Computed tomography may detect liver infiltration of canine diffuse hepatic lymphoma.

BACKGROUND: In dogs, hepatic lymphoma is characterized by neoplastic lymphocyte infiltration into the liver. Reports on the computed tomography (CT) findings of the liver for canine hepatic lymphoma are few, with only one study of multiple liver lesions type. OBJECTIVES: The purpose of this study was to retrospectively assess the CT findings of the liver in canine diffuse hepatic lymphoma. METHODS: As control, five dogs without abnormalities in the liver were included. CT data were analysed, and the following were noted: presence of edge bluntness of the liver, presence of periportal collar sign, the liver size:body weight (BW) ratio and the mean attenuation of liver lesions on pre-contrast, arterial-phase, portal-phase and equilibrium-phase post-contrast images. RESULTS: On CT examination, edge bluntness of the liver was significantly detected in lymphoma (4/5, 80%), as opposed to the control (0/5, 0%) (p = 0.048, φ = 0.82). The periportal collar sign was detected in lymphoma (3/5, 60%), as opposed to the control (0/5, 0%) (p = 0.17, φ = 0.65). The liver size:BW ratio of lymphoma cases was significantly higher compared to that of the control cases (p = 0.0002, r = 0.92). The mean Hounsfield unit of lymphoma cases in the pre-contrast, arterial-phase, portal-phase and equilibrium-phase images were significantly lower than in the control cases (p = 0.005, r = 0.81; p = 0.0003, r = 0.91; p = 0.01, r = 0.75 and p = 0.02, r = 0.71, respectively). CONCLUSIONS: Hepatic lymphoma should be a differential for a blunted and enlarged liver with hypoattenuation on CT examination.

Whole-genome analyses of extended-spectrum or AmpC ß-lactamase-producing Escherichia coli isolates from companion dogs in Japan.

The emergence and global spread of extended-spectrum or AmpC ß-lactamase (ESBL/AmpC)-producing Enterobacteriaceae in companion animals have led to the hypothesis that companion animals might be reservoirs for cross-species transmission because of their close contact with humans. However, current knowledge in this field is limited; therefore, the role of companion animals in cross-species transmission remains to be elucidated. Herein, we studied ESBL/AmpC-producing Enterobacteriaceae, Escherichia coli in particular, isolated from extraintestinal sites and feces of companion dogs. Whole-genome sequencing analysis revealed that (i) extraintestinal E. coli isolates were most closely related to those isolated from feces from the same dog, (ii) chromosomal sequences in the ST131/C1-M27 clade isolated from companion dogs were highly similar to those in the ST131/C1-M27 clade of human origin, (iii) certain plasmids, such as IncFII/pMLST F1:A2:B20/blaCTX-M-27, IncI1/pMLST16/blaCTX-M-15, or IncI1/blaCMY-2 from dog-derived E. coli isolates, shared high homology with those from several human-derived Enterobacteriaceae, (iv) chromosomal blaCTX-M-14 was identified in the ST38 isolate from a companion dog, and (v) eight out of 14 tested ESBL/AmpC-producing E. coli isolates (i.e., ST131, ST68, ST405, and ST998) belonged to the human extraintestinal pathogenic E. coli (ExPEC) group. All of the bla-coding plasmids that were sequenced genome-wide were capable of horizontal transfer. These results suggest that companion dogs can spread ESBL/AmpC-producing ExPEC via their feces. Furthermore, at least some ESBL/AmpC-producing ExPECs and bla-coding plasmids can be transmitted between humans and companion dogs. Thus, companion dogs can act as an important reservoir for ESBL/AmpC-producing E. coli in the community.

MRI findings, including diffusion-weighted imaging, in seven cats with nasal lymphoma and two cats with nasal adenocarcinoma.

OBJECTIVES: Primary nasal tumours in cats are rare, with lymphoma being the most common feline nasal tumour, followed by adenocarcinoma. Although CT can reliably detect feline nasal tumours, there are no specific CT features that identify each tumour type. To our knowledge, there have been no reports describing MRI findings, including diffusion-weighted imaging (DWI), for nasal lymphomas and adenocarcinomas in cats. Therefore, this retrospective study aimed to evaluate the MRI findings of nasal lymphoma and adenocarcinoma, including qualitative and quantitative analysis of DWI. METHODS: MRI examination was performed on seven cats with histologically confirmed lymphoma and on two with adenocarcinoma. The MRI protocol included T2-weighted imaging (T2WI), T1-weighted imaging (T1WI) and DWI. Apparent diffusion coefficient (ADC) values were measured using DWI. Contrast agent was not used in one cat with lymphoma. RESULTS: Of the cats with lymphoma, three (43%) were iso- and hyperintense on T2WI, seven (100%) were isointense on T1WI, five (83%) exhibited mild heterogeneous enhancement, including a prominent region of non-enhancement on post-contrast T1WI, and seven (100%) cats exhibited hyperintensity on DWI. The median ADC values were 0.45 × 10-3 mm2/s (range 0.37-0.53 × 10-3 mm2/s). For adenocarcinoma, two (100%) were iso- and hyperintense on T2WI, two (100%) were isointense on T1WI, two (100%) exhibited marked heterogeneous enhancement on post-contrast T1WI and two (100%) were isointense on DWI. The median ADC values were 1.08 × 10-3 mm2/s (range 0.88-1.27 × 10-3 mm2/s). The median ADC values of lymphoma tended to be lower than adenocarcinoma (P = 0.056). CONCLUSIONS AND RELEVANCE: Determining ADC value and tumours with a large area of non-enhancement may be helpful in differentiating nasal lymphoma from nasal adenocarcinoma.

Impaired bone quality characterized by apatite orientation under stress shielding following fixing of a fracture of the radius with a 3D printed Ti-6Al-4V custom-made bone plate in dogs.

Custom-made implants have recently gained attention in veterinary medicine because of their ability to properly fit animal bones having a wide variety of shapes and sizes. The effect of custom-made implants on bone soundness and the regeneration process is not yet clear. We fabricated a 3D printed Ti-6Al-4V custom-made bone plate that fits the shape of the dog radius, and placed it into the radius where an osteotomy had been made. The preferential orientation of the apatite c-axis contributes to the mechanical integrity of the bone and is a reliable measure of bone quality. We determined this parameter as well as the bone shape and bone mineral density (BMD). The bone portion which lies parallel to the bone plate exhibited bone resorption, decreased BMD, and significant degradation of apatite orientation, relative to the portion outside the plate, at 7 months after the operation. This demonstrates the presence of stress shielding in which applied stress is not transmitted to bone due to the insertion of a stiff bone plate. This reduced stress condition clearly influences the bone regeneration process. The apatite orientation in the regenerated site remained different even after 7 months of regeneration, indicating insufficient mechanical function in the regenerated portion. This is the first study in which the apatite orientation and BMD of the radius were evaluated under conditions of stress shielding in dogs. Our results suggest that assessment of bone repair by radiography can indicate the degree of restoration of BMD, but not the apatite orientation.

Assessment of hepatitis and fibrosis using Gd-EOB-DTPA MRI in dogs.

BACKGROUND: Gadoxetate sodium (Gd-EOB-DTPA) is taken into hepatocytes and excreted into the bile. Hepatocytes with reduced function or dysfunction due to hepatocellular carcinoma (HCC), hepatitis or hepatic fibrosis show impaired Gd-EOB-DTPA uptake. The purpose of the present retrospective case series was to assess the relationship between liver function and contrast enhancement using Gd-EOB-DTPA MRI. METHODS: Sixteen dogs with a histopathological diagnosis of liver disease, including six with HCC, three with nodular hyperplasia, two with hepatocellular adenoma, two with liver fibrosis and three with hepatitis were included in the study along with three dogs with suspected liver disease but no histopathological diagnosis of liver disease. Relative signal intensities (RSI) of the common bile duct and gall bladder were calculated, and their relationship with the following serum biochemical parameters was assessed: total bilirubin, alanine transaminase, alkaline phosphatase and albumin (Alb). To assess anatomical liver function, relative contrast enhancement indices (RCEI) of the liver were calculated, and differences were assessed between normal and diseased liver. RESULTS: RSI showed no significant differences between dogs without and with a histopathological diagnosis of liver disease (P=0.88) although they were significantly correlated with Alb (ρ=0.57, P=0.02) in dogs with a histopathological diagnosis of liver disease. RCEI was significantly higher in normal liver tissue than that in livers with hepatitis/fibrosis (P=0.048) and HCC (P=0.03) but not nodular hyperplasia/hepatocellular adenoma (P=0.51). CONCLUSIONS: Gd-EOB-DTPA MRI may be potentially useful in the assessment of anatomical liver function in dogs with liver disease.

Assessment of postoperative adjuvant treatment using toceranib phosphate against adenocarcinoma in dogs.

BACKGROUND: Toceranib phosphate (TOC) could be made widely available for treating tumors in dogs if evidence shows that TOC inhibits recurrence after surgery. OBJECTIVES: To investigate how postoperative adjuvant treatment with TOC modulates the tumor microenvironment (TME), by assessing effects on angiogenic activity, tumor-infiltrating regulatory T cells (Tregs), and intratumoral hypoxia. ANIMALS: Ninety-two client-owned dogs were included: 28 with apocrine gland anal sac adenocarcinoma, 24 with small intestinal adenocarcinoma, 22 with lung adenocarcinoma, and 18 with renal cell carcinoma. METHODS: Retrospective, multicenter study comparing time to progression (TTP) between 42 dogs treated by surgery and TOC and 50 dogs treated by surgery alone. Differences were analyzed in the expression of vascular endothelial growth factor receptor-2 (VEGFR2) and the number of Foxp3+ Tregs and hypoxia-inducible factor (HIF)-1α+ cells in tumor tissues sampled at the first and second (recurrence) surgeries. RESULTS: Median TTP for dogs treated by surgery and TOC (360 days) was higher than that for dogs treated by surgery alone (298 days; hazard ratio, 0.82; 95% confidence interval [CI], 0.65-0.96; P = .02). In dogs treated by surgery and TOC, VEGFR2 expression and the number of Tregs and HIF-1α+ cells were significantly lower in tissues sampled at the second surgery than in those sampled after the first surgery. In dogs treated by surgery alone, significant differences were found between samples from the 2 surgeries. CONCLUSIONS AND CLINICAL IMPORTANCE: Toceranib phosphate could prove to be a useful postoperative adjuvant treatment because of its modulation of the TME.

Less enhancement and low apparent diffusion coefficient value on magnetic resonance imaging may be helpful to detect canine prostate adenocarcinoma in case series.

In dogs, diagnosis of prostate cancer is often delayed because clinical signs are not pathognomonic. Although ultrasonography is mainly performed to detect prostate cancer, the ultrasonographic appearance is not specific. In humans, magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) is used to localize the prostate tumour. To our knowledge, there are no studies of MRI findings for detecting or localizing prostate cancer. The purpose of this study was to assess MRI findings of prostate cancer. As a control, three prostate hyperplasia cases were included. MRI data were analysed, and the following parameters were noted: signal intensity (SI) of prostate lesion on T2-weighted imaging, T1-weighted imaging and DWI, enhancement pattern of prostate lesion, and relative contrast enhancement indices (RCEI) and apparent diffusion coefficient (ADC) value of prostate lesion. For MRI examination, the mean RCEI of the adenocarcinoma was significantly lower than that of hyperplasia (P = .01, r = .8). The SI of the DWI of adenocarcinoma was significantly higher compared to hyperplasia (P = .03, φ = 1). The mean ADC values of the adenocarcinoma were significantly lower than that of hyperplasia (P = .03, r = .82). Thus, less enhancement on MRI, and low ADC value on MRI may help to detect prostate adenocarcinoma.

Urinary bladder reconstruction using autologous collagenous connective tissue membrane "Biosheet®" induced by in-body tissue architecture: A pilot study.

INTRODUCTION: In-body tissue architecture (iBTA) technology, based on cell-free tissue engineering, can produces collagenous tissues for implantation by subcutaneous embedding a designed mold. The aim of this study was to evaluate the biocompatibility of iBTA-induced "Biosheet®" collagenous sheets, as scaffold materials for bladder reconstruction. METHODS: Canine Biosheet® implants were prepared by embedding molds into subcutaneous pouches in beagles for 8 weeks. A part of canine bladder wall was excised (2 × 2 cm) and repaired by patching the same sized autologous Biosheet®. The Biosheet® implants were harvested 4 weeks (n = 1) and 12 weeks (n = 3) after the implantation and evaluated histologically. RESULTS: No disruption of the patched Biosheet® implants or urinary leakage into the peritoneal cavity was observed during the entire observation periods. There were no signs of chronic inflammation or Biosheet® rejection. The urine-contacting surface of luminal surface of the Biosheet® was covered with a multicellular layer of urothelium cells 4 weeks after implantation. α-SMA-positive muscle cells were observed at the margin of the Biosheet® implants at 12 weeks after the implantation. In addition, in the center of the Biosheet® implants, the formation of microvessels stained as α-SMA-positive was observed. CONCLUSION: Biosheet® implants have biocompatibility as a scaffold for bladder reconstruction, indicating that they may be applicable for full-thickness bladder wall substitution. Further studies are required for definitive evaluation as a scaffold for bladder reconstruction.

Contrast-enhanced computed tomography findings of canine primary renal tumors including renal cell carcinoma, lymphoma, and hemangiosarcoma.

In veterinary medicine, abdominal ultrasonography is used to rank the differential diagnosis of renal lesions. However, a conventional sonographic examination may show nonspecific findings. The purpose of this study was to assess the computed tomography (CT) findings of canine renal tumors, including renal cell carcinoma (RCC), lymphoma, and hemangiosarcoma (HSA). In this retrospective study, the following CT parameters were recorded for each dog: 1) extent of renal involvement of tumors, 2) enhancement pattern, 3) number of renal tumors, 4) renal tumor vessel enhancement in the corticomedullary phase, 5) presence of lymphadenopathy and lung metastasis, and 6) attenuation values of the renal tumors on the pre- and post-contrast corticomedullary, nephrographic, and excretory phase images. Fifteen dogs met the inclusion criteria, of which nine had RCCs, four had lymphomas, and two had HSAs. RCCs tended to show heterogeneous enhancement and unilateral renal involvement, and vessel enhancement was detected in the corticomedullary phase in dogs with RCC. Conversely, renal lymphomas showed homogeneous enhancement, bilateral renal involvement, and multiple masses; in these dogs, no vessel enhancement was detected in the corticomedullary phase, and the incidence of lymphadenopathy was low. However, in dogs with lymphadenopathy, the renal lymphoma was associated with regionally severe lymphadenopathy. Finally, renal HSAs tended to show heterogeneous enhancement with a non-enhanced area and unilateral renal involvement; in these dogs, vessel enhancement was detected in the nephrographic phase, with the enhancement expanding around the vessel. These findings had no significant differences. Further studies with a larger sample size are required to examine the association between CT and histopathological findings.

Evaluation of the accuracy of urine analyzers in dogs and cats.

The accuracy of urine analyzers used for dogs and cats has remained uncertain. This study examines the agreement between results of urine analysis obtained using two devices marketed for animals and for humans and the results of quantitative biochemical analysis. The degrees of concordance for bilirubin and ketones in the same category were ~80%, but for pH these were only ~60% in dogs and cats. Degrees of concordance for protein and the UP/C ratio clearly differed between the devices for animals and humans. We found that values for bilirubin and ketones obtained using urine analyzers may be reliable, but pH is unlikely to be accurate enough to be clinically useful for dogs and cats.

Contrast-enhanced computed tomography may be helpful for characterizing and staging canine gastric tumors.

In humans, computed tomography (CT) is a widely performed technique for the diagnosis and staging of gastric tumors. The purpose of this retrospective case series study was to describe CT findings in a group of dogs with confirmed gastric tumors. For each included dog, the following CT parameters were recorded: gastric tumor location, tumor shape, gastric involvement pattern, tumor enhancement pattern in early and late phases, presence and location of lymphadenopathy, gastric tumor attenuation values, attenuation values of enlarged lymph nodes, maximum short-axis diameter (mm) of enlarged lymph node, maximum long-axis diameter (mm) of enlarged lymph node, and short-axis diameter to long-axis diameter ratio (short axis/long axis). A total of 16 dogs met inclusion criteria and had the following final diagnoses: five lymphoma, six adenocarcinoma, three inflammatory polyps, and two leiomyoma. In the early- and delayed-phase postcontrast images, the mean CT attenuation value for lymphoma was lower than that of other gastric tumors. Lymphadenopathy was widespread in lymphomas and regional in adenocarcinomas. Lymphadenopathy was not detected in leiomyomas. Lymph node measurements in lymphoma were larger than lymph node measurements in adenocarcinoma. Although there were overlapping findings for the different types of gastric tumors, contrast-enhanced CT provided helpful information for characterizing gastric tumors based on the following criteria: early and late enhancement patterns, the site of origin of the mass lesion, and extent of local invasion and distant metastases. Lymphoma should be considered for canine gastric tumors with low mean attenuation values during early- and delayed-phase postcontrast images, and widespread, bulky, and rounded lymphadenopathy.

MRI findings, including diffusion-weighted imaging and apparent diffusion coefficient value, in two cats with nasopharyngeal polyps and one cat with lymphoma.

OBJECTIVES: Most nasopharyngeal masses in cats are lymphomas or polyps. To our knowledge, there is no report of MRI findings, including diffusion-weighted imaging (DWI) or apparent diffusion coefficient (ADC) values, of nasopharyngeal lymphomas and nasopharyngeal polyps in cats. This study aimed to evaluate the MRI findings of nasopharyngeal lymphomas and nasopharyngeal polyps, including DWI and ADC values. METHODS: MRI examination was performed on two cats with a histologically confirmed nasopharyngeal polyp and one cat with lymphoma. The magnetic resonance scanning protocol included T2-weighted imaging (T2WI), T1-weighted imaging (T1WI) and DWI. An ADC map was created based on DWI. ADC values were then calculated. RESULTS: MRI of the nasopharyngeal polyps revealed well-defined masses with strong rim enhancement, mass-associated stalk-like structures and asymmetric tympanic bulla lesions. The polyps appeared hyperintense on T2WI, hypo- to isointense on T1WI, and of mixed intensity or hypointense on DWI. On the ADC map, the masses appeared hyperintense. The ADC values of the polyps were 2.07 × 10-3 mm2/s and 2.28 × 10-3 mm2/s. MRI examination of the nasopharyngeal lymphoma revealed a strongly enhancing heterogeneous lesion. The mass appeared mildly hyperintense on T2WI, isointense on T1WI and hyperintense on DWI. On the ADC map, the mass appeared hypointense. The ADC value of the mass was 0.46 ×10-3 mm2/s. The ADC values of the nasopharyngeal polyps were higher than the ADC value of the nasopharyngeal lymphoma. CONCLUSIONS AND RELEVANCE: Measurement of ADC values may be useful for differentiating between nasopharyngeal polyps and nasopharyngeal lymphomas.

Anatomical variations in the circle of Willis in canines.

The circle of Willis (CW) supplies blood to the brain. In humans, anatomical variations in the CW are an important risk factor for transient ischaemic attack and stroke. In canines, anatomical variations in the CW have not been reported. The aim of this study was to determine anatomical variations in the CW in dogs by magnetic resonance angiography. Normal configuration of the CW was observed in 82%, aplasia of the precommunicating segment of the rostral cerebral artery was observed in 14%, and aplasia of the rostral communicating artery was observed in 4% of dogs included in the study.

Apparent diffusion coefficient value for a B-cell central nervous system lymphoma in a cat.

CASE SUMMARY: This report involves a 10-year-old male mixed-breed cat with a B-cell central nervous system (CNS) lymphoma. The cat presented with ataxia progressing to left hemiparesis. While haematological findings were normal, serum biochemistry showed a high creatine phosphokinase concentration. MRI revealed a homogeneously enhancing well-demarcated extra-axial lesion involving the region of the left lateral aperture with oedema in left flocculus and left medulla oblongata. On diffusion-weighted imaging, the lesion margins showed marked hyperintensity relative to the right cerebellar hemisphere. On an apparent diffusion coefficient map, the lesion appeared hypointense, with an apparent diffusion coefficient value of 0.57 ± 0.01 × 10-3 mm2/s. Cerebrospinal fluid (CSF) analysis and cytology, and genetic analysis of CSF lymphoblasts confirmed a diagnosis of B-cell lymphoma. The owner opted for palliative treatment with prednisolone (1 mg/kg q12h); however, the cat died of dyspnoea 10 days after presentation. RELEVANCE AND NOVEL INFORMATION: CNS lymphomas, which are the second most common intracranial tumours in cats, are highly infiltrative lesions and radical surgical excision is not recommended. Therefore, accurate diagnosis is crucial. However, contrast-enhanced MRI cannot always differentiate these lesions from other conditions, including other CNS tumours and strokes. To the best of our knowledge, this is the first report to document the diffusion-weighted imaging features and apparent diffusion coefficient value for a feline CNS lymphoma. These findings are expected to improve the diagnostic accuracy of these lesions in cats.

Drip infusion cholangiography with CT in cats.

OBJECTIVES: Ultrasonography can detect extrahepatic biliary obstructions. However, visualisation of part of the bile duct using ultrasonography can be technically difficult if there is overlying bowel gas. This study investigated the safety and value of drip infusion cholangiography with computed tomography (DIC-CT) in the visualisation of the bile duct in healthy cats and extrahepatic biliary obstruction in cats with cholelithiasis. METHODS: DIC-CT was performed in three healthy cats and two cats with cholelithiasis. Meglumine iotroxate was administered by intravenous drip infusion over 30 mins. The attenuation value was measured perpendicular to the lumen by a region of interest covering about 50% of the area of the lumen. RESULTS: The bile ducts were visualised successfully with DIC-CT in all healthy cats without any significant adverse events. The attenuation value of the contrast medium was 271 ± 37 HU. In the two cats with cholelithiasis, the presence or absence of extrahepatic biliary obstruction was determined using DIC-CT without any significant adverse events. The attenuation value of cholelithiasis in the cat with an extrahepatic biliary obstruction was 933 ± 119 HU. In the cat with no extrahepatic biliary obstruction, the attenuation value of the contrast medium was 249 ± 53 HU and the attenuation value of cholelithiasis was 167 ± 28 HU. CONCLUSIONS AND RELEVANCE: DIC-CT visualises bile ducts and detects obstructive biliary disease without significant adverse events. Therefore, it appears to be a safe procedure for visualisation of the bile duct in cats.

Intra-arterially infused carbon dioxide-saturated solution for sensitizing the anticancer effect of cisplatin in a rabbit VX2 liver tumor model.

The present study aimed to evaluate the efficacy of an intra-arterially infused carbon dioxide (CO2)-saturated solution in sensitizing the anticancer effect of cisplatin in a rabbit VX2 liver tumor model. Forty VX2 liver tumor-bearing Japanese white rabbits were randomly divided into four groups and infused via the proper hepatic artery with a saline solution (control group), CO2-saturated solution (CO2 group), cisplatin solution (cisplatin group), or CO2-saturated solution and cisplatin solution (combined group). The tumor volume (TV) and the relative tumor volume (RTV), RTV = (TV on day 3 or 7)/(TV on day 0) x 100, were calculated using contrast-enhanced computed tomography. Hypoxia-inducible factor-1α (HIF­1α) and carbonic anhydrase IX (CA IX) staining were used to evaluate cellular hypoxia. Cleaved caspase-3 and cleaved caspase-9 were analyzed to assess tumor apoptosis. The mean RTV on days 3 and 7 were 202.6±23.7 and 429.2±94.8%, respectively, in the control group; 172.2±38.1 and 376.5±61.1% in the CO2 group; 156.1±15.1 and 269.6±45.2% in the cisplatin group; and 118.3±28.1 and 210.3±55.1% in the combined group. RTV was significantly lower in the CO2 group than in the control group (day 3; P<0.05), and in the combined group than in the cisplatin group (days 3 and 7; P<0.05). HIF-1α and CA IX suppression, and increased cleaved caspase-3 and cleaved caspase-9 expression, were detected in the CO2 and combined groups, compared with the other two groups. An intra-arterially infused CO2-saturated solution inhibits liver VX2 tumor growth and sensitizes the anticancer effect of cisplatin.

Change in peripheral blood lymphocyte count in dogs following adoptive immunotherapy using lymphokine-activated T killer cells combined with palliative tumor resection.

We evaluated changes in peripheral blood lymphocyte (PBL) count in dogs following adoptive immunotherapy using lymphokine-activated T killer cells (T-LAK) in combination with surgery. Fifteen tumor-bearing dogs treated with T-LAK therapy combined with palliative resection of tumors were enrolled in the present study. T-LAK were generated from autologous peripheral blood mononuclear cells (PBMC) by culture with recombinant human interleukin -2 (rhIL-2) and solid phase anti-canine cluster of differentiation (CD)3 antibody. T-LAK were administrated intravenously at 2-4-week intervals. After the first administration of T-LAK, counts of PBL and T lymphocyte subsets (CD3(+), CD4(+) and CD8(+) cells) increased and the CD4/CD8 ratio decreased, with significant increases in CD8(+) cells (P<0.05). In 8 tumor-bearing dogs that were administered sequential T-LAK, available data on changes in PBL and T lymphocyte phenotypes until the fifth administration were also analyzed. In tumor-bearing dogs administered 5 rounds of T-LAK, CD8(+) cell counts were maintained high until the fifth administration of T-LAK. Moreover, the CD4/CD8 ratio remained low until the fifth administration of T-LAK. These results indicate that T-LAK therapy combined with surgery may increase peripheral blood T lymphocytes, particularly CD8(+) cells, in tumor-bearing dogs.

Influence of transfusion of lymphokine-activated T killer cells on inflammatory responses in dogs after laparotomy.

The influence of transfusion of lymphokine-activated T killer cells (T-LAK) on inflammatory responses was examined in dogs after laparotomy. Plasma C-reactive protein (CRP) level, cell numbers of peripheral blood lymphocytes (PBLs) and T lymphocyte subsets (CD3(+), CD4(+) and CD8(+)) and mRNA expression levels of cytokines including interleukin (IL)-2, IL-12, IL-4, IL-10 and transforming growth factor (TGF)-ß in peripheral blood mononuclear cells (PBMCs) were measured in dogs with (T-LAK group) or without (control group) a single T-LAK administration immediately after laparotomy. The plasma CRP level initially increased and then decreased to the normal range at 7 days after laparotomy in the T-LAK group, which was earlier than in the control group. The expression level of IL-10 mRNA showed a marked postoperative increase and was significantly higher than the preoperative level on day 7 (P<0.05), whereas the level in the control group showed no clear change after laparotomy. A significant increase in IL-2 mRNA expression level in the T-LAK group was observed on day 14, which was two weeks earlier than in the control group (P<0.05). These results suggest that T-LAK therapy in dogs after laparotomy leads to earlier resolution of postoperative inflammation by production of an anti-inflammatory cytokine (IL-10) in the early phase of the postoperative period and earlier restoration of cell-mediated immunity related to cytokine production by PBMCs.

Computed tomography and magnetic resonance imaging of thoracic chordoma in a Bengal tiger (Panthera tigris tigris).

A Bengal tiger was presented for evaluation of weakness, ataxia and inappetance. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass extending from the T7-8 vertebral body to the left rib and compressing the spinal cord. On CT, the bone destruction and sequestrum were shown. On MRI, the multilobulated mass appeared hypo- to isointense in T1-weighted and hyperintense in T2-weighted images. The tiger died after imaging, most likely from renal failure. Chordoma without metastasis was diagnosed on necropsy. The imaging characteristics were similar to those found in chordoma in humans. This report describes the use of CT and MRI in an exotic species.

Relationship between major histocompatibility complex class I expression and prognosis in canine mammary gland tumors.

The aim of this study was to evaluate MHC class I expression and prognosis using tumor tissues surgically removed from 9 dogs with mammary gland carcinomas and from 13 dogs with complex carcinomas. We assessed MHC class I expression and its correlation with tumor size, B2M expression, infiltration of lymphocytes, histological grade and prognosis. Hematoxylin and eosin-stained sections were histologically graded using the Elston and Ellis grading method. MHC class I expression on tumor cells was evaluated using the avidin-biotin peroxidase complex method. Loss of MHC class I expression from canine mammary gland carcinomas was significantly correlated with poor prognosis (P<0.05). Loss of MHC class I expression showed no association with poor prognosis in canine mammary gland complex carcinomas, because the data were not balanced. Only 1 of 13 (7.6%) canine mammary gland complex carcinomas showed loss of MHC class I expression. All 13 of these dogs showed good prognosis. Thus, the low frequency of MHC class I expression loss from canine mammary gland complex carcinomas may be associated with good prognosis. Taken together, these results suggest that loss of MHC class I expression may be associated with poor prognosis in canine mammary gland carcinomas.