Some patients have noted a foul odor during radiation therapy sessions, but the cause of the odor remains unknown. Since we suspected that this phenomenon is due to ozone generated by ionizing ...radiation, this experimental study measured ozone concentrations in the treatment room and in a coiled polyvinyl chloride (PVC) tube placed within the radiation field.
We measured ozone concentrations using an ultraviolet absorption method and an ozone monitor. A PVC tube (inner diameter 7 mm, outer diameter 10 mm) was used to mimic the environment of the nasal cavity. The tube (790 cm) was coiled and set between two 4-cm-thick (for X-rays) or 2-cm-thick (for electron beams) water-equivalent solid phantoms. The sampling tube of the ozone monitor was inserted into the PVC tube, and the joint was sealed to prevent environmental air contamination. To measure ozone concentrations in the atmosphere, the sampling tube supplied with the unit was used. A linac was used on a full-sized treatment field (40 cm × 40 cm at a source-to-axis distance of 100 cm). The effect of an electron beam on ozone concentrations was also evaluated with a full-sized treatment field (40 cm × 40 cm at a source-to-surface distance of 100 cm).
Ozone levels in the treatment room were undetectable before the start of daily treatment but reached 0.008 parts per million (ppm) or more at 1 h after the start of treatment. Concentrations then remained nearly constant at 0.010-0.015 ppm throughout the day. The maximum ozone concentration in the PVC tube was only 0.006 ppm, even when it was irradiated at 2400 monitor units/min. Depending on the X-ray dose rate, the concentration increased to a maximum of 0.010 ppm with oxygen flowing into the other end of the tube at 1.5 L/min. Ozone concentrations in the PVC tube did not differ significantly between X-ray and electron-beam irradiation.
Only traces of ozone were found in the PVC tube that was used to mimic the nasal passages during radiation, these concentrations were too low for human perception. However, ozone concentrations did reach potentially detectable levels in the treatment room.
Abstract
Gram-positive thermophilic Bacillus species contain cytochrome caa3-type cytochrome c oxidase as a terminal oxidase in the respiratory chain. To identify alternative oxidases, we isolated B. ...stearothermophilus mutants defective in the caa3-type oxidase activity. One mutant contained little cytochrome a and had low cytochrome c oxidase activity. However, growth and the respiratory activity of membranes in the presence of NADH were close to normal, suggesting that the mutant contains an alternative electron transfer pathway. A novel oxidase was isolated from the membrane fraction of the mutant. The enzyme is a cytochrome bd-type quinol oxidase composed of two subunits of 52 and 40 kDa, whose N-terminal regions show sequence similarity to polypeptides of the bd-type oxidase from Escherichia coli and Azotobacter vinelandii. This is the first report of a bd-type terminal oxidase purified from a Gram-positive bacterium.
Gram-positive thermophilic Bacillus species contain cytochrome caa sub(3)-type cytochrome c oxidase as a terminal oxidase in the respiratory chain. To identify alternative oxidases, we isolated B. ...stearothermophilus mutants defective in the caa sub(3)-type oxidase activity. One mutant contained little cytochrome a and had low cytochrome c oxidase activity. However, growth and the respiratory activity of membranes in the presence of NADH were close to normal, suggesting that the mutant contains an alternative electron transfer pathway. A novel oxidase was isolated from the membrane fraction of the mutant. The enzyme is a cytochrome bd-type quinol oxidase composed of two subunits of 52 and 40 kDa, whose N-terminal regions show sequence similarity to polypeptides of the bd-type oxidase from Escherichia coli and Azotobacter vinelandii. This is the first report of a bd-type terminal oxidase purified from a Gram-positive bacterium.
A 46-year-old man was admitted to our hospital because of an abnormal shadow on the chest roentgenogram. The operation was performed through left posterolateral thoracotomy. A tumor mass, 4.5 x 2.5 x ...2.5 cm in size, was found and its origin was the left main vagal nerve 0.5 cm distal the branching root of the recurrence nerve. The tumor and a part of the left vagal nerve was resected en bloc. Pathological study revealed tha the tumor was neurinoma of Antoni A+B. Postoperative course was uneventful. This is the 34th reported case in Japanese literature of neurinoma with its origin from the intrathoracic vagal nerve.
Owing to the poor detectability of the anatomic location of diaphragm on the parallel plane of computed tomography (CT), capability of CT to predict traumatic ruptured diaphragm has been debated in ...several reports. A specific hematoma (subhepatic hemothorax) adjacent to the posterior attachment of the right diaphragm was identified on CT. The finding originated from herniated liver that migrated to the posterior thoracic wall as a result of gravity, to separate the hemothorax in the supine position. This was surgically proven in two patients after blunt traumatic accident. The finding is useful in predicting right diaphragmatic rupture on CT study. The formation of subhepatic hemothorax, its differential diagnosis and a brief review of diaphragmatic rupture are discussed.
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