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>

Replication of duck plague virus in artificially infected ducks detected by in situ hybridization / 病毒学报

Replication of duck plague virus(DPV) in artificially infected ducks were detected by in situ hybridization (ISH) which employed a 37bp oligonucleotide as probe designed according to DPV DNA sequence in GenBank. The results indicated that DPV DNA was detected in liver, intestine and bursa Fabricius at 4 h, in spleen and esophagus at 6h, in thymus at 12h post infection; DPV DNA in lung and kidney was detected only in dead ducks and no positive signal was detected in muscle, heart, cerebrum and pancreas. DPV DNA was distributed in cell nucleus and cytoplasm. Hepatocytes, sinus endodermal cells and Kuffer's cells were the mainly infected cell types in liver. DPV DNA was mainly detected in epithelium of villi, in lamina propria of intestinal villi of duodenum, in stratum spinosum of esophagus, and in epithelium, cortex, medulla of bursa Fabricius. The positive signals were mainly detected in medulla of thymus, lymphocytes and macrophages of spleen. The research suggests that ISH is a direct and specific method in detecting DPV DNA in paraffin sections and it's also a good method for virus diagnosis and DNA location of DPV.

Effects of methamidophos on microtubule and microfilament proteins in sciatic nerve of hens / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the dynamic changes of alpha-tubulin, beta-tubulin and beta-actin in sciatic nerve of hen with organophosphorus ester-induced delayed neuropathy (OPIDN).</p><p><b>METHODS</b>OPIDN was induced in 10-month-old Roman hens by daily subcutaneous administration of 30 mg/kg methamidophos for 15 days. Hens were sacrificed 2, 10, and 23 days respectively after manifesting neuropathy. The sciatic nerves were dissected, homogenized and used for the determination of the alpha-tubulin, beta-tubulin and beta-actin levels by western blotting.</p><p><b>RESULTS</b>The levels of alpha-tubulin in supernatant of sciatic nerves were decreased by 6%, 15% and 25% respectively on day 2, 10 and 23 respectively, while those in pellet remained almost unchanged. beta-tubulin were decreased by 27%, 6%, 19% in pellet and 1%, 21%, 22% in supernatant of sciatic nerves on 2, 10 and 23 days. Beta-actin level in pellet of sciatic nerve increased by 24%, 48% and 17% on day 2, 10 and 23, and little changes were observed in supernatant.</p><p><b>CONCLUSION</b>Methamidophos may induced changes of alpha-tubulin, beta-tubulin and beta-actin levels in sciatic nerve of hen, which may be one of the mechanism of the contribution to the occurrence and development of OPIDN.</p>

Alterations of neurofilament proteins in sciatic nerve of hens induced the delayed neurotoxicity by methamidophos / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the dynamic alterations of neurofilament subunits (NF) in sciatic nerve of hens with organophosphorus ester induced the delayed neurotoxicity or neuropathy (OPIDN).</p><p><b>METHODS</b>Hens with OPIDN were produced by giving 30 mg/kg methamidophos subcutaneously to the 10-month-old Roman hens daily for 15 days, and sacrificed after manifesting neurotoxic clinical signs on the 2nd, 10th, and 23rd day respectively. The sciatic nerves were dissected, homogenized and centrifuged. The levels of NF in supernatant and pellet of sciatic nerves were examined by Western blotting respectively at different time from 2 to 23 days.</p><p><b>RESULTS</b>Integrated optional density (IOD) of high molecular weight neurofilament (NF-H) in sciatic nerve pellet of hens on the day 2, 10, 23 after appearance of OPIDN were 145,117 +/- 17,038, 55,917 +/- 17,333 and 45,038 +/- 6,662 respectively. As compared with the control group (78,875 +/- 22,569), the contents of NF-H in pellet were increased by 84% on day 2, and decreased by 29% and 43% on day 10 and 23 respectively. IOD of NF-H in supernatant of sciatic nerves were 4,709 +/- 1,739, 12,337 +/- 3,205 and 16,745 +/- 931, which were reduced significantly as compared with the control (44,083 +/- 6,895) at three different times. There was no significant difference in IOD of middle molecular weight neurofilament (NF-M) between control group (27,925 +/- 2,660) and on day 2 (31,493 +/- 4,625) in pellet. Those were 19,367 +/- 2,746 and 6,612 +/- 1,119 respectively on day 10 and day 23 in pellet of hen's sciatic nerve, which were much less than that in control. Little were detected in supernatant on day 10, and the IOD of NF-M were 3,196 +/- 269 and 5,206 +/- 1,292 on day 2 and day 23 respectively, which were lessened by 81% and 70% as compared with the control (17,243 +/- 3,232). In sciatic nerve pellet of hens, IOD of low molecular weight neurofilament (NF-L) on day 2 was 39,211 +/- 3,800, which was much higher than that in the control (28,749 +/- 9,319). There were no significant differences between IOD on day 10 (27,974 +/- 3,611), day 23 (21,507 +/- 2,286) and the control. There was no detection both on day 2 and 10 in supernatant of sciatic nerve, and IOD of NF-L were 5,962 +/- 1,929 on day 23, which were reduced significantly compared with the control (11,897 +/- 352).</p><p><b>CONCLUSION</b>The alterations of NF in sciatic nerve might contribute to the occurrence and development of OPIDN.</p>