An inhibitive assay of insecticides using Acetylcholinesterase (AChE) from the local fish Clarias batrachus is reported. AChE was assayed according to the modified method of Ellman. Screening of insecticide and heavy metals showed that carbofuran and carbaryl strongly inhibited C. batrachus AChE. The inhibition concentration (IC) IC50 values (and the 95% confidence interval) for both carbofuran and carbaryl inhibition on C. batrachus AChE at 6.66 (5.97-7.52) and 130.00 (119.3-142.5) microg l(-1), respectively was within the IC50 range of Electrophorus electricus at 6.20 (6.03-6.39) and 133.01 (122.40-145.50) microg l(-1), respectively and were much lower than bovine AChE at 20.94 (19.53-22.58) and 418.80 (390.60-451.60) microg l(-1), respectively. The results showed that C. batrachus have the potential to be used as a cheaper and more readily available source of AChE than other more commercially available sources.
Near-real-ime assay is anassay method that the whole process from sampling until results could be obtained in approximately Iess than one hour. The ElIman assay for acetyl cholinesterase (AChE) has near real-time potential due to its simplicity and fast assay time. The commercial acetylcholinesterase from Electrophorus electricus is well known for its uses in insecticides detection. A lesser known fact is AChE is also sensitive to heavy metals. A near real-time inhibitive assay for heavy metals using AChE from this source showed promising results. Several heavy metals such as copper, silver and mercury could be etected with IC50 values of1.212, 0.1185 and 0.097 mg I-1, respectively. The Limits of Detection (LOD) for copper, silver and mercury were 0.01, 0.015 and 0.01 mg I-1, respectively. TheLimits of quantitation (LOQ) or copper, silver and mercury were 0.196, 0.112 and 0.025 mg I-1, respectively. The LOQvalues for copper, silver and mercury were well below the maximum permissible limit for these metal ions as outlined by Malaysian Department of Environment. A polluted location demonstrated near real-time applicability of the assay with variation oftemporal levels of heavy metals detected. The results show that AChE from Electrophorus electricus has the potential to be used as a near real-time biomonitoring tool for heavy
The investigation of patellar tendon reflex involves development of a reflex hammer holder, kinematic data collection and analysis of patellar reflex responses using motion analysis techniques. The main aim of this research is to explore alternative means of assessing reflexes as a part of routine clinical diagnosis. The motion analysis system was applied to provide quantitative data which is a more objective measure of the patellar tendon reflex. Kinematic data was collected from 28 males and 22 females whilst subjected to a knee jerk test. Further analysis of kinematic data was performed to predict relationships which might affect the patellar tendon reflex. All subjects were seated on a high stool with their legs hanging freely within the capture volume of the motion analysis system. Knee jerk tests were applied to all subjects, on both sides of the leg, by eliciting hypo, hyper, and normal reflexes. An additional reinforcement technique called the Jendrassik manoeuvre was also performed under the same conditions to elicit a normal patellar tendon reflex. The comparison of reflex response between genders showed that female subjects generally had a greater response compared to males. However, the difference in reflex response between the left leg and the right leg was not significant. Tapping strength to elicit a hyper-reflex produced greater knee-jerk compared to the normal clinical tapping strength. All results were in agreement with clinical findings and results found by some early researchers.