ABSTRACT
Objective:To determine the half lethal dose(LD50) of paraquat in rats and to establish a relatively safe and stable pathological animals model of pulmonary fibrosis.Methods: Ninety-six SD rats totally in half genders.Fifty SD rats in half genders were randomly divided into 5 groups,each had 10 rats.Feed the rats with different doses of liquor of paraquat intraperitoneally one time and definite the half lethal dose of one and two weeks.After that,prepare another forty-six SD rats,also in half genders,as intonication group,twenty-eight rats were treated with the liquor of paraquat in dosage of 18 mg/kg intraperitoneally.As control group,sixteen rats were treated with equivalent volume of normal saline.Observe the toxic symptom daily and rats were sacrificed on day 1,3,5,7,14,21,28,35 and 42 respectively for the histological examination.Results: The half lethal doses of intraperitoneal paraquat of 1 and 2 weeks were 18.27 and 17.29,with 95% confidence intervals of 16.61-20.09 and 15.99-18.67,respectively.After intraperitoneal paraquat injection at the dose of 18 mg/kg,typical toxic symptoms were observed at different times in the rats.The whole process of acute lung injury and fibrosis induced by paraquat intoxication could be seen with the naked eyes or under the light microscope.Conclusion: Paraquat has a strong toxicity to rats.A proper dose of paraquat solution can not only reduce the number of experimental rats,but also induce typical pulmonary fibrosis in rats.
ABSTRACT
Objective: To explore the emergency treatment of acute respiratory tract injury caused by inhalation of phosphorus trichloride.Methods: The clinical data of 16 patients with acute respiratory tract injury caused by inhalation of phosphorus trichloride were analyzed.Intratracheal inhalation of salbutamol sulfate solution and pulmicort repules atomized liquid by aerosol rebreathing method was performed immediately after the diagnosis was made.Anti-inflammatory,fluid replacement,and other symptomatic treatment were given at the same time.Treatment lasted for 3-5 days.Results: The symptoms and signs improved significantly after 3-5 times of inhalation.Among the 16 patients,15 were cured and one improved;the cure rate was 93.75%.The shortest observation period was 2 days and the longest 7 days with an average period of 2.38 days.All cases were followed up for 3 months.No complications were found except one with pleural thickening.Conclusion: Early treatment of acute respiratory tract injury with intratracheal corticosteroid and?2 receptor activator is satisfactory for patients with inhalation of phosphorus trichloride.The method is fast-acting,efficient,with less side-effects,convenient,and easily accepted by patients.
ABSTRACT
OBJECTIVE: To evaluate the role of MHC II expression in posttrauma immune disturbances and infections. METHODS: In experimental study, peritoneal macrophages were harvested from traumatized mice and treated with GM-CSF, Ia molecules were determined by flow cytometry. In 24 trauma patients, monocyte HLA-DR expression was measured by APAAP technique. RESULTS: Marked inhibition of MHC II molecule expression was found in both traumatized mice and patients. In traumatic patients with infection, the inhibition was more severe. Treatment with GM-CSF in mice partially restored the Ia expression. CONCLUSIONS: Inhibition of MHC II molecules plays an important role in postrauma immune disturbances. There is a close relationship between HLA-DR inhibition and clinical infections.