Development of peripheral neuropathy rat model induced by 1-bromopropane / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the peripheral neurotoxicity of 1-bromopropane (1-BP) by developing an animal model of peripheral neuropathy through oral administration of 1-BP.</p><p><b>METHODS</b>Forty male Wistar rats were randomly and equally divided into low-dose group (200 mg/kg), medium-dose group (400 mg/kg), high-dose group (800 mg/kg), and control group. The rats in the low-dose, medium-dose, and high-dose groups were orally given 1-BP (dissolved in corn oil), while the rats in the control group were orally given an equal volume of corn oil. The oral administration (0.2 ml/100 g BW) was performed once per day, 5 days per week, for 16 consecutive weeks. Neurobehavioral indices including gait score, hindlimb grip strength, and hindlimb landing foot splay were recorded periodically. Hematological and biochemical parameters were also measured during and after 1-BP exposure.</p><p><b>RESULTS</b>The gait scores were significantly higher in the high-dose group (after 8 ∼ 16 weeks of 1-BP exposure), medium-dose group (after 14 ∼ 16 weeks of 1-BP exposure), and low-dose group (after 15 ∼ 16 weeks of 1-BP exposure) than in the control group (P < 0.05, P < 0.01). Compared with the control group, the high-dose group showed significantly decreased hindlimb grip strength after 9, 12, and 14 weeks of 1-BP exposure (P < 0.05, P < 0.01), with the hindlimbs paralyzed after 16 weeks of 1-BP exposure. After 16 weeks of 1-BP exposure, the hindlimb grip strengths of rats in the medium-dose and low-dose groups were decreased to 72.6% and 91.2% of the control value (P < 0.01, P < 0.05). Compared with the control group, the high-dose group showed significantly increased hindlimb landing foot splay after 12, 14, and 16 weeks of 1-BP exposure, and the medium-dose group showed significantly increased hindlimb landing foot splay after 14 and 16 weeks of 1-BP exposure (P < 0.05, P < 0.01). The high-dose and medium-dose groups showed significantly higher serum alanine aminotransferase (ALT) activity than the control group after 8 weeks of 1-BP exposure, and so did the low-dose group after 16 weeks of 1-BP exposure (P < 0.01).</p><p><b>CONCLUSION</b>The nervous system is sensitive to the toxic effect of 1-BP, and 1-BP exposure can induce peripheral neuropathy in rats.</p>

Protective effects of garlic oil on n-hexane-induced neurotoxicity in rats via inhibition of hepatic alcohol dehydrogenase activity / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the protective effects of garlic oil (GO) on the peripheral nerve injuries induced by n-hexane.</p><p><b>METHODS</b>Male Wistar rats were randomly divided into four groups (10 rats in each group): the control, the n-hexane treatment (2000 mg/kg), the low dose GO, and the high dose GO groups. The rats in the low and high doses of GO groups were pretreated with GO (40 and 80 mg/kg) before exposure to n-hexane (2000 mg/ kg), while the animals of the n-hexane treatment group were given normal saline and then 2000 mg/ kg n-hexane. The rats were exposed to GO and n-hexane 6 times a week for 10 weeks. The gait scores and staying time on the rotating rod for all rats were detected every two weeks. The rats were sacrificed at the end of ten weeks, then the levels of alcohol dehydrogenase (ADH), maleic dialdehyde (MDA), reduced glutathione (GSH), glutathione peroxidase(GSH-Px), total antioxidation capacity(T-AOC) and the ability of inhibition of *OH in livers were examined.</p><p><b>RESULTS</b>The gait scores increased significantly and the time staying on the rotating rod obviously decreased in rats of n-hexane treatment group, as compared with control group (P < 0.05 or P < 0.01). In the hepatic tissues of n-hexane group, the levels of MDA and ADH significantly increased, the activities of GSH-Px, T-AOC and the ability of inhibition of *OH obviously decreased, as compared to control group (P < 0.05 or P < 0.01). In 2 GO groups, the gait scores and the staying time on the rotating rod were significantly improved, the levels of MDA and ADH significantly decreased, the activities of GSH-Px, T-AOC and the ability of inhibition of *OH obviously increased, as compared with n-hexane group (P < 0.05 or P < 0.01 ).</p><p><b>CONCLUSION</b>ADH could play an important role in the protective effects induced by garlic oil on the peripheral nerve injuries produced by n-hexane.</p>

Effects of 1-bromopropane exposure on cognitive function in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of 1-bromopropane (1-BP) on the functions of learning-memory and the central cholinergic system in rats.</p><p><b>METHODS</b>Forty male Wistar rats were randomly divided into four groups: low 1-BP group (200 mg/kg), middle 1-BP group (400 mg/kg), high 1-BP group (800 mg/kg) and control group, and the exposure time was 7 days. The Morris water maze (MWM) test was applied to evaluate the learning-memory function in rats. After the MWM test, the rats were sacrificed, the cerebral cortex and hippocampus were quickly dissected and homogenized in ice bath. The activity of acetylcholine esterase (AChE) and choline acetyltransferase (ChAT) in supernatant of homogenate were detected.</p><p><b>RESULTS</b>The latency and swim path-length of rats in middle and high 1-BP groups prolonged significantly in place navigation test and the efficiency of searching strategy obviously decreased, as compared with control group (P < 0.05 or P < 0.01). In spatial probe test, the number of crossing platform in three 1-BP groups decreased significantly, as compared with control group (P < 0.05 or P < 0.01). The cortical AChE activity of rats in middle and high 1-BP groups was significantly higher than that of control and low 1-BP group (P < 0.05 or P < 0.01). The AChE activity in rat hippocampus of high 1-BP group obviously increased, as compared with control group as compared with control group (P < 0.05). There was no significant difference of cortical ChAT activity between three 1-BP groups and control group (P > 0.05). In the hippocampus, there was no difference of ChAT activity among the groups (P > 0.05).</p><p><b>CONCLUSION</b>1-BP exposure could significantly influence the learning-memory function in rats due to the increase of AChE activity.</p>

Efficient expression and purification of human beta-defensin-2 in E.coli / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To demonstrate the possibility of high-level expression of bioactive human beta-defensin-2 (hBD2) in E.coli, and to purify the recombinant hBD2.</p><p><b>METHODS</b>DNA fragment containing mature hBD2 coding region (smhBD2-cDNA) was amplified by PCR, multiple copies of smhBD2-cDNA were linked using Bgl II and BamH I enzymes, pET32-nsmHBD2-cDNA with 1, 2, 4, or 8 copies of smhBD2-cDNA was constructed. The soluble and insoluble hBD2 proteins were separated and analyzed by SDS-PAGE analysis. The soluble protein underwent a separation process containing affinity chromatography, enterokinase digestion and ion exchange chromatography to get the recombinant hBD2 peptide. The bioactivity of recombinant hBD2 was examined by bacteria-inhibition tests in liquid culture.</p><p><b>RESULT</b>The plasmids pET32-nsmHBD2-cDNA with 1, 2, 4 copies of smhBD2-cDNA were constructed and the expressed soluble protein accounted for 52 %, 48 %, and 31 % respectively. The plasmids with 8 copies expressed mainly insoluble protein with few in soluble form. The growth of E.coli K12D31 was dramatically suppressed with a inhibition rate of 90 %, when the final concentration of recombinant hBD2 reached between 0.4 to 0.5 mug/ml.</p><p><b>CONCLUSION</b>Fusion expression of human beta-defensin-2 with multiple joined genes in E.coli could increase the expression of hBD2.</p>