[Route and preparation of 5-Fu administration as preoperative adjuvant chemotherapy in rectal cancer. I. Concentration and distribution of 5-Fu in tissues monitored by 14C-isotopically tagged 5-Fu].

Experimental studies on more rational route and preparation of preoperative administration of 5-Fu were undertaken from March 1981 to June 1985. The experimental observation shows that intrarectal administration of radioisotope 14C tagged 5-Fu (suppository and emulsion) produces a much higher concentration in the rectal wall and mesenteric lymph nodes compared with its intravenous administration (40 rabbits) and produces a much higher concentration in cancer tissue than in surrounding tissues and in mesenteric lymph nodes than in the inferior mesenteric veins (4 patients). These findings favor the attenuation or destruction of cancer cells in the tumor and regional lymph nodes-the main route of spread. Also, after intrarectal administration of 14C tagged 5-Fu, its concentration in the lung, liver and bone marrow is much lower than that after intravenous administration (40 rabbits), and hence systemic toxicity is decreased. The above results indicate that the intrarectal route stands better than the conventional intravenous route for 5-Fu preoperative adjuvant chemotherapy in rectal cancer. Administration of 5-Fu emulsion produces a higher concentration in the rectal wall and mesenteric lymph nodes than that of 5-Fu suppository and peak concentration also appears earlier, i.e. 2 hours after the administration of 5-Fu emulsion. This will lessen the interference of 5-Fu absorption owing to its premature evacuation, indicating that emulsion is a better form for intrarectal 5-Fu.

Wounding properties of steel pellets with different velocities and quality on soft tissue of dogs.

The characteristics of the soft-tissue wounds of the hind legs of 155 dogs produced by stainless steel spheres with four different masses and at various impact velocities were observed. It was found that when the mass of the spheres was identical, the velocity became the main factor to determine the severity of the damage; when the mass of the spheres was different but their kinetic energy was similar, then a smaller but faster sphere produced more severe damage than a larger but slower one. Shallow but wide and severe wounds usually resulted. The rate of disability of extremities with such wounds was very high. These wounding properties of steel spheres have caused some new problems in the treatment of war injuries.

Wounding effects of two types of bullets on soft tissue of dogs.

The wounding effects of 5.56 and 7.62 mm calibre bullets, hitting on soft tissues of 130 dogs at various velocities ranging from 513 to 933 m/s have been studied. The injury caused by 5.56 mm bullet was more severe than that caused by 7.62 mm bullet. This is due to the difference in ballistic behavior between the two types of bullets. The wound caused by 5.56 mm bullet was characterized by a trumpet-shaped channel with large defect. The skin around the exit was torn away and its shape was irregular, which, however, occurred only when the tumbling and the breaking of the bullet existed. High-speed X-ray photograph demonstrated that in 5.56 mm bullet group, temporary cavity was much larger and lasted longer. Splashing phenomenon could be seen at the exist and the fragments of the bullet could be found somewhere. Based on the comparisons the amount of absorbed energy, the volume of wound channel, the frequency of developing complex wound and the ratio of dimensions between the entrance and the exit, it proved that the injury caused by 5.56 mm bullet was several to dozens of time as severe as that caused by 7.62 mm bullet. Nevertheless, wound extents by both types of bullet would be similar if the inflicting bullet did not show any significant tumbling, breaking or deformation.