Gholamreza Reza Poorheidari; Mahdi Mashhadi Akbar Boojar
Volume 23, Issue 4 , 2021
Abstract
Background: One of the most toxic effects of organophosphorus poisoning (OP) is the paralysis of skeletal muscles. The oximes are a group of available antidotes. This study investigated the effects of different concentrations of paraoxon on the function of skeletal muscle and reversal or prevention of ...
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Background: One of the most toxic effects of organophosphorus poisoning (OP) is the paralysis of skeletal muscles. The oximes are a group of available antidotes. This study investigated the effects of different concentrations of paraoxon on the function of skeletal muscle and reversal or prevention of these effects by three different oximes (i.e., pralidoxime, obidoxime, and HI-6).
Materials and Methods: This study was conducted based on the chicken biventer cervices (CBC) nerve-muscle preparation and the use of twitch tension recording technique. The twitches of the CBC were evoked by stimulating the motor nerve at 0.1 Hz with pulses of 0.2 msec duration and a voltage greater than that required to produce the maximum response. Moreover, twitches and contractures were recorded isotonically using Grass Biosystems.
Results: Paraoxon at 0.1 µM induced a significant increase (more than 100%) in the twitch amplitude, while higher concentrations (0.3 and 1µM) induced partial or total contracture. Therefore, paraoxon at a concentration of 0.1 µ M was used to examine the capability of oximes to prevent or reverse its effects. Pralidoxime, obidoxime, and HI-6 dose-dependently prevented (when it was used as pre-treatment, 20 min before or at the same time of administration of the toxin) and reversed (when it was used as post-treatment, 20 min after the administration of the toxin) the effect of paraoxon.
Conclusion: In conclusion, these results revealed that oximes were very useful in the prevention and reversal of the OP toxic effects on the skeletal muscle. Moreover, it was suggested that oximes were more effective when used as pre-treatment. Pralidoxime was more potent than obidoxime and HI-6. The HI-6, which is a newer oxime, was unexpectedly less effective than the other two.
Gholamreza Poorheidari; Alireza Shahriary; Mahdi Mashhadi Akbar Boojar
Volume 23, Issue 2 , 2021
Abstract
Background: It is generally believed that the anticholinesterase effect is induced by the organophosphate insecticide parathion only through its bioactive metabolite (i.e., paraoxon) that is created in the liver.
Objectives: This study aimed to evaluate the intrinsic anticholinesterase ...
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Background: It is generally believed that the anticholinesterase effect is induced by the organophosphate insecticide parathion only through its bioactive metabolite (i.e., paraoxon) that is created in the liver.
Objectives: This study aimed to evaluate the intrinsic anticholinesterase effect of parathion, compared to its main metabolite.
Methods: This study has been conducted to prepare the isolated chick biventer cervicis nerve-muscle using the twitch tension recording method.
Results: According to the results, paraoxon (0.1 µM) induced a highly significant increase (more than 100%) in the twitch height, while higher concentrations (0.3 and 1 µM) induced partial or total contractures. Furthermore, parathion induced almost the same percentage of increase in the twitch height at 1 µM and partial or total contractures at 3 and 10 µM. It should be noted that pralidoxime (2-PAM), at 300 µM, reversed the effects of paraoxon and its parent (i.e., parathion).
Conclusion: These results demonstrate that both parathion and its metabolite inhibit the acetylcholinesterase enzyme which can be reactivated by pralidoxime, whereas parathion is about 10 times less potent, compared to its metabolite. Therefore, the intrinsic toxic effects of parathion, regardless of its metabolite, should be considered in future studies.
Gholamreza Poorheidari; Mahdi Mashhadi Akbar Boojar; Ahmad Soltani
Volume 22, Issue 8 , 2020
Abstract
Background: A conceptual model is always a suitable way to show the relationship between the different components of a process or among different processes. In the field of incident management, there are several models. However, there is almost no simple, natural, conceptual model to show the relationship ...
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Background: A conceptual model is always a suitable way to show the relationship between the different components of a process or among different processes. In the field of incident management, there are several models. However, there is almost no simple, natural, conceptual model to show the relationship between disaster risk management.
Methods: Because of the need for the development of a simple model that can quickly and at a glance relate the overall steps and components of the risk management process and various phases of disaster management, this model has been invented based on the evaluation of previous studies and reviewing current literature as well as refining the research and innovation done by the authors.
Results: In this article, a new model, which is called the Egg model, including the shell, the white (albumen) and the yellow (yolk) parts, is introduced. In which, risk management includes three steps. The first step is the assignment of a body, either a person, team or organization, as responsible (the resembling the shell). In the second step, the body does the assessment of the risk (resembling the white part). Risk assessment, on its own, includes risk identification, risk analysis, and risk evaluation. Finally, (resembling the yellow part), treatment of the risk(s) is begun which includes, prevention and mitigation, and preparedness before the disaster and, response and recovery after the disaster occurrence. Obviously, without an intact shell, the whole egg (albumen and yolk) will decay and all resources will be lost. Also without assessment of the risks, proper and effective management of the disaster is almost impossible. The third step of the risk management, the risk treatment, is in fact the disaster management.
Conclusion: This simple model shows the relationship between risk management and risk treatment. Although this model may have oversimplified the process of Risk Management, it helps to create a unique overview and understanding for almost everyone
