原 康

Propofol was used as an induction agent of general anesthesia in 77 dogs and 64 cats, all client owned, for a variety of surgeries/treatments or diagnostic procedures. The mean intravenous doses of propofol required to achieve endotracheal intubation in dogs and cats were 6.5 +/- 1.4 mg/kg and 10.1 +/- 2.8 mg/kg, respectively. Most of the animals could be induced to anesthesia smoothly by the administration of propofol with a high incidence of apnea. Propofol is a clinically valuable anesthetic induction agent in both dogs and cats. however, care must be taken for apnea.

Cushing症候群を呈した11歳, 雌, 体重8.3kgのウェストハイランドホワイトテリアが頭部MRI検査により下垂体巨大腺腫と診断された。本症例に対して下垂体切除術とホルモン補充療法による治療を試みた。手術中に摘出した組織は病理学的にACTH産生性前葉腺腫と診断された。手術前に認められたALP, Tcho値の上昇は術後に正常値範囲内に回復し, またACTH刺激試験の成績もまた顕著に改善した。さらに全身性の皮膚病変 (脱毛、皮膚結石症) は術後3ヵ月の時点ではほぼ消退した。本症例の一連の臨床経過は, 巨大腺腫と早期診断された下垂体性副腎皮質機能充進症において, 下垂体切除術は有用な治療法となることを強く示唆するものと考えられた。

Experimental osteotomy model of canine tibia was prepared to investigate the changes in biomechanical characteristics during the healing process. After 16 weeks, although radiographs revealed that fracture healing proceeded, the recovery rates of the mechanical parameters ranged from 12.3 to 47.3%, compared to the intact side. After 32 weeks, those recovered to 68.9-93.2%. These results suggested that the biomechanical characteristics of the healing bone could not be recovered sufficiently even after the passage of the healing period which has been empirically proposed from clinical findings. It was also considered that evaluation of the mechanical parameters using this osteotomy model would be suitable for investigating the effect of osteoinductive growth factors on fracture healing.

The prophylactic efficacy of desmopressin acetate (DDAVP) on diabetes insipidus (DI) after hypophysectomy was investigated in the dog. In the control group, hypernatremia with a plasma level of 155 mEq/l or higher persisted for 12 hr from the 4th to the 16th hour after hypophysectomy, and symptoms of DI developed within five days after surgery. In the DDAVP treatment group, these changes were not observed, showing that administration of DDAVP (4 mug, instillation, twice daily) effectively prevented hypernatremia that develops immediately after surgery and DI-like symptoms that persists for about one week after surgery.

Cushing症候群を呈した11歳, 雌, 体重8.3kgのウェストハイランドホワイトテリアが頭部MRI検査により下垂体巨大腺腫と診断された。本症例に対して下垂体切除術とホルモン補充療法による治療を試みた。手術中に摘出した組織は病理学的にACTH産生性前葉腺腫と診断された。手術前に認められたALP, Tcho値の上昇は術後に正常値範囲内に回復し, またACTH刺激試験の成績もまた顕著に改善した。さらに全身性の皮膚病変 (脱毛、皮膚結石症) は術後3ヵ月の時点ではほぼ消退した。本症例の一連の臨床経過は, 巨大腺腫と早期診断された下垂体性副腎皮質機能充進症において, 下垂体切除術は有用な治療法となることを強く示唆するものと考えられた。

Experimental osteotomy model of canine tibia was prepared to investigate the changes in biomechanical characteristics during the healing process. After 16 weeks, although radiographs revealed that fracture healing proceeded, the recovery rates of the mechanical parameters ranged from 12.3 to 47.3%, compared to the intact side. After 32 weeks, those recovered to 68.9-93.2%. These results suggested that the biomechanical characteristics of the healing bone could not be recovered sufficiently even after the passage of the healing period which has been empirically proposed from clinical findings. It was also considered that evaluation of the mechanical parameters using this osteotomy model would be suitable for investigating the effect of osteoinductive growth factors on fracture healing.

The prophylactic efficacy of desmopressin acetate (DDAVP) on diabetes insipidus (DI) after hypophysectomy was investigated in the dog. In the control group, hypernatremia with a plasma level of 155 mEq/l or higher persisted for 12 hr from the 4th to the 16th hour after hypophysectomy, and symptoms of DI developed within five days after surgery. In the DDAVP treatment group, these changes were not observed, showing that administration of DDAVP (4 mug, instillation, twice daily) effectively prevented hypernatremia that develops immediately after surgery and DI-like symptoms that persists for about one week after surgery.

Objective-To determine whether small intestinal ischemia and reperfusion induces bacterial translocation and proinflammatory cytokine response in either the systemic or portal circulation in dogs. Animals-17 healthy adult Beagles. Procedure-The superior mesenteric artery (SMA) was occluded for 0 (group-3 dogs), 30 (group-1 dogs), or 60 (group-2 dogs) minutes, followed by reperfusion for 180 minutes; serum lactate and endotoxin concentrations and tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 activities in the systemic and portal circulation and intramucosal pH were measured at various time points. Results-In group-2 dogs, TNF-alpha activity was found to be significantly increased in the portal circulation, peaking at 60 minutes of reperfusion; TNF-alpha activity, in the systemic circulation, gradually increased from 60 minutes of reperfusion to the end of the experiment; however, the increase was not significant. In group-1 and -2 dogs, IL-6 activities significantly and gradually increased in the systemic and portal circulation during the reperfusion phase, and the magnitude of these increases was dependent on the duration of the ischemic phase. There were no significant changes in IL-1beta activity or endotoxin concentration in any dog group. Conclusions and Clinical Relevance-Results of the our study indicate that intestinal ischemia and reperfusion leads to significant increases of the circulating TNF-alpha and IL-6 activities, depending on the duration of the ischemia phase, in the absence of detectable endotoxin in the circulation. This finding suggests that intestinal ischemia and reperfusion induces a systemic proinflammatory cytokine response in dogs.

Changes in hip joint congruity was evaluated in dogs with hip dysplasia before and after triple pelvic osteotomy by computed tomography examination in the standing position. Lateral center edge angle significantly increased, and center distance (CD) significantly decreased after surgery compared to the values before surgery, respectively. There was an inverse proportion between the postoperative period and the change in the ratio of CD. These results suggested that joint laxity was improved with time after surgery, providing evidence of the clinical usefulness of this surgery.

Changes in hip joint congruity was evaluated in dogs with hip dysplasia before and after triple pelvic osteotomy by computed tomography examination in the standing position. Lateral center edge angle significantly increased, and center distance (CD) significantly decreased after surgery compared to the values before surgery, respectively. There was an inverse proportion between the postoperative period and the change in the ratio of CD. These results suggested that joint laxity was improved with time after surgery, providing evidence of the clinical usefulness of this surgery.

An intradural tumor in the upper cervical region was found in a dog with quadriparesis and chronic respiratory acidosis. Surgical removal of the tumor in the atlas and intraoperative radiotherapy were attempted. The tumor was histologically diagnosed as a neural glioma. A preoperative acid-base disturbance was dramatically improved after surgery. The clinical changes appeared in this case suggest that compression of the spinal cord at this region may cause paralysis of the respiratory muscles and secondarily result in chronic respiratory acidosis following the respiratory insufficiency.

An intradural tumor in the upper cervical region was found in a dog with quadriparesis and chronic respiratory acidosis. Surgical removal of the tumor in the atlas and intraoperative radiotherapy were attempted. The tumor was histologically diagnosed as a neural glioma. A preoperative acid-base disturbance was dramatically improved after surgery. The clinical changes appeared in this case suggest that compression of the spinal cord at this region may cause paralysis of the respiratory muscles and secondarily result in chronic respiratory acidosis following the respiratory insufficiency.

Objectives-To determine whether small intestinal ischemia and reperfusion affects intestinal intramucosal pH (pHi), arterial and portal venous blood gas values, and intestinal blood flow (IBF) and to investigate relationships between regional intestinal tissue oxygenation and systemic variables in dogs. Animals-15 healthy adult Beagles. Procedure-Occlusion of superior mesenteric artery (SMA) for 0, 30, or 60 minutes, followed by reperfusion for 180 minutes, was performed; IBF, pHi, arterial and portal venous blood gas values, arterial pressure, and heart rate were measured at various time points; and intestinal mucosal injury was histologically graded. Results-Occlusion of the SMA induced significant decreases in pHi and IBF After the release of the occlusion, IBF returned rapidly to baseline values, but improvement in pHi was slow. Arterial and portal venous blood gas analyses were less sensitive than tonometric measurements of pHi, and there was no correlation between results of blood gas analyses and tonometric measurements. Histologic score for intestinal mucosal injury increased significantly, depending on duration of ischemia, and there was a correlation between tonometric results and the histologic score. Conclusions and Clinical Relevance-Results suggest that it is difficult to accurately evaluate local oxygenation disorders by monitoring at the systemic level, whereas clinically pHi is the only reliable indicator of inadequate regional intestinal tissue oxygenation in dogs.

Objectives-To determine whether small intestinal ischemia and reperfusion affects intestinal intramucosal pH (pHi), arterial and portal venous blood gas values, and intestinal blood flow (IBF) and to investigate relationships between regional intestinal tissue oxygenation and systemic variables in dogs. Animals-15 healthy adult Beagles. Procedure-Occlusion of superior mesenteric artery (SMA) for 0, 30, or 60 minutes, followed by reperfusion for 180 minutes, was performed; IBF, pHi, arterial and portal venous blood gas values, arterial pressure, and heart rate were measured at various time points; and intestinal mucosal injury was histologically graded. Results-Occlusion of the SMA induced significant decreases in pHi and IBF After the release of the occlusion, IBF returned rapidly to baseline values, but improvement in pHi was slow. Arterial and portal venous blood gas analyses were less sensitive than tonometric measurements of pHi, and there was no correlation between results of blood gas analyses and tonometric measurements. Histologic score for intestinal mucosal injury increased significantly, depending on duration of ischemia, and there was a correlation between tonometric results and the histologic score. Conclusions and Clinical Relevance-Results suggest that it is difficult to accurately evaluate local oxygenation disorders by monitoring at the systemic level, whereas clinically pHi is the only reliable indicator of inadequate regional intestinal tissue oxygenation in dogs.

Purpose. An investigation was made of the population and function of lymphocytes in canine peripheral blood, in animals with or without laparotomy under inhalation anesthesia. Methods. Fourteen healthy beagles were allocated to two experimental groups: laparotomy (group A) and without laparotomy (group B). Induction of anesthesia in both groups was carried out with an intravenous injection of thiopentone, and was maintained by isoflurane inhalation. Ten blood samples, consisting of 10 ml of venous blood withdrawn by venipuncture into syringes containing 200 units of preservative-free heparin, were taken, from before anesthesia to the 28th postoperative day. The blood samples were collected, and the number of lymphocytes, the lymphocyte subpopulations, the proportion of apoptotic lymphocytes, and plasma cortisol level were measured, and the blastoid transformation of lymphocytes was observed. Results. Lymphopenia was observed in both groups after anesthesia. Flow cytometry indicated a greater reduction in the proportion of T lymphocytes than of B lymphocytes. Blast transformation was also depressed in both groups. Progression of apoptosis after anesthesia was demonstrated in both groups, with a higher percentage of apoptotic cells being observed in group A at 12h after anesthesia (28.5 ± 3.2% by TUNEL assay). Plasma levels of cortisol were elevated to a greater extent in group A at the end of anesthesia (10.3 ± 0.8μg/dl) than in group B (7.8 ± 1.9 μg/dl). Conclusions. These results indicate that surgical trauma concomitant with anesthesia could impair immunocompetence by reducing the number and function of lymphocytes.

Purpose. An investigation was made of the population and function of lymphocytes in canine peripheral blood, in animals with or without laparotomy under inhalation anesthesia. Methods. Fourteen healthy beagles were allocated to two experimental groups: laparotomy (group A) and without laparotomy (group B). Induction of anesthesia in both groups was carried out with an intravenous injection of thiopentone, and was maintained by isoflurane inhalation. Ten blood samples, consisting of 10 ml of venous blood withdrawn by venipuncture into syringes containing 200 units of preservative-free heparin, were taken, from before anesthesia to the 28th postoperative day. The blood samples were collected, and the number of lymphocytes, the lymphocyte subpopulations, the proportion of apoptotic lymphocytes, and plasma cortisol level were measured, and the blastoid transformation of lymphocytes was observed. Results. Lymphopenia was observed in both groups after anesthesia. Flow cytometry indicated a greater reduction in the proportion of T lymphocytes than of B lymphocytes. Blast transformation was also depressed in both groups. Progression of apoptosis after anesthesia was demonstrated in both groups, with a higher percentage of apoptotic cells being observed in group A at 12h after anesthesia (28.5 ± 3.2% by TUNEL assay). Plasma levels of cortisol were elevated to a greater extent in group A at the end of anesthesia (10.3 ± 0.8μg/dl) than in group B (7.8 ± 1.9 μg/dl). Conclusions. These results indicate that surgical trauma concomitant with anesthesia could impair immunocompetence by reducing the number and function of lymphocytes.