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A retrograde angiography method for the detection of a portosystemic shunt was studied. The retrograde angiography was done by compressing the caudal vena cava in the chest by applying pressure to the thoracic cavity, then feeding a contrast medium into the caudal vena cava without releasing the pressure loading. The angiography could detect shunt vessels in experimental cases as well as clinical cases. This method is useful for the confirmation of a portal-caudal caval shunt, which can be performed without technical difficulty and without the need for a special kind of catheter.

To compare the cardiovascular effects of dibutyryl cyclic AMP (DBcAMP) and milrinone, we used the right heart bypass method in intact anesthetized dogs. The preload of the left ventricle was maintained constant throughout the experiment. Therefore, the effects of DBcAMP and milrinone on cardiac contractility and afterload of the left ventricle were investigated respectively without preload influence. DBcAMP and milrinone exhibited marked positive chronotropic-, positive inotropic-, vasodilative- and diuretic-activity. DBcAMP expressed these effects gradually and continuously, whereas milrinone expressed its pharmacological actions rapidly, but for a short duration of time. Both the afterload-reducing and the cardiac contractile force-enhancing activities of DBcAMP were longer lasting than those of milrinone. Mean arterial pressure was not altered by DBcAMP infusion, whereas it was increased significantly (p < 0.05) by milrinone infusion. The results of this study suggested that DBcAMP appeared to be indicated when there is a need to increase cardiac output by reducing afterload and increasing cardiac contractile force gradually and continuously. On the other hand, milrinone would seem to be indicated when the goal is to raise blood pressure rapidly and to increase cardiac output simultaneously.

The clinical usefulness of biodegradable oriented poly-L-lactide (PLLA) screws for experimental Salter-Harris type 4 fracture in the distal femoral condyle of dogs was evaluated. Bony union of the osteotomized fragment of the condyle was almost completed radiographically and histologically within 1 to 2 months after surgery, suggesting that PLLA screws maintained strength long enough to fix the fragment until bone healing. At 4 to 6 months after surgery, minute fissures were histologically confirmed on the surface of the screw thread, suggesting the early stage of biodegradation and absorption of the polymer. During the observational period, no significant difference between the treated femur and the contralateral non-treated femur in either total femoral length or maximum condyle width was observed, indicating no growth disturbance in the treated femur. From these results it was concluded that the PLLA screw might be an ideal implant for the reduction and fixation of epiphyseal plate fractures such as Salter-Harris type 3 or type 4 fractures.

Computed tomography after myelography (CTM) was performed pre- and postoperatively on four dogs diagnosed as having cervical intervertebral disc protrusion. The surgery was performed by ventral slot technique in all the cases. The direction of the ventral slot was precisely adjusted according to the location of the protruded discs as seen on CTM. Postoperative values for the transversal area of the spinal cord were greater than those measured preoperatively, suggesting effective decompression of the cord. The prognosis for these patients was excellent. In view of these results, it was considered that preoperative confirmation of the positional relationship between the spinal cord and the protruded disc by CTM was quite useful in planning the surgical technique for disc disease in the dog.

We studied the pressure-volume (PV) relationships of the total respiratory system, lung and chest wall in 8 anesthetized and paralyzed normal adult cats. The PV relationships of the total respiratory system had a sigmoid shape with a relatively linear portion with an alveolar pressure between 0 to +15 cmH2O. The relative impact of the lung and chest wall to the total elastic recoil forces of the respiratory system was approximately equal within a physiological pressure range. The results suggest that measurements of PV relationships of the respiratory system may offer a physiologic basis for accurate interpretation of pulmonary functions, leading to a better therapeutic strategy in animals with lung diseases.

The aim of these studies was to investigate the effect of body posture on circulatory and respiratory system function in unmediated cattle. The plasma cortisol concentration was also measured and served as an indication of the level of stress imposed by animal handling and positional manipulation. Six mature, healthy Holstein cows were physically restrained and studied in standing, supine and right lateral postures. The plasma cortisol concentration increased with the change in body position. In a supine position, the value was increased to more than three times the control value (p < 0.001). The arterial oxygen tension and oxygen saturation were significantly decreased (p < 0.001) with changes in body position. The decrease was most pronounced when cattle were restrained in a supine position. Arterial carbon dioxide tension, heart rate, mean arterial pressure and central venous pressure did not change significantly with changes in body posture. Restraining of cattle in a lateral recumbent or supine position without introducing anesthesia was found to exert a strong stress which affected the respiratory function and increased the plasma cortisol level.

Seven of the 25 dogs (4 to 15 years old) with benign prostatic hypertrophy (BPH) at the teaching hospital of Nippon Veterinary and Animal Science University from 1989 through 1990 were treated orally with chlormadinone acetate (CMA), a synthetic anti-androgen, 2 mg/kg/day, twice a day for 3 or 4 weeks. Prostatic size was measured by radiography and ultrasonography before and after CMA treatment, and prostatic volume was calculated from the images. Semen quality was examined in 3 of the dogs with BPH. Peripheral blood samples were collected and plasma levels of LH, 4-androstenedione, 5 alpha-dihydrotestosterone, testosterone and estradiol-17 beta were measured. Clinical signs disappeared within 10 days after the start of CMA treatment. The mean (+/- S.E.) prostatic volume 3 or 4 weeks after treatment decreased to 39 +/- 4% of the pretreatment volume. The mean level of plasma testosterone in the dogs with BPH before treatment was significantly lower than that in the normal dogs (P < 0.01). In 6 of the CMA-treated dogs the levels of all hormones examined, except LH, were significantly lower after CMA treatment than before (P < 0.05). The sperm count and motility decreased and the percentage of abnormal sperms increased after CMA treatment. These results demonstrate that, although CMA treatment in dogs with BPH inhibits testicular function, the prostatic volume is markedly reduced and clinical signs disappear in a short period after the therapy. However, a relapse of BPH was observed approximately 6 months after oral CMA treatment in some dogs.

A 2-year-old female Japanese domestic cat weighing 3.6 kg was presented due to marked abdominal distention and was diagnosed as hepatic cyst. The bile acid concentration of the hepatic cyst was as low as the serum bile acid concentration. The membrane of the cysts was excised from the edge of the compressed hepatic tissue and no other surgical manipulation was performed. This surgical procedure is simple and quick compared to hepatic lobectomy, however, it is necessary to evaluate the fluid of the cyst before performing this procedure.

L-glutamine markedly suppressed the development of the gastric lesions induced by aspirin in pylorus-ligated rats. In non-ligated normal rats, aspirin was absorbed rapidly after administration and was maintained in the blood in high salicylate concentration thereafter. When aspirin was administered in combination with L-glutamine, the absorption of aspirin was at nearly the same level as when aspirin had been given alone. In pylorus-ligated rats, administration of aspirin was followed by slow increment in blood salicylate concentration. Blood salicylate level in these rats was higher when aspirin was administered in combination with L-glutamine than when it had been given alone. Combined administration of aspirin and L-glutamine produced little influence on the antipyretic, analgesic and anti-inflammatory effects of aspirin in non-ligated normal rats.

The distribution of Adriamycin (ADM), Mitomycin C (MMC) and 7-N-(p-Hydroxyphenyl)-Mitomycin C (KW 2083) in various organs inclusiding plasma level after intraarterial or intravenous infusion was determined in mongrel dogs and experimental dogs. Similar plasma time-course of ADM was obtained with both routes, showing the maximum level at 5 minutes after infusion. The maximum level with intravenous infusion was twice as highs as that with intraarterial administration. High levels of ADM were encountered in the liver, gallbladder and kidney after proper hepatic arterial infusion, in the angular region of the stomach after left gastric arterial infusion and in the gastric antrum after right gastroepiploic arterial infusion (0.8 mg/kg). There was no significant difference in plasma levels of MMC (0.2 mg/kg) and KW 2083 (1.0 mg/kg) between intraarterial and intravenous infusion. It was of interest that MMC was hardly measurable in the liver after proper hepatic arterial infusion of 0.4 mg/kg. On the other hand, rather high level of KW 2083 was observed in the liver, gallbladder and pancreas after proper hepatic arterial infusion of 1.0 mg/kg. Hepatic necrosis around the central hepatic vein noted at the histological examination seems to be due to infusion of above-mentioned anticancer agents. It is worth mentioning that the concentration of KW 2083 in tumor tissue of the stomach of experimental dog after right gastroepiploic arterial infusion was twice as high as that in intact gastric wall. Grade IIA histological alterations of tumor cells by Oboshi and Shimosato's Classification such as vacuolation of cytoplasm and pyknosis of nuclei were noted after KW 2083 infusion.

Therapeutic effects and dynamics of UFT were studied using beagles with ENNG-induced gastric cancers. Nine canine subjects confirmed to have gastric cancers by punch biopsy under gastrofiberscopy were divided into 3 group given 5 mg/kg/day of UFT for 101 days, 7.5 mg/kg/day for 67 days and 12 mg/kg/day for 45 days, respectively. Although the extent of macroscopic change revealed by gastrofiberscopy was minor, one of the dogs in the third group did show a Grade II b effect according to the criteria of Histopathological Effects on Cancer Tissues by Chemotherapy proposed by Oboshi and Shimozato. Animals were sacrificed by bleeding 4 hours after the last administration of anticancer agent and concentration of 5-FU and tegafur in the serum and each organ were determined. It was recognized that the concentration of anticancer agent in gastric cancer tissue was higher than that in neighboring normal gastric tissue.

The arrhythmogenicity of dopamine, its effects on cardiac function, hemodynamics, and diuresis under halothane anesthesia were evaluated in dogs. The induction time of arrhythemias and the effect of arrhythmias on cardiac function, hemodynamics, and diuresis were determined after infusion of dopamine for 30-min period at increasing doses of 3, 5, 7, 10, and 15 micrograms/kg/min. The results were as follows. 1. Arrhythmia induction percentage was 28.6% at 5 micrograms/kg/mn, 42.9% at 7 micrograms/kg/min, 25% at 10 micrograms/kg/min, and 41.7% at 15 micrograms/kg/min. The induction time of arrhythemias (sec) was 459 at 5 micrograms/kg/min, 332 at 7 micrograms/kg/min, 152 at 10 micrograms/kg/min, and 279 at 15 micrograms/kg/min. No arrhythmias were present at 3 micrograms/kg/min. 2. Heart rate and myocardial oxygen consumption was increased in the arrhythmia-induced group compared to the non-arrhythmia-induced group. 3. Myocardial contractility, mean aortic pressure, mean pulmonary arterial pressure, and diuresis increased dose-dependently in the non-arrhythmia-induced group; however, these measures were increased in the arrhythmia-induced group without regard to dose.

In order to examine the change in adrenocortical responses with age in dogs, 36 healthy beagle dogs were divided by age into 6 groups and were treated with ketamine or thiopental. The plasma cortisol concentrations were determined before and after the treatment. The concentrations prior to the induction of anesthesia were 2.23 +/- 0.44 micrograms/dl (mean +/- SD) in pups (2 to 3 months old), 4.35 +/- 2.04 micrograms/dl in adults (2 years old), and 3.40 +/- 1.25 micrograms/dl in aged dogs (8 to 10 years old). This result indicated the following order of plasma cortisol levels in dogs: pups less than aged dogs less than adults. The plasma cortisol concentrations after ketamine administration tended to increase. This suggested that the adrenocortical function in the dog was stimulated by ketamine. In the ketamine treated dogs, significant differences were demonstrated among the age groups. Namely, a significantly lower response was noted in pups compared to adults or aged dogs (p less than 0.001). On the other hand, the plasma cortisol levels after the thiopental treatment showed a temporary slight increase in aged dogs but tended to decrease in pups and adults. Thiopental was found to have a suppressive effect on the adrenocortical function in dogs in contrast to ketamine.

Studies were made on the number of sperms required for fertilization of ova ovulated from the bilateral ovaries in bitches. The experiment was carried out with 44 female beagles, which were divided into four groups of seven to eleven bitches each. The four groups were inseminated with 40 X 10(6) sperms/0.2 ml, 20 X 10(6) sperms/0.1 ml, 10 X 10(6) sperms/0.1 ml, and 3-5 X 10(6) sperms/0.1 ml, respectively. All the bitches were laparotomized at an optimum time for mating and inseminated at the tip of the horn of an unilateral uterus. In the four groups conception took place at a rate of 7/7, 8/8, 10/11, and 2/7, respectively. The number of puppies exceeded the number of ova ovulated on the inseminated side at a rate of 5/7, 6/8, 0/10, and 0/2 in the four groups, respectively. Therefore, it was clarified that when more than 20 X 10(6) sperms/0.1 ml were inseminated in the ipsilateral uterine horn, ova ovulated on the contralateral side were fertilized also. Then a unilateral ovary was ovariectomized in 11 bitches, which were inseminated with 10 X 10(6) sperms/0.1 ml in the ipsilateral uterine horn. As a result, only one bitch became conceptive and gave birth to only one puppy. From these results, it was considered that 10 X 10(6) sperms/0.1 ml may be most adequate for the ova on the side of insemination alone to be fertilized.

The present experiment was carried out to clarify the effect of administration of the prostaglandin F2 alpha (PGF2 alpha)-analogue on the luteal function and the maintenance of pregnancy in bitches. Fifty-one bitches received a single inoculation of PGF2 alpha-analogue by intramuscular injection. The effect of this agent was observed by monitoring progesterone (P) levels and the state of the uterus by laparotomy, the occurrence of abortion, and the state of parturition. As a result, when bitches were administered with 100-400 micrograms at the beginning of the luteal phase, the decrease in the P level was temporary. In bitches inoculated with 100-800 micrograms of PGF2 alpha-analogue at the functional luteal stage, the P level began to decrease as early as on the following day after injection. In those treated with 100-200 micrograms of PGF2 alpha-analogue at 10-15 days of pregnancy, pregnancy was maintained in 3 of 5 bitches that had received the treatment at day 10, while in the remaining two, all embryos died after implantation. In those that had received the same treatment at day 15, only 2 of 7 maintained pregnancy. Pregnancy was interrupted in eight bitches treated with doses of 100-200 micrograms at days 25-45. In four bitches treated with doses of 100-200 micrograms at day 55, premature birth was induced after 30-44 hr. In conclusion, regression of the corpus luteum, abortion, and premature birth were induced in bitches treated with 100-200 micrograms at each stage, except the beginning of the luteal phase and of the pregnancy.