Intraoperative hypertensive crisis in a dog with functional paraganglioma of the gall bladder.

A 15-year-old spayed female mongrel presented with anorexia and an abdominal mass. The mass originated from the gall bladder and was surgically resected along with divisionectomy of the central hepatic division. Paroxysmal hypertension and tachycardia were noted during manipulation of the mass. Following resection, arterial blood pressure decreased significantly. Histopathological analysis confirmed a diagnosis of neuroendocrine neoplasm. Immunohistochemical staining for synaptophysin and chromogranin A yielded diffuse and strong positive results, while gastrin was positive in only 10% of the cells. The preoperative elevated concentrations of catecholamine in the urinalysis showed a marked decrease after surgery. Based on these findings, the tumour was diagnosed as a functional paraganglioma of the gall bladder. The patient has undergone regular thoracic radiographs and ultrasound examinations and, until 431 days after surgery, has shown no signs of metastases or recurrences. Based on our literature search, we report the first case of functional paraganglioma of the gall bladder in a dog.

Clinical relationship between histopathological necrotic/partial necrotic findings and disease condition of gallbladder mucoceles in dogs.

Gallbladder mucocele (GM) is a common extrahepatic biliary disease recognized in dogs and is defined as the expansion and extension of the gallbladder by an accumulation of semi-solid bile or bile acid. Histopathological diagnosis of necrotizing cholecystitis and transmural coagulative necrosis of the gallbladder wall shows poor prognosis. Conversely, histopathological diagnosis with partial necrotic findings is often achieved. We hypothesized that histopathological partial necrosis of the gallbladder wall is the primary lesion of necrotic cholecystitis or transmural ischemic necrosis. Therefore, we investigated the relationship between histopathological necrosis/ partial necrosis findings and their clinical conditions. We retrospectively analyzed 55 dogs diagnosed with GM that had undergone cholecystectomy at the Yamaguchi University Animal Medical Center. The group with histopathological necrosis/partial necrosis of the gallbladder wall showed elevated levels of preoperative white blood cells, alanine transaminase, alkaline phosphatase, γ-glutamyltransferase, total bilirubin, and C-reactive protein compared to the non-necrotic group. Partial necrosis of the gallbladder wall may affect the progression of the disease and hematological abnormalities. Additionally, all death cases until 2 weeks were included in the histopathological necrosis/partial necrosis group. In this study, we found that poor prognosis factors were associated with partial necrosis of the gallbladder wall. Furthermore, these cases of partial necrosis showed elevated levels of blood test parameters. These results suggest that necrosis of the gallbladder wall is associated with poor prognosis and poor pathophysiological conditions.

GM2 gangliosidosis variant 0 (Sandhoff-like disease) in a family of toy poodles.

BACKGROUND: GM2 gangliosidosis variant 0 (human Sandhoff disease) is a lysosomal storage disorder caused by deficiencies of acid ß-hexosaminidase (Hex) A and Hex B because of an abnormality of the ß-subunit, a common component in these enzyme molecules, which is coded by the HEXB gene. OBJECTIVE: To describe the clinical, pathological, biochemical, and magnetic resonance imaging (MRI) findings of Sandhoff-like disease identified in a family of Toy Poodles. ANIMALS: Three red-haired Toy Poodles demonstrated clinical signs including motor disorders and tremor starting between 9 and 12 months of age. The animals finally died of neurological deterioration between 18 and 23 months of age. There were some lymphocytes with abnormal cytoplasmic vacuoles detected. METHODS: Observational case study. RESULTS: The common MRI finding was diffuse T2-hyperintensity of the subcortical white matter in the cerebrum. Bilateral T2-hyperintensity and T1-hypointensity in the nucleus caudatus, and atrophic findings of the cerebrum and cerebellum, were observed in a dog in the late stage. Histopathologically, swollen neurons with pale to eosinophilic granular materials in the cytoplasm were observed throughout the central nervous system. Biochemically, GM2 ganglioside had accumulated in the brain, and Hex A and Hex B were deficient in the brain and liver. Pedigree analysis demonstrated that the 3 affected dogs were from the same family line. CONCLUSIONS AND CLINICAL IMPORTANCE: The Sandhoff-like disease observed in this family of Toy Poodles is the 2nd occurrence of the canine form of this disease and the 1st report of its identification in a family of dogs.

Oncolytic reovirus therapy: Pilot study in dogs with spontaneously occurring tumours.

Oncolytic virotherapy is a novel treatment involving replication-competent virus in the elimination of cancer. We have previously reported the oncolytic effects of reovirus in various canine cancer cell lines. This study aims to establish the safety profile of reovirus in dogs with spontaneously occurring tumours and to determine a recommended dosing regimen. Nineteen dogs with various tumours, mostly of advanced stages, were treated with reovirus, ranging from 1.0 × 108 to 5.0 × 109 TCID50 given as intratumour injection (IT) or intravenous infusion (IV) daily for up to 5 consecutive days in 1 or multiple treatment cycles. Adverse events (AEs) were graded according to the Veterinary Cooperative Oncology Group- Common Terminology Criteria for Adverse Events (VCOG-CTCAE) v1.1 guidelines. Viral shedding, neutralizing anti-reovirus antibody (NARA) production and immunohistochemical (IHC) detection of reovirus protein in the tumours were also assessed. AE was not observed in most dogs and events were limited to Grade I or II fever, vomiting, diarrhoea and inflammation of the injected tumour. No infectious virus was shed and all dogs had elevated NARA levels post-treatment. Although IHC results were only available in 6 dogs, 4 were detected positive for reovirus protein. In conclusion, reovirus is well-tolerated and can be given safely to tumour-bearing dogs according to the dosing regimen used in this study without significant concerns of viral shedding. Reovirus is also potentially effective in various types of canine tumours.

Development of multidrug resistance in a canine lymphoma cell line.

New multidrug resistant cell lines developed from the canine B cell lymphoma cell line (GL-1) were characterized in terms of chemosensitivity to some antineoplastics and P-glycoprotein (Pgp) expression. GL-1 was continuously exposed to a culture medium containing gradually increasing levels of doxorubicin and the cells that could grow in the presence of doxorubicin were obtained. Chemosensitivity of these cells to various antineoplastics were investigated with or without verapamil, which reversed Pgp-mediated drug resistance. The expression of Pgp on the cells was also examined by Western blot analysis. As a result, three kinds of resistant cell lines, designated as GL-DOX60, 300, and 4000 were obtained. These cell lines showed stable proliferation in the medium containing 60, 300, and 4000 ng/ml, respectively. These cells were much more resistant to vincristine than doxorubicin. This resistance was strongly reversed by the presence of verapamil. On the other hand, cisplatin was effective enough in killing these derived cells. In the Western Blot analysis, some bands that reacted to the anti-human Pgp monoclonal antibodies were observed in GL-DOX4000. The cells derived from GL-1 have multidrug resistance potential mediated by canine Pgp. The cells produced in this experimental trial are considered to be useful models for various investigations on canine multidrug resistance.

Embryotoxic effects of ethylene glycol monomethyl ether in mice.

An embryotoxicity study on ethylene glycol monomethyl ether (EGM) was carried out in ICR mice. They were given EGM daily at 6 dose levels (31.25, 62.5, 125, 250, 500 or 1000 mg/kg body wt) by gastric intubation on days 7 through 14 of gestation. On day 18 of gestation all fetuses were examined. Marked and dose-related embryotoxic effects were observed. Skeletal and gross anomalies, reduced fetal weight and fetal death were all observed at lower dosages of EGM, while marked leucopenia of the dams occurred at the highest dose.

In-vitro anti-proliferative effects of some anti-tumour drugs on feline mammary tumour cell lines.

Six anti-tumour drugs namely; doxorubicin, mitoxantrone, vincristine, cisplatin, recombinant human tumour necrosis factor alpha (rh-TNFalpha) and recombinant feline interferon gamma (rf-IFNgamma) were singly evaluated for their anti-proliferative effects on two feline cell lines (FRM and NAC) derived from mammary adenocarcinoma and grown as monolayers. We obtained concentration response curves that enabled the determination of the concentration inhibiting growth by 50 per cent (IC50) for the chemotherapeutic agents with VCR exhibiting exponential-plateau curves. Differences in anti-proliferative effects of drugs to a given cell line and between the cell lines were also observed. NAC cells were relatively more resistant compared with FRM cells. The relative resistances for NAC cells were 4.19, 12.96, 0.05 and 2.10-fold to doxorubicin, mitoxantrone, vincristine and cisplatin, respectively. FRM cells were more resistant to VCR at lower concentrations compared with NAC cells. The cells appeared, at least in vitro, least sensitive to rh-TNFalpha and rf-IFNgamma. rh-TNFalpha and rf-IFNgamma were 23 and 29 per cent inhibitory to FRM cells and only 13 and 15 per cent inhibitory to NAC cells, respectively.

The antitumor activity of the DNA fraction from Mycobacterium bovis BCG (MY-1) for glioblastoma.

The antitumor activity of the DNA fraction extracted from Mycobacterium bovis BCG (MY-1) for glioblastoma was investigated in the experimentally produced brain tumor in rats. The tumor-bearing rats were given intralesional injection of 1 mg of MY-1 twice a week for three weeks, and were sacrificed for comparison with those of control rats. The main macroscopic features of the tumors treated with serial injections of MY-1 were cystic and destructive structures, which were histologically characterized by multiple microcysts containing macrophages. Furthermore, infiltration of leukocytes as well as the perivascular cuffing in the marginal area was observed. These findings suggested that the serial injections of MY-1 into the brain tumor have the therapeutic potential for glioblastoma.

Effect of directly ultraviolet-irradiated allografts of fetal pancreas in experimental diabetic dogs.

The proliferative responses of UV-irradiated islets from fetal pancreas decreased to 53.8 +/- 4.7% (mean +/- SEM) compared to that of UV-irradiated islets by allogeneic mixed islet-cell lymphocyte culture. In 5 pancreatectomized dogs, UV irradiated fetal dog pancreas was transplanted either into omentum pouches or the spleen without immunosuppressive agents. The diabetic status (daily insulin requirement for hyperglycemia, decrease in body weight, urine glucose) improved in dogs after allo-transplantation. The survival time after total pancreatectomy was significantly longer in allografted dogs than those treated only with daily insulin injections.

Intrauterine transplantation of isogenic pancreatic islets in experimental diabetic rats.

The effect of intrauterine transplantation (IU group) as a potential immunologically privileged site on the diabetic state of the recipient was compared with that of conventional intraperitoneal transplantation (IP group) using Fisher 344 rats. Islets were isolated from the pancreata of normal rats and transplanted into the uterus and peritoneal cavity of the isogenic rats with experimental diabetes, which were treated with estradiol benzoate and progesterone. Although all the rats in both groups became normoglycemic within 4 days after transplantation, all of those in the IU group relapsed into a diabetic state up to the 20th day after transplantation. On the other hand, 6 of 8 rats in the IP group remained normoglycemic throughout the experimental period. Weight gain and diminution of urinary glucose excretion in the IU group were significantly lower than those in the IP group (P < 0.01). The glycosylated hemoglobin level in the IU group did not differ significantly from that in the IP group, but the serum level of fructosamine in the IU group was significantly higher than that in the IP group (P < 0.01). These results indicate that the response to fluctuations of blood glucose of islets in the uterine cavity is less than that of islets in the peritoneal cavity. Histologically, islets were observed to be aggregated in the uterine cavity, however the number of cells decreased markedly with time. Although this study demonstrated that blood glucose was normalized by transplantation of islets into the uterine cavity of diabetic rats, long-term survival of the islets in this location was not obtained.

Suppression of delayed-type hypersensitivity (DTH) responses in xenografts by pretreatment with ultraviolet (UV)-irradiated hepatocytes.

F344 Rat hepatocytes (HCs) that had been exposed to ultraviolet (UV) light were transplanted into the dorsal subcutaneous tissues of Balb/c mice. Four days after the transplantation, the anti-HC delayed-type hypersensitivity (DTH) response was assessed by determining the response to a direct challenge with non-irradiated HCs. The DTH response in mice transplanted with 600 J/m2-UVB-irradiated HCs was suppressed significantly compared with that with non-irradiated HCs. Furthermore, the DTH responses evoked by challenge with non-irradiated HCs were similar to those evoked by UV-irradiated HCs.

Antitumor activity of natural-type human tumor necrosis factor on experimental brain tumors in rats.

The effects of intralesional injection of newly synthesized natural-type human tumor necrosis factor (nh-TNF) on experimental brain tumors in rats were investigated. The repeated injection of 5,000 U of nh-TNF into the tumor resulted in the prolongation of the survival time of the rats. More than half of the nh-TNF treated tumors were red, and were characterized by histopathological features of marked congestion of tumor vessels. Fibrin formations were also found in the tumor vessels. These histological findings were not observed in the control tumors. Furthermore, coagulative necrosis was observed in the center of some reddish tumors. Leukocytes adhering to vascular endothelium and infiltration of the leukocytes were also observed in the tumors of nh-TNF treated rats. In the immunohistochemical examination, these infiltrated cells were primarily polymorphonuclear leukocytes and macrophages. Expression of intercellular adhesion molecule-1 (ICAM-1) increased on the tumor endothelial cells after the administration of nh-TNF. These results suggest that repeated injection of nh-TNF has a therapeutic effect on brain tumors through its extensive influences on tumor vasculature.

Morphological change in tumor endothelial cells induced by natural-type human tumor necrosis factor.

The effects of natural-type human tumor necrosis factor (nh-TNF) on tumor endothelial cells of experimental brain tumors were investigated electron microscopically. Tumor vessels with hypertrophic endothelial cells were observed 12 and 24 hr after an intralesional administration of 5,000 U of nh-TNF. Increased biosynthetic organelles such as the Golgi complex and rough endoplasmic reticulum were evident in the plump cytoplasms. These endothelial cells resembled those in high endothelial venules (HEV) functionally characterized by the high permeability of leukocytes. In addition, close interactions between these endothelial cells and leukocytes were observed. Our findings indicated that nh-TNF could promote the morphological change in tumor endothelial cells into HEV-like cells.

Delayed type hypersensitivity responses in mice transplanted with rat hepatocytes.

The delayed type hypersensitivity (DTH) response to xenogeneic hepatocytes (HCs) was investigated in mice received subcutaneous (s.c.), intrasplenic (i.s.), or intravenous (i.v.) transplantation of rat HCs. The DTH response in mice preimmunized i.s. or i.v. with rat HCs (1 x 10(6) cells) was significantly lower than that in mice preimmunized s.c. with the same doses of rat HCs. Co-transfer of spleen cells from i.s. immunized mice with spleen cells from s.c. immunized mice to naive recipient mice did not suppress the DTH response induced by transfer of spleen cells from s.c. immunized mice. On the other hand, co-transfer of spleen cells from i.v. immunized mice with spleen cells from s.c. immunized mice suppressed the DTH response to rat HCs in recipients. Furthermore, the levels of DTH responses in recipients transferred with spleen cells from mice sensitized i.s. or i.v. with rat HCs, immunized s.c. with rat HCs 6 hr after transfer, and challenged with rat HCs 7 days later was almost similar to those in recipients transferred with spleen cells from s.c. immunized mice. These results suggest that antigen-specific suppression of DTH responses to rat HCs in mice is associated with the presence of suppressive spleen cells induced by i.s. or i.v. immunization with rat HCs.

Differential freezing tolerance of rat pancreatic islets depending on their size variation.

We have investigated the freezing tolerance of rat pancreatic islets. Freshly isolated rat pancreatic islets were divided into three groups based on their longest diameter (small; 100 - 200 microns, medium; 201 - 300 microns, large; > 300 microns). They were then cryopreserved at a slow cooling rate (-0.3 degrees C/min) in the presence of dimethyl sulfoxide (Me2SO) or ethylene glycol (EG). After storage at -196 degrees C for 1 - 4 weeks, they were thawed and their ability to secrete insulin in response to fluctuations in glucose concentration was examined during three consecutive static incubations in vitro (1st; 2.8 mM, 2nd; 16.7 mM, 3rd; 2.8 mM). Morphological examination of the beta-granule population was determined by image analysis, and correlation with islets size was analyzed. The amount of insulin released from large-sized islets was significantly suppressed in EG (p < 0.05) and Me2SO (p < 0.01) groups compared to unfrozen islets. However, the mean volume of the large-sized islets isolated from one rat accounted for 43.0% of the total volume. On the other hand, the amount of insulin released from small- and medium-sized islets did not differ from those of unfrozen islets, and their mean volumes were 13.2 and 43.8% respectively. The percentage of cells with beta-granules was significantly correlated with size in both EG (r = -0.52) and Me2SO (r = -0.35) groups, but no significant correlation was observed in the unfrozen islets groups. These findings suggest that large-sized islets are more susceptible to freezing injury than small- or medium-sized islets. Moreover, the volume distribution of isolated islets indicated that it may be important to retain the ability of insulin secretion from the large-sized islets.

Changes in lymphoproliferation and DTH responses after vaccination immediately before surgery in puppies.

To clarify the effects of the presurgical vaccination canine parvovirus vaccine (CPV) on immunological responses to surgery in puppies, we assessed it by measuring the blastogenic responses of lymphocytes and delayed type hypersensitivity (DTH) responses after laparotomy in the non- and vaccinated puppies. The inhalation anesthetic used was isoflurane or halothane. In post-surgery, the blastogenic responses of lymphocytes in the non-vaccinated puppies decreased, especially, those in these puppies with halothane anesthesia (GOF) did significantly, and the duration of this decrease prolonged more than that in the non-vaccinated puppies with isoflurane anesthesia (GOI). However, the responses in the vaccinated puppies with each anesthesia didn't almost decrease below the presurgical levels. In GOI groups, the DTH responses in vaccinated puppies increased significantly over those in non-vaccinated ones, but in GOF groups, there were few differences between the DTH responses in the non- and vaccinated puppies. These results suggest that the CPV vaccination immediately before surgery possibly prevents the postsurgical immunosuppression, and that GOI may depress the immunocompetence less than GOF.

Primary brain tumors in two dogs treated by surgical resection in combination with postoperative radiation therapy.

Primary brain tumors in two dogs were surgically removed followed by postoperative radiation therapy. The two tumors were confirmed histologically to be astrocytoma and meningioma, respectively. After the surgery, the neurological status of each dog improved dramatically and a total dose of 40 Gy was delivered to the surgical site to treat residual tumor tissue. Although the dog with astrocytoma died 6 months after surgery due to unknown causes, the dog with meningioma has lived for over 24 months with a degree of neurological disorder less severe than that before treatment. These results suggested the effectiveness of this type of therapy on brain tumor in dogs and therapeutic modality should be positively planned to treat canine brain tumors.

Antemortem evaluation for magnetic resonance imaging of the equine flexor tendon.

In this study antemortem evaluation of equine flexor tendons--the superficial digital flexor tendon and the deep digital flexor tendon--using magnetic resonance (MR) images was performed. Postmortem flexor tendons were used to prepare the slice positions, coil and body positions for MR imaging. It was possible by this method to take antemortem MR images of equine limbs that distinguished features as well as postmortem images described in previous studies. The total time of antemortem scanning was about 40 min. This study is the first to report antemortem MR images in horses.

Establishment and characterization of a new cell line derived from feline mammary tumor.

A new cell line designated FRM was established from pleural effusion of a 13-year-old female cat with mammary adenocarcinoma. The cell line exhibited irregular round and polygonal shaped epithelial cells and demonstrated cell growth in a monolayer fashion with a doubling time of 22.4 hr. It possessed a modal chromosome number of 79. The immortality of this cell line was demonstrated using the TRAP assay which revealed a high telomeric activity of these cells. Scatchard analysis revealed quite low levels of estrogen receptors in both tumor mass produced in nude mice and FRM cells. Subcutaneous transplantation of the cells produced localized palpable masses in athymic nude mice within two weeks. This cell line may provide a good model for in vivo and in vitro studies on feline mammary tumors.

Establishment and characterization of a new canine B-cell leukemia cell line.

A new cell line derived from a spontaneous canine leukemia was established and designated GL-1. The cells have been cultured in a floating fashion and passaged for over two years. They were round with rich cytoplasm containing many rough endoplasmic reticula and mitochondria. Peroxidase staining was negative. The nuclei of many cells were round, but segmented nuclei were seen frequently. The doubling time of the cells was 27.3 hr and they had 78 chromosomes. Surface marker analysis using monoclonal antibodies (MABs) and flowcytometry revealed that GL-1 possessed CD45 and surface IgG. However, the cells did not react with MABs detecting T-cell markers. These results indicate that GL-1 has a lymphocytic lineage and is derived from a B-cell leukemia.