The toxicity of HCN inhaled via the respiratory tract in dogs and the therapeutic effects of DMAP and AmNO2 for such form of HCN intoxication were studied. The LD50 of HCN when inhaled was 850.4?80.4?g/kg.When the dosage of 2?LD50 of HCN was given to the experimental animals, the signs of intoxication developed rapidly. Uneasiness, struggling, strident barking, and respiratory excitation were observed several seconds after the exposure. Subsequently there was spasm of the extensors and rigidity of the extremities. Finally general inhibition and paralysis ensued. Respiration and heart beat stopped 6 and 7 minutes after exposure. If DMAP (3.25 mg/kg intramuscularly) or AmNO2 (2 ampules through inhalation) was administered 15 seconds after exposure, the survival rate of the animals was 90% or 100% respectively.When the dosage of 4?LD50 of HCN was inhaled and the two drugs were administered 45 seconds after exposure, the survival rate of the animals treated with DMAP remained as high as 90% (9/10) .But the survival rate of those treated with two ampules of AmNO2 or even three ampules reduced to 20% or 40% respectively.The amount of HCN inhaled during respiratory intoxication, the problems of early diagnosis and the administration of DMAP at the site of accident were analyzed and discussed.

Objective To investigate the reference intervals of mean corpuscular volume (MCV) ,mean corpuscular hemoglo‐bin(MCH) and mean corpuscular hemoglobin concentration (MCHC) examined by the MindrayBC‐6800 hematological analyzer to establish the reference intervals suitable for our laboratory .Methods According to the method recommended by the NCCLS C28‐A3 ,600 healthy adult individuals were selected as the reference individuals .MCV ,MCH and MCHC levels were determined by the MindrayBC‐6800 hematological analyzer for constructing the reference intervals ;other 150 healthy persons undergoing the physical examination were selected and their MCH ,MCV and MCHC detection results were collected for verifying the established reference intervals .Results The detection results of MCV ,MCH and MCHC in healthy adults showed a normal distribution ,MCV had sta‐tistical difference among different age periods (P<0 .05);the reference intervals :82 .278 -94 .242 fL for young adults ,83 .032-94 .608 fL for the middle‐aged persons and 83 .137-96 .343 fL for the elderly .MCH had statistical differences between different se‐xes and among different age periods ;the reference intervals :27 .785-32 .415 pg for male young adults ,28 .324-32 .456 pg for male middle‐aged persons and 28 .274-32 .966 pg for male elderly ;27 .367-31 .973 pg for female young adults ,27 .445-32 .215 pg for female middle‐aged persons and 27 .532 -32 .468 pg for female elderly .MCHC had statistical difference between different sexes (P<0 .05) ;the reference intervals :328 .611-352 .810 g/L for male and 323 .771-348 .750 g/L for female .In 150 individuals un‐dergoing the physical examination ,the proportion of individuals locating at the outside of reference interval was less than 10 .0% , therefore the newly established intervals were suitable for this laboratory .Conclusion The sex difference or/and age differences of MCV ,MCH and MCHC exist among adult populations .So the reference intervals are respectively established according to the prac‐tical situation ,which are suitable for this laboratory by verification .