bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mouse Bioassay to Assess Oestrogenic and Anti‐oestrogenic Compounds: Hydroxytamoxifen, Diethylstilbestrol and Genistein
Authors: Köhlerová E. , Škarda J. 
Published: August 2004

SummaryYoung intact and adult gonadectomized C3H male and female mice were utilized as bioassay models to detect endocrine disruption chemicals. Animals treated with oestradiol (E) or progesterone (Prog) or E plus Prog were used to assess steroid hormone agonist and antagonist activities of 4‐OH‐tamoxifen (TAM), diethylstilbestrol (DES) and genistein (GEN) by bioassay. The stimulation or inhibition of mammary growth by TAM depended on sex, the state of animal (intact or gonadectomized), hormonal treatment (Prog, E, E plus Prog) and dose of TAM. TAM stimulated mammary growth in untreated ovariectomized (OV‐X) females and in Prog‐treated intact males and OV‐X females. In intact males, mammary growth was increased by TAM at dose 0.1–1 μg day−1and decreased at dose 10 μg day−1. Mammary growth was inhibited by TAM in Prog‐treated intact females and in E or E plus Prog‐treated intact and gonadectomized males and females. Uterine weights were increased by TAM in both untreated and treated (E, Prog, E plus Prog) intact and OV‐X females; however, seminal vesicle weights were decreased by TAM in both untreated and treated (E, Prog, E plus Prog) intact males. DES alone affected mammary growth (an inverted‐U‐shaped dose–response curve) both in male and female mice. DES increased uterine weights; however, seminal vesicle weights were decreased. GEN increased mammary and uterine growth in OV‐X females, GEN plus Prog stimulated mammary growth in intact males. The results obtained in these studies show clearly that only a bioassay consisting of several endpoints reflective to the mechanism of oestrogen and anti‐oestrogen action has the ability to evaluate activities of a molecule.
Development of a two‐antibody model for the evaluation of copper‐64 radioimmunotherapy
Authors: Bryan J. N. , Lewis M. R. , Henry C. J. , Owen N. K. , Zhang J. , Mohsin H. , Jia F. , Sivaguru G. , Anderson C. J. 
Published: August 2004

AbstractCopper‐64 emits β+ and β– particles suitable for positron emission tomography and radioimmunotherapy (RIT) of cancer. Copper‐64‐labelled antibodies have caused complete responses in laboratory animal RIT studies at far lower radiation doses than traditionally prescribed. The intracellular localization of copper radioisotopes may lead to cytotoxic effects by mechanisms beyond ionizing radiation damage. The purpose of this research was to develop a model using both internalizing and non‐internalizing antibodies for direct comparison in future RIT studies using the same animal model of cancer. The monoclonal antibodies, cBR96 and cT84.66, were conjugated with N‐hydroxysulfosuccinimidyl DOTA. All conjugates retained high immunoreactivity and labelled efficiently with 64Cu with high specific activity and radiochemical purity. Twenty‐four hour biodistributions determined in LS174T tumour‐bearing nude mice demonstrated low organ and high tumour uptakes for both monoclonal antibodies. This model constitutes a promising system for elucidating whether internalization of 64Cu is responsible for an enhanced tumour cytotoxicity in vivo.
Feline epitheliotrophic T‐cell lymphoma with paraneoplastic eosinophilia – immunochemotherapy with vinblastine and human recombinant interferon α2b
Authors: Cave T. A. , Gault E. A. , Argyle D. J. 
Published: August 2004

AbstractA cat with epitheliotrophic T‐cell lymphoma with paraneoplastic eosinophilia is described. Initial attempts to control the disease with conventional therapies failed. The addition of recombinant human interferon α2b (rhINFα2b) resulted in a clinical, haematogenous and sonographic improvement for 49 days. The overall survival time from initial diagnosis was 100 days. Relapse was correlated with the development of serum antibodies directed against rhINFα2b. To our knowledge, this is the first report describing the clinical use of IFNα in the treatment of neoplasia in the cat.
Trends in veterinary cancer imaging
Authors: Wisner E. R. , Pollard R. E. 
Published: August 2004

AbstractWith the recent advances in diagnostic imaging technology, cancer imaging in veterinary medicine has become more specific for disease diagnosis, more accurate for determining tumour margins and more sensitive for detecting metastatic disease. Ultrasound provides highly detailed images of parenchymal masses and infiltrative lesions while providing a means for aspiration or biopsy using real‐time image guidance. Computed tomography and magnetic resonance‐imaging techniques provide exquisite anatomical resolution that improves diagnostic accuracy, provides an accurate means of radiation or surgical treatment planning and a quantitative means for monitoring response to therapy. In addition to traditional anatomic imaging, new techniques are being developed for estimating functional parameters such as tumour perfusion, cell metabolism and gene expression. While conventional planar scintigraphy has been available for some time, newer nuclear imaging modalities such as positron emission tomography promise to further improve the accuracy of initial tumour diagnosis and staging and determination of response to therapy. Although many of these functional techniques are not yet clinically available, it is highly likely that some will be integrated into routine clinical practice in the near future.
Correlation of histologic grading of canine mast cell tumors with Ki67/PCNA/AgNOR/c‐Kit scores: 38 cases (2002–2003)
Authors: Bergman P. J. , Craft D. M. , Newman S. J. , Baer K. , Camps‐Palau M. A. , McKnight J. A. , Leibman N. F. , Brenn S. , Finora K. , Hohenhaus A. E. , Bartick T. , Patnaik A. K. , Scase T. 
Published: August 2004

Introduction:  The Patnaik grading system for canine cutaneous MCT is currently one of the best determinants of prognosis; however, clinical outcome does not always correlate with histologic grade. The development of molecular markers offers a potential advantage and may complement subjective grading. The primary purpose of this study was to correlate histologic grading to Ki67/PCNA/AgNOR/c‐Kit scores.Methods:  Thirty‐eight dogs with cutaneous MCT underwent surgical resection. Tumors were graded, with expansion of grade II MCT to low, medium (or II only) and high. For statistical purposes, MCT grade I, II (low, medium, high) and III were assigned a score of 1, 2, 3, 4, or 5, respectively. Sections were processed for AgNOR staining and expression of PCNA, Ki67 and c‐Kit as previously described (modified biotin‐strepavidin with DAB substrate). Paraffin‐embedded canine tissue arrays were used as positive and negative controls (primary antibody replaced with pre‐immune sera). Parametric statistical testing was performed using Statview statistical software with P ≤ .05 as significant.Results:  There were 12, 20, 5 and 1 grade II low, grade II medium, grade II high and grade III MCT, respectively. The mean Ki67 score was 9.114 (median 8.0, range 1–28), mean PCNA score was 26.25 (median 24.0, range 5–65), mean AgNOR score was 1.499 (median 1.35, range 1.02–2.76) and c‐Kit scores were +1 (9/37), +2 (19/37) and +3 (9/37). With parametric statistical testing, significantly positive correlations were found for Ki67/Grade, PCNA/Grade, AgNOR/Grade, Ki67/PCNA, Ki67/AgNOR and PCNA/AgNOR (all P < .0001). No significant correlation was found for c‐Kit and grade; however, +3 c‐Kit scores had statistically significantly higher grades than +2 c‐Kit scores (P = .0458).Conclusions:  Ki67/PCNA/AgNOR scores are positively correlated to grade in dogs with MCT. Further studies to correlate Ki67/PCNA/AgNOR/c‐Kit scores with clinical variables are ongoing.
A two‐antibody model for copper‐64 radioimmunotherapy: biodistributions and tumor dosimetry in a mouse model of cancer
Authors: Bryan J. N. , Mohsin H. , Jia F. , Siegall C. B. , Anderson C. J. , Miller W. H. , Henry C. J. , Lewis M. R. 
Published: August 2004

Objectives:  We previously presented preliminary data on pilot biodistributions of 64Cu‐labeled monoclonal antibodies (mAbs).1 The purpose of the present studies was to obtain comprehensive biodistributions using a two‐antibody model for direct comparison of an internalizing and a non‐internalizing mAb in the same animal model of cancer. These studies will allow evaluation of the efficacies of the two 64Cu‐labeled mAbs for radioimmunotherapy (RIT) and are part of a larger, ongoing project examining the unusual tumoricidal properties of internalized 64Cu.Methods:  DOTA (1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid) was conjugated to an internalizing antibody, cBR96, and a non‐internalizing antibody, cT84.66. Biodistributions of the 64Cu‐labeled conjugates in nude mice bearing LS174T human colorectal carcinoma xenografts were obtained at time points from 15 min to 48 h. Mouse tumor dosimetry was calculated using a Monte Carlo N‐Particle Transport Code.Results:  The 64Cu‐DOTA‐cBR96 conjugate demonstrated rapid tumor uptake, reaching 20.2% injected dose per gram of tissue (% ID/g) at 3 h and peaking at 35.4% ID/g by 24 h. Tumor accumulation of 64Cu‐DOTA‐cT84.66 was more gradual, 8.19% ID/g at 3 h (p = 0.002), and reached 43.8% ID/g by 24 h, but maximum uptake was not statistically different from 64Cu‐DOTA‐cBR96 (p = 0.05). Liver, spleen, and kidney uptakes were statistically similar at 24 h for both conjugates (p = 0.05). Tumor absorbed radiation doses were estimated to be 1128 rad/mCi for 64Cu‐DOTA‐cBR96 and 1409 rad/mCi for 64Cu‐DOTA‐cT84.66.Conclusion:  The biodistributions and tumor dosimetry of these two radiolabeled antibodies were sufficiently similar for direct comparison of the therapeutic efficacies of internalizing versus non‐internalizing 64Cu RIT agents in the same animal model of cancer. RIT studies using this two‐antibody model are currently in progress to test the hypothesis that internalization of 64Cu is necessary for enhanced cytotoxic properties at low tumor absorbed doses.
Investigating the molecular mechanism of pamidronate‐induced in vitro cytotoxicity in canine osteosarcoma cells
Authors: Fan T. M. , Charney S. C. , De Lorimier L. P. 
Published: August 2004

Introduction:  Pamidronate is used to treat metastatic bone lesions in human cancer patients. By directly inhibiting the mevalonate pathway, pamidronate disrupts GTPase‐binding protein prenylation, resulting in osteoclast apoptosis. Pamidronate has been demonstrated to exert dose‐ and time‐dependent cytotoxic effects in several canine malignant osteoblastic cell lines. However, the exact cytotoxic mechanism remains speculative. The purpose of this study was to investigate and characterize the molecular mechanism of pamidronate‐induced cytotoxicity in canine malignant osteoblasts.Methods:  The involvement of farnesyl or geranylgeranyl pyrophosphate synthase inhibition was evaluated by performing rescue experiments with cells incubated for 48 hours with cytotoxic concentrations of pamidronate (50 and 100 μM), with or without farnesol (FOH) and geranylgeraniol (GGOH). Cell lysates were fluorometrically‐assessed for caspase‐3‐like activity (R&D Systems) following incubation with varying concentrations of pamidronate (control, 50 and 100 μM) for 48 hours. The expression of a prenylated GTPase protein, Rap1 A, was qualitatively evaluated with immunoblotting using a polyclonal goat antibody (Santa Cruz Biotechnology) in cells incubated for 48 hours with varying concentrations of pamidronate (0, 1, 10, 50, and 100 μM).Results:  In cells treated with lower cytotoxic concentrations of pamidronate (50 μM) for 48 hours, the addition of GGOH, but not FOH, was able to diminish the degree cytotoxicity, p ≤ 0.05. However, cells incubated with higher cytotoxic concentrations of pamidronate (100 μM), neither GGOH nor FOH were able to reduce the level of pamidronate‐induced cytotoxicity. Caspase‐3‐like activity directly correlated with the degree of pamidronate‐induced cytotoxicity. Cells treated with pamidronate at 50 μM and 100 μM increased caspase‐3‐like activity by 5.3 and 7.1‐fold, respectively over untreated controls. The detection of Rap1A by immunoblotting requires further optimization.Conclusions:  Pamidronate‐induced cytotoxicity in canine osteosarcoma cells may share a similar mechanism as has been demonstrated for osteoclasts. Inhibition of the mevalonate pathway appears to contribute to the observed cytotoxicity at lower doses of pamidronate. In addition, caspase‐3‐like activity contributes to the apoptotic process induced by pamidronate in malignant canine osteoblasts.
Monitoring response to aminobisphosphonate therapy in canine osteosarcoma using dual energy x‐ray absorptiometry (dexa)
Authors: Lorimier L. P. , Fan T. M. , Charney S. C. , Lacoste H. I. , Heller D. A. , Endicott M. M. , Souza C. H. 
Published: August 2004

Introduction:  Palliative therapy is essential to improve the quality of life of dogs with osteosarcoma (OSA), when definitive therapy is not considered a valid option. Bisphosphonates, a novel class of antiosteoclastic drugs, are widely used in humans for several painful osteolytic conditions. Dual energy x‐ray absorptiometry (DEXA) is recognized as a reliable tool to measure bone mineral density (BMD), and to monitor treatment response to bisphosphonates in humans. A prospective evaluation of pamidronate, an injectable aminobisphosphonate, is ongoing in dogs with appendicular OSA. The potential value of DEXA for objective evaluation of BMD variations with palliative therapies is concurrently being assessed.Materials and Methods:  Dogs with naturally occurring appendicular OSA treated with pamidronate constitute the patient population. A DEXA scan (QDR‐4500 W, Hologic, Bedford, MA) is performed on day 0 (baseline) and on every treatment day with pamidronate thereafter (every 28 days). For each dog, a whole body scan is performed, followed by a scan of the tumor, and contralateral normal bone. Three regions of interest are subsequently analyzed for BMD changes in tumor and normal bone. Statistical analysis was performed using Student t‐test and paired t‐tests, with significance being set at p < 0.05.Results:  Nineteen dogs have been enrolled to date. Seven responders and 6 non‐responders have suitable data for analysis. A significant difference is observed (p = 0.04) between tumor BMD variations of responders and non‐responders at day 28 (mean variations +18.0% and −4.6% respectively). The changes at day 28 are significant only in the responders (p = 0.038 vs p = 0.05 in non‐responders). When BMD of tumor and normal bone at day 84 is compared to day 0 in six responders, only tumor had a significant increase (p = 0.017 vs p = 0.279, respectively).Conclusions:  Objective measurements of response to therapy are essential in pain palliation studies. Increased tumor bone BMD, as obtained by DEXA analysis, may correlate with subjective clinical improvement in pamidronate‐treated dogs with appendicular OSA.
RNA‐transfected CD40‐activated B cells as a vaccine strategy in canine malignancies
Authors: Overley B. , Coughlin C. M. , Leibowitz M. S. , Sorenmo K. U. , Vonderheide R. H. 
Published: August 2004

Introduction:  Cell‐based vaccine strategies using dendritic cells as cellular adjuvant have entered phase III trials in humans and have been found to be safe, feasible, and potentially efficacious. Canine patients are generally smaller than adult human patients, which makes production of canine dendritic cell (DC) vaccines problematic, given patient size and the small number of available DC precursors. Here we describe feasibility studies of a novel cell‐based vaccine strategy which uses CD40‐activated B‐cells (CD40‐B) loaded with RNA. This strategy is based on our observations that RNA‐transfected human CD40‐B can drive anti‐tumor T cell responses. One advantage of using CD40‐B cells is the ability to expand this cell population ex vivo, allowing for the numbers of cells required for therapeutic vaccines.Methods:  Twenty milliliters of blood were drawn from 6 normal dogs and 5 canine lymphoma patients. Peripheral blood mononuclear cells were separated by Ficoll centrifugation. Culture conditions for B cell activation were optimized using CD40‐ligand, canine IL‐4, and Toll‐like receptor stimulus with CpGoligodinucleotides (ODN). Cyclosporine was added to eliminate peripheral T lymphocytes. Proliferation and activation of CD40‐B cells were demonstrated by CFSE dilution of B cells quantified by flow cytometry. Gene transfer was achieved by mRNA electroporation.Results:  Marked in vitro stimulation and proliferation of canine peripheral B cells were achieved with soluble trimeric CD40L, canine IL‐4, and ODN. CD40‐B cells showed dramatic upregulation of MHC class II molecules and CD21 (B‐cell activation marker). After two weeks in culture, cells were negative for CD3 and CD4. Canine CD40‐B cells were efficiently transfected with mRNA, with >60% of CD40‐B expressing green fluorescent protein after GFP mRNA electroporation.Conclusion:  RNA‐transfected CD40‐B cells can be efficiently generated from normal and tumor‐bearing dogs. These results provide rationale to test tumor RNA‐transfected CD40‐B as a novel therapeutic approach to treating canine malignancies. Clinical trials in canine lymphoma have been proposed.
Differentiating effect of pamidronate on canine osteo‐sarcoma cell lines in vitro
Authors: Lacoste H. I. , Fan T. M. , De Lorimier L. P. , Charney S. C. 
Published: August 2004

Introduction:  Pamidronate has been traditionally used to manage pathologic osteoclastic disorders. In addition to its effects on osteoclasts, pamidronate has also been demonstrated to promote phenotypic maturation and inhibition of proliferation in osteoblasts. Canine osteosarcoma (OSA) consists of malignant, undifferentiated osteoblasts. The objective of this study was to determine if micromolar concentrations of pamidronate could induce malignant osteoblastic differentiation as evaluated by an increase in alkaline phosphatase (ALP) activity and/or osteocalcin (OC) production, two specific markers of normal osteoblastic activity.Methods:  Two canine OSA cell lines (HMPOS and COS 31) were used for all experiments. Cells were incubated for 48 or 72 hours with various pamidronate concentrations (0, 0.1, 1, 5, 10, and 20 μM). After incubation, the supernatants were sampled and the relative amounts of viable cells were determined with a cell proliferation assay (Cell Titer 96® AQuous, Promega). An ALP detection kit (Starbright®, Sigma®) was used to measure the ALP activity and an ELISA (Osteocalcin EIA kit, Biomedical Technologies) was used to determine the concentration of osteocalcin in the supernatants. The ALP and osteocalcin values were corrected for the amount of viable cells.Results:  Pamidronate induced a dose‐dependent reduction in the number of viable COS 31 and HMPOS cells at both 48 and 72 hours. A dose‐dependent elevation in ALP activity from baseline was observed. At 20 μM, a 2.3‐fold increase was observed for HMPOS at 72 hours, while a 1.43‐fold increase was observed for COS 31 at 72 hours. Very low level (less than 2 ng/ml) of osteocalcin pre‐ and post‐pamidronate treatment was detected for both COS 31 and HMPOS.Conclusion:  The data suggests that pamidronate increases alkaline phosphatase activity in canine OSA cells in a dose‐dependent manner. However, cytotoxic assays are needed in order to accurately characterize any concurrent decrease in the number of viable cells. The potential differentiating effect of pamidronate on malignant osteoblasts provides an additional argument for its use in the palliative treatment of OSA.
Noninvasive monitoring of doxorubicin cardiotoxicity: a pilot study of two dogs
Authors: Selting K. A. , Spier A. W. , Dodam J. R. , Skimming J. W. , Lattimer J. C. , Britt L. G. , Turk J. R. , Tyler J. W. , Durham H. E. , Garro M. 
Published: August 2004

The cardiotoxicity of anthracycline anticancer agents, most notably doxorubicin, limits their use in treating a wide variety of cancers. Currently available methods for assessment of anthracycline‐induced cardiotoxicity (AIC) often lack specificity and sensitivity. The purpose of this pilot investigation was to determine noninvasive diagnostic methods that are predictive for AIC. Two mongrel dogs were anesthetized for injection of doxorubicin (22.5 mg) directly into the left coronary artery. Doxorubicin injection was repeated 2 weeks later. Dogs were followed for 12 weeks or until heart failure was documented. Dogs were monitored before and at serial time points after doxorubicin using echocardiography and signal‐averaged electrocardiography as well as ambulatory ECG monitoring. Blood was also collected for measurement of cardiac troponin I and T concentrations. Doxorubicin was readministered at 6 and 12 weeks after the second injection, as interim data analysis did not reveal adequate evidence of cardiomyopathy.Dog‐1 appeared to be more sensitive than Dog‐2 to AIC based upon gradual changes in variables of cardiac function and earlier time to failure (113 days). In contrast, Dog‐2 had inconsistent changes in cardiac function and a longer time to failure (139 days). Dog‐1 also had greater peak plasma cardiac troponin I levels (17.96 ng/ml) as compared to peak levels in Dog‐2 (4.08 ng/ml). In addition, Dog‐1 had increased ventricular extrasystolic contractions (VE)(0/day at baseline, 443/day one week prior to death), whereas dog‐2 showed very few VE's throughout. Spectral analysis of ECG data also revealed a significant decrease over time in total spectral power in Dog‐1 from 37,148 at baseline to 603 msec2/Hz one week prior to death, indicating decreased parasympathetic tone. Endomyocardial biopsies revealed minor changes despite significant clinical abnormalities. These data indicate differences in susceptibility to AIC between Dog‐1 and Dog‐2, and suggest a role for these noninvasive measures in monitoring the heart during chemotherapy.