JP2000316418A - X-ray irradiation apparatus for animal test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray irradiation apparatus for animal test, hardly causing death of the animal by the generated ozone and allowing the data to be got even if the X rays are irradiated for a long time. SOLUTION: This X-ray irradiation apparatus has an X-ray source 25 installed in the ceiling surface, a freely rotatable turn table 12 capable of being moved in the upper and lower direction while loading a mouse cage 1 at the center part 5, and a protective cabinet 10 having vent holes 15 and a blower 13 for exhaustion on the back surface. The mouse cage 1 has vent holes 8 formed at the upper or lower part of the position at the respiratory tract of the animal for the test, and the ozone generated by the ionizing activities of the X rays irradiated to the mouse cage 1 from the X-ray source 25 is exhausted to the exterior of the cabinet 10 by using the ventilating activities of the blower 13 for exhaustion or the ventilation through the vent holes 8 of the mouse cage 1 by utilizing the specific gravity of the ozone heavier than that of air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray irradiation apparatus for animal experiments, which is used for experiments on immunosuppression of animals by radiation and investigation of half-lethal doses.

[0002]

2. Description of the Related Art An X-ray irradiating apparatus for animal experiments applies X-ray protection to a cabinet having a door, and arranges an X-ray source above the X-ray protection cabinet. 2. Description of the Related Art There is known a cabinet provided with a storage container for storing an animal inside a door of a cabinet.

[0003] The part where the animal container is placed is separated from the part where the X-ray source is placed and the part where the control device of the X-ray source is placed in a central part in the height direction of the cabinet, and is separated into an independent room (hereinafter referred to as a room). This is abbreviated as a sample chamber.). In addition, since there are many mice used for experiments with such a device, the animal storage container is called a mouse cage, and the mouse cage is provided with a vent.

[0004]

When an X-ray is irradiated for a long time for an experiment using such an apparatus, the air irradiated with the X-ray in the sample chamber and in the mouth cage is ionized to generate ozone. Ozone has a higher specific gravity than air, so ozone generated in the sample chamber fills the lower part of the sample chamber,
The periphery of the mouse cage placed below the sample chamber will be surrounded by ozone. Therefore, not the air but the ozone enters the cage through the vent hole of the mouse cage. Further, ozone generated in the mouse cage was difficult to be discharged because the vent hole was on the upper surface. For this reason, when the X-ray irradiation time was prolonged, the mice in the cage became oxygen deficient due to the generation of ozone, and sometimes died.

In view of the above problems, the present invention provides an animal experimental X-ray system capable of obtaining experimental data without causing death of the animal due to ozone generated even after long-time irradiation with X-rays.
It is an object to provide a line irradiation device.

[0006]

According to the present invention, there is provided a mouse cage containing an experimental animal, an X-ray source above the mouse cage, and an outer periphery surrounded by an X-ray protection cabinet. In an X-ray irradiation device for animal experiments,
A side plate of the mouse cage, or a lower surface, or a ventilation hole provided at a position above and below the respiratory organ of the experimental animal housed in the mouse cage of the upper lid, and an exhaust means provided in the X-ray protective cabinet; Is done.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of a protective cabinet of an X-ray irradiation apparatus for animal experiments according to the present invention. In FIG. 1, reference numeral 1 denotes a mouse cage as an experimental animal storage container, 10 denotes a protective cabinet provided with X-ray protection, 11 denotes a turntable on which the mouse cage 1 is mounted and rotated, and 12 denotes a turn on which the turntable 11 is mounted. A table substrate, 13 is an exhaust blower for exhausting ozone generated by X-ray irradiation from the inside of the protective cabinet 10, and 14 is a ventilation hole of the exhaust blower 13 for preventing scattered X-rays from leaking outside during X-ray irradiation. The protective cover is covered, 15 is a ventilation hole for ventilating the inside of the protective cabinet 10 from outside, and 16a is the protective cabinet at the lower end.
A first link, which is freely movable in the horizontal direction on the base plate of 10, a rotatable center on the second link, and an upper end rotatably engaged with the lower surface of the turntable substrate 12, 16b has a lower end. A second link 17 is rotatably engaged with the base plate of the protective cabinet 10, the center of which is the first link 16 a, the upper end of which is movably engaged with the lower surface of the turntable substrate 12, and the first link 17 is a first link. A stud for rotatably engaging a central portion of the second link 16a with the first link 16a.
A base plate that supports 16b and partitions the central part in the protection cabinet 10, 25 is an X-ray source installed on the top of the protection cabinet 10 above the mouse cage 1, and 33 is a measurement display of the irradiated X-ray dose A dosimeter 36 indicates a protective door provided at the front center of the protective cabinet 10.

A schematic configuration of the above-described X-ray irradiation apparatus for animal experiments will be described. An X-ray source 25 is provided on a top surface in a protection cabinet 10 having an X-ray protection door 36, and a first link 16a and a second link 16 are provided on a base plate 18 installed in the center.
The turntable substrate 12 is set via b. And the turntable 11 mounted on the turntable substrate 12
A mouth cage 1 and an exhaust blower 13 on the rear side.

A turntable 11 on which the mouse cage 1 is mounted is installed at the center of the inside of the protective cabinet 10 having the above-described configuration. The turntable 11 has a non-uniform irradiation because the X-ray irradiation intensity is different between the cathode side and the anode side. To prevent this, a function has been added to rotate the mouse cage which is the irradiation target at the time of X-ray irradiation. ing.
Further, a vertical movement mechanism is provided so that a large amount of X-rays can be irradiated in a short time near the X-ray source 25.

First, the function of rotating the turntable 11 will be described without detailed illustration of components. A lower part of the turntable 11 is supported by a bearing whose center is the axis, and forms a cylindrical skirt part whose axis is the center.

A motor serving as a rotational driving force source is disposed at a position away from the center by a predetermined amount from the center, a pulley is directly connected to a rotary shaft of the motor, and an annular timing belt is hung on the pulley and the skirt. A turntable having a belt drive drive system in which the motor is rotated under the control of a control device (not shown) for irradiating X-rays from the X-ray source 25, the pulley is rotated, and the torque is transmitted to the skirt portion by a timing belt. To rotate.

Next, a mechanism for moving the turntable 11 up and down will be described. In FIG. 1, the first link 16
When the distance between a and the lower end of the second link 16b is reduced by a screw means (not shown), the first link 16a and the second link 16b are reduced.
Of the upper end of the first link 16a and the center of the second link 16b, that is, the stud 17
And its upper end rises. Then, the turntable substrate 12 engaging with each link 16a, 16b
The mouse cage 1 also rises, and X-rays are emitted from the X-ray source 25 toward the mouse cage at a predetermined position for a predetermined time. When the X-ray irradiation is completed, the turntable 11 is lowered and returned to the original position in a procedure reverse to that of raising the X-ray. The timing of the X-ray irradiation and the X-ray specifications are not shown, but are performed under the control of the controller of the X-ray irradiation apparatus. Next, the configuration of the mouse cage 1 will be described.

FIG. 2 shows a front view of the mouse cage, and FIG. 3 shows a plan view of the mouse cage. 2 is a side plate that forms the side wall of the mouse cage, 3 is an upper lid that forms the top surface of the mouse cage 1, 4 is a screw engagement with a nut (not shown) at the center of the upper surface of the mouse cage 1, and upper and lower lids Thumbscrews 3 are fixed, and 5 is an entrance provided in the side plate 2, from which the mouse enters and exits. 2a is a guide groove provided at both ends of the entrance 5 of the side plate 2, 6 is a side door which is inserted into the guide groove 2a and closes the entrance, and 8 is a vent which may be located above and below the respiratory organ of the experimental animal. May be provided on the upper lid 3, the side plate 2, and the lower surface. Reference numeral 9 denotes a partition plate which divides the internal space of the side plate 2 radially from the center of the inside of the mouse cage 1, and one mouse is put in the space partitioned by this partition plate. For this reason, at least one ventilation hole 8 is formed in the space separated by the partition plate.

In the mouse cage 1 having the above structure, the side door 6 is moved upward, the doorway 5 is opened, the thumb screw 4 is loosened, and one mouse is put in the space defined by the partition plate 9. In addition, the material of the side plate 2 and the top lid 3 absorbs X-rays as little as possible,
It is preferable to use a transparent acrylic resin that can prevent deterioration due to X-rays to some extent and allows the inside to be observed. Also mouse cage 1
Although not shown in the figures, any structure may be used as long as it is formed of a wire material having a strength that does not allow the mouse to bite, has a ventilation hole 8 and has a ventilation function.

The operation of irradiating X-rays of the animal experiment X-ray irradiator having the above-described configuration to exhaust the ozone generated outside the mouse cage 1 or the protective canet 10 will be described. In each of FIGS. 1 to 3, a mouse cage 1 containing an experimental animal is placed on a turntable, placed in a protective cabinet 10, a protective door 36 is closed, and a turntable 11
Is raised to a predetermined position and rotated by the method described above to irradiate X-rays from the X-ray source 25 toward the mouse cage 1, and the exhaust ventilator 13 on the back of the protection cabinet 10.
To start. After a certain period of time after the irradiation of the X-rays, the air inside the protection cabinet 10 is converted into ozone by the ionizing action of the X-rays.

Ozone has a specific gravity of 1.61, which is heavier than air.
After flowing on the upper surface of the turntable 12 and the floor of the base plate 18 at a position below the lower surface of the mouse cage 1 and disappear for a long time, it disappears due to the degree of diffusion. However, at the time of X-ray irradiation, the ozone flowing downward because the exhaust ventilator 13 is rotating is strongly blown by the exhaust ventilator, and passes through the vent hole 15 outside the X-ray protection cabinet. Exhausted, diffused in the air and extinguished naturally. X-ray is a protective cabinet
Because it is blocked by 10, it does not leak to the outside.

The ozone in the mouth cage 1 also accumulates in the base plate 18 of the protective cabinet 10 from the ventilation hole 8 and diffuses and disappears naturally, or the ozone is blown strongly by the exhaust ventilator 13 and blown off. And is exhausted to the outside, diffuses, and disappears. The rotation of the exhaust blower 13 is continued for a certain period of time after the end of the X-ray irradiation. As a result, the mice do not die due to oxygen depletion due to ozone, and can be irradiated with X-rays for a long period of time in immunosuppression experiments and investigation of half-lethal dose.

[0018]

According to the present invention, the ozone generated by the ionizing action of X-rays does not fill the mouse cage, and the ozone is naturally left from the inside of the mouse cage through the vent hole and the exhaust hole, or the ozone is strongly discharged. In an immunosuppression experiment and a semi-lethal dose investigation, ozone generated due to long-term irradiation with X-rays is effectively removed from the mouse cage.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an X-ray protection cabinet of an X-ray irradiation apparatus for animal experiments according to the present invention.

FIG. 2 is a front view of a mouse cage according to the present invention.

FIG. 3 is a plan view of a mouse cage according to the present invention.

[Explanation of symbols]

 1 Mouse cage 2 Side plate 3 Top lid 8 Vent hole 11 Turntable 13 Exhaust blower 14 Protective cover 15 Ventilation hole 25 X-ray source

Claims (1)

[Claims] An animal experiment X-ray irradiator comprising a mouse cage containing an experimental animal and an X-ray source above the mouse cage, the outer periphery of which is surrounded by an X-ray protective cabinet,
The side plate of the mouse cage, or the lower surface, or vent holes provided above and below the respiratory organ of the experimental animal housed in the mouse cage of the upper lid, and the X-ray protection cabinet is provided with exhaust means. Characteristic X-ray irradiation device for animal experiments.