Pathology and neurophysiology analysis for peripheral neuropathy of four patients with chemicals poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the nerve electromyogram results by analysing the pathological characters of 4 cases diagnosed as peripheral neuropathy caused by n-hexane and arsenic.</p><p><b>METHODS</b>The nerve electromyogram examination and pathology data of 4 patients, who had been diagnosed as toxic chemicals peripheral neuropathy, were studied retrospectively.</p><p><b>RESULTS</b>Two patients in this group were exposed to n-hexane, their nerve electromyogram examinations and biopsy pathology of superficial peroneal nerve indicated the peripheral neuropathy was mainly manifests the lesion of medullary sheath. Another two patients were exposed to arsenic, their nerve electromyogram examinations showed axonal degeneration associated with demyelination, and their biopsy pathology showed the peripheral neuropathy was mainly axonal degeneration.</p><p><b>CONCLUSION</b>Axonal degeneration and demyelination always coexist in peripheral neuropathy caused by chemicals.</p>

Establishment of acute pulmonary edema model induced by high concentrations of nitrogen dioxide in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish the rats model of acute pulmonary edema induced by inhalation of high concentrations of nitrogen dioxide (NO2).</p><p><b>METHODS</b>38 SD rats were divided into the experimental group (n = 30) and the control group (n = 8). 30 rats in the experimental group were exposed to (6747.47 ± 25.24) mg/m(3) NO2 in the exposure system. At the time point of 6, 12, 18, 24 h, chest X-ray examination was taken for the experimental group. And at each time point, 6 rats were sacrificed after taking blood samples. After sacrificing, the lung of rats was taken for pathological examination and calculated lung wet/dry weight ratio. Erythrocyte superoxide dismutase (SOD) activity and plasma atrial natriuretic peptide (ANP) concentration of blood samples were detected.</p><p><b>RESULTS</b>Acute pulmonary edema was successfully induced by exposure to NO2 in 30 rats within 24 hours. There were some cloudy shadows without clear edge on the chest X-ray. To the time point of 12 hours, shadows combined with each other, and to the time point of 18 hours, the whole lung became "white" on the X-ray. The situation stabilized but not improved at the time point of 24 hours. HE staining of the lung tissue showed that to the time point of 6 hours, the alveolar gap increased and small amount of eosinophilic liquid leaked into alveolar. To the time point of 12 hours, alveolar combined with each other and eosinophilic liquid increased in amount. To the time point of 18 hours, the whole alveolar was filled with eosinophilic liquid and the situation stabilized till the time point of 24 hours. Wet/dry weight ratio of the experimental group at each time point were 5.6 ± 0.20, 6.89 ± 0.25, 8.03 ± 0.47, 7.81 ± 0.45. There was significant difference compared with the control group which was 4.72 ± 0.06 (P < 0.01). There was statistical difference between 12, 18, 24 h and 6 h time points (P < 0.01). Moreover, statistical difference was observed between 18, 24 h and 12 h time points for wet/dry weight ratio (P < 0.01). The erythrocyte SOD activity reduced significantly. Compared with the control group, there was a statistical difference (P < 0.01) at each time point. After exposure of 18 and 24 hours, plasma ANP concentration (136.66 ± 35.37) and (134.10 ± 60.41) ng/ml respectively, which were higher than (31.31 ± 13.06) ng/ml of control group and (34.71 ± 13.42) ng/ml of 6 hours time point and (47.98 ± 7.86) ng/ml. The differences were significant (P < 0.01).</p><p><b>CONCLUSION</b>High concentrations of NO2 can induce acute pulmonary edema model successfully in SD rats.</p>

Preliminary experimental research on glucocorticoid for treatment of nitrogen dioxide induced acute pulmonary edema in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic effect of glucocorticoids on the acute pulmonary edema in rats induced by nitrogen dioxide (NO₂).</p><p><b>METHODS</b>Thirty SD female rats were randomly equally divided into 5 groups: normal control group, NO₂ exposed group, high-, middle- and low-dose of glucocorticoids treated group (6 rats per group). 6 rats in the normal control group were exposed to room air for 30 min, and the other rats to NO₂. 18 rats in the glucocorticoids group were treated with different doses of dexamethasone (6.0, 3.0, 1.0 mg/kg), while the rats in the NO₂ poisoning group were treated with normal saline (2.5 mg/kg). The lung wet/dry (W/D) weight ratio was calculated, and plasma atrial natriuretic peptide (ANP) levels, superoxide dismutase (SOD) activity from whole blood, plasma interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-α (TNF-α) and Interferon-γ (IFN-γ) were detected by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>The lung W/D ratios were increased significantly in glucocorticoids treated group and NO₂-exposed group compared with normal control group (P < 0.05), while they were significantly reduced in glucocorticoids treated group as compared with NO₂-exposed group (P < 0.05). SOD activity in whole blood in glucocorticoids treated group and NO₂-exposed group was significantly lower than that of normal control group (P < 0.05), while it was no significant difference between that of glucocorticoids treated group and NO₂-exposed group (P > 0.05). Plasma ANP was significantly increased in NO₂-exposed group compared with normal control group (P < 0.05), while it was significantly decreased in glucocorticoids treated group compared with NO₂-exposed group (P > 0.05). Plasma TNF-α of high-, middle- and low-dose of glucocorticoids treated group [(27.04 ± 8.19), (40.10 ± 9.09), (39.76 ± 9.60) pg/ml] was decreased significantly as compared with NO₂-exposed group (68.55 ± 27.84 pg/ml) (P < 0.05). Plasma IL-6 in high- and middle-dose of glucocorticoids treated group [(15.97 ± 6.18), (19.69 ± 5.52) pg/ml] was significantly decreased as compared to NO₂-exposed group [(29.29 ± 9.31) pg/ml] (P < 0.05). Plasma IL-10 in high-, middle- and low-dose of glucocorticoids treated group [(23.24 ± 5.14), (27.78 ± 8.17), (33.29 ± 10.42) pg/ml] was significantly reduced compared with NO₂-exposed group [(44.38 ± 9.19) pg/ml] (P < 0.05). Plasma IFN-γ in high- and middle-dose of glucocorticoids treated group [(7.21 ± 4.55), (19.23 ± 4.35) pg/ml] was reduced compared with NO₂-exposed group [(30.83 ± 6.82) pg/ml] (P < 0.05).</p><p><b>CONCLUSION</b>High-, middle-, low-dose glucocorticoids all can improve the permeability of alveolar wall and capillary, and have nonspecific anti-inflammatory effects. The therapeutic effects on pulmonary edema are significant. High and middle dose of glucocorticoids treated group are more useful for decreased inflammatory factors.</p>