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1.
Osteoarthritis Cartilage ; 31(3): 351-362, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36473675

RESUMO

OBJECTIVE: Drug delivery platforms that allow for gradual drug release after intra-articular administration have become of much interest as a treatment strategy for osteoarthritis (OA). The aim of this study was to investigate the safety and efficacy of an intra-articular sustained release formulation containing celecoxib (CXB), a cyclooxygenase-2 (COX-2) selective inhibitor. METHODS: Amino acid-based polyesteramide microspheres (PEAMs), a biodegradable and non-toxic platform, were loaded with CXB and employed in two in vivo models of arthritis: an acute inflammatory arthritis model in rats (n = 12), and a randomized controlled study in chronic OA dog patients (n = 30). In parallel, the bioactivity of sustained release of CXB was evaluated in monolayer cultures of primary dog chondrocytes under inflammatory conditions. RESULTS: Sustained release of CXB did not alleviate acute arthritis signs in the rat arthritis model, based on pain measurements and synovitis severity. However, in OA dog patients, sustained release of CXB improved limb function as objective parameter of pain and quality of life based on gait analysis and owner questionnaires. It also decreased pain medication dependency over a 2-month period and caused no adverse effects. Prostaglandin E2 levels, a marker for inflammation, were lower in the synovial fluid of CXB-treated dog OA patients and in CXB-treated cultured dog chondrocytes. CONCLUSION: These results show that local sustained release of CXB is less suitable to treat acute inflammation in arthritic joints, while safe and effective in treating pain in chronic OA in dogs.


Assuntos
Osteoartrite , Qualidade de Vida , Animais , Cães , Ratos , Anti-Inflamatórios não Esteroides/uso terapêutico , Celecoxib/farmacologia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/uso terapêutico , Inflamação/tratamento farmacológico , Osteoartrite/tratamento farmacológico , Dor/tratamento farmacológico
2.
Vet J ; 286: 105854, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35781075

RESUMO

L-asparaginase is a frequently used drug in the treatment of canine malignant lymphoma. Since production and availability of native E. coli-derived L-asparaginase are limited, PEG-L-asparaginase (PEG-ASP) is an alternative. However, recommended doses and dosing intervals are mainly empirically determined. A multi-phase clinical dose-finding study with seven healthy Beagle dogs was conducted to find the minimum effective dose and, potentially, a dosing interval for PEG-ASP in dogs. Plasma concentrations of amino acids and PEG-ASP activity were measured at various time points after administration of different doses of PEG-ASP. Anti-PEG and anti-asparaginase antibody titres were measured. Administration of 10 IU/kg PEG-ASP resulted in asparagine depletion in all dogs, albeit for various durations: for 9 days in all dogs, 15 days in five dogs, 21 days in three dogs and 29 days in one dog. Asparagine suppression occurred at PEG-ASP plasma concentrations < 25 IU/L. Subsequent administrations of a second and third dose of 20 IU/kg and 40 IU/kg PEG-ASP resulted in asparagine suppression at < 9 days in five dogs, accompanied by the development of antibodies against PEG and L-asparaginase. Two dogs with prolonged asparagine suppression after the second and third administration did not develop antibodies. Marked individual variation in the mechanism and duration of response to PEG-ASP was noted. Antibody formation against PEG-ASP was frequently observed and sometimes occurred after one injection. This study suggests that PEG-ASP doses as high as the currently used dose of 40 IU/kg might not be needed in treatment of canine malignant lymphoma.


Assuntos
Antineoplásicos , Doenças do Cão , Linfoma , Animais , Antineoplásicos/uso terapêutico , Asparagina/uso terapêutico , Doenças do Cão/tratamento farmacológico , Cães , Escherichia coli , Linfoma/tratamento farmacológico , Linfoma/veterinária , Polietilenoglicóis/uso terapêutico
3.
Vet Comp Oncol ; 17(1): 11-20, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30588734

RESUMO

Chemokine (C-C motif) ligand 2 (CCL2) is a chemotactic cytokine recruiting monocytes, releasing growth factors and promoting adhesion in vascular endothelium. Elevated serum and urinary CCL2 levels and expression of its receptor (CCR2) have been associated with tumorigenesis in human urinary malignancies. CCL2 implication has not been investigated in canine urothelial carcinoma. The aim of this study was to evaluate CCL2 serum and urine levels (measured by ELISA) in dogs with urothelial carcinoma or non-neoplastic urinary tract disease. CCL2 serum and urine levels were significantly higher in diseased dogs compared with healthy dogs (P < 0.001). Dogs with carcinoma had significantly higher serum and urine CCL2 levels (P = 0.001) than healthy dogs. Dogs with metastases showed significantly lower serum and urine CCL2 levels compared with the non-metastasised tumour group (P = 0.007). CCL2 as a diagnostic marker for urothelial carcinoma held a sensitivity of 95.2% and a specificity of 38.2% in the urine. As a staging marker, sensitivity was 85.7% and specificity was 57.1% with a positive predictive value of 75.7% and a negative predictive value of 71.9%. Further investigation is needed to define the role of CCL2 as a prognostic marker in canine urothelial carcinoma.


Assuntos
Quimiocina CCL2/sangue , Doenças do Cão/diagnóstico , Neoplasias da Bexiga Urinária/veterinária , Animais , Biomarcadores Tumorais , Quimiocina CCL2/urina , Doenças do Cão/sangue , Doenças do Cão/urina , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Regulação da Expressão Gênica , Masculino , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia , Urotélio
4.
Vet J ; 234: 96-101, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29680402

RESUMO

Respiratory rate is commonly recorded during physical examinations. However, reference intervals are only available for resting and sleeping respiratory rates in cats at home. This observational study aimed to establish reference intervals for the respiratory rate in clinically healthy adult cats at primary-care veterinary clinics. Respiratory rates were recorded from 131 cats, in 6 primary-care veterinary clinics, by observation under four circumstances: by the investigator in the consultation room prior to and during a physical examination, by the owner at home when the cat was resting or sleeping, and by the investigator when watching a video-film of the cat recorded by the owner at home. The respiratory rate of the 88 clinically healthy adult (≥12 months) cats in the consultation room ranged 28-176breaths/min (median 64) with a calculated reference interval of 32-135breaths/min. Based on video-recordings, the resting (n=32) and sleeping (n=38) respiratory rates of the same cats were determined: median 27 (range 16-60)breaths/min and median 20 (range 9-28)breaths/min, respectively, which were lower than the respiratory rates recorded in the consultation room (both P<0.0001). We conclude that the reference intervals proposed for cats in textbooks reflect the resting respiratory rate at home. These values are inappropriate for using in the veterinary consultation room, because based on such reference intervals, many cats would erroneously be categorized as having tachypnea. Since the resting and sleeping respiratory rates at home show less variation, owners should be encouraged to film their pets before they visit their veterinarian.


Assuntos
Gatos/fisiologia , Exame Físico/veterinária , Respiração , Taxa Respiratória/fisiologia , Animais , Doenças do Gato , Valores de Referência , Descanso/fisiologia , Sono/fisiologia
5.
Vet J ; 226: 40-45, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28911840

RESUMO

Peripheral nerve tumours (PNTs) affecting the limbs may lead to chronic pain, lameness and/or monoparesis that is refractory to medical treatment. The most common radical therapy for PNTs has been surgical excision with limb amputation. However, compartmental resection with preservation of the limb has been performed by the authors with favourable clinical results and therefore this bi-institutional retrospective study was undertaken to assess limb function, survival and recurrence. Sixteen dogs that had been diagnosed with PNTs between 1995 and 2011 met the inclusion criteria for this study. In the majority of the cases, good to excellent limb function was achieved. The overall median survival time (MST) was 1303days (42.8 months; range, 14 days-4639 days, [0.5-152.4 months]), with two dogs still alive at time of evaluation. Non-infiltrated margins were the best prognostic indicator; dogs with non-infiltrated margins had a MST of 2227days (P<0.001) compared to dogs with infiltrated margins (MST of 487 days). The 1-year calculated survival rate was 68.8% and the 2- and 3-year calculated survival rates were 62.5%. Surgical treatment with tumour removal and limb spare for proximal and distal PNTs can be successful. Compartmental excision can lead to good limb function, producing survival comparable to limb amputation, and should therefore be considered as an alternative to limb amputation in canine PNTs.


Assuntos
Doenças do Cão/cirurgia , Salvamento de Membro/veterinária , Mixossarcoma/veterinária , Neoplasias de Bainha Neural/veterinária , Neoplasias do Sistema Nervoso Periférico/veterinária , Sarcoma/veterinária , Animais , Cães , Extremidades/cirurgia , Feminino , Masculino , Mixossarcoma/cirurgia , Neoplasias de Bainha Neural/cirurgia , Nervos Periféricos/cirurgia , Neoplasias do Sistema Nervoso Periférico/cirurgia , Prognóstico , Estudos Retrospectivos , Sarcoma/cirurgia
6.
Vet Q ; 37(1): 8-15, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27786603

RESUMO

BACKGROUND: Although scientific evidence is limited, clopidogrel is frequently used as prophylaxis for arterial thromboembolism in cats with hypertrophic cardiomyopathy (HCM). OBJECTIVES: Evaluating effects of clopidogrel therapy in asymptomatic cats with HCM on (1) conventional whole blood aggregation (WBA), (2) alternative platelet aggregation assessed with tubes of the Plateletworks® assay and (3) standard coagulation parameters. ANIMALS AND METHODS: Prospective, randomized, double-blind, placebo-controlled pilot study. Fourteen asymptomatic HCM cats were randomly allocated to receive placebo (n = 5) or clopidogrel (18.75 mg/cat q24h, n = 9) as part of a larger study. Aggregation responses (to 20 µM adenosine diphosphate (ADP) and 10 µg/ml collagen) in WBA and the Plateletworks® assay and standard coagulation parameters were evaluated at baseline and after seven days of therapy. RESULTS: Clopidogrel therapy significantly reduced aggregation responses to ADP and collagen in the Plateletworks® agonists tubes (ADP and collagen: P < 0.001), but did not significantly reduce aggregation responses to ADP and collagen in the WBA technique (ADP: P = 0.07, collagen: P = 0.30). Clopidogrel therapy did not show a significant effect on prothrombin time, activated partial thromboplastin time, antithrombin, D-dimers and fibrinogen concentrations. CONCLUSION AND CLINICAL IMPORTANCE: Clopidogrel therapy at a dose of 18.75 mg/cat q24h for seven days causes a significant decrease in in vitro platelet aggregation evaluated with the Plateletworks® assay, without affecting standard coagulation parameters in cats with asymptomatic HCM.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Cardiomiopatia Hipertrófica/veterinária , Doenças do Gato/tratamento farmacológico , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Ticlopidina/análogos & derivados , Difosfato de Adenosina/administração & dosagem , Animais , Doenças Assintomáticas/terapia , Cardiomiopatia Hipertrófica/tratamento farmacológico , Cardiomiopatia Hipertrófica/etiologia , Doenças do Gato/etiologia , Gatos , Clopidogrel , Método Duplo-Cego , Feminino , Masculino , Projetos Piloto , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Estudos Prospectivos , Ticlopidina/efeitos adversos , Ticlopidina/farmacologia , Ticlopidina/uso terapêutico
7.
Vet Comp Oncol ; 14 Suppl 1: 127-35, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26364581

RESUMO

This study evaluated efficacy and side effects of masitinib in canine epitheliotropic lymphoma. Complete remission occurred in 2 of 10 dogs and lasted for median 85 days. Five dogs went into partial remission for median 60.5 days. Three pretreated dogs did not respond to therapy. Side effects occurred in six dogs and were mostly mild to moderate. Immunohistochemistry was available for eight dogs. KIT receptor was negative in all of them, six of eight lymphomas stained strongly positive for stem cell factor (SCF). platelet-derived growth factor (PDGF)-AA was weakly positive in two and negative in six. PDGF-BB was negative in four tumours, weakly positive in one and strongly positive in three. One was strongly positive for PDGF receptor (PDGFR)-ß, seven were negative for that receptor. Five showed strong expression of PDGFR-α, two showed weak expression, one was negative. In conclusion, masitinib is effective in treating canine epitheliotropic lymphoma. But its effects are most likely not generated through the KIT receptor.


Assuntos
Doenças do Cão/tratamento farmacológico , Linfoma de Células T/veterinária , Tiazóis/farmacologia , Animais , Becaplermina , Benzamidas , Doenças do Cão/sangue , Cães , Imuno-Histoquímica/veterinária , Linfoma de Células T/tratamento farmacológico , Piperidinas , Fator de Crescimento Derivado de Plaquetas/análise , Proteínas Proto-Oncogênicas c-kit/sangue , Proteínas Proto-Oncogênicas c-sis/sangue , Piridinas , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/sangue , Receptor beta de Fator de Crescimento Derivado de Plaquetas/sangue , Indução de Remissão , Resultado do Tratamento
9.
J Vet Intern Med ; 29(6): 1524-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26415555

RESUMO

BACKGROUND: The aims of this study were to establish the prevalence of innocent cardiac murmurs in clinically healthy puppies, to investigate a possible correlation between the presence of an innocent murmur and hematocrit, and to describe the auscultation characteristics of innocent murmurs. HYPOTHESIS: Lower hematocrit contributes to the genesis of innocent murmurs. ANIMALS: Five hundred and eighty-four client-owned clinically healthy puppies, between 20 and 108 days old. METHODS: Two cross-sectional surveys with a 1-year (n = 389 pups) pilot and a half-year (n = 195 pups) principal study periods. Cardiac auscultation was performed by a single, board-certified cardiologist. Hematocrit was measured with an automatized hematology analyzer. Echocardiography was performed only on puppies with a cardiac murmur in the principal study. RESULTS: In the pilot study, 15% of the dogs had a murmur. Innocent murmur was diagnosed in 28% of the 195 dogs in the principal study. Innocent murmurs were systolic, mostly with a musical character and with a maximal intensity of 2 of 6, and mostly with the point of maximal intensity in the left cardiac base. The hematocrit was significantly lower in the group with a murmur compared to the group without (P = .023). CONCLUSIONS AND CLINICAL IMPORTANCE: Innocent murmur was a common finding in puppies at the age when the first veterinary controls usually take place. Physiologic anemia contributes to the genesis of innocent murmurs in puppies. Rising hematocrit in growing puppies can explain the spontaneous disappearance of innocent murmurs with aging. Hematocrit did not differentiate innocent murmurs from abnormal murmurs.


Assuntos
Cães , Auscultação Cardíaca/veterinária , Sopros Cardíacos/veterinária , Animais , Estudos Transversais , Sopros Cardíacos/sangue , Sopros Cardíacos/diagnóstico , Projetos Piloto
10.
J Small Anim Pract ; 56(7): 446-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25882569

RESUMO

OBJECTIVE: To determine whether polyxylon bandage contact lenses influence healing time and ocular comfort in the management of spontaneous chronic corneal epithelial defects in dogs. METHODS: Twenty dogs with spontaneous chronic corneal epithelial defects were included. All dogs were treated by debridement under topical anaesthesia at the first presentation. Ten dogs were assigned to the study group (application of a polyxylon bandage contact lens), and the remaining ten served as a control group. The healing time and ocular (dis)comfort were evaluated by assessment of the clinical findings and an owner-based questionnaire. All dogs received the same topical and systemic medication. RESULTS: Healing time for dogs in the study population was significantly shorter (mean 14±0 days) than for dogs in the control group (mean 36±17 days; P=0·005). The spontaneous chronic corneal epithelial defects had completely healed at the first recheck in all dogs with a polyxylon bandage contact lens. The duration of blepharospasm following debridement was significantly shorter in the study population (mean 4±4 days) than in the control group (mean 30±20 days; P=0·001). CLINICAL SIGNIFICANCE: The use of polyxylon bandage contact lenses is beneficial in the management of spontaneous chronic corneal epithelial defects.


Assuntos
Lentes de Contato/veterinária , Doenças da Córnea/veterinária , Doenças do Cão/cirurgia , Animais , Doenças da Córnea/patologia , Doenças da Córnea/cirurgia , Desbridamento/veterinária , Cães , Epitélio Corneano/patologia , Epitélio Corneano/cirurgia , Feminino , Masculino , Inquéritos e Questionários , Resultado do Tratamento
11.
Artigo em Inglês | MEDLINE | ID: mdl-25599379

RESUMO

OBJECTIVE: To evaluate the diagnostic value of cytology of endoscopically obtained biopsies in cats presented for chronic gastrointestinal complaints with emphasis on the diagnosis of low-grade alimentary lymphoma (LGAL). MATERIALS AND METHODS: Data of endoscopically obtained duodenal biopsies from 137 cats were evaluated retrospectively. Cytology was performed using the squash smear technique with subsequent Diff Quick® staining. Pathological findings were categorized according to type and grade of the inflammatory infiltrate. Moreover, reports were reviewed with regard to diagnosis of LGAL. Histopathology reports were analysed correspondingly and compared to cytology results. Histopathological samples were further evaluated by immunohistochemistry (IHC) if a diagnosis of LGAL had been expressed. RESULTS: Squash smear preparation of intestinal biopsies was adequate for cytological examination in >97% of cases. Using histopathology as gold standard, with cytology, a sensitivity and specificity for detection of a pathologic process in feline intestinal biopsies of 68.1% and 70.6% were calculated, respectively. Regarding the detection of lymphoplasmacytic (LPE) and eosinophilic enteritis a statistically significant correlation with histopathology (p<0.05) was observed. With regard to grade of the inflammatory infiltrate, a weak correlation was calculated (r=0.482). Of 21 cats diagnosed or suspected with LGAL by cytology, IHC confirmed nine cases whereas 11 cases were reclassified as LPE. None of the confirmed LGAL had been missed with histopathology. A sensitivity of 60.0% and specificity of 90.6% for cytological detection of feline LGAL was obtained. CONCLUSION AND CLINICAL RELEVANCE: The sensitivity of cytology to diagnose LGAL is low and it has no additional significance to histological biopsies.


Assuntos
Biópsia , Doenças do Gato , Endoscopia Gastrointestinal , Enteropatias , Animais , Biópsia/métodos , Biópsia/veterinária , Doenças do Gato/diagnóstico , Doenças do Gato/cirurgia , Gatos , Doença Crônica , Endoscopia Gastrointestinal/métodos , Endoscopia Gastrointestinal/veterinária , Enteropatias/diagnóstico , Enteropatias/cirurgia , Enteropatias/veterinária , Estudos Retrospectivos , Sensibilidade e Especificidade
12.
J Vet Intern Med ; 29(1): 395-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25407950

RESUMO

BACKGROUND: Hypophosphatemia in early lactating dairy cows has been implicated as primary cause for postparturient hemoglobinuria in cattle. Decreased availability of phosphorus has been proposed to reduce adenosine triphosphate synthesis of erythrocytes and thereby reduce osmotic resistance of these cells. HYPOTHESIS/OBJECTIVES: To study the effect of phosphorus depletion on the phosphate concentration ([Pi]) in plasma and erythrocytes and the osmotic resistance of erythrocytes and to determine the association between plasma [Pi] and erythrocyte [Pi]. ANIMALS: Ten healthy midlactating dairy cows in their 3rd to 5th lactation. METHODS: Prospective study. Dietary phosphorus depletion for 5 weeks followed by phosphorus supplementation. Plasma and erythrocyte [Pi] and erythrocyte osmotic resistance were measured. Four cows underwent continuous dextrose infusion at the end of phosphate depletion to exacerbate hypophosphatemia. RESULTS: Dietary P depletion resulted in a marked decline of the plasma [Pi] from 4.1 ± 1.0 mg/dL to a nadir of 1.7 ± 0,5 mg/dL, but did not alter erythrocyte [Pi] or osmotic resistance. Similarly, dextrose infusion induced a decline of the plasma [Pi] from 2.4 ± 0.5 mg/dL to 1.5 ± 0.5 mg/dL, but had no effect on erythrocyte [Pi] or osmotic resistance. CONCLUSIONS AND CLINICAL IMPORTANCE: In cattle, marked hypophosphatemia induced by dietary P depletion was neither associated with a decline in erythrocyte [Pi] nor with decreased osmotic resistance of erythrocytes. Phosphorus depletion alone is therefore unlikely to cause intravascular hemolysis and the plasma [Pi] is an unreliable index for the intracellular [Pi] of erythrocytes.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Dieta/veterinária , Eritrócitos/fisiologia , Fosfatos/metabolismo , Fósforo na Dieta/administração & dosagem , Animais , Eritrócitos/química , Feminino , Pressão Osmótica , Fosfatos/administração & dosagem , Fosfatos/farmacologia , Fósforo na Dieta/farmacologia
13.
Vet J ; 205(2): 263-71, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25475167

RESUMO

Canine lymphoma is typically treated with a doxorubicin-based multidrug chemotherapy protocol. Although this is often initially successful, tumour recurrence is common and frequently refractory to treatment. Failure to respond to chemotherapy is thought to represent drug resistance and has been associated with active efflux of cytostatic drugs by transporter proteins of the ATP-binding cassette (ABC) family, including P-glycoprotein (ABCB1), MRP1 (ABCC1) and BCRP (ABCG2). In this study, ABC transporter mRNA expression was assessed in 63 dogs diagnosed with multicentric lymphoma that were treated with a doxorubicin-based chemotherapy protocol. Expression of ABCB1, ABCB5, ABCB8, ABCC1, ABCC3, ABCC5 and ABCG2 mRNA was quantified in tumour samples (n = 107) obtained at the time of diagnosis, at first tumour relapse and when the tumour was no longer responsive to cytostatic drugs while receiving chemotherapy. Expression data were related to patient demographics, staging, treatment response and drug resistance (absent, intrinsic, acquired). ABC transporter expression was independent of sex, weight, age, stage or substage, but T cell lymphoma and hypercalcaemia were associated with increased ABCB5 and ABCC5 expression, and decreased ABCC1 mRNA expression. Drug resistance occurred in 35/63 (55.6%) dogs and was associated with increased ABCB1 mRNA expression in a subset of dogs with B cell lymphoma, and with increased ABCG2 and decreased ABCB8, ABCC1 and ABCC3 mRNA expression in T cell lymphomas. ABC transporter expression in the pre-treatment sample was not predictive of the length of the first disease-free period or overall survival. Glucocorticoids had no effect on ABC transporter mRNA expression. In conclusion, drug resistance in canine multicentric lymphoma is an important cause of treatment failure and is associated with upregulation of ABCB1 and ABCG2 mRNA.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Doenças do Cão/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Linfoma/veterinária , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Antineoplásicos/uso terapêutico , Doenças do Cão/tratamento farmacológico , Cães , Feminino , Estudos Longitudinais , Linfoma/tratamento farmacológico , Linfoma/metabolismo , Masculino
14.
Toxicol In Vitro ; 28(8): 1498-506, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24975508

RESUMO

Canine lymphoma is routinely treated with a doxorubicin-based multidrug chemotherapy protocol, and although treatment is initially successful, tumor recurrence is common and associated with therapy resistance. Active efflux of chemotherapeutic agents by transporter proteins of the ATP-Binding Cassette superfamily forms an effective cellular defense mechanism and a high expression of these transporters is frequently observed in chemotherapy-resistant tumors in both humans and dogs. In this study we describe the ABC-transporter expression in a canine lymphoid cell line and a sub-cell line with acquired drug resistance following prolonged exposure to doxorubicin. This sub-cell line was more resistant to doxorubicin and vincristine, but not to prednisolone, and had a highly increased P-glycoprotein (P-gp/abcb1) expression and transport capacity for the P-gp model-substrate rhodamine123. Both resistance to doxorubicin and vincristine, and rhodamine123 transport capacity were fully reversed by the P-gp inhibitor PSC833. No changes were observed in the expression and function of the ABC-transporters MRP-1 and BCRP. It is concluded that GL-40 cells represent a useful model for studying P-gp dependent drug resistance in canine lymphoid neoplasia, and that this model can be used for screening substances as potential P-gp substrates and their capacity to modulate P-gp mediated drug resistance.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Resistência a Múltiplos Medicamentos , Linfoma/tratamento farmacológico , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/análise , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Linhagem Celular , Modelos Animais de Doenças , Cães , Resistencia a Medicamentos Antineoplásicos , Linfoma/patologia , Rodamina 123/metabolismo
15.
Vet Comp Oncol ; 12(1): 37-46, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22489828

RESUMO

In this retrospective study, the efficacy and safety were examined for an intraperitoneal chemotherapy protocol-cyclophosphamide, vincristine and prednisolone (IP-COP) in 26 cats with malignant lymphoma. Certainly in cats fiercely resisting IV administration the IP route is a more practical method, safer for the administrator and less stressful for the cat. Complete remission (CR) rate was 76.9% (n = 20). Median duration of first remission was 421 days. Estimated 1- and 2-year disease free period were 67.1 and 48.0%, respectively. Median duration of survival was 388 days and estimated overall 1- and 2-year survival periods were 54.7 and 46.9% respectively. Young cats had a more favourable prognosis. Reaching CR was essential for long-term survival. No specific IP-related adverse events (AE) were seen. AE were generally scored as mild and were not excessively abundant. These results indicate that the IP route is a safe and effective alternative for the administration of COP protocol chemotherapeutics.


Assuntos
Antineoplásicos/uso terapêutico , Doenças do Gato/tratamento farmacológico , Ciclofosfamida/uso terapêutico , Linfoma/veterinária , Prednisolona/uso terapêutico , Vincristina/uso terapêutico , Animais , Antineoplásicos/administração & dosagem , Gatos , Ciclofosfamida/administração & dosagem , Feminino , Injeções Intraperitoneais , Linfoma/tratamento farmacológico , Masculino , Prednisolona/administração & dosagem , Vincristina/administração & dosagem
16.
Vet J ; 197(3): 656-61, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23746872

RESUMO

Chemotherapy protocols for canine lymphoma include the routine use of glucocorticoids for their lympholytic effect. However, glucocorticoids are associated with side effects (e.g. polyphagia, polyuria, and weight gain), limit the use of non-steroidal anti-inflammatory drugs, and can induce drug transporter expression that could lead to drug resistance. Despite these negative effects, there are no data to support the use of glucocorticoids as part of a multidrug chemotherapy protocol for the treatment of canine lymphoma. A prospective, randomized clinical trial was conducted in 81 dogs with multicentric lymphoma and no history of recent glucocorticoid use. All dogs were staged and treated with the same chemotherapy protocol (L-asparaginase, cyclophosphamide, doxorubicin, vincristine, and prednisolone) with half of the dogs receiving prednisolone. Both treatment groups were similar with respect to demographics, immunophenotype, and clinical stage, except for a higher number of substage b patients in the prednisolone group (5 vs. 14; P=0.015). Treatment results obtained with the initial treatment (complete response rate 75%, disease-free period 176 days) and rescue treatment (complete response rate 45%, disease-free period 133 days), overall survival (283 days) and adverse events (number and grade) were similar for both groups. In conclusion, prednisolone, as part of a multidrug chemotherapy protocol, has no additional effect on treatment results and can be omitted from first-line multidrug protocols used for the treatment of canine lymphoma.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doenças do Cão/tratamento farmacológico , Linfoma/veterinária , Prednisolona/uso terapêutico , Animais , Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/uso terapêutico , Cães , Feminino , Linfoma/tratamento farmacológico , Masculino , Prednisolona/administração & dosagem , Resultado do Tratamento
17.
J Vet Pharmacol Ther ; 36(6): 583-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23363222

RESUMO

Overexpression of ABC-transporters including Pgp, MRP1, and BCRP has been associated with multidrug resistance (MDR) in both human and canine oncology. Therapeutic interventions to reverse MDR are limited, but include multidrug protocols and the temporary concomitant use of inhibitors of ABC-transporters. Recently, the use of tyrosine kinase inhibitors has been proposed to overcome MDR in human oncology. One of the tyrosine kinase inhibitors, masitinib, is licensed for veterinary use in the treatment of canine mast cell tumors. Therefore, this study aimed to assess the potential of masitinib to revert MDR in canine malignant lymphoma using an in vitro model with canine lymphoid cell lines. Masitinib had a mild antiproliferative effect on lymphoid cells, inhibited Pgp function at concentrations equal to or exceeding 1 µm and was able to reverse doxorubicin resistance. The current findings provide the rationale for a combined use of masitinib with doxorubicin in the treatment of dogs with doxorubicin-resistant malignant lymphoma but await confirmation in clinical trials.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Tiazóis/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Benzamidas , Linhagem Celular Tumoral , Cães , Relação Dose-Resposta a Droga , Fluoresceínas/metabolismo , Regulação da Expressão Gênica , Piperidinas , Piridinas , Rodamina 123/metabolismo , Succinimidas/metabolismo
18.
Vet Comp Oncol ; 9(4): 283-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22077409

RESUMO

Safety and efficacy of pegylated liposome encapsulated doxorubicin (PL-DOX) was compared with free doxorubicin as an adjuvant monotherapy in dogs with splenic haemangiosarcoma after splenectomy in a randomized prospective clinical trial. A total of 17 dogs in each group were treated. No significant difference in survival between the two treatments was found. The calculated median overall survival time for the 34 dogs was 166 days [95% confidence interval (CI) 148-184]. The ½ year and one-year survival was 41.2% (95% CI 24.8-56.9) and 22.7% (95% CI 9.9-37.4), respectively. In dogs treated with PL-DOX, a desquamating dermatitis like palmar-plantar erythrodysesthesia (PPES) was seen in two dogs, while three other dogs showed anaphylactic reactions. Cardiotoxicity was not seen in either treatment groups.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Doenças do Cão/tratamento farmacológico , Doxorrubicina/análogos & derivados , Doxorrubicina/toxicidade , Hemangiossarcoma/veterinária , Polietilenoglicóis/toxicidade , Neoplasias Esplênicas/veterinária , Animais , Antibióticos Antineoplásicos/normas , Quimiorradioterapia Adjuvante/veterinária , Cães , Doxorrubicina/normas , Feminino , Alemanha , Hemangiossarcoma/tratamento farmacológico , Masculino , Polietilenoglicóis/normas , Neoplasias Esplênicas/tratamento farmacológico , Neoplasias Esplênicas/patologia , Análise de Sobrevida
19.
Vet Immunol Immunopathol ; 144(3-4): 346-54, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21899896

RESUMO

A high mortality occurs in dogs with idiopathic immune-mediated haemolytic anaemia (IMHA) during the first 2 weeks after the diagnosis. The aim of this study was to investigate the inflammatory response and coagulation abnormalities in dogs with IMHA in relation to the prognosis and to establish the contribution of whole blood tissue factor (TF) and IL-8 gene expressions. Gene expressions in dogs with IMHA were compared to healthy dogs, dogs with DIC, dogs with sepsis, and in two groups of dogs that underwent intensive care treatment but had no evidence for either DIC or sepsis. The whole blood TF and IL-8 expressions were up regulated in all non-IMHA groups. Similarly, the TF expression in IMHA dogs was high, but the intravascular IL-8 expression was not increased. The dogs with IMHA had a pronounced inflammatory response that included a high WBC, left shift and monocytosis in comparison to the other disease groups. Coagulation factor activities in IMHA dogs were decreased fitting consumptive coagulopathy and the acute phase proteins FVIII and fibrinogen were increased. The platelet parameters suggested platelet activation and high platelet turnover in IMHA dogs. The model that best explained mortality contained monocytosis, increased activated partial thromboplastin time and elevated creatinine. Whole blood TF gene expression is up regulated and may contribute to consumptive coagulopathy in dogs with IMHA. Increased TF expression by activated platelets is an alternative explanation and should be investigated.


Assuntos
Anemia Hemolítica Autoimune/veterinária , Doenças do Cão/metabolismo , Tromboplastina/biossíntese , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/imunologia , Anemia Hemolítica Autoimune/metabolismo , Animais , Coagulação Sanguínea , Coagulação Intravascular Disseminada/imunologia , Coagulação Intravascular Disseminada/metabolismo , Coagulação Intravascular Disseminada/veterinária , Doenças do Cão/diagnóstico , Doenças do Cão/imunologia , Cães , Feminino , Inflamação/imunologia , Inflamação/veterinária , Interleucina-8/biossíntese , Interleucina-8/sangue , Masculino , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Sepse/imunologia , Sepse/metabolismo , Sepse/veterinária , Tromboplastina/análise
20.
Vet Pathol ; 48(1): 7-18, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20664014

RESUMO

There is an increasing need for more accurate prognostic and predictive markers in veterinary oncology because of an increasing number of treatment options, the increased financial costs associated with treatment, and the emotional stress experienced by owners in association with the disease and its treatment. Numerous studies have evaluated potential prognostic and predictive markers for veterinary neoplastic diseases, but there are no established guidelines or standards for the conduct and reporting of prognostic studies in veterinary medicine. This lack of standardization has made the evaluation and comparison of studies difficult. Most important, translating these results to clinical applications is problematic. To address this issue, the American College of Veterinary Pathologists' Oncology Committee organized an initiative to establish guidelines for the conduct and reporting of prognostic studies in veterinary oncology. The goal of this initiative is to increase the quality and standardization of veterinary prognostic studies to facilitate independent evaluation, validation, comparison, and implementation of study results. This article represents a consensus statement on the conduct and reporting of prognostic studies in veterinary oncology from veterinary pathologists and oncologists from around the world. These guidelines should be considered a recommendation based on the current state of knowledge in the field, and they will need to be continually reevaluated and revised as the field of veterinary oncology continues to progress. As mentioned, these guidelines were developed through an initiative of the American College of Veterinary Pathologists' Oncology Committee, and they have been reviewed and endorsed by the World Small Animal Veterinary Association.


Assuntos
Oncologia/normas , Neoplasias/veterinária , Guias de Prática Clínica como Assunto , Medicina Veterinária/normas , Animais , Progressão da Doença , Neoplasias/patologia , Prognóstico
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