Due to the widely documented and diverse toxic effects of acrylamide, the authors decided to evaluate the impact of high and low doses of this compound on the process of granulopoiesis in porcine bone marrow. The experiment was conducted on 15 Danish Landrace pigs at the age of 8 weeks. The animals were randomly assigned into three equal groups (n = 5). Control animals received empty gelatine capsules as placebo. Animals in the first experimental group (the LD group) received a low dose of acrylamide of 0.5 μg/kg b.w./day, and animals in the second experimental group (the HD group) received a tenfold higher dose of acrylamide of 5 μg/kg b.w./day. Placebo and acrylamide capsules were administered with feed every morning for 28 days. Bone marrow was collected into tubes without an anticoagulant twice – before the first capsule administration (day 0) and on the 28ᵗʰ day of the study. After drying and staining, bone marrow smears were subjected to detailed cytological evaluation under a light microscope. Changes in cell morphology, i.e. degenerative changes in the cellular nuclei, were observed in both experimental groups. Both low and high doses of acrylamide decreased the number of segmented eosinophils, neutrophilic and segmented metamyelocytes, neutrophils, as well as basophils and basophilic metamyelocytes. Acrylamide at doses of 0.5 μg/kg b.w./day and 5 μg/kg b.w./day clearly influences porcine granulopoiesis.

Due to the widespread occurrence of acrylamide in the environment, its likely carcinogen status, and the suitability of the pig model as a human analogue, the authors decided to evaluate the impact of high and low doses of this compound on the processes of erythropoiesis in swine bone marrow. The experiment was carried out on Danish Landrace pigs at the age of eight weeks and body weight about 20 kg. The animals were divided into three equal groups consisting of five pigs in each. Control animals received empty gelatin capsules (placebos). Animals from the first experimental group received a low dose of acrylamide of 0.5 μg/kg b.w./day (> 99% purity; Sigma-Aldrich, Poland), and animals from the second experimental group received a dose 10 times higher. Placebos and acrylamide capsules were administered with feed every morning for 28 days. After anaesthetisation of the animals, bone marrow from the femur was collected into tubes without an anticoagulant on days 0 and 28. After drying and staining, bone marrow smears were subjected to detailed cytological evaluation using a light microscope. This study showed that high and low doses of acrylamide affected the process of porcine erythropoiesis. The cytotoxic effect of acrylamide on this process was demonstrated in a change of the polychromatic erythroblasts/normochromatic erythroblasts ratio. Both doses of acrylamide caused a decrease in the number of ortho- and polychromatic erythroblasts.

OBJECTIVE To investigate in vitro carboplatin release from 6 carrier media. SAMPLE 6 carboplatin-containing carrier media. PROCEDURES An in vitro release study was performed with 6 commercially available carrier media: a hemostatic gelatin sponge, a poloxamer copolymer gel, and 2 sizes (3 and 4.8 mm in diameter) of beads molded from each of 2 commercial calcium sulfate products. All carrier media contained 10 mg of carboplatin. Carrier media specimens were placed in 37°C PBS solution for 96 hours. Carboplatin concentrations in PBS solution were measured by use of high-performance liquid chromatography at 15 time points to calculate the amount and proportion of carboplatin released from each specimen. RESULTS Peak release of carboplatin from the poloxamer copolymer gel and hemostatic gelatin sponge were achieved after 4 and 20 hours, respectively. Maximum release did not differ significantly between the poloxamer copolymer gel and hemostatic gelatin sponge, but both released significantly more carboplatin within 96 hours than did both of the commercial calcium sulfate products. The poloxamer copolymer gel released 99% of the carboplatin, and the hemostatic gelatin sponge released 68.5% of the carboplatin. Peak release of carboplatin from the calcium sulfate beads was not reached within 96 hours. CONCLUSIONS AND CLINICAL RELEVANCE In this study, carboplatin release from the hemostatic gelatin sponge was incomplete. The poloxamer copolymer gel and hemostatic gelatin sponge released carboplatin rapidly in vitro, whereas calcium sulfate beads did not.

OBJECTIVE To determine the effects of coadministration of naltrexone, a human opioid abuse deterrent, on the pharmacokinetics and pharmacodynamics of a methadone-fluconazole combination administered orally to dogs. Animals: 12 healthy Beagles. PROCEDURES Dogs (body weight, 10.7 to 13.9 kg) were randomly allocated to 2 groups in a parallel design study. All dogs received fluconazole (100 mg [7.19 to 9.35 mg/kg], PO). Twelve hours later (time 0), dogs were administered methadone (10 mg [0.72 to 0.93 mg/kg]) plus fluconazole (50 mg [3.62 to 4.22 mg/kg]; methadone-fluconazole) or methadone (10 mg [0.72 to 0.93 mg/kg]) plus fluconazole (50 mg [3.60 to 4.67 mg/kg]) and naltrexone (2.5 mg [0.18 to 0.23 mg/kg]; methadone-fluconazole-naltrexone), PO, in a gelatin capsule. Blood samples were collected for pharmacokinetic analysis, and rectal temperature and sedation were assessed to evaluate opioid effects at predetermined times up to 24 hours after treatment. RESULTS Most dogs had slight sedation during the 12 hours after drug administration; 1 dog/group had moderate sedation at 1 time point. Mean rectal temperatures decreased significantly from baseline (immediate pretreatment) values from 2 to ≥ 12 hours and 2 to ≥ 8 hours after methadone-fluconazole and methadone-fluconazole-naltrexone treatment, respectively. Geometric mean maximum observed concentration of methadone in plasma was 35.1 and 33.5 ng/mL and geometric mean terminal half-life was 7.92 and 7.09 hours after methadone-fluconazole and methadone-fluconazole-naltrexone treatment, respectively. Naltrexone was sporadically detected in 1 dog. The active naltrexone metabolite, β-naltrexol, was not detected. The inactive metabolite, naltrexone glucuronide, was detected in all dogs administered methadone-fluconazole-naltrexone. CONCLUSIONS AND CLINICAL RELEVANCE Opioid effects were detected after oral administration of methadone-fluconazole or methadone-fluconazole-naltrexone. Further studies assessing additional opioid effects, including antinociception, are needed.

Objective—To construct and optimize a fiducial marker suitable for both CT and MRI. Sample—Fiducial markers containing serial dilutions of iopamidol mixed with water. Procedures—IV tubing sets were infused with serial dilutions (0% to 100%; increments of 10%) of iopamidol. Tubing ends were sealed; additional seals were added to create an equilateral triangle. A reference point was created by placing a crimp in 1 side. Markers were fixed to a gelatin soft tissue–attenuating phantom and evaluated by use of CT and MRI. For CT, simple linear regression analysis was used to assess the relationship between the percentage of marker contrast medium and quantitative variables, including marker attenuation, attenuation changes in the phantom, and beam-hardening artifact length. A subjective grading scheme for artifact creation on CT images and marker visibility on MRI images was used. Measurements were obtained by investigators who were unaware of the contents of each marker. Results—Percentage of contrast medium in each marker was strongly correlated with marker attenuation (r2 = 0.96), artifact length (r2 = 0.765), and mean attenuation changes within the phantom (r2 = 0.826) for CT. Subjective CT scores indicated that concentrations of contrast medium > 50% resulted in excessive artifacts. Markers with concentrations of iopamidol > 50% had poor subjective MRI visibility scores. No artifacts were seen on MRI. Conclusions and Clinical Relevance—A marker containing a 10% solution of iodinated contrast medium mixed with water provided ideal contrast for both CT and MRI.

Objective: To identify matrix metalloproteinase (MMP)-2 and -9 in CSF from dogs with intracranial tumors. Sample: CSF from 55 dogs with intracranial tumors and 37 control dogs. Procedures: Latent and active MMP-2 and -9 were identified by use of gelatin zymography. The presence of MMPs in the CSF of dogs with intracranial tumors was compared with control dogs that were clinically normal and with dogs that had idiopathic or cryptogenic epilepsy or peripheral vestibular disease. Relationships between MMP-9 and CSF cell counts and protein were also investigated. Results: Latent MMP-2 was found in CSF samples from all dogs, although active MMP-2 was not detected in any sample. Latent MMP-9 was detected in a subset of dogs with histologically documented intracranial tumors, including meningiomas (2/10), gliomas (3/10), pituitary tumors (1/2), choroid plexus tumors (5/6), and lymphoma (4/4), but was not detected in any control samples. Dogs with tumors were significantly more likely than those without to have detectable MMP-9 in the CSF, and the presence of MMP-9 was associated with higher CSF nucleated cell counts and protein concentration. Conclusions and Clinical Relevance: Latent MMP-9 was detected in most dogs with choroid plexus tumors or lymphoma but in a smaller percentage of dogs with meningiomas, gliomas, or pituitary tumors. Detection of MMP in CSF may prove useful as a marker of intracranial neoplasia or possibly to monitor response of tumors to therapeutic intervention.

Objective: To identify a subantimicrobial dose of doxycycline hyclate (SDD) and for the treatment of periodontitis in dogs. Animals: 20 healthy Beagles for measurement of serum doxycycline concentration and 15 Beagles with periodontitis for evaluation of the efficacy of the SDD. Procedures: 5 dogs each received doxycycline hyclate PO at a dose of 1, 2, 3, or 5 mg/kg. Blood samples were collected before and after administration, and serum concentrations of doxycycline were measured via high-performance liquid chromatography. Mean serum doxycycline concentrations were calculated, and SDDs were identified. In a separate trial, the identified SDDs (1 or 2 mg/kg) were administered PO once a day for 1 month to dogs with periodontitis (n = 5/group) and a control group (5) was fed vehicle only during the same period. Degree of gingival attachment and bleeding on probing (present or absent) were recorded. Gingival samples were collected before and after the 1-month period from the same anatomic sites. Degree of matrix metalloproteinase inhibition in gingival samples was determined via gelatin zymography and compared among treatment groups. Results: Mean serum doxycycline concentrations in healthy dogs that received 1 or 2 mg of doxycycline/kg were consistently significantly lower than the minimal inhibitory doxycycline concentration for treatment of periodontitis throughout the 24-hour posttreatment period. Zymographic intensities were lower in dogs given 1 and 2 mg/kg than in the control dogs, and the degree of gingival attachment and bleeding significantly improved in dogs given 2 mg/kg, compared with in the control dogs and dogs given 1 mg of doxycycline/kg. Conclusions and Clinical Relevance: A doxycycline dosage of 2 mg/kg daily appeared to be an appropriate subantimicrobial regimen for dogs with periodontitis. Furthermore, this dosage may be suitable for long-term treatment of gelatinolytic inflammatory diseases such as periodontitis in this species.

OBJECTIVE To investigate the effects of specific cysteine protease (CP) inhibitors on cytopathic changes to porcine intestinal epithelial cells induced by Tritrichomonas foetus isolated from naturally infected cats. SAMPLE T foetus isolates from 4 naturally infected cats and nontransformed porcine intestinal epithelial cells. PROCEDURES T foetus isolates were treated with or without 0.1 to 1.0mM of the CP inhibitors antipain, cystatin, leupeptin, and chymostatin and the vinyl sulfone inhibitors WRR-483 and K11777. In-gel gelatin zymography was performed to evaluate the effects of these inhibitors on CP activity of T foetus isolates. Each treated or untreated isolate was also cocultured with monolayers of porcine intestinal epithelial cells for 24 hours, and cytopathic effects of T foetus were evaluated by light microscopy and crystal violet spectrophotometry. RESULTS Results of in-gel gelatin zymography suggested an ability of WRR-483, K11777, and cystatin to target specific zones of CP activity of the T foetus isolates. These inhibitors had no effect on T foetus growth, and the cytopathic changes to the intestinal epithelium induced by all 4 T foetus isolates were significantly inhibited. CONCLUSIONS AND CLINICAL RELEVANCE This study revealed that certain protease inhibitors were capable of inhibiting regions of CP activity (which has been suggested to cause intestinal cell damage in cats) in T foetus organisms and of ameliorating T foetus–induced cytopathic changes to porcine intestinal epithelium in vitro. Although additional research is needed, these inhibitors might be useful in the treatment of cats with trichomonosis.

Overexpression of matrix metalloproteinases (MMPs) has been associated with increased tumor aggressiveness and metastasis dissemination. We investigated whether the contrasting metastatic behavior of feline and canine osteosarcoma is related to levels and activities of MMP2 and MMP9. Zymography and immunohistochemistry were used to determine expression levels of MMP2 and MMP9 in canine and feline osteosarcoma. Using immunohistochemistry, increased MMP9 levels were identified in most canine osteosarcomas, whereas cat samples more often displayed moderate levels. High levels of pro-MMP9, pro-MMP2, and active MMP2 were detected by gelatin zymography in both species, with significantly higher values for active MMP2 in canine osteosarcoma. These findings indicate that MMP2 is probably involved in canine and feline osteosarcoma and their expression and activity could be associated with the different metastatic behavior of canine and feline osteosarcoma.

Objective—To investigate the effects of twice-daily oral administration of hydrocortisone on the bile acids composition of gallbladder bile in dogs. Animals—6 placebo-treated control dogs and 6 hydrocortisone-treated dogs. Procedures—Dogs received hydrocortisone (median dose, 8.5 mg/kg) or a gelatin capsule (control group) orally every 12 hours for 84 days. Gallbladder bile samples were obtained via percutaneous ultrasound-guided cholecystocentesis from each dog before (day 0 [baseline]), during (days 28, 56, and 84), and after (days 28p, 56p, and 84p) treatment for differentiated quantification of unconjugated bile acids and taurine-conjugated and glycine-conjugated bile acids via high-performance liquid chromatography–tandem mass spectrometry. Results—Treatment with hydrocortisone for 84 days resulted in significant and reversible increases in the concentrations of unconjugated bile acids (ie, cholic, chenodeoxycholic, and deoxycholic acids) and a significant and reversible decrease in the concentration of total taurine-conjugated bile acids, compared with baseline or control group values. Treatment with hydrocortisone had no effect on bile concentrations of glycine-conjugated bile acids. Conclusions and Clinical Relevance—In dogs, hydrocortisone administration caused reversible shifts toward higher concentrations of the more hydrophobic unconjugated bile acids (chenodeoxycholic acid and deoxycholic acid) and toward lower concentrations of the amphipathic taurine-conjugated bile acids in gallbladder bile. These data suggest that similar bile acids changes could cause major alterations in gallbladder structure or function over time in hypercortisolemic dogs.