In vivo protection studies of bis-quaternary 2-(hydroxyimino)-N-(pyridin-3-yl) acetamide derivatives against sarin poisoning in mice

2016 ◽  
Vol 36 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Devyani Swami ◽  
Hitendra N Karade ◽  
Jyotiranjan Acharya ◽  
Pravin Kumar

In vivo antidotal efficacy of new bis- quaternary 2-(hydroxyimino)- N-(pyridin-3yl) acetamide derivatives (HNK series), to counter multiples of lethal doses of nerve agent sarin (GB) and reactivation of acetylcholinesterase (AChE), was evaluated in Swiss albino mice. [Protection index PI; median lethal dose (LD50) of sarin with treatment/LD50 of sarin] was estimated, using 0.05, 0.10, and 0.20 LD50 as treatment doses of all the oximes with atropine against sarin poisoning. Dose-dependent time course study was conducted at 0.2, 0.4 and 0.8 LD50 dose of sarin for estimating maximum AChE inhibition. At optimized time (15 min), in vivo enzyme half inhibition concentration (IC50) was calculated. AChE reactivation efficacy of HNK series and pralidoxime (2-PAM) were determined by plotting shift of log IC50 doses. HNK-102 with atropine showed three fold higher PI compared to 2-PAM. In vivo IC50 of sarin for brain and serum AChE was found to be 0.87 LD50 (139.2 µg/kg) and 0.48 LD50 (77.23 µg/kg), respectively. Treatment with HNK-102 and HNK-111 (equal to their 0.20LD50) significantly reactivated sarin-intoxicated AChE ( p < 0.05) at 2× IC50 dose of sarin, compared to 2-PAM. The study revealed that HNK-102 oxime was three times more potent as antidote, for acute sarin poisoning compared to 2-PAM in vivo.

1918 ◽  
Vol 28 (5) ◽  
pp. 571-583
Author(s):  
Julia T. Parker

1. The livers of rabbits inoculated with cultures of Bacillus typhosus or Bacillus prodigiosus under certain conditions contain a toxic substance extractable with salt solution. When the toxic extracts are injected intravenously into normal rabbits the latter animals develop symptoms resembling those of anaphylactic shock and succumb. The lethal doses of the toxic extracts are far smaller than those of normal liver extract. 2. The livers of rabbits injected with typhoid antigen also yield a toxic extract. 3. Boiling as well as filtration through a Berkefeld filter only partially detoxicates the extract. 4. Tolerance to one to two lethal doses of the poisonous extracts can be induced by cautious immunization. 5. Rabbits actively immunized to Bacillus typhosus or Bacillus prodigiosus usually resist one lethal dose of the homologous liver poison; and animals tolerant to the typhoid liver poison resist one minimum lethal dose at least of Bacillus typhosus. 6. Typhoid immune serum is not detoxicating either in vivo or in vitro for the typhoid liver poison. 7. The liver poisons are specific, since rabbits actively immunized to either Bacillus typhosus or Bacillus prodigiosus withstand at least one minimum lethal dose of the homologous but not of the heterologous-liver poisons.


1989 ◽  
Vol 170 (2) ◽  
pp. 467-479 ◽  
Author(s):  
Y Kurimoto ◽  
A L de Weck ◽  
C A Dahinden

The anaphylatoxin C5a is a potent trigger for basophil degranulations, but in contrast to IgE-dependent basophil activation, it does not result in the synthesis of sulfidoleukotrienes (leukotriene C4/D4/E4). Thus, degranulation and the generation of lipid mediators are separately regulated cellular responses. Exposure of human blood basophils to the cytokine IL-3 alone does not induce the release of histamine in cells from most donors and never leads to the generation of LTC4, indicating that IL-3 is not a direct agonist for basophil mediator release. However, preincubation of basophils with IL-3 enhances the degranulation response to C5a. Most importantly, IL-3 "primes" basophils to release large amounts of leukotriene C4 after challenge with C5a (mean of 50 gp LTC4 per nanograms cellular histamine), while neither peptide alone is capable of inducing the formation of bioactive lipids. This effect is dose dependent, occurring at IL-3 concentrations considerably lower than are required to stimulate the growth of bone marrow progenitor cells. IL-3 affects the extent but not the time course of basophil degranulation, and leukotriene release of cells sequentially exposed to IL-3 and C5a occurs very rapidly concomitant with degranulation. A preincubation of the basophils with IL-3 is strictly required for C5a-induced LTC4 synthesis, but not for an enhancement of degranulation. Priming for C5a-induced lipid mediator generation occurs rapidly after exposure of the cells to IL-3, starting at 1 min and reaching maximal effects at 5 min, but this altered state of responsiveness is relatively long lasting. Cell fractionation studies indicate that the basophil is the source of lipid mediators and that IL-3 affects the basophil response directly. This study demonstrates that IL-3 is a potent modifier of effector functions of mature basophils; this is possibly of greater in vivo significance than its growth factor properties. The large amounts of LTC4 formed after triggering of IL-3-primed basophils may not only enhance but also qualitatively change the pathophysiological consequences of complement activation, and this might be important in the pathogenesis of immediate type hypersensitivity reactions, shock syndromes, and inflammation.


Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 107-117
Author(s):  
J.D. Horton ◽  
J.H. Russ ◽  
P. Aitchison ◽  
T.L. Horton

These experiments employ the X. borealis (quinacrine-fluorescence) cell marker to illustrate that froglet (normal or in vivo-irradiated) thymuses, alloimplanted to 4- to 6-week-old, 7-day-thymectomized hosts, become filled with host lymphoid cells, while a range of thymic stromal cell types (e.g. epithelial derivatives and reticuloendothelial cells) remain donor derived. A time-course study of 4 micron historesin-embedded sections reveals that for normal thymus implants, host cells begin to immigrate in good number only after metamorphosis. In contrast, 3000 rad-irradiated thymus implants begin to be repopulated with host lymphocytes within 2 weeks postimplantation, when hosts are still at a late larval stage of development. Despite rapid colonization by host lymphoid cells, irradiated thymuses remain small and often disappear in early adult life. Donor-derived lymphocytes frequent the blood and both the red pulp and perifollicular regions of the spleen following normal thymus implantation, whereas such thymic emigrants were not seen in the periphery of thymectomized hosts grafted with irradiated thymus glands.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Derek S. Wheeler ◽  
John S. Giuliano ◽  
Patrick M. Lahni ◽  
Alvin Denenberg ◽  
Hector R. Wong ◽  
...  

Albumin appears to have proinflammatory effectsin vitro. We hypothesized that albumin would induce a state of tolerance to subsequent administration of lipopolysaccharide (LPS)in vitroandin vivo. RAW264.7 and primary peritoneal macrophages were treated with increasing doses of bovine serum albumin (BSA) and harvested for NF-κB luciferase reporter assay or TNF-αELISA. In separate experiments, RAW264.7 cells were preconditioned with 1 mg/mL BSA for 18 h prior to LPS (10 μg/mL) treatment and harvested for NF-κB luciferase reporter assay or TNF-αELISA. Finally, C57Bl/6 mice were preconditioned with albumin via intraperitoneal administration 18 h prior to a lethal dose of LPS (60 mg/kg body wt). Blood was collected at 6 h after LPS administration for TNF-αELISA. Albumin produced a dose-dependent and TLR-4-dependent increase in NF-κB activation and TNF-αgene expressionin vitro. Albumin preconditioning abrogated the LPS-mediated increase in NF-κB activation and TNF-αgene expressionin vitroandin vivo. The clinical significance of these findings remains to be elucidated.


2017 ◽  
Vol 36 (12) ◽  
pp. 1270-1285 ◽  
Author(s):  
P Kumar ◽  
D Swami ◽  
DP Nagar ◽  
KP Singh ◽  
J Acharya ◽  
...  

The study reports antidotal efficacy of three HNK [ bis quaternary 2-(hydroxyimino)-N-(pyridin-3yl) acetamide derivatives] and pralidoxime (2-PAM), against soman and tabun poisoning in Swiss albino mice. Protection index (PI) was determined (treatment doses: HNK oximes, ×0.20 of their median lethal dose (LD50) and 2-PAM, 30 mg/kg, intramuscularly (im)) together with atropine (10 mg/kg, intraperitoneally). Probit log doses with difference of 0.301 log of LD50 of the nerve agents administered and inhibition of acetylcholinesterase (AChE) activity by 50% (IC50) was calculated at optimized time in brain and serum. Using various doses of tabun and soman (subcutaneously (sc)), in multiples of their IC50, AChE reactivation ability of the oximes was studied. Besides, acute toxicity (0.8× LD50, im, 24 h postexposure) of HNK-102 and 2-PAM was also compared by determining biochemical, hematological variables and making histopathological observations. Protection offered by HNK-102 against tabun poisoning was found to be four times higher compared to 2-PAM. However, nearly equal protection was noted with all the four oximes against soman poisoning. HNK-102 reactivated brain AChE activity by 1.5 times more than 2-PAM at IC50 dose of soman and tabun. Acute toxicity studies of HNK-102 and 2-PAM showed sporadic changes in urea, uric acid, aspartate aminotransferase, and so on compared to control group, however, not supported by histopathological investigations. The present investigation showed superiority of newly synthesized HNK-102 oxime over standard 2-PAM, as a better antidote, against acute poisoning of tabun (4.00 times) and soman (1.04 times), in Swiss albino mice.


1995 ◽  
Vol 269 (6) ◽  
pp. H1955-H1964 ◽  
Author(s):  
J. Panes ◽  
M. A. Perry ◽  
D. C. Anderson ◽  
A. Manning ◽  
B. Leone ◽  
...  

The aim of the present study was to characterize and compare the expression of intercellular adhesion molecule 1 (ICAM-1) on unstimulated and endotoxin-challenged endothelial cells in different tissues of the rat. ICAM-1 expression was measured using 125I-labeled anti-rat ICAM-1 monoclonal antibody (MAb) and an isotype-matched control MAb labeled with 131I (to correct for nonspecific accumulation of the binding MAb). Under baseline conditions, ICAM-1 MAb binding was observed in all organs. The binding of 125I-ICAM-1 MAb varied widely among organs, with the largest accumulation (per g tissue) in the lung, followed by heart (1/30th of lung activity), splanchnic organs (1/50th of lung activity), thymus (1/100th of lung activity), testes (1/300th of lung activity), and skeletal muscle (1/800th of lung activity). Endotoxin induced an increase in ICAM-1 MAb binding in all organs except the spleen. Endotoxin-induced upregulation of ICAM-1 was greatest in heart and skeletal muscle (5- to 10-fold), whereas the remaining organs exhibited a two- to fourfold increase in ICAM-1 expression. Maximal upregulation of ICAM-1 occurred at 9-12 h after endotoxin administration. A dose-dependent increase in ICAM-1 expression was elicited by 0.1-10 microgram/kg, with higher doses (up to 5 mg/kg) producing no further increment. Induction of ICAM-1 mRNA after endotoxin was observed in all tissues examined (lung, heart, intestine), peaked at 3 h, and then rapidly returned to control levels. These findings indicate that ICAM-1 is constitutively expressed on vascular endothelium in all organs of the rat and that there are significant regional differences in the magnitude and time course of endotoxin-induced ICAM-1 expression.


2017 ◽  
Vol 10 (3) ◽  
pp. 99-106 ◽  
Author(s):  
Islam M. Sadiqul ◽  
Saimon Mohiful Kabir ◽  
Zannatul Ferdous ◽  
Khan Mst. Mansura ◽  
Rahman Md. Khalilur

AbstractAnin vivostudy was carried out on the freshwater fishBarbonymus gonionotusto evaluate the genotoxic effects of the organophosphate quinalphos. The fish were exposed to sub-lethal doses of quinalphos (0%, 10%, 25%, and 50% of LC50) for a period of 30 days. Analysis of biochemical characteristics (protein and lipid contents of different organs), nuclear abnormalities of erythrocytes (NAE) and morphological abnormalities of erythrocytes (MAE) were performed on peripheral erythrocytes sampled at post-treatment intervals of 0 and 30 days. The biochemical results revealed a significant dose-dependent decline in protein and lipid contents and increase in the frequencies of NAE as well as MAE. Our findings also confirmed that the morphological deformations of erythrocytes in addition to NAE on fish erythrocytesin vivoare effective tools in determining the potential genotoxicity of organophosphates.


2021 ◽  
Vol 95 (4) ◽  
pp. 1287-1301
Author(s):  
Isaac Omwenga ◽  
Shensheng Zhao ◽  
Laetitia Kanja ◽  
Hans Mol ◽  
Ivonne M. C. M. Rietjens ◽  
...  

AbstractOrganophosphate pesticides (OPs) are known to inhibit acetylcholine esterase (AChE), a critical effect used to establish health-based guidance values. This study developed a combined in vitro–in silico approach to predict AChE inhibition by the OP profenofos in rats and humans. A physiologically based kinetic (PBK) model was developed for both species. Parameter values for profenofos conversion to 4-bromo-2-chlorophenol (BCP) were derived from in vitro incubations with liver microsomes, liver cytosol, and plasma from rats (catalytic efficiencies of 1.1, 2.8, and 0.19 ml/min/mg protein, respectively) and humans (catalytic efficiencies of 0.17, 0.79, and 0.063 ml/min/mg protein, respectively), whereas other chemical-related parameter values were derived using in silico calculations. The rat PBK model was evaluated against literature data on urinary excretion of conjugated BCP. Concentration-dependent inhibition of rat and human AChE was determined in vitro and these data were translated with the PBK models to predicted dose-dependent AChE inhibition in rats and humans in vivo. Comparing predicted dose-dependent AChE inhibition in rats to literature data on profenofos-induced AChE inhibition revealed an accurate prediction of in vivo effect levels. Comparison of rat predictions (BMDL10 of predicted dose–response data of 0.45 mg/kg bw) and human predictions (BMDL10 of predicted dose–response data of 0.01 mg/kg bw) suggests that humans are more sensitive than rats, being mainly due to differences in kinetics. Altogether, the results demonstrate that in vivo AChE inhibition upon acute exposure to profenofos was closely predicted in rats, indicating the potential of this novel approach method in chemical hazard assessment.


1993 ◽  
Vol 265 (2) ◽  
pp. G224-G230 ◽  
Author(s):  
M. T. Runnegar ◽  
S. Kong ◽  
N. Berndt

Administration of microcystin (MCYST)-YM or -LR (peptide hepatotoxins produced by the cyanobacterium Microcystis aeruginosa) to mice resulted in the inhibition of liver protein phosphatase 1 and 2A activity. In all cases significant inhibition preceded or accompanied clinical changes due to MCYST intoxication. Fifteen minutes after intraperitoneal injection of lethal doses of MCYST-YM protein phosphatase activity was already decreased to 44% of controls, and by 60 min was further decreased to 22% of controls. The inhibition was dose dependent: intraperitoneal injection with 84 nmol/kg of MCYST-YM and 48 nmol/kg of MCYST-LR were the minimum doses required for significant inhibition at 60 min. Pretreatment of mice with 200 mumol/kg of rifamycin prevented the inhibition of liver protein phosphatase. The inhibition was tissue specific, with none detected in the kidneys, an organ that, unlike the liver, does not accumulate MCYST. In contrast to MCYST intoxication, lethal doses of phalloidin, a peptide hepatotoxin that produces clinical and pathological changes similar to MCYST, did not cause any inhibition of protein phosphatases.


Sign in / Sign up

Export Citation Format

Share Document