Dennis B. DeNicola

Naturally-occurring canine transitional cell carcinoma of the urinary bladder A relevant model of human invasive bladder cancer

Invasive bladder cancer results in over 10,000 deaths yearly in the United States alone. More effective therapy for invasive bladder cancer is clearly needed. As new cellular and molecular targets for therapy are identified, relevant animal models are needed to test new therapeutic strategies aimed at these targets prior to human clinical trials. The purpose of this review is to characterize spontaneous invasive transitional cell carcinoma of the urinary bladder (TCC) in dogs, to summarize the similarities and differences between canine and human invasive TCC, and to describe how canine TCC could serve as a relevant model of human invasive bladder cancer. Information was summarized from 102 dogs with TCC evaluated and treated at the Purdue University Veterinary Teaching Hospital, from a review of the Veterinary Medical Data Base, and from reports in the literature. Canine TCC was found to be very similar to human invasive bladder cancer in histopathologic characteristics, molecular features, biological behavior including metastasis, response to medical therapy, and prognosis. Differences between canine and human TCC were few, but included gender predilection with a male:female ratio of 2.8:1 in humans versus a male:female ratio of 0.5:1 in dogs. The location of the TCC within the bladder also differed: Most canine TCC was trigonal in location, whereas more than 50% of human TCC was in the lateral and posterior walls of the bladder. Considering the great similarity between invasive bladder cancer in humans and dogs, spontaneous canine TCC can be considered a relevant animal model of human invasive bladder cancer.

Early damage indicators in the lung: V. Biochemical and cytological response to NO2 inhalation☆

Abstract In an extension of earlier work on the usefulness of analysis of pulmonary lavage fluid as a probe to detect lung injury, we have examined lavage fluid from animals with a multifocal, terminal bronchiolitis induced by exposure to an oxidant gas. Syrian hamsters were exposed to concentrations of 0, 12, 17, and 22 ppm NO2 gas for 48 hr. Bronchopulmonary lavage fluids were profiled biochemically and cytologically to determine (1) the indicators of a multifocal, deep lung injury that could be detected in the lung washings and (2) the lowest level of this type of injury that could be detected by the lavage fluid screen. Lung homogenates were assayed for the enzymatic activities measured in lavage fluid and the lungs were evaluated histologically. Highest response for all parameters measured was at 2 days (end of the exposure) when the lavage fluid showed dose-dependent elevations in lactate dehydrogenase, alkaline phosphatase, acid phosphatase, glutathione reductase, and glutathione peroxidase activities, sialic acid, and total protein content, as well as increases in macrophage and neutrophil cell counts. By far the most sensitive indicator of this type of injury, as measured by the lavage fluid screen, was the neutrophil cell count, which showed a 10-fold increase even at the lowest level of exposure. The greatest change seen in the biochemical parameters measured in lavage fluid was the increase in sialic acid and protein content. There was good correlation between the degree of alteration of biochemical and cytologic indicators of injury seen in the lavage fluid and the morphological alterations seen in tissue.

Cisplatin versus cisplatin combined with piroxicam in a canine model of human invasive urinary bladder cancer

Purpose: More than 12,000 people are expected to die from invasive transitional cell carcinoma (TCC) of the urinary bladder each year in the United States, indicating that more effective therapy is needed. Drugs inhibiting cyclooxygenase (cox) have recently been found to have chemopreventive and antitumor activity and may potentiate the effects of chemotherapy. The purpose of this study was to determine whether cisplatin combined with the cox-inhibitor piroxicam would induce remission more frequently than cisplatin alone in a relevant animal model of human invasive TCC. Methods: Pet dogs with naturally occurring, histopathologically confirmed, measurable TCC of the urinary bladder were randomized to receive cisplatin (60 mg/m2 i.v. every 21 days) or cisplatin (same dosage) combined with piroxicam (0.3 mg/kg orally every 24 h). Complete staging was performed prior to and at 6-week intervals during therapy. Results: After eight dogs had been evaluated in each treatment group, a significant difference in remission rate was noted (Fishers Exact test, P < 0.004). Tumor responses in the cisplatin/piroxicam group included two complete remissions (CR), four partial remissions (PR), two stable disease (SD), and no progressive disease (PD). Tumor responses to cisplatin alone in eight dogs were no CR, no PR, four SD, and four PD. Six additional dogs were treated with cisplatin/piroxicam, and in total 10 of 14 dogs had remission (two CR, eight PR). Renal toxicity of cisplatin/piroxicam was frequent and dose limiting. Conclusions: Cisplatin/piroxicam induced remission more frequently than cisplatin alone in a canine model of human invasive TCC. Strategies to reduce renal toxicity need to be developed prior to evaluation of cisplatin/piroxicam in humans or general use of this treatment in pet dogs.

Bronchoalveolar Lavage in the Evaluation of Pulmonary Disease in the Dog and Cat

Bronchoalveolar lavage is a diagnostic procedure used to obtain specimens representative of disease processes involving the deep lung. Saline is instilled into an airway in sufficient volumes to bathe the alveoli dependent on that airway. The saline is retrieved by suction along with cellular and acellular material lining the epithelial surfaces of the lung. Cytologic and microbiologic evaluation of the fluid can be used to characterize pulmonary diseases in the dog and cat.

Prognosis following surgical excision of canine cutaneous mast cell tumors with histopathologically tumor-free versus nontumor-free margins: A retrospective study of 31 cases

The purpose of this study was to determine if the presence of histopathologically tumor-free versus nontumor-free margins was prognostic for relapse or tumor-related death in dogs following surgical excision of single or multiple cutaneous mast cell tumors confined to the skin without evidence of metastasis to lymph nodes or other noncutaneous sites. Differences in tumor-related death or frequency of relapse between the two groups were not significant. Failure to achieve histopathological tumor-free margins frequently did not lead to local relapse. All tumor-related deaths occurred following local relapse. The lack of statistical support for an association between prognosis and histopathological tumor-free versus nontumor-free margins may be a result of small sample size.

Pneumotoxicity and hepatotoxicity of styrene and styrene oxide.

The purpose of this study was to investigate the toxicity of styrene and styrene oxide in the lung in comparison to the toxicity in the liver. Pneumotoxicity caused by styrene or styrene oxide was measured by elevations in the release of gamma-glutamyltranspeptidase (GGT) and lactate dehydrogenase (LDH) into bronchoalveolar lavage fluid (BALF), while hepatotoxicity was measured by increases in serum sorbitol dehydrogenase (SDH) in non-Swiss Albino (Hsd:NSA) mice. Intraperitoneal administration of styrene at doses of 500-1000 mg/kg caused consistent dose-dependent increases in both sets of biomarkers with the hepatic effect appearing earlier than the pulmonary effect. Pyridine, phenobarbital, and beta-naphthoflavone, inducers of CYP2E1, CYP2B, and CYP1A, respectively, increased the toxicity of styrene. Pyridine and phenobarbital treatments increased mortality due to styrene. Styrene oxide exists in two enantiomeric forms: (R)- and (S)-styrene oxide, and the differential toxicities of the two enantiomers and racemic styrene oxide were compared. In all studies, (R)-styrene oxide caused greater toxicity than the (S) enantiomer, especially in the liver. Trichloropropene oxide, an epoxide hydrolase inhibitor, was used to inhibit styrene oxide detoxification and increased its hepatotoxicity, while buthionine sulfoxamine, a glutathione depletor, did not. These results demonstrated the greater role of epoxide hydrolase in styrene oxide detoxification.

Early damage indicators in the lungs. IV. Biochemical and cytologic response of the lung to lavage with metal salts

Abstract A rapid screening test for estimating the acute toxicity level of substances in the lung has been developed and evaluated using metal salts as the toxic agents. In the test, animals were exposed in vivo to the metal salts by bronchopulmonary lavage, and toxicity was determined by the enzymatic and cytologic response observed in the airways 1 day after exposure. The airway response was determined by analysis of bronchopulmonary lavage fluid for lactate dehydrogenase, acid and alkaline phosphatase, and β-glucuronidase activity as well as for total sialic acid and protein content and total and differential cell counts. These values showed a dose-dependent response in the lavage fluid. The enzymatic response of the lung tissue itself was not as marked as that seen in the lavage fluid. Histopathological evaluations of lung tissue were made in order to correlate morphological change with the airway response. The test allowed a rapid determination of the lung dose of metal salt which caused acute toxicity. Based on the biochemical response in the airway, the relative toxicity of the heavy-metal-containing compounds tested was: CdCl2>SeO2, NH4VO3, NiCl2>CrCl3.

T-2 toxin mycotoxicosis in the guinea-pig

Summary Purified T-2 toxin dissolved in saline-dimethylsulphoxide (DMSO) 10: 1 (v/v) was administered by gastric intubation in single doses of 1·85, 2·52, 3·45 and 4·66 mg/kg body weight to male guinea-pigs. The acute oral LD 50 in the male guinea-pig was estimated to be 3·06 (2·38–3·93) mg/kg. Single doses of 2·5 or 5·0 mg T-2 toxin/kg body weight administered orally in ethanol-DMSO, 1:1 (v/v) resulted in gross lesions including gastric and caecal hyperaemia and haemorrhage, watery-fluid distension of the caecum, oedematous intestinal lymphoid tissue and adrenal gland hyperaemia. Histological alterations included necrosis of lymphoid tissue, bone marrow and testes, and necrosis and ulceration of the gastro-intestinal tract, most severe in the stomach and caecum. Guinea-pigs, treated orally with T-2 toxin dissolved in saline-DMSO, 10:1 (v/v) at the rate of 0·5 mg/kg/day for 21 days and then 0·75 mg/kg/day for 21 days, remained clinically normal and did not have gross or microscopic lesions, but a moderate leucopenia and an absolute lymphopenia were observed. Oral administration of T-2 toxin to guinea-pigs at a rate of 0·9mg/kg/day for 27 days produced neither clinical disease nor gross and microscopic lesions, but did produce a decrease in erythrocyte numbers, a leucopenia and an absolute lymphopenia. Alterations in erythrocyte morphology and a marked decrease in the lymphocyte content of the bone marrow were also noted.

Plasma and cerebrospinal fluid pharmacokinetics of cytosine arabinoside in dogs

SummaryCytosine arabinoside (ara-C) is a component of many protocols for the treatment of CNS (central nervous system) leukemia and lymphoma in humans and dogs. It is also used for the prophylaxis of CNS metastasis in acute lymphoblastic leukemia. Although ara-C enters the cerebrospinal fluid (CSF) of human cancer patients after i.v. administration, it is unclear whether a similar CNS distribution occurs in humans whose blood-brain barrier has not been compromised by invasive disease. No information on the penetration of ara-C into the CSF in dogs is available. We studied the plasma and CSF pharmacokinetics of 600 mg/m2 ara-C in ten healthy male dogs after its administration as a rapid i.v. bolus (six dogs) or as a 12-h i.v. infusion (four dogs). Ara-C concentration in blood and CSF samples was determined by high-performance liquid chromatography (HPLC). After an i.v. bolus of ara-C, the mean plasma distribution half-life was 7.1±4.5 min and the mean elimination half-life was 69±28 min. The mean plasma clearance was 227±125 ml min−1 m−2. The peak concentration of ara-C in the CSF was 29±11 μm, which occurred at 57±13 min after the ara-C bolus. The CSF elimination half-life was 113±26 min. During a 12-h infusion of ara-C (50 mg m−2 h−1), the plasma steady-state concentration was 14.1±4.2 μm, the CSF steady-state concentration was 8.3±1.1 μm, and the CSF: plasma ratio was 0.62±0.14. The plasma eleimination half-life was 64±19 min and the plasma clearance was 214±69 ml min−1 m−2. The CSF elimination half-life was 165±28 min. No clinically significant toxicity was observed over a 21-day period following drug administration in either of the treatment groups. Our data indicate that ara-C crosses the blood-brain barrier in normal dogs and that i.v. administration of this drug has potential as a treatment modality for neoplasia involving the CNS.

γ-Glutamyltranspeptidase in rat bronchoalveolar lavage fluid as a probe of 4-lpomeanol and α-naphthylthiourea-induced pneumotoxicity

Bronchoalveolar lavage fluid analysis has gained popularity as a rapid in vivo screen to evaluate the toxicity of both systemic and inhaled pneumotoxicants and is used in addition to the more commonly evaluated pathologic changes. This study evaluated gamma-glutamyltranspeptidase (GGT) in the bronchoalveolar lavage fluid (BALF) along with the more commonly measured enzyme, lactate dehydrogenase (LDH), as a useful indicator of acute lung injury from systematically administered pneumotoxicants. Adult male rats were injected ip with 2, 3, or 3.5 mg/kg body weight of alpha-naphthylthiourea (ANTU) or 5, 10, or 20 mg/kg of 4-ipomeanol, and measurements were made 8 or 24 hr postdose, respectively. ANTU, which selectively damages pulmonary endothelial cells, caused extensive pleural effusions with striking increases in BALF protein and white blood cell (WBC) content. 4-Ipomeanol, which selectively damages nonciliated bronchiolar Clara cells, caused dose dependent increases in both GGT and LDH activities in the BALF with GGT being increased at all doses tested. BALF protein content was also increased in the 4-ipomeanol-treated groups, but this change was not dose dependent. Analysis of GGT in BALF was a sensitive method to assess cytotoxicity associated with 4-ipomeanol-induced injury but was less useful in monitoring pulmonary endothelial cell damage induced by ANTU. Measurements of BALF protein and WBC content proved to be better in assessing injury by agents such as ANTU that primarily affect vascular permeability.