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1.
Vet Comp Oncol ; 16(3): 352-360, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29380929

ABSTRACT

Immunotherapies targeting checkpoint molecule programmed cell death 1 (PD-1) protein were shown to be effective for treatment of non-Hodgkin lymphoma in people, but little is known about the expression of PD-1 or its ligand PD-L1 by canine lymphoma. Therefore, flow cytometry was used to analyse expression of PD-1 and PD-L1 in canine lymphoma, using fine-needle aspirates of lymph nodes from 34 dogs with B cell lymphoma (BCL), 6 dogs with T cell lymphoma (TCL) and 11 dogs that had relapsed. Furthermore, fine-needle aspirates were obtained from 17 healthy dogs for comparison. Lastly, the impact of chemotherapy resistance on expression of PD-1 and PD-L1 was assessed in vitro. These studies revealed increased expression of PD-L1 by malignant B cells compared to normal B cells. In the case of TCL, tumour cells and normal T cells both showed low to negative expression of PD-1 and PD-L1. In addition, tumour infiltrating lymphocytes from both BCL and TCL had increased expression of both PD-1 and PD-L1 expression compared to B and T cells from lymph nodes of healthy animals. In vitro, chemotherapy-resistant BCL and TCL cell lines exhibited increases in both PD-1 and PD-L1 expression, compared to non-chemotherapy selected tumour cells. These findings indicate that canine lymphomas exhibit upregulated checkpoint molecule expression, though the impact of checkpoint molecule expression on tumour biological behaviour remains unclear.


Subject(s)
B7-H1 Antigen/metabolism , Dog Diseases/metabolism , Lymphoma, B-Cell/veterinary , Lymphoma, T-Cell/veterinary , Programmed Cell Death 1 Receptor/metabolism , Animals , B-Lymphocytes/metabolism , Case-Control Studies , Cell Line, Tumor , Dogs , Flow Cytometry/veterinary , In Vitro Techniques , Lymphocytes, Tumor-Infiltrating/metabolism , Lymphoma, B-Cell/metabolism , Lymphoma, T-Cell/metabolism , T-Lymphocytes/metabolism
2.
J Vet Intern Med ; 32(1): 394-405, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29194765

ABSTRACT

BACKGROUND: KIT inhibitors, such as toceranib (TOC), and vinblastine (VBL) have not been prospectively compared in the treatment of macroscopic mast cell tumors (MCTs). Also, it is unknown whether VBL or TOC is superior for treating MCT without c-kit mutations. HYPOTHESIS/OBJECTIVES: To determine the value of KIT genotyping and localization in treatment decisions for dogs with macroscopic MCT. We hypothesized that c-kit mutated MCT would have a better response to TOC than VBL. ANIMALS: Eighty-eight client-owned dogs with macroscopic MCT. METHODS: Prospective, randomized trial. Dogs were randomized to TOC (2.75 mg/kg EOD) or VBL (2.5 mg/m2 weekly × 4 then EOW) by KIT localization and c-kit mutation status using an adaptive randomization scheme. RESULTS: Sixty dogs were allocated to TOC and 28 to VBL. Of the dogs receiving TOC, 20% had c-kit mutations, compared to 30% receiving VBL (P = 0.74). Overall response rates were 46% (TOC) and 30% (VBL) (odds ratio = 1.56 [0.62-3.92]; P = 0.28). Median progression-free survival (PFS) for dogs receiving VBL was 78 days (7-1,521) and for TOC 95.5 (14-990); hazard ratio (HR) = 1.34 [0.72-2.50]; P = 0.36. Median overall survival (OS) was 241.5 days (10-1,521) for the VBL group and 159 (20-990) for the TOC group; HR = 0.80 ([0.45-1.41]; P = 0.44). CONCLUSIONS AND CLINICAL IMPORTANCE: Neither PFS nor OS was significantly different between treatment groups. As the proportion of dogs with c-kit mutations was not different between treatment groups in this population of dogs, c-kit mutation status did not predict treatment response.


Subject(s)
Dog Diseases/drug therapy , Indoles/therapeutic use , Mastocytosis, Cutaneous/veterinary , Prednisone/therapeutic use , Proto-Oncogene Proteins c-kit/genetics , Pyrroles/therapeutic use , Vinblastine/therapeutic use , Animals , Antineoplastic Agents/therapeutic use , Disease-Free Survival , Dogs , Female , Male , Mastocytosis, Cutaneous/drug therapy , Mastocytosis, Cutaneous/genetics , Mutation , Prospective Studies
3.
J Vet Intern Med ; 31(3): 872-878, 2017 May.
Article in English | MEDLINE | ID: mdl-28370378

ABSTRACT

BACKGROUND: Standard of care treatment for multicentric lymphoma in dogs remains doxorubicin (DOX)-based combination chemotherapy, but owners may hesitate to commit the time and financial resources to complete such a protocol, typically requiring 12-16 visits. Rabacfosadine (RAB), a double prodrug of the nucleotide analog 9-(2-phosphonylmethoxyethyl) guanine, has substantial single-agent activity in dogs with lymphoma, and a different mechanism of action than DOX. HYPOTHESIS/OBJECTIVES: Our objective was to evaluate the efficacy and adverse effect (AE) profile of alternating doses of RAB and DOX in dogs with naïve multicentric lymphoma. ANIMALS: Fifty-four dogs with previously untreated lymphoma. METHODS: Open-label, multicenter prospective clinical trial. Dogs received alternating RAB (1.0 mg/kg IV weeks 0, 6, 12) and DOX (30 mg/m2 IV weeks 3, 9, 15). Dogs that achieved complete response (CR) were followed by monthly evaluations. Complete clinicopathological evaluation and assessment of remission and AEs were performed every 21 days. RESULTS: The overall response rate was 84% (68%; CR; 16%; partial response [PR)]. The overall median progression-free interval (PFI) was 194 days (216 for CR and 63 for PR). Most AEs were mild and self-limiting: gastrointestinal and hematologic AEs were most common. Thirteen dogs experienced dermatologic AEs, and 2 dogs developed grade 5 pulmonary fibrosis. CONCLUSIONS AND CLINICAL IMPORTANCE: Alternating RAB/DOX generally was well tolerated and resulted in PFIs comparable to standard DOX-based multi-agent protocols, with fewer treatment visits. Most adverse events were mild or moderate and self-limiting. Further studies are warranted to explore long-term outcome and other RAB chemotherapy combinations.


Subject(s)
Alanine/analogs & derivatives , Antineoplastic Agents/therapeutic use , Dog Diseases/drug therapy , Doxorubicin/therapeutic use , Lymphoma/veterinary , Prodrugs/therapeutic use , Purines/therapeutic use , Alanine/administration & dosage , Alanine/adverse effects , Alanine/therapeutic use , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Dogs , Doxorubicin/administration & dosage , Doxorubicin/adverse effects , Drug Administration Schedule/veterinary , Female , Lymphoma/drug therapy , Male , Prodrugs/administration & dosage , Prodrugs/adverse effects , Purines/administration & dosage , Purines/adverse effects , Treatment Outcome
4.
J Vet Intern Med ; 28(2): 538-46, 2014.
Article in English | MEDLINE | ID: mdl-24495161

ABSTRACT

BACKGROUND: Canine T-cell lymphoma (TCL) is conventionally considered an aggressive disease, but some forms are histologically and clinically indolent. CD4 TCL is reported to be the most common subtype of TCL. We assessed flow cytometric characteristics, histologic features when available, and clinical outcomes of CD4+ TCL to determine if flow cytometry can be used to subclassify this group of lymphomas. OBJECTIVE: To test the hypothesis that canine CD4+ T-cell lymphoma (TCL) is a homogeneous group of lymphomas with an aggressive clinical course. ANIMALS: Sixty-seven dogs diagnosed with CD4+ TCL by flow cytometry and treated at 1 of 3 oncology referral clinics. METHODS: Retrospective multivariable analysis of outcome in canine CD4+ TCL including patient characteristics, treatment, and flow cytometric features. RESULTS: The majority of CD4+ TCL were CD45+, expressed low class II MHC, and exhibited an aggressive clinical course independent of treatment regimen (median survival, 159 days). Histologically, CD4+ TCL were classified as lymphoblastic or peripheral T cell. Size of the neoplastic lymphocytes had a modest effect on both PFI and survival in this group. A small number of CD4+ TCL were CD45- and class II MHC high, and exhibited an apparently more indolent clinical course (median survival not yet reached). CONCLUSIONS AND CLINICAL IMPORTANCE: Although the majority of CD4+ TCL in dogs had uniform clinical and flow cytometric features and an aggressive clinical course, a subset had a unique immunophenotype that predicts significantly longer survival. This finding strengthens the utility of flow cytometry to aid in the stratification of canine lymphoma.


Subject(s)
CD4 Lymphocyte Count/veterinary , Dog Diseases/blood , Lymphoma, T-Cell/veterinary , Animals , Antineoplastic Agents/therapeutic use , CD4-Positive T-Lymphocytes/pathology , Dog Diseases/diagnosis , Dog Diseases/drug therapy , Dog Diseases/pathology , Dogs , Female , Flow Cytometry/veterinary , Lymphoma, T-Cell/blood , Lymphoma, T-Cell/diagnosis , Lymphoma, T-Cell/drug therapy , Lymphoma, T-Cell/pathology , Male , Retrospective Studies , Treatment Outcome
5.
Vet Comp Oncol ; 11(4): 296-305, 2013 Dec.
Article in English | MEDLINE | ID: mdl-22540967

ABSTRACT

Increased numbers of tumour-associated macrophages correlate with rapid tumour growth and metastasis in tumours. Thus, macrophage depletion has potential as a novel cancer therapy and positive responses have been reported in rodent tumour models. To investigate the effectiveness of this approach in dogs with cancer, we evaluated the effects of the macrophage-depleting agent liposomal clodronate (LC) in dogs with soft-tissue sarcoma (STS). To this end, we conducted a clinical trial of LC therapy in 13 dogs with STS. Repeated LC administration was well tolerated clinically. Preliminary examination of tumour biopsy sets from 5 of the 13 dogs demonstrated that the density of CD11b(+) macrophages was significantly decreased after LC treatment. Circulating concentrations of interleukin-8 were also significantly reduced. These preliminary studies are the first to suggest that LC can be used as a systemic macrophage-depleting agent in dogs to reduce numbers of tumour-associated macrophages.


Subject(s)
Clodronic Acid/therapeutic use , Dog Diseases/drug therapy , Macrophages/physiology , Sarcoma/veterinary , Animals , Clodronic Acid/administration & dosage , Cytokines/genetics , Cytokines/metabolism , Dog Diseases/etiology , Dogs , Female , Gene Expression Regulation , Male , Sarcoma/complications
6.
J Vet Intern Med ; 26(3): 598-607, 2012.
Article in English | MEDLINE | ID: mdl-22390318

ABSTRACT

BACKGROUND: Effective treatments for dogs with advanced stage mast cell tumors (MCT) remain a pressing need. A micellar formulation of paclitaxel (paclitaxel [micellar]) has shown promise in early-phase studies. HYPOTHESIS/OBJECTIVES: The objective was to demonstrate greater activity for paclitaxel (micellar) compared with lomustine. The null hypothesis was µ(p) = µ(L) (ie, proportion of responders for the paclitaxel [micellar] and lomustine groups, respectively). ANIMALS: Two hundred and fifty-two dogs with advanced stage nonresectable grade 2 or 3 MCT. METHODS: Prospective multicenter randomized double-blind positive-controlled clinical trial. The primary endpoint was confirmed overall response rate (CORR) at 14 weeks. A secondary endpoint, biologic observed response rate (BORR), also was calculated. Safety was assessed by the characterization and grading of adverse events (AE). RESULTS: Overall CORR (7% versus 1%; P = .048) and BORR (23% versus 10%; P = .012) were greater for paclitaxel (micellar) compared with lomustine. Paclitaxel (micellar)-treated dogs were 6.5 times more likely to have a confirmed response and 3.1 times more likely to experience a biologic observed response. The majority of AE with paclitaxel (micellar) were transient and clinically manageable. Twenty-seven dogs (33%) receiving lomustine were discontinued because of hepatopathy compared with 3 dogs (2%) receiving paclitaxel (micellar) (P < .0001; odds ratio 26.7). CONCLUSIONS AND CLINICAL IMPORTANCE: Paclitaxel (micellar)'s activity and safety profile are superior to lomustine. The addition of an active and novel taxane to the veterinary armamentarium could fill a substantial need and, as its mechanism of action and AE profile do not overlap with currently available TKI, its availability could lead to effective combination protocols.


Subject(s)
Antineoplastic Agents, Phytogenic/therapeutic use , Dog Diseases/drug therapy , Mast-Cell Sarcoma/veterinary , Micelles , Paclitaxel/therapeutic use , Animals , Antineoplastic Agents, Phytogenic/chemistry , Dog Diseases/pathology , Dogs , Double-Blind Method , Female , Male , Mast-Cell Sarcoma/drug therapy , Paclitaxel/chemistry , Prospective Studies , Statistics, Nonparametric , Treatment Outcome
7.
J Vet Intern Med ; 23(4): 875-81, 2009.
Article in English | MEDLINE | ID: mdl-19496904

ABSTRACT

BACKGROUND: Regulatory T cells (Treg) have been shown to suppress antitumor immunity and often are increased in humans and rodents with cancer. However, Tregs have not been well studied in dogs with cancer and it is not known if certain tumor types are associated with increased Tregs. HYPOTHESIS: We hypothesized that Treg percentages would be increased in dogs with cancer and that Treg percentages would be higher in dogs with certain types of cancer. ANIMALS: The percentages and numbers of Tregs and nonregulatory T cells and B cells were assessed in 34 dogs with cancer and 9 age-matched control dogs. Dogs evaluated included 14 dogs with sarcoma, 7 dogs with carcinoma, 7 dogs with lymphoma, and 6 dogs with mast cell tumor. METHODS: Numbers and percentages of Tregs, CD4+, and CD8+ T cells and B cells were determined using flow cytometry and compared between control dogs and dogs with cancer. RESULTS: The percentage of Tregs was significantly increased overall in dogs with cancer compared with control dogs. When tumor types were compared, Treg percentages were significantly increased in dogs with carcinoma. The Treg/CD8 T cell ratio was significantly higher in dogs with cancer compared with control dogs and was also significantly increased in 2 dogs with T-cell lymphoma. CONCLUSIONS: Treg percentages in blood were increased in dogs with cancer, particularly in dogs with carcinoma. The Treg/CD8 ratio also identified tumor-specific abnormalities in dogs with cancer. These findings indicate that tumor-specific factors may affect Tregs in dogs.


Subject(s)
Dog Diseases/metabolism , Neoplasms/veterinary , T-Lymphocytes, Regulatory/physiology , Animals , Carcinoma/metabolism , Carcinoma/veterinary , Case-Control Studies , Dogs , Lymphoma/metabolism , Lymphoma/veterinary , Mastocytoma/metabolism , Mastocytoma/veterinary , Neoplasms/metabolism , Sarcoma/metabolism , Sarcoma/veterinary
8.
J Vet Intern Med ; 22(6): 1373-9, 2008.
Article in English | MEDLINE | ID: mdl-18976288

ABSTRACT

BACKGROUND: Continuous administration of low doses of cyclophosphamide and standard doses of cyclooxygenase-inhibiting drugs has been shown to suppress tumor angiogenesis, reverse immunosuppression, and deplete regulatory T cells in cancer models. HYPOTHESIS: We hypothesized that continuous treatment with low-dose cyclophosphamide and full-dose piroxicam would delay tumor recurrence in dogs with soft tissue sarcomas (STS). ANIMALS: Eighty-five dogs with incompletely resected STS, 30 treated dogs, and 55 contemporary control dogs. METHODS: Treatment outcomes in 85 dogs with incompletely resected STS were evaluated in a retrospective study. Dogs in the treatment group received continuously administered low-dose cyclophosphamide (10 mg/m2) and standard dose piroxicam (0.3 mg/kg) therapy. Time to local tumor recurrence (disease-free interval; DFI) was compared between the 30 treated dogs and 55 untreated control dogs matched for age and tumor site and grade. RESULTS: DFI was significantly (P < .0001) prolonged for STS of all sites (trunk and extremity) in treated dogs compared with untreated control dogs. The DFI also was significantly longer in treated dogs when tumor site (trunk and extremity) was compared. Twelve treated dogs (40%) experienced mild toxicity (grade 1 and 2) at some point during treatment and 1 dog developed grade 4 cystitis. Every other day dosing was tolerated better than daily dosing. CONCLUSIONS: Metronomic therapy with cyclophosphamide and piroxicam was very effective in preventing tumor recurrence in dogs with incompletely resected STS. These findings suggest that further evaluation of this approach is warranted as adjuvant therapy in dogs with highly metastatic tumors such as osteosarcoma and melanoma.


Subject(s)
Cyclophosphamide/therapeutic use , Dog Diseases/drug therapy , Neoplasm Recurrence, Local/veterinary , Piroxicam/therapeutic use , Sarcoma/veterinary , Soft Tissue Neoplasms/veterinary , Animals , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Dogs , Neoplasm Recurrence, Local/prevention & control , Neoplasm Recurrence, Local/surgery , Piroxicam/administration & dosage , Piroxicam/adverse effects , Retrospective Studies , Sarcoma/prevention & control , Sarcoma/surgery , Soft Tissue Neoplasms/prevention & control , Soft Tissue Neoplasms/surgery
9.
Vet Immunol Immunopathol ; 116(1-2): 69-78, 2007 Mar 15.
Article in English | MEDLINE | ID: mdl-17224188

ABSTRACT

Regulatory T cells (Treg) are a distinct group of T lymphocytes with immunosuppressive properties that serve normally to prevent harmful autoimmune responses. However, Tregs can also interfere with beneficial immune responses such as anti-tumor and anti-viral immunity in humans and rodents. Given the overall importance of Tregs, it is likely that they play an important role in diseases of dogs as well. However, at present reagents required for identification of Tregs in dogs are not available. Therefore, we investigated whether expression of FoxP3, a transcription factor that is highly expressed in Tregs in humans and rodents could also be used to identify Tregs in dogs. We found that a cross-reactive FoxP3 antibody identified a subset of CD4(+) T cells in blood and lymph nodes of dogs. By flow cytometry the mean percentage of FoxP3(+)CD4(+) T cells in normal dogs was 4.3% in blood and 9.8% in the lymph nodes. In dogs with cancer, there was a significant increase in numbers of Treg in blood (7.5%) and tumor-draining lymph nodes (17.1%) compared to age-matched healthy control dogs. We also found that FoxP3(+)CD4(+) T cells in dogs could be significantly expanded in vitro by TCR activation together with addition of TGF-beta and IL-2. Treated cells also significantly increased expression of TGF-beta and IL-10mRNA. We conclude from these studies that a cross-reactive FoxP3 antibody can be used to identify Tregs in dogs and that this reagent may serve as a useful tool for investigating the role of Treg in a variety of diseases of dogs.


Subject(s)
Biomarkers, Tumor/immunology , Dog Diseases/immunology , Dogs/immunology , Forkhead Transcription Factors/immunology , Melanoma/veterinary , Osteosarcoma/veterinary , T-Lymphocytes, Regulatory/immunology , Animals , Biomarkers, Tumor/biosynthesis , Biomarkers, Tumor/genetics , Dog Diseases/genetics , Dog Diseases/pathology , Flow Cytometry/veterinary , Forkhead Transcription Factors/biosynthesis , Forkhead Transcription Factors/genetics , Interleukin-10/genetics , Interleukin-10/immunology , Lymph Nodes/immunology , Lymphocyte Activation/immunology , Melanoma/genetics , Melanoma/immunology , Osteosarcoma/genetics , Osteosarcoma/immunology , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Statistics, Nonparametric , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/immunology
10.
Vet Comp Oncol ; 5(3): 156-67, 2007 Sep.
Article in English | MEDLINE | ID: mdl-19754787

ABSTRACT

The purpose of this retrospective study was to determine the efficacy and toxicity of a combined protocol of vinblastine, cyclophosphamide and prednisone (VCP) in 35 dogs with mast cell tumours (MCTs). Eleven dogs had measurable disease (group 1) and 24 dogs had incompletely excised MCT or were at high risk for metastasis (group 2). Five patients in group 1 achieved complete response, two partial responses, two stable diseases and two progressive diseases. The median progression-free survival time (PFST) for group 1 and 2 dogs was 74 and 865 days, respectively. The median overall survival time (OST) for group 1 and 2 dogs was 145 and >2092 days, respectively. Significant negative multivariate prognostic factors included macroscopic disease and reduced vinblastine (VBL) treatments for PFST, and presence of MCT in bone marrow analysis, Patnaik grade III MCT and reduced VBL treatments for OST. Toxicity was infrequent and self-limiting. This study suggests that the VCP protocol should be considered as an option in the treatment of MCT in dogs.

11.
Cancer Gene Ther ; 13(3): 306-17, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16138118

ABSTRACT

Intravenous gene delivery using liposome-DNA complexes (LDC) has previously been shown to elicit antitumor activity, but only in rodent tumor models. Therefore, we conducted a study to determine in a large animal spontaneous tumor model whether intravenous infusions of LDC could target gene expression to cutaneous tumor tissues and whether repeated treatments had an effect on tumor growth or angiogenesis. A total of 13 dogs with cutaneous soft tissue sarcomas were enrolled in the study and were randomized to receive a series of 6 weekly infusions of LDC containing either canine endostatin DNA or DNA encoding an irrelevant gene (luciferase). Serial tumor biopsies were obtained to assess transgene expression, tumor microvessel density (MVD), and intratumoral leukocyte inflammatory responses. We found that intravenous infusion of LDC did not result in detectable gene expression in cutaneous tumor tissues. However, two of 13 treated dogs had objective tumor responses and eight dogs had stable disease during the treatment period. In addition, a significant decrease in tumor MVD was noted in six of 12 treated dogs at the completion of six treatments. These results suggest that intravenous infusions of LDC may elicit nonspecific antitumor activity and inhibit tumor angiogenesis.


Subject(s)
DNA/administration & dosage , Dog Diseases/prevention & control , Endostatins/genetics , Neovascularization, Pathologic/veterinary , Sarcoma/veterinary , Skin Neoplasms/veterinary , Animals , Dog Diseases/metabolism , Dogs , Endothelium, Vascular/metabolism , Endothelium, Vascular/pathology , Fibrosarcoma/blood supply , Fibrosarcoma/therapy , Fibrosarcoma/veterinary , Genetic Vectors , Infusions, Intravenous , Liposomes/administration & dosage , Luciferases/genetics , Luciferases/metabolism , Mice , Neovascularization, Pathologic/metabolism , Sarcoma/blood supply , Sarcoma/metabolism , Skin Neoplasms/blood supply , Skin Neoplasms/metabolism , Spleen/metabolism , Spleen/pathology , Transgenes/physiology , Vascular Endothelial Growth Factor A/metabolism
13.
Hum Gene Ther ; 10(18): 2961-72, 1999 Dec 10.
Article in English | MEDLINE | ID: mdl-10609657

ABSTRACT

Local expression of cytokine genes by ex vivo transfection or intratumoral gene delivery can control the growth of cutaneous tumors. However, control of tumor metastases by conventional nonviral gene therapy approaches is more difficult. Intravenous injection of lipid-DNA complexes containing noncoding plasmid DNA can significantly inhibit the growth of early metastatic lung tumors. Therefore, we hypothesized that delivery of a cytokine gene by lipid-plasmid DNA complexes could induce even greater antitumor activity in mice with established lung metastases. The effectiveness of treatment with lipid-DNA complexes containing the IL-2 or IL-12 gene was compared with the effectiveness of treatment with complexes containing noncoding (empty vector) DNA. Treatment effects were evaluated in mice with either early (day 3) or late (day 6) established lung tumors. Lung tumor burdens and local intrapulmonary immune responses were assessed. Treatment with either noncoding plasmid DNA or with the IL-2 or IL-12 gene significantly inhibited the growth of early tumors. However, only treatment with the IL-2 or IL-12 gene induced a significant reduction in lung tumor burden in mice with more advanced metastases. Furthermore, the reduction in tumor burden was substantially greater than that achieved by treatment with recombinant cytokines. Treatment with the IL-2 or IL-12 gene was accompanied by increased numbers of NK cells and CD8+ T cells within lung tissues, increased cytotoxic activity, and increased local production of IFN-gamma by lung tissues, compared with treatment with noncoding DNA. Thus, cytokine gene delivery to the lungs by means of intravenously administered lipid-DNA complexes may be an effective method of controlling lung tumor metastases.


Subject(s)
Cell Division/genetics , Interleukin-12/genetics , Interleukin-2/genetics , Lung Neoplasms/pathology , Lung Neoplasms/secondary , Animals , CD8-Positive T-Lymphocytes/immunology , Cytotoxicity, Immunologic , DNA/administration & dosage , Genetic Vectors , Interferon-gamma/biosynthesis , Killer Cells, Natural/immunology , Lipids/administration & dosage , Lung/metabolism , Lung Neoplasms/immunology , Lymphocyte Depletion , Mice , Mice, Inbred Strains
14.
J Clin Invest ; 101(11): 2406-14, 1998 Jun 01.
Article in English | MEDLINE | ID: mdl-9616212

ABSTRACT

In vivo transfection of established tumors with immunostimulatory genes can elicit antitumor immunity. Therefore, we evaluated the safety and efficacy of intratumoral injections of a bacterial superantigen with a cytokine gene in dogs with malignant melanoma, a spontaneous and highly malignant canine tumor. 26 dogs with melanoma were treated with lipid-complexed plasmid DNA encoding staphylococcal enterotoxin B and either GM-CSF or IL-2. Dogs were evaluated for treatment-associated toxicity, tumor responses, immunologic responses, and survival times. The overall response rate (complete or partial remissions) for all 26 dogs was 46% (12 of 26), and was highest in patients with smaller tumors. Toxicity was minimal or absent in all dogs. Injected tumors developed marked infiltrates of CD4+ and CD8+ T cells and macrophages, and tumor regression was associated with development of high levels of antitumor cytotoxic T lymphocyte activity in peripheral blood lymphocytes. Survival times for animals with stage III melanomas treated by intratumoral gene therapy were prolonged significantly compared with animals treated with surgical tumor excision only. Thus, local tumor transfection with superantigen and cytokine genes was capable of inducing both local and systemic antitumor immunity in an outbred animal with a spontaneously developing malignant tumor.


Subject(s)
Dog Diseases/therapy , Enterotoxins/genetics , Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Interleukin-2/genetics , Melanoma/therapy , Melanoma/veterinary , Superantigens/genetics , Animals , Antibodies, Bacterial/blood , Dog Diseases/mortality , Dog Diseases/pathology , Dogs , Enterotoxins/immunology , Melanoma/mortality , T-Lymphocytes, Cytotoxic/immunology , Transfection
15.
Semin Vet Med Surg Small Anim ; 12(3): 193-205, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9283245

ABSTRACT

The application of gene therapy to the treatment of human and veterinary diseases offers an innovative addition to the clinician's treatment options. Gene therapy can potentially be used to (1) replace defective or missing genes, (2) treat cancer, and (3) deliver drugs. The focus of this paper is the use of gene therapy in the treatment of cancer. To be effective, genes must be delivered to target cells which can then serve as the factory to produce the gene product. Delivery systems include retroviral vectors, adenoviral vectors, and direct introduction of plasmid DNA into cells. In the case of cancer immunotherapy, introduced genes produce products that enhance tumor immunosurveillance and tumor cell killing by immune mechanisms.


Subject(s)
Dog Diseases/therapy , Genetic Therapy/veterinary , Immunotherapy/veterinary , Neoplasms/veterinary , Animals , Dog Diseases/genetics , Dog Diseases/immunology , Dogs , Genetic Therapy/methods , Genetic Vectors , Immunotherapy/methods , Neoplasms/immunology , Neoplasms/therapy , Plasmids
16.
J Am Vet Med Assoc ; 202(11): 1839-44, 1993 Jun 01.
Article in English | MEDLINE | ID: mdl-8320152

ABSTRACT

Eighty-seven cats with histologically confirmed malignant tumors were used in a prospective study to determine the toxicity of mitoxantrone, a dihydroxyquinone derivative of anthracene, which was administered at 21-day intervals at dosages ranging from 2.5 to 6.5 mg/m2 of body surface, IV. Eleven of these cats were treated concurrently with radiation but were evaluated separately. Each cat was evaluated for signs of toxicosis for 3 weeks after each dose was administered or until the cat developed progressive disease, or until the cat's quality of life diminished to an unacceptable level as determined by the owner or attending veterinarian. Although the primary purpose of this study was to determine a clinically useful dosage and to characterize the toxicoses associated with mitoxantrone administration, each cat was monitored for response to treatment. Forty-nine cats had been refractory to 1 or more treatment modalities prior to inclusion in this study. The most common signs of toxicosis after treatment with mitoxantrone were vomiting, anorexia, diarrhea, lethargy, sepsis secondary to myelosuppression, and seizures. Two cats died of complications that may have been attributed to mitoxantrone: 1 of cardiomyopathy and the other of pulmonary edema of an undetermined cause. Older cats were more likely to develop signs of toxicosis after the third or fourth mitoxantrone treatment than younger cats (P < or = 0.05). Cats with signs of toxicosis during the 21-day interval after administration of the first dose of mitoxantrone were significantly (P < or = 0.05) more likely to develop signs of toxicosis during the 21-day interval between the second and third doses of mitoxantrone.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Cat Diseases/drug therapy , Mitoxantrone/toxicity , Neoplasms/veterinary , Animals , Anorexia/chemically induced , Anorexia/veterinary , Carcinoma, Squamous Cell/drug therapy , Carcinoma, Squamous Cell/radiotherapy , Carcinoma, Squamous Cell/veterinary , Cat Diseases/chemically induced , Cat Diseases/radiotherapy , Cats , Chemotherapy, Adjuvant , Dose-Response Relationship, Drug , Female , Male , Mitoxantrone/administration & dosage , Mitoxantrone/therapeutic use , Neoplasms/drug therapy , Neoplasms/radiotherapy , Prospective Studies , Remission Induction , Vomiting/chemically induced , Vomiting/veterinary
17.
Am J Vet Res ; 53(10): 1787-90, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1280926

ABSTRACT

Fifteen dogs were given doxorubicin, IV, at a dosage of 30 mg/m2 of body surface. A commercially available biological extract of Serratia marcescens (BESM) was administered SC to 9 of these dogs (0.04 mg/kg of body weight every third day, n = 2; 0.08 mg/kg every other day, n = 2; and 0.08 mg/kg daily, n = 5), beginning the day after administration of doxorubicin, in an attempt to find an optimal dosage and schedule of administration of BESM to reduce the duration and severity of chemotherapy-induced myelosuppression. Nine additional dogs were randomized into 3 groups of 3 dogs to receive 1 of the following dosages of BESM SC: 0.08, 0.16, and 0.32 mg/kg. Serum was harvested immediately prior to treatment and at 2, 4, 6, 8, 12, 24, 48, and 72 hours from this latter group of dogs for subsequent analysis of canine granulocyte colony-stimulating factor (G-CSF) by enzyme immunoassay. Increasing the dosage and schedule of administration of BESM reduced the duration and severity of doxorubicin-induced myelosuppression. Neutrophil counts of the group of dogs given BESM daily at a dosage of 0.08 mg/kg and the controls were evaluated statistically. The neutrophil count increased significantly (P < 0.05) above pretreatment values in BESM-treated dogs after day 7. Median neutrophil counts of the BESM-treated dogs were never significantly lower than pretreatment values, whereas the median counts of the dogs treated with doxorubicin alone were significantly below normal for 6 days (days 7-12).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Biological Products/therapeutic use , Dog Diseases/prevention & control , Doxorubicin/antagonists & inhibitors , Neutropenia/veterinary , Serratia marcescens , Animals , Dog Diseases/chemically induced , Dogs , Female , Granulocyte Colony-Stimulating Factor/metabolism , Male , Neutropenia/chemically induced , Neutropenia/prevention & control , Neutrophils/metabolism
18.
Obes Surg ; 2(3): 245-252, 1992 Aug.
Article in English | MEDLINE | ID: mdl-10765181

ABSTRACT

As part of the Adelaide Obesity Surgery Study, we have reviewed all patients who have undergone revisional surgery. Of the 31 0 trial patients, 63 (20%) had revisions 1-69 (median 32) months following their original surgery-30% of all 105 gastrogastrostomy (GG) operations, 22% of 106 gastroplasty (GP) procedures, and 9% of 99 gastric bypasses (GB). Failure was due to stomal dilatation, 11% of all trial patients (71% of GG revisions), stomal stenosis, 6% (52% of GP revisions) and staple dehiscence, 4%. There was no mortality and a low hospital morbidity. Long-term success was only 23% (follow-up at least 3 years) and was achieved at considerable expense (3 reversals, 10 further revisions, 44 endoscopic procedures). Revisional surgery was successful in 45% of patients with stomal dilatation or dehiscence but in only 17% with stenosis. Overall, the most successful operation was revision of, or conversion to, gastric bypass (58% success rate), compared with gastroplasty (24%) and gastrogastrostomy (25%). Our long-term results following revisional surgery were disappointing, particularly for stenosis, and most failures followed revision to GG or GP. Roux-en-Y gastric bypass is the procedure of choice when considering revision.

19.
Mol Biother ; 3(4): 231-8, 1991 Dec.
Article in English | MEDLINE | ID: mdl-1768375

ABSTRACT

Normal feline bone marrow-derived macrophages released maximum concentrations of interleukin-6, tumor necrosis factor, and interleukin-1 when stimulated with ImuVert (Cell Technology Inc, Boulder, CO, USA) at dosages of 1.0 microgram/ml, 5.0 micrograms/ml, and 10.0 micrograms/ml, respectively. When ImuVert was administered to healthy adult cats, significant elevations in rectal temperature and neutrophil counts were observed 10 and 24 hours after each treatment. Weekly treatment with ImuVert failed to prevent or reverse viremia in cats when initiated prior to or 6 weeks after inoculation with feline leukemia virus.


Subject(s)
Antineoplastic Agents/therapeutic use , Immunologic Factors/therapeutic use , Leukemia, Experimental/prevention & control , Macrophages/drug effects , Serratia marcescens/metabolism , Viremia/prevention & control , Animals , Antineoplastic Agents/metabolism , Biological Products , Bone Marrow Cells , Cats , Cells, Cultured , Female , Immunologic Factors/biosynthesis , Leukemia, Experimental/therapy , Male , Tumor Necrosis Factor-alpha/analysis , Viremia/therapy
20.
Aust N Z J Surg ; 61(10): 780-8, 1991 Oct.
Article in English | MEDLINE | ID: mdl-1929980

ABSTRACT

This paper concerns a dispute at the Adelaide Hospital in September 1896 between Professor Archibald Watson, Pathologist, Honorary Consulting Surgeon and sole remaining University teacher at the hospital, and Alexander Disney Leith Napier, who had arrived from England to fill the place of the honorary surgeons who had resigned from the hospital. Watson accused Napier of incompetence in his management of 'Mrs L.', who died after a femoral hernia operation. Mrs L had a form of internal hernia causing intestinal obstruction, whereas all the medical attendants, including Watson, originally thought an old femoral hernia was the cause of her illness. By fortuitous coincidence the operation on the femoral hernia could have cured the internal hernia if the band of omentum attached to the femoral hernia had been divided. Watson became aware of the band at the post-mortem and then asserted that the operation should have taken it into account. Napier complained to the Board of the Hospital, alleging that Watson had misrepresented the facts when he conducted the post-mortem on the patient and that he was disloyal to the hospital. The Board found the complaint proved and invited Watson to resign; he declined and was dismissed. Undaunted, Watson circulated a privately printed pamphlet (entitled 'Mrs L.'s case'), which re-stated the events of the case and graphically described his post-mortem findings. It was submitted to the Chairman of a Select Committee of the Legislative Council of South Australia established to review the running of the hospital. The Committee recommended the setting up of a Royal Commission but the Government let the matter lapse.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
General Surgery/history , Hernia, Femoral/surgery , History, 19th Century , Hospitals, Teaching/history , Humans , Intestinal Obstruction/surgery , South Australia
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