, e) virulence for some isolates was highly variable possibly corresponding with quality of the embryos/fertile eggs used, and f) ELA pathogenicity was much lower for our BCO isolates than previous reports which may reflect maternal environment. Overall, ELA virulence and BCO virulence are not always concordant indicating that that ELA may not be an effective measure for assessing virulence with respect to BCO.ImportanceLameness is among the most significant animal welfare issues in the poultry industry. Bacterial infections are a major cause of lameness and different bacterial species have been obtained from lame broilers. Reliable lab-based assays are required to assess relative virulence of bacteria obtained from lame broilers. Embryo Lethality Assays have been used to compare virulence. Our results suggest that this assay may not be an effective measure of virulence related to lameness.


2021 ◽  
Vol 7 ◽  
Author(s):  
Baotun Wang ◽  
Can Mao ◽  
Juan Feng ◽  
Yong Li ◽  
Jianmei Hu ◽  
...  

The sea bass, Lateolabrax maculatus is commercially farmed in Zhuhai, located in the Guangdong Province of China. L. maculatus in aquaculture have suffered acute death, characterized by ulcerations on the body surface, congestion, and hemorrhage in internal organs such as liver, kidney, and spleen. The dominant infecting strain of bacteria isolated from the kidneys of diseased fish was identified as Aeromonas veronii (strain 18BJ181). This identification was based on analysis of morphological, physiological, and biochemical features, as well as 16S rRNA and gyrB gene sequences. Drug sensitivity testing showed that the strain 18BJ181 isolate was resistant to four antibacterial drugs, including amoxicillin, madinomycin, penicillin and sulfamethoxazole, while moderately sensitive to erythromycin and rifampicin. The detection of growth characteristics showed that the strain 18BJ181 exhibited adaptability to the environment. In addition, some virulence genes, such as aer, act, gcaT, tapA and fla, were detected in the strain 18BJ181. The median lethal dosage of the strain 18BJ181 isolate in L. maculatus was 8.5 × 105 and 4.2 × 105 cfu/g under the conditions of intraperitoneal injection and intramuscular injection, respectively. The experimentally induced infection showed that the 18BJ181 isolate caused considerable histological lesions in L. maculatus, including tissue degeneration, necrosis, and different degrees of hemorrhage. These results provided evidence for a more comprehensive understanding of A. veronii strain 18BJ181 infection in L. maculatus.


2021 ◽  
Author(s):  
Yan-Yu Zhang ◽  
Yu-Feng Huang ◽  
Jie Liang ◽  
Hua Zhou

Abstract Background: Up-and-down procedure (UDP) was recommended to replace traditional acute toxicity methods. However, it was limited due to the long experimental period (20 - 42 days). To improve UDP, an improved UDP method (iUDP) was developed by shortening observation time between sequence dosages. The aim of this study was to test the reliability of iUDP to provide a reliable method for the acute toxicity measurement of valuable or minor amount compounds. Methods: Oral median lethal dosage (LD50) of nicotine, sinomenine hydrochloride and berberine hydrochloride were measured both by iUDP and modified Karber method (mKM). Results: LD50 of the three alkaloids measured by iUDP with 23 mice were 32.71 ± 7.46, 453.54 ± 104.59, 2954.93 ± 794.88 mg/kg, respectively. LD50 of the three alkaloids measured by mKM with 240 mice were 22.99 ± 3.01, 456.56 ± 53.38, 2825.53 ± 1212.92 mg/kg, respectively. The average time consumed by the two methods were 22 days and 14 days respectively. Total grams of the alkaloids used by the two methods were 0.0082 and 0.0673 (nicotine), 0.114 and 1.24 (sinomenine hydrochloride), 1.9 and 12.7 (berberine hydrochloride). Conclusion: iUDP could replace mKM to detect acute toxicity of substances with comparable and reliable result. And it was suitable for valuable or minor amount substances.


2020 ◽  
Vol 6 (4) ◽  
pp. 196
Author(s):  
Sengodan Karthi ◽  
Prabhakaran Vasantha-Srinivasan ◽  
Raja Ganesan ◽  
Venkatachalam Ramasamy ◽  
Sengottayan Senthil-Nathan ◽  
...  

The present investigation aimed to determine the fungal toxicity of Isaria tenuipes (My-It) against the dengue mosquito vector Aedes aegypti L. and its non-target impact against the aquatic predator Toxorhynchitessplendens. Lethal concentrations (LC50 and LC90) of My-It were observed in 2.27 and 2.93 log ppm dosages, respectively. The sub-lethal dosage (My-It-1 × 104 conidia/mL) displayed a significant oviposition deterrence index and also blocked the fecundity rate of dengue mosquitos in a dose-dependent manner. The level of major detoxifying enzymes, such as carboxylesterase (α-and β-) and SOD, significantly declined in both third and fourth instar larvae at the maximum dosage of My-It 1 × 105 conidia/mL. However, the level of glutathione S-transferase (GST) and cytochrome P-450 (CYP450) declined steadily when the sub-lethal dosage was increased and attained maximum reduction in the enzyme level at the dosage of My-It (1 × 105 conidia/mL). Correspondingly, the gut-histology and photomicrography results made evident that My-It (1 × 105 conidia/mL) heavily damaged the internal gut cells and external physiology of the dengue larvae compared to the control. Moreover, the non-target toxicity against the beneficial predator revealed that My-It at the maximum dosage (1 × 1020 conidia/mL) was found to be less toxic with <45% larval toxicity against Tx.splendens. Thus, the present toxicological research on Isaria tenuipes showed that it is target-specific and a potential agent for managing medically threatening arthropods.


Author(s):  
Pietro Brunetti ◽  
Filippo Pirani ◽  
Jeremy Carlier ◽  
Raffaele Giorgetti ◽  
Francesco Paolo Busardò ◽  
...  

ABSTRACT The aim of this review was to report the most recent cases of acute intoxication, fatalities and “driving under the influence” cases, involving illicit fentanyl and its newest analogs. When available, information on age, sex, circumstances of exposure, intoxication symptoms, cause of death (if applicable) and toxicology results from biological fluid testing was described. Scientific publications reporting fatalities or acute intoxications involving use of fentanyl derivatives were identified from PubMed, Scopus and institutional/governmental websites from January 2017 up to December 2019. The search terms, used alone and in combination, were as follows: fentanyl, street fentanyl, analogs, compounds, derivatives, abuse, fatality, fatalities, death, toxicity, intoxication and adverse effects. When considered relevant, reports not captured by the initial search but cited in other publications were also included. Of the 2890 sources initially found, only 44 were suitable for the review. Emergent data showed that the most common analogs detected in biological samples and seized materials are acetylfentanyl, acrylfentanyl, butyrfentanyl, carfentanil, cyclopropylfentanyl, fluorofentanyl, 4-fluorobutyrfentanyl, 4-fluoroisobutyrfentanyl, furanylfentanyl, 2-methoxyacetylfentanyl, 3-methylfentanyl and ocfentanil. These compounds were frequently administered in association with other illicit substances, medicinal drugs and/or alcohol; patients and the victims often had a previous history of drug abuse. The trend of fentanyl analogs is rapidly evolving with illicit market fluctuations. Since information about potency and lethal dosage are frequently unknown, it is important to identify the new trends for further investigation on therapeutic use, toxicity and fatal doses, and implement public health measures. Recently marketed fentanyl analogs such as crotonylfentanyl and valerylfentanyl were not involved in intoxications to date, but should be carefully monitored. Many intoxications and fatalities might have gone unnoticed, and research efforts should focus on metabolite identification studies and the implementation of updated and comprehensive analytical methods


2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Chuan Wang ◽  
Tianfan Cheng ◽  
Xuan Li ◽  
Lijian Jin

ABSTRACT Periodontitis as a biofilm-associated inflammatory disease is highly prevalent worldwide. It severely affects oral health and yet closely links to systemic diseases like diabetes and cardiovascular disease. Porphyromonas gingivalis as a “keystone” periodontopathogen drives the shift of microbe-host symbiosis to dysbiosis and critically contributes to the pathogenesis of periodontitis. Persisters represent a tiny subset of biofilm-associated microbes highly tolerant to lethal treatment of antimicrobials, and, notably, metronidazole-tolerant P. gingivalis persisters have recently been identified by our group. This study further explored the interactive profiles of metronidazole-treated P. gingivalis persisters (M-PgPs) with human gingival epithelial cells (HGECs). P. gingivalis cells (ATCC 33277) at stationary phase were treated with a lethal dosage of metronidazole (100 μg/ml, 6 h) for generating M-PgPs. The interaction of M-PgPs with HGECs was assessed by microscopy, flow cytometry, cytokine profiling, and quantitative PCR (qPCR). We demonstrated that the overall morphology and ultracellular structure of M-PgPs remained unchanged. Importantly, M-PgPs maintained the capabilities to adhere to and invade HGECs. Moreover, M-PgPs significantly suppressed proinflammatory cytokine expression in HGECs at a level comparable to that seen with the untreated P. gingivalis cells, through the thermosensitive components. The present report reveals that P. gingivalis persisters induced by lethal treatment of antibiotics were able to maintain their capabilities to adhere to and invade human gingival epithelial cells and to perturb the innate host responses. Novel strategies and approaches need to be developed for tackling P. gingivalis and favorably modulating the dysregulated immunoinflammatory responses for oral/periodontal health and general well-being.


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