In an experiment, cells are subjected to radiant energy in the form of x-rays. This results in cell injury caused by hydrolysis of water. Which of the following cellular enzymes protects the cells from this type of injury?
Reperfusion of ischemic tissues, as may occur after therapeutic use of thrombolytic agents, sometimes leads to cell death after the blood flow resumes. The biochemical basis for cell death under these circumstances is most likely which of the following?
Reduction in protein synthesis
Increased generation of oxygen derived free radicals
Increased activity of catalase
Reduced oxidative phosphorylation
Release of calcium from endoplasmic reticulum
A nurse of radiological department is exposed to radiation as a result of violation of the rules of safety appliances. In 8 days she develops ulcero-gangrenous stomatitis. The patient’s blood test shows: RBC – 3.2 x 1012/L, reticulocytes – 0.01 %, Hb – 60 g/L, WBC – 2.3 x 109/L, and platelets – 50 x 109/L. Which of the following stages of acute radiation sickness is described?
Manifest illness stage
Pretended well-being stage
During nuclear power plant breakdown elimination a firefighter receives 30 Gy dose of ionizing radiation. Which of the following organs is damaged most?
During nuclear power plant breakdown elimination a 24-year old firefighter receives 7 Gy dose of ionizing radiation. Which of the following findings is likely to be in his blood on the 10th day after the accident?
A worker is exposed to ionizing radiation due to an accident at a nuclear power plant. On his examination agranulocytosis is revealed. Which of the following mechanisms is responsible this phenomenon?
Increased entrance of agranulocytes from the bone marrow
Loss of granulocytes via hemorrhage
Increased migration of granulocytes to tissues
Increased destruction of granulocytes in blood
Oppression of leucopoiesis
Hemorrhagic syndrome develops in a 35-year old man who took part in nuclear power plant breakdown elimination. Which of the following mechanisms is likely underlines this syndrome?
Decreased synthesis of fibrinogen
During an accident in the radiological department a 40-year old lab technician received 6 Gy dose of ionizing radiation. Which of the following signs or symptoms is likely occurs in the patient in the latent period of acute radiation sickness?
A 19-year old firefighter who took part in nuclear power plant breakdown elimination is admitted to hospital because he got 9 Gy dose of ionizing radiation. Which of the following body systems is damaged first?
Which of the following processes is considered as a direct effect of ionizing radiation?
Inhibition of DNA-synthesis
Radiolysis of water
Inhibition of antioxydants
Interaction between free radicals and enzymes
Injury to chromosomes by free radicals
Radiosensitivity of tissues is determined first of all by which of the following its characteristics:
Rate of proliferation
Rate of basal metabolism
Level of antioxidants
Number of mitochondria
Rate of functional activity
A 29-year old firefighter who took part in nuclear power plant breakdown elimination is admitted to hospital because he got 7 Gy dose of radiation. Which of the following findings in his blood is likely to be in 18 hours after an accident?
A worker who took part in nuclear power plant breakdown elimination consults a doctor about marked weakness, increase in body temperature to 37,8oC, multiple punctate hemorrhages on his skin and mucous membranes, diarrhea. The patient’s blood test shows the following: ESR – 25 mm/h, RBC – 2,4x1012/L, WBC - 2,2x109/L, platelets – 70x103/L. Which of the following periods of acute radiation sickness is this picture typical of?
Manifest illness stage
Pretended well-being stage
Primary reactions period
A patient with acute radiation sickness complains of splitting headache, marked weakness, difficulty in swallowing of food. On his examination gingivitis, necrotic angina, multiple skin hemorrhages and blood in urine and feces are revealed. Which of the following body tissues is damaged most?
In an experiment a rabbit was exposed to radiation and it received 5 Gy dose. Which of the following mechanisms are involved in cell damage primarly?
A 34-year old firefighter develops marked weakness, tachycardia, decreased blood pressure, abdominal pain, vomiting. On his examination hypovolemia and blood in feces are reveals. Two weeks ago he received 30 Gy dose of radiation. Which of the following forms of acute radiation sickness are these signs and symptoms typical of?
A white rat is exposed to ionizing radiation and it receives 5 Gy dose. Which of the following findings in its blood can be expected in 10 hours after the exposure?
Collapse, anuria, loss of consciousness, convulsions and paralysis occur in a firefighter who received radiation in dose of 80 Gy. Which of the following forms of radiation sickness develops in the patient?