藤田 道郎

9歳,去勢雄の日本猫が努力性呼吸困難を主訴に上診した.胸部X線所見より,右中葉の吸飲性肺炎あるいは原発性び漫性腫瘍が疑われた.組織学的には,異型細胞で構成された肺胞壁のびまん性肥厚が右中葉病変部に認められた.これらの異型細胞は,ファクターVIII関連抗原陽性を示した.以上より,本症例を管内性血管肉腫と診断した.

An imbalance of excitatory and inhibitory transmitters in the brain has been suggested to cause epileptic seizures. In this study, we investigated the kinetics of glutamate (GLU) and gamma-aminobutyric acid (GABA) in cerebrospinal fluid (CSF-GLU and CSF-GABA, respectively) using a high performance liquid chromatography (HPLC) in a canine model of complex partial status epilepticus (CPSE) induced by the microinjection of kainic acid (KA) into the unilateral amygdala. During the acute phase (3, 6, 12 and 48 hr after the onset of CPSE), CSF-GLU was significantly increased, while CSF-GABA was decreased, although not significantly. In the chronic phase, both CSF-GLU and CSF-GABA were significantly lower than normal at 72 hr after the onset of CPSE, and their levels returned to normal at 2 months. Results of the present study demonstrate that CSF-GLU is gradually increased in relation with seizure severity, and suggested the possibility that CSF-GABA was consistently decreased during CPSE induced by KA in dogs.

腸間膜リンパ腫に罹患した犬にCTとMR検査を実施した.その結果,単純CT,造影CTおよび単純MR(T1WI,T2WI)では一つの巨大な腫瘤として描出されたが,造形MR(T1WI)では腫瘤塊と腫瘤塊に癒着した腸管として描出された.開腹手術で腫瘤は総腸間膜リンパ腫と回腸と盲腸が癒着したもので遺影MRとほぼ一致していた.以上の結果から,犬の腸間膜リンパ腫の診断にMRIが有用である可能性が示唆された.

OBJECTIVE: To investigate diffusion-weighted imaging (DWI) in status epilepticus, a canine model of kainic acid (KA)-induced complex partial status epilepticus (CPSE) was produced. In order to validate its usefulness, MR imaging was carried out at various times following onset of CPSE followed by histopathology. MATERIAL AND METHODS: Six normal dogs were used in this study. In each dog, a cannula was stereotactically inserted into the left amygdala. One week after surgery, all dogs were imaged at MRI. Pre-injection imaging consisted of T2 weighted (T2W) imaging, fluid attenuated inversion recovery (FLAIR), and DWI. Two weeks after surgery, five dogs received intraamygdaloid KA microinjections. One dog was used as a control. MRI was carried out at 3, 6, 12, 24 and 48 h after onset of CPSE. Animals were euthanized immediately after MRI for histopathological evaluation. The average of each apparent diffusion coefficient (ADC) in the regions of interest was calculated from each DWI. RESULTS: At 3 and 6 h, DWI hyperintensity and low ADC were found in the injected amygdala, without any T2W and FLAIR imaging changes. At 12 and 24 h, all imaging showed hyperintensity with higher ADC in the amygdala and the hippocampus. At 48 h, all imaging techniques showed continued hyperintensity, but ADC showed a trend towards normalization. This increasing hyperintensity in DWIs were in agreement with the degree of histopathology during CPSE. SUMMARY: This study suggests that DWI is a useful imaging method for finding the epileptic focus or for examining potential epileptic brain damage in status epilepticus.

Objective: In order to investigate kainic acid (KA)-induced amygdaloid seizure and seizure-induced brain damage in dogs, and to compare these findings with that in other species, a KA-induced seizure model in dogs was produced. Material and methods: Normal beagle dogs Were used. A Teflon cannula for KA injection was inserted into the left amygdala, and cortical or depth electrodes were positioned. One week after surgery, 1.5 mug of KA was microinjected into the left amygdala. EEGs and the behavior of the animals were monitored for 2 months after KA injection. In addition, neuron-specific enolase levels in the cerebrospinal fluid (CSF-NSE) were measured intermittently. At 2 months after the injection, histopathological studies were performed. Results: KA-treated dogs showed limbic seizures that started from the left amygdala within 30 min after injection. The seizures developed into complex partial status epilepticus (CPSE), and started independently from the bilateral amygdala during the CPSE. The CPSE lasted for 1-3 days, and the animals showed no spontaneous' seizures during the 2-month observation period. A significant increase in CSF-NSE was observed immediately after CPSE. Histopathologically, extensive necrosis, which formed large cavity lesions, was observed around the bilateral amygdala. Summary: A microinjection of KA into unilateral amygdala in dogs induced CPSE. The seizures elicited independently from bilateral amygdala, and bilateral limbic structures suffered extensive injury. In addition, CSF-NSE was demonstrated as a useful marker of acute neuronal damage. (C) 2002 Elsevier Science B.V. All rights reserved.

四肢不全麻痺および慢性呼吸性アシドーシスを呈した雑種犬が第一頚椎領域の硬膜内腫瘍と診断され,脊髄の減圧を目的として腫瘍の外科的切除と放射線治療が行われた.本症例の呼吸機能は術後に顕著に改善し,経時的に四肢の随意的運動も回復した.本症例で認められた換気不全は上位頚髄領域に発生した腫瘍による脊髄圧迫に起因した呼吸筋麻痺に続発したものと考えられた.

Microcystic hamartoma was detected as a tumorlike mass in the left caudal lung lobe of a 12-year-old mixed-breed dog. Histologically, the mass was characterized by microcysts of various sizes that mimicked alveoli and were surrounded by thin fibrous septal tissue. However, unlike the adjacent lung parenchyma, bronchial or bronchiolar trees were absent, and the septal vascular channels were extremely underdeveloped. Immunohistochemically, the cells lining the microcysts were consistently positive for cytokeratin but not for vimentin, whereas the septal fibroblast-like cells were negative for cytokeratin and positive for vimentin. Electron microscopy confirmed that the microcysts were lined with a layer of type I and type II mature pneumocytes. This is the first description of the detailed morphologic features of microcystic hamartoma.

Eight beagles with benign prostatic hypertrophy (BPH) were treated by subcutaneous implantation of pellets containing 10 mg/kg chlormadinone acetate (CMA), a synthetic anti-androgen, plus daily oral administration of CMA at 2 mg/kg, per day for 7 days as a therapy for BPH. Prostatic and testicular size were measured and prostatic and testicular biopsies were performed by laparotomy before and after CMA treatment. Plasma levels of luteininzing hormone (LH), testosterone and oestradiol were also measured. The clinical signs of BPH, for example haematuria and dysuria, resolved within 1 week of treatment. Mean prostatic volume decreased to 56% of the pretreatment value. At 40 weeks after treatment, prostatic volume had decreased by 36%. Histological examination of the prostate 1 week after treatment revealed reduction in diameter of the alveoli and in height of the glandular epithelium. Degeneration and atrophy of the glands were marked 4-12 weeks after treatment. In the testis, the diameter of seminiferous tubules and the number of germ cells in the seminiferous tubules had decreased markedly at 12 and 24 weeks after treatment. Although plasma LH concentrations did not undergo any marked fluctuntions after CMA treatment, levels of testosterone and oestradiol were lower than before treatment. The results indicate that implantation of 10 mg/kg CMA, plus 7-day oral administration of 2 mg/kg CMA, bring about resolution of the clinical signs and marked reduction in prostatic volume within 1 week of treatment.

Neurogenic muscular atrophy was examined using computed tomography (CT) in dogs induced by crushing the sciatic nerve. The CT number and cross-sectional area in denervated muscles decreased in 1 to 2 weeks after denervation. Those were significant after 3 weeks. The examination with CT might be useful to diagnose canine neurogenic muscular atrophy.

Objective: To compare the pathophysiologic changes occurring during drowning in cold fresh water and cold salt water with reference to viability. Design: Randomized, prospective, controlled submersion experiments in two contrasting cold liquids. Setting: A laboratory at a large university- affiliated medical institution. Subjects: Thirteen healthy, anesthetized mongrel dogs. Three dogs served as controls and were immersed but not submerged. The remainder were submerged in cold fresh water or cold salt water (4°C). Interventions: Catheters were placed in the femoral artery, right carotid artery and right internal jugular vein. Electrocardiogram, pneumogram, and rectal temperatures were measured continuously during submersion/immersion. Measurements and Main Results: Cold water submersion with drowning produced a large initial decrease in carotid artery temperature ~7.5°C in the first 2 mins) compared with a minor decrease ~0.8°C with immersion). No significant differences were noted in the rate of decrease of temperature between drowning in fresh water and salt water. During cold fresh water drowning, aspiration produced gross hemodilution with an average increase in body weight of 16.5%. Hematocrit values, serum sodium concentrations, and osmolality decreased while serum potassium concentrations, catecholamines, and free hemoglobin increased. All measured biochemical data (except PaO2) remained at viable levels. By contrast, during cold salt water drowning, average body weight increased by only 6%, with hemoconcentration and a shrinkage of vascular volume. Hematocrit and hemoglobin values increased by 30%, but initial plasma free hemoglobin values remained unchanged. Serum sodium concentrations, osmolality, and potassium concentrations increased rapidly to critical levels. Conclusions: On submersion in cold water, all of the experimental animals developed tachypnea immediately, followed by aspiration with predictable effects. The biochemical and pathophysiologic changes in cold water drowning approximated those changes reported for warm water drowning for both fresh and salt water with one exception and continued aspiration of cold water produced extremely rapid core cooling as long as the circulation remained intact. This process of acute submersion hypothermia may protect the brain temporarily from lethal damage, as reported in cases of cold fresh water drowning. Concentrations of circulating catecholamines increased exponentially in both groups of test animals. Clinically, their acute effects on the circulation, compounded by significant hypothermia and extreme anoxia, must hamper the detection of residual circulation at rescue and may play a role in sudden death from cold water in the absence of drowning.

The effects of intratracheal administration of MKS 492, selective phosphodiesterase (PDE) 111 inhibitor, were studied in five anesthetized bronchoconstricted cats. The animals were challenged by four repeated doses of intratracheal methacholine (67 μg/kg), and the degree of bronchoconstriction was assessed from increases in respiratory system resistance (Rrs). All animals demonstrated good bronchoconstrictive responses (i.e., 86–99% increases in Rrs) to methacholine without tachyphylaxis. On separate day, the cats received the same four doses of methacholine after being pretreated with either intratrachael saline or three different doses of MKS 492 (0.17, 1.7, and 17 μg/kg). The increases in Rrs with 1.7 μg/kg [ 52.6 ± 8.4% (SE)] and 17 μg/kg of MKS 492 (44.4 ± 10.1%) were smaller than those with saline pretreatment (88.1 ± 16.8%) (P &lt 0.05). There were no treatment‐associated changes in mean arterial pressure or heart rate during administration of MKS 492. We conclude that intratracheal MKS 492 effectively reduced methacholine‐induced bronchoconstriction in dose‐dependent fashion without substantial systemic effects. These preliminary results suggest that inhalation of isozyme‐selective PDE inhibitors may deserve consideration for clinical trials provided that more extensive preclinical investigations justify such trials. © 1995 Wiley‐Liss, Inc. Copyright © 1995 Wiley‐Liss, Inc., A Wiley Company

Canine patellar luxation is seen in toy and miniature breeds, and in the majority of cases the problem is medial patellar luxation. When the luxation is left alone, it causes deformity and disorder in the growth of the affected limb. In severe cases, the limb may cease to afunction. Early surgical correction is therefore essential, but the owners are not able to detect the disorder at an early age and surgical intervention in most cases will take place after 6 months of age. The authors were able to have the opportunity to operate at an earlier age by educating breeders and owners. Various techniques have been developed and implemented to correct this disorder with varying Therapeutic results. The authors have devised a unique surgical method which has been applied to the numerous cases with good results since 1985. The procedure is to make a longitudinal groove on the medial cortical bone of the tibial tuberosity along the tibial crest, and to place small pieces of artificial ceramic bone or autoplastic bone grafts in the groove, thus laterally transposing the tibial tuberosity and crest. This method makes it possible to put the quadriceps muscles of the thigh, the patella and the patellar ligament in the correct alignment over the femoral trochlea. It is considered appropriate to conduct this operation at 1.0-3.0 months of age when the dog has matured enough to be able to withstand anesthesia and surgical stress. © 1995, JAPANESE SOCIETY OF VETERINARY SCIENCE. All rights reserved.

Five beagles out of 11 dogs aged 7-10 years with benign prostatic hypertrophy (BPH) were implanted subcutaneously with pellets of the synthetic anti-androgen chlormadinone acetate (CMA) at a dose of 10 mg/kg bodyweight. The remaining six dogs (one beagle and five mongrel dogs) underwent bilateral orchidectomy. Changes in prostatic volume, histological findings in the prostate and the testis, and peripheral plasma levels of LH, testosterone and oestradiol-17β (E2) were assessed up until 24 and 4 weeks after CMA-implantation and orchidectomy, respectively. Measurements of the size of the prostate and biopsies of the prostate were performed by laparotomy. Mean prostatic volume had decreased to 71% and 41%, respectively, of its pretreatment volume,by 4 weeks after CMA-implantation and orchidectomy, and was 49% and 47%, respectively, of pretreatment volume at 12 and 24 weeks after CMA-implantation. The clinical signs of BPH, e.g. haematuria, resolved within 2 weeks after either treatment. When the prostate was examined histologically 4 weeks after either treatment, hardly any evidence of active secretion (e.g. glandular epithelium projecting markedly into the lumen), was observed in CMA-implanted dogs, alveolar diameter and height of the glandular epithelium had decreased markedly and the glandular lumen had become very small in the orchidectomized dogs. By 12 weeks after CMA-implantation, degenerative and atrophic glands were observed in the prostate nearly the same as at 4 weeks after orchidectomy. In the testis the number of germ cells in the seminiferous tubules decreased markedly after CMA-implantation. The mean level of plasma LH at 4 weeks after orchidectomy had increased to 14.9 ng/ml, twice the value before operation. The mean levels of plasma testosterone and E2 at 4 weeks after CMA-implantation had decreased to 0.7 ng/ml and 9 pg/ml from 1.5 ng/ml and 15 pg/ml, the values before treatment, respectively. CMA-implantation resulted in poor semen quality. The results indicate that CMA-implantation at a dose of 10 mg/kg results in the same prostate-shrinking effect as orchidectomy.

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.

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. © 1994, JAPANESE SOCIETY OF VETERINARY SCIENCE. All rights reserved.

激しい運動時のみ失神が起こるシェパード犬の心機能を評価したところ,肺動脈狭窄症であった.パッチワークによる肺動脈拡張手術で著明な心機能の改善および運動時の失神の消失が見られた.