Brain impairment induced by oral intake of lead and its effects on expression of Hoxa9 Gen in Rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe effects of oral intake of lead on the expression of Hoxa9 gen and the ability of learning and memory and explore the the toxic molecular mechanisms of lead.</p><p><b>METHODS</b>Thirty male Wistar rats were chosen and randomly divided into the low lead dosage group, the high lead dosage group and the control group, 10 rats in each group. The low lead dosage group and the high lead dosage group were given respectively 0.06%, 0.2% lead acetate orally while the control group was given distilled water orally. The Y-maze test was used to measure the ability of learning and memory, the graphite heat atomic absorption spectrum method to determine the lead concentration in blood and brain, and the in situ hybridization (ISH) method to determine the expression of Hoxa9 mRNA in brain.</p><p><b>RESULTS</b>(1) The number of electric shocks of the lead poisoned rats were significantly increased over time. The number of electric shocks of the lead poisoning rats was much higher than that of the control group (P < 0.01) (at the end of the experiment, the low lead dosage group: 31.8 +/- 2.26; the high lead dosage group: 37.3 +/- 1.70; the control group: 18.4 +/- 1.51). (2) The brain of the lead poisoned rats including the hippocampus, the cerebellum and the cerebral cortex were significantly atrophic and the apoptosis and necrosis occurred in the cells of the brain. Purkinje's cells in the cerebellum showed significant necrosis and disappearance. The structure of brain in rats of the control group demonstrated no atrophy. (3) The expression of Hoxa9 mRNA in the lead poisoned rats was significantly decreased compared with the control group. There were few Hoxa9 positive cells in the brain of the lead poisoned rats, but many of them were observed in the control group.</p><p><b>CONCLUSION</b>Lead may inhibit the expression of Hoxa9 and induce atrophy and necrosis of brain, which gives rise to a damage of learning and memory.</p>

Protective effect of Gastrodia elata and E-gelatin on lead-induced damage to the structure and function of rat hippocampus / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the counteraction of Gastrodia elata and E-gelatin on the effect of subchronic lead poisoning on the ability of learning and memory and the ultrastructure in hippocampus.</p><p><b>METHODS</b>Subchronic lead acetate exposure was given to rats (0.2 g x kg(-1) x d(-1)). Single and combined administration of Gastrodia elata (4 g x kg(-1) x d(-1)) and E-gelatin (1 g x kg(-1) x d(-1)) were conducted at the same time. Pb concentration in blood, and the ability of learning and memory (Y-maze test) of rats were measured. Ultrastructure of CA3 pyramidal cells in hippocampus under transmission electron microscope was observed.</p><p><b>RESULTS</b>Blood Pb concentrations in each group (Pb group: 690.6 micro g/L, Pb + Gastodiae eleta group: 688.8 micro g/L, Pb + E-gelatin group: 663.8 micro g/L, Pb + combined group: 667.2 micro g/L) were higher than that in the control (28.24 micro g/L, P < 0.01). But there was no significant difference (P > 0.05) among these groups. In Y-maze test, the number of electric stroke in Pb group is higher than that in control (P < 0.01). Gastrodia elata or E-gelatin used singly could significantly reduce the number of electric stroke of lead-exposed groups (P < 0.05 in the first month and P < 0.01 in the second and third month). And the effect of combined use of them was more efficient than single use (P < 0.01). Under electron microscope, no anomaly was seen in the pyramidal cells of CA3 area in hippocampus of control group. But there was significant anomaly such as neucleus separation in the cells of Pb exposed group. In Pb-Gastrodia elata group, there were some stress response phenomena such as the occurrence of huge mitochondria while in Pb-E-gelatin group, the anomaly was mild. The cells in the CA3 area in hippocampus of the pb-Gastrodia-E-gelatin group were almost normal, and also showed some stress response phenomena.</p><p><b>CONCLUSION</b>Gastrodia elata and E-gelatin may protect the neurons in CA3 area of hippocampus against damage induced by lead to improve the ability of learning and memory, and they have synergistic effect.</p>

The antagonistic action of Gastrodia elata combined with E-gelatin on lead-induced down regulation of c-fos expression in rat brain / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effect of lead on the expression of c-fos mRNA in hippocampus and cerebellum and the ability of learning and memory in rat, and to observe the antagonistic action of Gastrodia elata and E-gelatin on the effect mentioned above.</p><p><b>METHODS</b>Rats were exposed to lead acetate (0.2 g x kg(-1) x d(-1) and 0.1 g x kg(-1) x d(-1)). The single and combined administration of Gastrodia elata (4 g x kg(-1) x d(-1)) and E-gelatin (1 g x kg(-1) x d(-1)) were conducted at the same time. Blood lead concentration in rats were measured. The ability of learning and memory by Y-maze test were examined. The expression of c-fos mRNA in hippocampus and cerebellum during Y-maze test were observed by in situ hybridization (ISH).</p><p><b>RESULTS</b>(1) Blood lead concentrations were significantly increased in both high and low doses of lead-exposed rats (P < 0.01). But there were no differences among high dose groups or low dose groups (P > 0.05). (2) In Y-maze test, the number of electric stroke during learning in lead-exposed group was significantly increased (P < 0.01) while that in Gastrodia elata and E-gelatin groups was significantly decreased (P < 0.05), and that in combined use group was more significantly decreased (P < 0.01). (3) There were much more deep-colored c-fos positive cells in CA3 area of hippocampus in low dose of Pb-exposed with Gastrodia elata + E-gelatin group. These cells were also found in high Pb with combined use or single use group, but which were not so densely distributed as the former. And they were hardly found in high and low doses of Pb alone groups. The changes of expression of c-fos cells in cerebellam were similar to those in hippocampus.</p><p><b>CONCLUSION</b>The down regulation of c-fos expression may be one of the molecular mechanism of lead-induced impairment of learning and memory. Gastrodia elata and E-gelatin may antagonize the effect of lead on c-fos expression, and combined use of both drugs may potentiate the antagonism.</p>

The comparative study of the scanning parameters for diffusion tensor imaging of cervical cord / 中华放射学杂志

Objective To investigate the optimal scanning parameters for diffusion tensor imaging of the cervical cord.Methods MRI and diffusion tensor imaging of the cervical cord was performed in 80 healthy adult volunteers.Different parameters including b values,the number of the diffusion sensitive gradient directions,the number of excitations,and slice thickness were applied and their effects on the quality of the images were compared.DTI was performed on the cervical spinal cord with different b-values (400,700,and 1000 s/mm~2)in group 1,with different numbers of diffusion gradient directions(6,13, and 25)in group 2,with different numbers of excitations(2,4,and 8)in group 3,and with different slice thicknesses(2,3,and 4 mm)in group 4.Two radiology experts gave a score to every image with double blind methods,then compared the image quality.Results In the comparison of the four different parameters,DTIs using a b value of 700 s/mm~2(2.25?0.58)showed better image quality than those with the b values of 400 s/mm~2(1.86?0.53)and 1000 s/mm~2(1.48?0.35)(P