The clinical, radiographic, and histopathologic features of 26 primary a n d 35 secondary vertebral tumors of the dog with varying periods of clinical signs, possibly influenced by their being referred dogs, a r e presented. Pain without neurologic signs was the predominant initial sign with both primary a n d secondary tumors. However, by the time of hospital admission, most dogs had neurologic deficits. The time from pain onset to neurologic deficit ranged from two days to nine months. German Shepherd Dogs, Standard Poodles, a n d Labrador Retrievers were heavily represented; the average age was 7 years a n d there was a slight predominance of male dogs. Both primary a n d secondary tumors showed a destructive pattern, often with cortical destruction a n d adjacent disc space collapse. An associated paravertebral soft tissue mass was frequently present in the secondary tumors, 13 of 35 being secondary to intrapelvic tumors. Osteosarcomas were the most common primary tumor; the secondary tumor cell type varied. Most dogs were euthanized immediately upon histopathologic confirmation of the disease. Vctot-itiiiry Kodiology,

The effects of hyperthermia on vascular permeability in Walker carcinosarcomas and host liver tissue were studied in Sprague-Dawley rats. A quantitative Evans blue technique was used to measure permeability. With tumors heated to 40 degrees C, a nontherapeutic level, no changes in tumor vascular permeability as compared to control levels were noted. However, with tumors heated to 43 degrees C, within the therapeutic range of hyperthermia, significant rises in tumor vascular permeability occurred. Permeability was increased at both time periods studied, 30 minutes and 6 hours after hyperthermia and injection of Evans blue. These changes are similar to those seen after physical damage from freeze-thaw. It is likely that alterations in tumor microcirculation play a role in the therapeutic effect of intense hyperthermia.

Transverse ultrasound images from three live boa constrictors (Boa constrictor) were compared to the corresponding gross sections of a euthanized boa constrictor. The snakes were anesthetized, placed into dorsal recumbency, and imaged through the ventral scutes. Ultrasound images were produced with a real time, B‐mode scanner and a linear 7.5‐MHz transducer. The heart, liver, stomach, gall bladder, pancreas, kidneys, and fat body were the coelomic structures most consistently recognized ultrasonographically. Results of this study indicate that ultrasound is a useful imaging technique in snakes.

Studies on the circulatory perfusion of liver tumor implants in rats indicated that the tumors, when small, are nourished by both hepatic artery and portal vein blood. As the tumors grow larger, the arterial system becomes predominant, although portal vessels appear to terminate near the edges of the tumors. When blood flow through the portal system is acutely interrupted, the immediate reaction is that of a decreased relative perfusion of the tumors via the arterial system. A probable shunting of blood through the arterioles to the liver occurs. When blood flow through the hepatic artery is acutely interrupted, there appears to be little change in the distribution of portal blood to the tumor or liver. However, in about half of the rats studied by microcirculatory techniques, filling of the tumor plexus via the portal system was observed. When vasoactive drugs, both constrictors and dilators, were administered arterially, a decreased arterial perfusion of the tumors occurred. This change appeared to involve only the small arterial vessels.