Sheltering device for small animals

Abstract

To provide a shielding device that can easily set a small animal and can be shielded so that radiation is not directly irradiated to areas other than the target area of the small animal. 【Solution means】The shielding device 1 includes a fixing means for fixing the small animal so that the posture and / or body length do not change in a state where the small animal is accommodated, and a shielding cover 5 that is detachably attached to the outside of the fixing means and shields radiation so that it is not directly irradiated to areas other than the target area of the small animal accommodated in the fixing means. The fixing means may include a cylindrical member 2 that has an opening 21 provided at one end side in the longitudinal direction and accommodates a small animal with the other end side in the longitudinal direction closed, and a holding member 3 that is slidably attached to the opening 21 of the cylindrical member 2 and holds the posture of the small animal together with the cylindrical member 2.

Description

Technical Field

[0001] The present invention relates to a shielding device for small animals.

Background Art

[0002] It is known that radiation-induced oral mucositis (RIOM) frequently appears due to radiation exposure to the head and neck of patients. In the treatment of oral mucositis, coping therapies such as pain relief are mainly used, and etiological therapies have not been established. For this reason, animal experiments using mice have been conducted for the purpose of establishing etiological therapies. For example, Non-Patent Document 1 discloses a method in which a mouse's head is irradiated with low-dose radiation multiple times and then the radiation is locally boosted to a part of the sublingual surface.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method of Non-Patent Document 1, a shielding device that can selectively shield regions other than the head and neck or the sublingual surface of a mouse is used, and this shielding device is configured to be able to irradiate multiple mice with radiation simultaneously. For this reason, there is a problem that the setting of the shielding device is complicated. Such a problem exists not only when irradiating radiation limited to the head and neck of a mouse, but also when irradiating radiation limited to the target region of other small animals.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a shielding device that can easily set small animals and can shield them so that radiation is not directly irradiated to regions other than the target region of the small animals.

Means for Solving the Problem

[0006] To achieve the above object, the shielding device according to the present invention includes fixing means for fixing so that the posture and / or body length do not change in a state where a small animal is accommodated, a shielding cover that is detachably attached to the outside of the fixing means and shields so that radiation is not directly irradiated to areas other than the target area of the small animal accommodated in the fixing means, and is provided with.

[0007] The fixing means includes a cylindrical member having an opening provided at one end side in the longitudinal direction and the other end side in the longitudinal direction being closed, and accommodating the small animal inside, and a holding member that is slidably attached to the opening of the cylindrical member and holds the posture of the small animal together with the cylindrical member.

[0008] A recess that contacts the head of the small animal is provided on the inner surface of the holding member, and air holes for allowing air for the small animal to breathe to enter and exit may be provided in the recess.

[0009] A slit through which the tail of the small animal accommodated in the cylindrical member can protrude to the outside may be formed on the other end side of the cylindrical member.

[0010] The cross sections of the cylindrical member and the holding member may each be formed in a rectangular shape.

[0011] A part of the shielding cover may be cut out so that radiation is directly irradiated only to the target area of the small animal accommodated in the cylindrical member.

[0012] The upper surface portion of the shielding cover may be cut out in a rectangular shape so as to shield the brain of the small animal and irradiate radiation to the oral cavity of the small animal.

Effect of the Invention

[0013] According to the present invention, it is possible to provide a shielding device that can easily set small animals and can shield so that radiation is not directly irradiated to areas other than the target area of the small animals.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0015] Hereinafter, the shielding device according to an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are denoted by the same reference numerals. In the embodiment, "fixing small animals" includes not only the case of fixing small animals so that they do not move at all, but also the case of fixing them so that the posture and / or body length of the small animals do not change significantly while allowing a certain degree of movement.

[0016] The shielding device according to the embodiment is a device that shields so that radiation is not directly irradiated to areas other than the target area of the small animal when the small animal is accommodated inside. The shielding device according to the embodiment is installed, for example, inside a radiation irradiation device, such as an X-ray irradiation device, with a small animal accommodated inside. The small animal may be any animal as long as it can be transported by hand and can be accommodated in the shielding device. For example, rodents, particularly mice, hamsters, and rats are suitable. Hereinafter, taking a mouse as the small animal and irradiating radiation directly only to the head and neck area of the mouse, particularly the area between the tip of the nose excluding the brain and the hyoid bone, as an example, will be described.

[0017] As shown in FIG. 1, the shielding device 1 includes a cylindrical member 2, a holding member 3 slidably attached inside the cylindrical member 2, a bolt 4 for fixing the holding member 3 to the cylindrical member 2, and a shielding cover 5 attached so as to cover a part of the cylindrical member 2 and shielding the radiation irradiated from the outside. The cylindrical member 2, the holding member 3, and the bolt 4 are an example of fixing means for fixing so that the body posture and / or body length do not change when a small animal is accommodated, and all are formed of an acrylic resin. The shielding cover 5 is formed of a lead plate. The thickness of the lead plate is set to, for example, 2 mm in consideration of the dose of the irradiated radiation, the required shielding performance, ease of processing, etc.

[0018] As shown in FIGS. 2 and 3, the cylindrical member 2 is a cylindrical part for accommodating a mouse. The cylindrical member 2 is formed by combining four rectangular plate members. The cross section of the cylindrical member 2 is formed in a rectangular shape, preferably a square shape. Since the cross section of the cylindrical member 2 is formed in a rectangular shape, the cylindrical member 2 can be stably installed in the radiation irradiation device, and it is possible to prevent the body posture of the mouse from changing inside the cylindrical member 2, particularly, the mouse rotating around the body axis and the direction of the head changing.

[0019] On the tip side (one end side) of the cylindrical member 2, an opening 21 is formed to which the holding member 3 can be detachably attached. On the other hand, on the base end side (the other end side) of the cylindrical member 2, an additional rectangular plate member that connects to the ends of the four plate-like members is connected and is blocked so that the mouse cannot escape.

[0020] On the upper surface portion and the base end portion of the cylindrical member 2, slits 22 are formed that allow the tail of the mouse housed in the cylindrical member 2 to protrude outside the cylindrical member 2. The slit 22 extends in an L shape from the middle portion of the upper surface portion to the lower end portion of the base end portion. On the side surface portion on the left side (one side) of the cylindrical member 2, a slit 23 is formed in which a bolt 4 attached to the side surface portion of the holding member 3 is slidably disposed. Each slit 23 extends from the middle portion to the tip portion of the cylindrical member 2 so that the bolt 4 can be removed from the cylindrical member 2.

[0021] The holding member 3 is slidably attached to the opening 21 of the cylindrical member 2 and is a member that holds the posture of the small animal together with the cylindrical member 2. The holding member 3 is set to press the head of the mouse in the cylindrical member 2 from the tip side toward the base end side. The cross section of the holding member 3 is formed in a rectangular shape, preferably a square, in accordance with the cross section of the cylindrical member. On the inner surface of the holding member 3, a recess 31 that contacts the head of the mouse is formed. The recess 31 is curved in a bowl shape in accordance with the shape of the head of the mouse. Further, in the recess 31 of the holding member 3, air holes 32 are formed through which air can enter and exit so that the mouse can breathe. The air holes 32 are formed, for example, at the center of the recess 31.

[0022] Of the pair of side portions of the holding member 3, a female screw hole 33 into which the bolt 4 can be screwed is formed in the side portion corresponding to the slit 23 of the cylindrical member 2. The female screw hole 33 is formed so as to have a height corresponding to the slit 23 of the cylindrical member 2 in a state where the holding member 3 is accommodated in the cylindrical member 2. The bolt 4 is an example of a stopper that is attached to the holding member 3 and fixes the holding member 3 to the cylindrical member 2 by contacting the holding member 3. The bolt 4 includes a threaded portion 41 and a head portion 42 provided at the base end portion of the threaded portion 41 and capable of contacting the outer surface of the side portion of the cylindrical member 2. When the bolt 4 is screwed into the female screw hole 33 through the slit 23 with the holding member 3 accommodated in the cylindrical member 2, the head portion 42 of the bolt 4 contacts the outer surface of the side portion of the cylindrical member 2, and the holding member 3 can be fixed to the cylindrical member 2 by the frictional force therebetween.

[0023] Returning to FIG. 1, the shielding cover 5 shields so that radiation is not directly irradiated to areas other than the target area of the small animal accommodated in the cylindrical member 2. The shielding cover 5 is formed to be detachable from the outside of the cylindrical member 2 and is formed in a cylindrical shape according to the cross-sectional shape of the cylindrical member 2. As shown in FIG. 4, a notch 5A is provided at the end of the shielding cover 5 so that radiation is directly irradiated only to the target area of the small animal accommodated in the cylindrical member 2 and the radiation is shielded in other areas.

[0024] Specifically, as shown in FIG. 5, when looking at the shielding cover 5 from above, with the mouse's side face housed in the cylindrical member 2 in a posture facing the vertical direction, the mouse's body and brain are set as the shielding region, and a part of the front end sides of the upper and lower surfaces are notched in a rectangular shape so that the oral cavity becomes the irradiation region directly irradiated with radiation. More specifically, as illustrated in FIG. 6 and described using the X-ray imaging of the mouse, the notch is made such that radiation is directly irradiated only to the irradiation region set between the mouse's nose tip and the hyoid bone. The reason for setting the pharynx on the body side of the hyoid bone as the shielding region is to reduce the possibility that the mouse may have difficulty in feeding due to inflammation of the pharyngeal mucosa. The dimensions and shape of the notch 5A can be set based on the morphological characteristics of the tongue that vary according to the strain, age, and body weight of the mouse to be irradiated, for example, the distance between the nose tip and the hyoid bone. Note that a part of the lower surface of the shielding cover 5 is notched to check the fluoroscopic image when determining the position of the shielding device 1 before radiation irradiation.

[0025] Also, as shown in FIG. 7, when looking at the shielding cover 5 from the side, a part of the side surface is notched in a rectangular shape continuously from the notch 5A of the upper and lower surfaces. For this reason, when looking at the shape of the notch 5A extending to the upper surface and the side surface of the shielding cover 5 from the front, it is U-shaped. Note that a part of the side surface of the shielding cover 5 is notched to prevent the shielding cover 5 from interfering with the movement of the bolt 4 within the slit 23. Even if this part is notched, since the mouse's brain is not directly irradiated with radiation, there is no problem with the function as the shielding cover 5. The above is the configuration of the shielding device 1.

[0026] Next, the procedure of the radiation irradiation method for the mouse executed using the shielding device 1 according to the embodiment will be described. First, set the mouse on the shielding device 1. Specifically, first, place the anesthetized mouse in the cylindrical member 2 of the shielding device 1. At this time, as shown in FIGS. 5 and 7, place the mouse in the cylindrical member 2 with the side surface of the mouse facing in the vertical direction of the shielding device 1. Next, align the nose of the mouse with the through-hole of the holding member 3 and attach the holding member 3 into the cylindrical member 2. Next, by pressing the holding member 3 from the tip side to the base end side of the cylindrical member 2, fix the mouse so that it cannot change its posture, and in this state, tighten the bolt 4 to fix the holding member 3 to the cylindrical member 2. Next, attach the shielding cover 5 to the outside of the cylindrical member 2.

[0027] Next, set the shielding device 1 containing the mouse in the radiation irradiation device, and irradiate radiation from the radiation irradiation device toward the oral cavity of the mouse contained in the shielding device 1.

[0028] After the radiation irradiation, take out the shielding device 1 from the radiation irradiation device and take out the mouse from the shielding device 1. The taken-out mouse can be bred as usual in the cage, and it is only necessary to observe whether RIOM develops. The above is the flow of the radiation irradiation method.

[0029] As described above, the shielding device 1 according to the embodiment includes a cylindrical member 2, a holding member 3, and a bolt 4 for fixing the posture and / or body length of the mouse so as not to change in the state of accommodating the mouse, and a shielding cover 5 that is detachably attached to the outside of the cylindrical member 2 and shields the radiation from directly irradiating the area other than the target area of the mouse accommodated in the cylindrical member 2. Therefore, the mouse can be easily set, and the radiation can be shielded so that it is not directly irradiated to the area other than the target area of the mouse.

[0030] The present invention is not limited to the above embodiment, and the following modifications are also possible.

[0031] (Modification example) In the above-described embodiment, the cross-sections of the cylindrical member 2, the holding member 3, and the shielding cover 5 were all rectangular, but the present invention is not limited to this. As long as the posture of the small animal housed in the cylindrical member 2 does not change, the cross-section may have any shape, for example, a pentagon or a hexagon.

[0032] In the above-described embodiment, the cylindrical member 2 was constituted by assembling a plurality of plate members, but the present invention is not limited to this. For example, all or part of the cylindrical member 2 may be integrally formed.

[0033] In the above-described embodiment, the holding member 3 was a block member, but the present invention is not limited to this. The holding member 3 may be a hollow member having a cavity inside.

[0034] In the above-described embodiment, the holding member 3 was detachable from the cylindrical member 2, but the present invention is not limited to this. For example, the holding member 3 may be made non-removable from the cylindrical member 2, and the plate member on the proximal end side may be configured to be openable and closable so that a mouse can be inserted into and removed from the cylindrical member 2, and fixable in the closed state.

[0035] In the above-described embodiment, the concave portion 31 that is curved in a bowl shape was provided on the inner surface of the holding member 3, but the present invention is not limited to this. As long as the inner surface of the holding member 3 can hold the head of the mouse, it may have any shape, for example, a conical shape.

[0036] In the above-described embodiment, the air holes 32 were provided in the holding member 3 formed in a block shape, but the present invention is not limited to this. For example, the holding member 3 may be formed of a material that allows air to pass through, such as a porous material or a mesh.

[0037] In the above-described embodiment, the bolt 4 screwed into the holding member 3 was passed through the slit 23 of the cylindrical member 2, but the present invention is not limited to this. For example, instead of the slit 23 of the cylindrical member 2, a plurality of through holes may be arranged side by side, and pins may be inserted through both any of these through holes and the holes formed in the holding member 3.

[0038] In the above-described embodiment, the separate bolt 4 from the cylindrical member 2 and the holding member 3 is used as the stopper, but the present invention is not limited thereto. For example, by performing rough machining or uneven machining on at least one surface of the cylindrical member 2 and the holding member 3, the frictional resistance can be increased, and the bolt 4 may be omitted.

[0039] In the above-described embodiment, the rectangular notch 5A is formed at the corners of the upper end portion and the lower surface portion when the shielding cover 5 is viewed from above, but the present invention is not limited thereto. For example, the notch 5A may be formed by cutting the corners of the upper end portion and the lower surface portion of the shielding cover 5 into an arc shape. Further, the notch 5A does not necessarily have to be formed at the end portion or the corner portion of the shielding cover 5, and may be, for example, a closed hole.

[0040] The above-described embodiments are examples, and the present invention is not limited to these, and various embodiments are possible without departing from the spirit of the invention described in the scope of utility model registration claims. The constituent elements described in the embodiments and the modified examples can be freely combined. Further, the inventions equivalent to the invention described in the scope of utility model registration claims are also included in the present invention.

Example

[0041] In the examples, it was verified whether RIOM could be stably induced in the oral region of mice by radiation irradiation using a shielding device. First, the X-ray irradiation range required for the design of the shielding device was examined. In this examination, C57BL / 6, C3H / He, and BALB / c mice aged 9 to 12 weeks were used (n = 9 for each strain, all males), and X-ray imaging was performed on the head and neck of each mouse. For the X-ray imaging, a micro-CT imaging device (Cosmo Scan GX) was used. Next, the distance between the tip of the nose and the hyoid bone was measured using the X-ray imaging images, and the average value of this distance was calculated for each strain and age. As a result, as the body weight of the mice increased, the average value of the distance between the tip of the nose and the hyoid bone also gradually increased, but all remained in the teens of millimeters, and it was found that the increase was very small considering the body length. From the above, it was confirmed that there was no need to change the irradiation range for each strain and age.

[0042] Based on the above results, a shielding device as disclosed in the embodiments was created. As shown in FIG. 8, 10-week-old mice were housed in this shielding device, and each was irradiated once with a dose of 18.0 Gy. The number of mice used in the experiment was 18. For the radiation irradiation, an X-ray irradiation device (MBR-1520R-3) was used. As a result, none of the mice died, and RIOM occurred in some mice on the 7th day after the radiation irradiation, and RIOM occurred in all mice on the 11th day. From the above, it was confirmed that when using the shielding device according to the embodiments, RIOM can be stably induced without the mice dying even when irradiated with radiation.

Explanation of Signs

[0043] 1 Shielding device 2 Cylindrical member 3 Holding member 4 Bolt 5 Shielding cover 5A Notch 21 Opening 22, 23 Slit 31 Depression 32 Air hole 33 Female screw hole 41 Threaded portion 42 Head

Claims

1. A fixing means for fixing the small animal so that its posture and / or length do not change when the small animal is housed; a shielding cover that is detachably attached to the outside of the fixing means and blocks radiation from being directly irradiated to areas other than a target area of ​​the small animal accommodated in the fixing means; A shielding device comprising:

2. The fixing means is a cylindrical member having an opening at one end in a longitudinal direction and a closed other end in the longitudinal direction, the cylindrical member accommodating the small animal therein; a holding member that is slidably attached to the opening of the cylindrical member and that holds the posture of the small animal together with the cylindrical member; 2. The shielding device of claim 1.

3. The inner surface of the holding member is provided with a recess that comes into contact with the head of the small animal, The recess is provided with an air hole for letting in and out air for the small animal to breathe.

3. The shielding device of claim 2.

4. The other end of the cylindrical member is provided with a slit through which the tail of the small animal accommodated in the cylindrical member can be exposed.

3. The shielding device of claim 2.

5. The cross sections of the cylindrical member and the holding member are each formed in a rectangular shape.

3. The shielding device of claim 2.

6. a part of the shielding cover is cut out so that radiation is directly irradiated only to the target area of ​​the small animal accommodated in the cylindrical member; 6. The shielding device of claim 5.

7. The upper surface of the shielding cover is cut out in a rectangular shape so as to shield the brain of the small animal and to irradiate the oral cavity of the small animal.

7. The shielding device of claim 6.

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