Effect of acetamide on histopathology in cerebral cortex of rats with tetramine poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effect of different doses of acetamide on the histopathology in the cerebral cortex of rats with tetramine (TET) poisoning and to provide a basis for the treatment of fluoroacetamide poisoning with acetamide.</p><p><b>METHODS</b>Eighty clean Sprague-Dawley rats were randomly divided into five groups: saline control group,dimethylsulfoxide water solution control group,TET poisoning group, acetamide (2.88 g/kg/d) treatment group, and acetamide (5.68 g/kg/d) treatment group, with 16 rats in each group. Rats in the poisoning group and treatment groups were poisoned with TET by intragastric administration after fasting; then, saline was injected intramuscularly into rats of the poisoning group, and different doses of acetamide were injected intramuscularly into rats of treatment groups; the course of treatment was 5 d. At 3 h, 12 h, 48 h, and 7 d after treatment, the cerebral cortex was harvested from rats in each group, and the histopathological changes in the cerebral cortex were evaluated under light and electron microscopes.</p><p><b>RESULTS</b>The light microscopy showed that the TET poisoning group had hypoxia changes in the cerebral cortex, which worsened over time; the treatment groups had reduced hypoxia changes, and the acetamide (2.88 g/kg/d) treatment group had more reduction than the acetamide (5.68 g/kg/d) treatment group. The electron microscopy showed that the apoptosis of neuronal cells were the main pathological changes in the TET poisoning group; the treatment groups had reduced apoptotic changes, and the acetamide (2.88 g/kg/d) treatment group had more reduction than the acetamide (5.68 g/kg/d) treatment group.</p><p><b>CONCLUSION</b>No pathological changes associated with the synergistic toxic effect of acetamide and TET are found in the cerebral cortex. Acetamide (2.88 g/kg/d) could reduce central nervous lesions, but the efficacy is not improved after increasing the dose. For patients who cannot be identified with TET or fluoroacetamide poisoning, acetamide could be considered for treatment.</p>

Effects of acetamide at different doses on expression of amino acids in cerebral cortex of rats with acute tetramine poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of acetamide at different doses on the expression of inhibitory amino acids (gamma-aminobutyric acid, GABA) and excitatory amino acid (glutamate, Glu) in the cerebral cortex of rats with acute tetramine (TET) poisoning.</p><p><b>METHODS</b>Eighty Sprague-Dawley rats (SPF) were randomly divided into five groups, with 16 rats in each group: saline control group, dimethyl sulfoxide (DMSO) control group, TET exposure group, high-dose (2.8 g/kg/d) acetamide treatment group, and super-high-dose (5.6 g/kg/d) acetamide treatment group. Rats in the exposure group and treatment groups were exposed to TET by intragastric administration after fasting, and were then intramuscularly injected with saline or different doses of acetamide in the following 5 days. The cortex of the temporal lobe was collected at 3 h, 12 h, 48 h, or 7 d after treatment. The expression levels of GABA and Glu in the cortex of the temporal lobe were determined by average optical density (OD) values in immunohistochemistry.</p><p><b>RESULTS</b>1) Expression of GABA: The OD value of GABA in TET exposure group started to increase at 12 h after treatment, reached the peak at 48 h, and decreased to the normal level at 7 d. In the high-dose acetamide treatment group, the increase in OD at 12 h was not so significant as that in the TET exposure group, OD value decreased to the normal level at 48 h and was lower than that in the exposure group, and the changes were more like those in the control groups. In the super-high-dose acetamide treatment group, OD value began to increase significantly at 3 h and was significantly higher than that in the TET exposure group (P < 0.01), it reached the peak at 12 h, and was restored to the normal value at 48 h. 2) Expression of Glu: The OD value of Glu in TET exposure group at 3 h after treatment was significantly lower than those in the two control groups, it increased gradually from 12 h to 48 h, and recovered to the normal level at the 7th d. The changes in the high-dose acetamide treatment group were similar to those in the TET exposure group, but became more like those in the control groups after 48 h; the OD value in super-high-dose acetamide treatment group was significantly higher than that in the TET exposure group at 3 h after treatment (P < 0.01), while no significant difference was found at 12 h; it was significantly lower than those of all other groups at 48 h and 7 d (P < 0.01).</p><p><b>CONCLUSIONS</b>Treatment with high dose of acetamide has some curative effect on TET poisoning-induced central nervous lesion, while the effect of super-high-dose acetamide on expression of neurotransmitters is too complex to evaluate.</p>

Effects of grade of ischemia on arrhythmia in patients with acute myocardial infarction / 中华急诊医学杂志

Objective To evaluate clinical significance of the grade of ischemia by QRS complex on the admission electrocardiogram(ECG)to predict severe arrithmia in patients with acute ST-segment elevation myocardial infarction(STEMI).Methods Patients with acute ST-segment elevation myocardial infarction(STEMI)admitted to emergency department from July 2003 to April 2008 were enrolled.A total of 223 patients met the criteria(ischemic chest pain ≥ 30 min,2 or more adjacent leads of ST segment elevation and onset time within 12 h).Exclusion criteria were bundle branch block and left ventricular hypertrophy.All enrolled patients were divided into two groups based on the enrollment electrocardiogram:grade 2 ischemia(ST elevation without terminal QRS distortion; n =134)and grade 3 ischemia(ST elevation with terminal QRS distortion; n =89).Patients of the two groups had comparable genderproportion,average age and coronary heart disease risk factors etc.All patients received thrombolytic therapy.The incidence rate of ST segment resolution(STR)and severe arrithmia in hospital stay were observed.Numerical variables were expressed mean ± standard deviation and compared by unpaired Student't test,Categorical variables were expressed percentage and compared by chi square test.Multiple logistic regression analysis was used to determine independent predictors of severe arrithmia.Results Patients with grade 3 ischemia had greater Σ ST on admission and 2 h after thrombolysis ECGs(P ＜ 0.01),the incidence rate of STR in patients with grade 3 ischemia was lower than that in patients with grade 2 ischemia(P ＜0.01).The peak creatine kinase MB fraction was higher in patients with grade 3 ischemia than that in patients with grade 2 ischemia(P ＜ 0.01).There was no significant difference of the incidence of severe arrithmia,such as ventricular premature beat,ventricular tachycardia or fibrillation,second-degree or third-degree atrioventricular block,and sinus arrest between the two groups(P ＞ 0.05),but there was a trend of higher incidence of severe arrithmia in patients with grade 3 ischemia compared with that in patients with grade 2 ischemia.Multiple logistic regression analysis demonstrated that the independent predictors of severe arrithmia were duration from symptom to thrombolysis and initial.Σ ST,whereas grade 3 ischemia remained a strong predictor of severe arrithmia.Conclusions Grade 3 ischemia on admission is associated with lower incidence of STR in patients with ST-segment elevation myocardial infarction(STEMI)after thrombolysis and a strong predictor of severe arrithmia.

Effects of N-acetylcysteine on apoptosis and expressions of Fas/FasL in lung tissue of rats with paraquat poisoning / 中华急诊医学杂志

Objective To investigate the effects of N - acetylcysteine (NAC) on apoptosis and the expressions of Fas/FasL mRNA in lung tissue of rats with paraquat - induced acute lung injury.Methods Forty five male SD rats were randomly (random number) divided into normal control group,paraquat (PQ) group,and NAC treatment group.The rat model of acute lung injury was made with 2％ PQ induction in dose of 25 mg/kg injected,and NAC was injected into the PQ poisoning rats (200 mg/kg) 30 minutes after PQ administration in NAC treatment group.In the control group,equal amount of saline instead was injected into the rats.Apoptosis was detected by using TUNEL method and the expressions of Fas/FasL mRNA were evaluated by using reverse transcription polymerase chain reaction (RT- PCR),and the levels of Fas/FasL protein were detected by using western blot analysis.Results Compared with control group,cell apoptosis and expressions Fas/FasL mRNA in PQ group were significantly different ( P ＜ 0.05 ).Compared with PQ group,cell apoptosis and expressions Fas/FasL mRNA in NAC group were significantly decreased,were significant lower (P ＜ 0.05).Conclusions NAC inhibited apoptosis in lung tissue of rats with paraquat induction by regulating the activation of Fas/FasL systems.

The study on expression of TNF-α in acute lung injury caused by paraquat arid the protection effect of rhubarb / 中华急诊医学杂志

Objective To observe the expression of tumor necrosis factor-α(TNF-α)in acute lung injury caused by paraquat(PQ)in rats,and investigate the mechanism of the rhubarb in respect of pmteetive effects.Method PQ intragastrically poisoning at the dose of 50 mg/kg made a model of the acute lung injury in Sprague-Dawley(SD)rats.Totally 144 adult healthy SD rats(72 female,72male)were randomly divided into control group (group A,n=24),poisoned group(group B,n=48),rhubarb treated group(group C,n=48)and the shaln poisoning group(group D,n=24).Rats of group B and group C were poisoned intmgastrically with PQ(50 mg/kg).and rats of group C and group D were intervened intragastrieally with 300 mg/(kg·d)of rhubarb in 15 min-utes.The white blood cells and total cells in bronchoalveolar lavage fluid(BALF)were counted by using a blood cell counting plate and the protein content of BALF was measured by using the way of Lowry in order to calculate the neutmphiks pereentage and lung permeability index.A small portion of left lung was stained with HE to observe the pathological changes and the expression oftumor necrosis factor-α in the rest of the left lung was observed with immunohistochemistry.The data were handled by the analysis of variance and NK method using SPSS 14.0.Re-suits Compared with group A,the lungs of rats mainly showed congestion,edema and leukocytes infiltration in group B,and fibrosis was found onlyt in a few rats.And the rate neutrophils percentage,protein content and lung permeability index in BALF increased(P＜0.01).The expression of TNF-α were obviously inereased at 12 hours after PQ poisoning,and immtmohistochemistry score (IHS)was higher,and peaked at 24 hours later(P＜0.05),then remained on a high level for a while and sluggishly declined.Compared with group B,the changes of above mentioned were alleviated obviously,and the expression of TNF-α delayed with the less magnitude of increasing an an obvious tendency of less expression.Compared with group B,delayed,lower increasing extent,obviously re-ducing tendency in group C with statistical difference in IHS(P＜0.05).Conclusions Rhubarb ameliorates a-cute lung injury caused by PQ poisoning in rats by means of inhibiting the expression of TNF-α in turn to alleviate inflammatory reaction.

Use of melatonin in rats with acute paraquat posoning / 中华急诊医学杂志

Objective To investigate the effects of melatonin (MT) on rats with acute paraquat (PQ) poisoning. Method Fifty-four Sprague-Dawley (SD) rats were randomly divided into three groups (each group 18 rats) and given the following treatment: intragastric injection of PQ at 50 mg/kg (PQ); intragastric injection of paraquat followed by intraperitoneal injection of MT at 10mg/kg once a day (MT); intragastric injection of normal saline (Control). Serum assays for malondialdehyde (MDA) levels and superoxide dismutase (SOD) and glu tathione peroxidase (GSH-Px) activities were determined on the 1st, 3rd and 7th day post treatment. Clinical manifestations of poisoning and pathological changes in the lungs were also observed. Results Serum MDA levels were significantly increased (P ＜ 0.01), and SOD and GSH-Px activities significantly decreased (P ＜ 0.05) in the PQ group compared to the control group. Serum MDA levels were significantly decreased, and serum SOD and GSH-Px activities increased in MT group compared to the PQ group (P ＜ 0.05). Clinical manifestations of intoxication and pathological lung changes were also ameliorated in poisoned rats treated with MT. Condutions Administration of MT alleviates clinical manifestations of acute paraquat poisoning in rats by Limiting the damage from lipid peroxidation.