Abstract: A stable trihydrate of (2S, 5R, 6R)-6-{(2R)-2-[(2R)-2-amino-3-(N-methylcarbamoyl)propionamido]-2-(p-hydrox yphenyl)acetamido}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-c arboxylic acid and process for preparing the same are disclosed.

Abstract: Fiber optic endoscopes exposed to X-ray or .gamma.-ray irradiation suffer discoloration of the optical fiber bundles with a reduction in light transmittance. This makes observation or examination using these devices difficult or impossible. The irradiation-induced reduction in light transmittance of image-transmitting optical fiber bundles is restored by visible light radiation emitted from a light source unit which is in turn transmitted to an end of the image-transmitting optical fiber bundle by a light-transmitting mechanism.

Abstract: A photographic camera with a shutter release means is removably mounted on the eyepiece of an endoscope. Additional shutter release means is provided on the mounting body of the endoscope on which remote control means such as a dial for changing the direction of the head of the endoscope are mounted, whereby the shutter of the camera can be released without need for the operator to remove his hand from the vicinity of the remote control members.

Abstract: One or more inflatable balloons are provided on the outer surface of the tube of an endoscope which encloses the fiber optical light transmitting bundle. When only one balloon is provided, the balloon is provided on one side of the tube near the end thereof to enlarge the space within a body cavity in one direction and the flexible part of the tube may be bent in said direction. When moe than one balloon is provided, one of the balloons is selectively inflated to enlarge the space within the body cavity in the desired direction. In a preferred embodiment of the invention, the balloons are located at equal intervals around the tube. In another embodiment of the invention, an outer sleeve is provided around the tube with balloons on the outer face thereof and is made slidable with respect to the tube. The outer sleeve and the tube are inserted into the body cavity alternately by alternately inflating the balloons on the outer sleeve and those on the tube to facilitate the insertion thereof into the body cavity.