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1.
OBJECTIVE: To evaluate cyclooxygenase isozyme distribution in tissues from dogs and determine the differential sensitivity of canine cyclooxygenase (COX)-1 and -2 isozymes to nonsteroidal anti-inflammatory drugs (NSAIDs). SAMPLE POPULATION: Canine tissue samples (stomach, duodenum, ileum, jejunum, colon, spleen, cerebral cortex, lung, ovary, kidney, and liver) were obtained from 2 dogs for northern and western blot analyses, and blood for whole blood COX assays was obtained from 15 dogs. PROCEDURE: 11 NSAIDs were evaluated to determine their COX-2 selectivity in whole blood assays. The concentrations of the drug needed to inhibit 50% of enzyme activity (IC50) were then calculated for comparison. Expression and tissue distribution of COX isozymes were determined by northern and western blot analysis. RESULTS: Aspirin, diclofenac, indomethacin, ketoprofen, meclofenamic acid, and piroxicam had little selectivity toward COX isozymes, whereas NS398, carprofen, tolfenamic acid, nimesulide, and etodolac had more than 5 times greater preference for inhibiting COX-2 than COX-1. All canine tissues examined, including those from the gastrointestinal tract, coexpressed COX-1 and -2 mRNA, although protein expression was observed only for COX-1. CONCLUSIONS AND CLINICAL RELEVANCE: Canine COX-2 was selectively inhibited by etodolac, nimesulide, and NS398; tolfenamic acid and carprofen also appeared to be preferential COX-2 inhibitors in dogs. The roles of COX-1 as a constitutive housekeeping enzyme and COX-2 as a proinflammatory inducible enzyme (as determined in humans) appear to apply to dogs; therefore, COX-2-selective inhibitors should prove useful in reducing the adverse effects associated with nonselective NSAIDs.  相似文献   

2.
The canine Mcl-1 gene was cloned and sequenced. Canine Mcl-1 clone was 2694 base pairs in length and encoded 350 amino acids. The predicted amino acid sequence was 87.7%, 77.1% and 75.7% homologous to predicted human, mouse and rat Mcl-1, respectively. RT-PCR analysis revealed that canine Mcl-1 mRNA was expressed in PBMCs (peripheral blood mononuclear cells), bone marrow cells, MDCK (Madin-Darby canine kidney) and GL-1 (canine B cell leukemia) whereas undetectable in CL-1 (canine T cell lymphoma) cell line.  相似文献   

3.
OBJECTIVE: To evaluate cyclooxygenase (COX) selectivity of several nonsteroidal anti-inflammatory drugs (NSAID) in canine blood in vitro. ANIMALS: 11 healthy adult male hound crosses. PROCEDURE: 9 NSAID were studied at 5 concentrations. Thromboxane B2 (TxB2) was assayed as a measure of COX-1 activity in clotted blood. Prostaglandin E2 (PGE2) was assayed as a measure of COX-2 activity in heparinized, lipopolysaccharide (LPS)-stimulated blood. All assays were competitive ELISA tests. Cyclooxygenase selectivity was expressed as a ratio of the concentration of an NSAID that inhibited 50% of the activity (IC50) of COX-1 to the IC50 of COX-2. A separate ratio of the concentration that inhibited 80% of COX activity (IC80) was also determined. A ratio of < 1.0 indicated selectivity for COX-1, whereas a ratio of > 1.0 indicated COX-2 selectivity. RESULTS: Ketoprofen, aspirin, and etodolac were COX-1 selective. Piroxicam, meloxicam, and carprofen had COX-2 selectivity. The IC50 and IC80 values were similar for most NSAID. CONCLUSIONS: This methodology provides repeatable data from individual dogs and is comparable to results of previous in vitro and ex vivo models. Findings are also consistent with those of canine studies performed in vivo, suggesting that this is a viable in vitro assessment of the COX selectivity of NSAID in dogs.  相似文献   

4.
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5.
对流行病学调查、临床症状检查和ELISA检测为犬瘟热阳性的自然发病犬,取肠内容物为病料,采用同步培养方法接种于犬肾细胞系(MDCK)进行病毒的分离,并对分离株进行了形态学特征、血凝特性、动物感染及RT-PCR鉴定。结果表明:病料接种MDCK细胞产生明显的细胞病变(CPE),电镜负染观察接毒细胞培养物见有典型的犬瘟热病毒粒子。分离株不凝集鸡及人“O”型红细胞,接种犬出现明显的临床症状和病理变化。用RT-PCR技术检测病毒细胞培养液,扩增出的片段长为760 bp,与预期设计的长度相同,由此确证分离株为犬瘟热病毒,命名为CDV-GZ2株。  相似文献   

6.
Cyclooxygenase (COX) performs the critical initial reaction in the arachidonic metabolic cascade, leading to formation of proinflammatory prostaglandins, thromboxanes, and prostacyclins. The discovery of a second COX isoform (COX-2) associated with inflammation led to agents that selectively inhibit COX-2. Cyclooxygenase-2 inhibitors are also being developed for canine applications. To assess the compound potency on canine enzymes, canine COX-1 and COX-2 were cloned, expressed, and purified. Cyclooxygenase-1 was cloned from a canine kidney complementary DNA (cDNA) library, with 96 % sequence homology to human COX-1. Cyclooxygenase-2 was cloned from canine kidney and lipopolysaccharide-stimulated macrophage cDNA libraries, with a 93 % sequence homology to human COX-2. The arachidonic acid Michaelis constants for canine COX-1 and COX-2 were 4.8 and 6.6 micrometer, respectively, compared with 9.6 and 10.2 micrometer for ovine. Inhibition results indicated that, for all compounds tested, there was no significant difference between potencies determined for canine enzymes and those for human enzymes.  相似文献   

7.
OBJECTIVE: To induce chemoresistance in a normal canine cell line through the transduction of the canine multidrug resistance 1 gene (mdr1). SAMPLE POPULATION: Madin-Darby canine kidney (MDCK) epithelial cell line. PROCEDURES: The full-length canine mdr1 cDNA clone isolated in our laboratory was inserted into a Moloney murine leukemia virus-based vector to construct the retroviral vector, pLNC-cMDR1. After retroviral transduction of pLNC-cMDR1 into MDCK cells, the expression and function of the P-glycoprotein, a product of mdr1, were assessed by immunoblotting, measurement of rhodamine123 (Rh123) retention, and drug sensitivity assays. RESULTS: P-glycoprotein was strongly expressed in cells transduced with pLNC-cMDR1. This P-glycoprotein was fully functional, as demonstrated by the decreased Rh123 retention and the increased resistance to chemotherapeutic drugs. Measured as 50% inhibitory concentrations, resistance increased 59 times to vincristine and 25 times to doxorubicin in MDCK cells after transduction of pLNC-cMDR1. CONCLUSIONS AND CLINICAL RELEVANCE: Transduction of canine mdr1 is an effective method for inducing chemoresistance in normal canine cells. This system may be applicable to the induction of drug resistance in hematopoietic cells.  相似文献   

8.
OBJECTIVES: To determine the role that cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) play in malignant transformation in canine transitional cell carcinoma and rectal tumours. METHODS: Histological sections of 21 canine rectal adenocarcinomas and 18 canine transitional cell carcinomas were stained for COX-1 and COX-2. Mann-Whitney non-parametric tests were applied to determine if there was any relationship between the percentage of cells expressing COX-1 or COX-2, and between COX-1 and COX-2 staining intensity and age, breed or sex. RESULTS: For rectal adenocarcinomas, 19.0 per cent of the sections were negative for COX-1 and COX-2. A further 38.1 per cent of the sections were negative for COX-2 but positive for COX-1, and 38.1 per cent of the sections had rare or occasional single cells positive for COX-2. No significant differences were found in COX staining when compared with age, breed or sex. For transitional cell carcinomas, all of the sections were positive for COX-1 and COX-2. For COX-2 staining, 16.7 per cent had more than 30 per cent positive cells. For COX-1 staining, 38.9 per cent had more than 30 per cent positive cells. There was a significant increase in the percentage of COX-1 positive cells in small breed dogs (P = 0.0337). CLINICAL SIGNIFICANCE: The variations in COX expression reported in this study may explain the differences in the clinical response of transitional cell carcinomas and rectal adenocarcinomas following treatment with non-steroidal anti-inflammatory drugs.  相似文献   

9.
Canine and human platelets (washed 4 times in a solution containing EDTA, prostaglandin E1, and theophylline to prevent release of alpha-granule constituents) were lysed by being frozen and thawed in the presence of detergent. Radioelectroimmunoassay for von Willebrand factor (vWf) in 5 human platelet lysates produced precipitin rockets, shaped like those produced from vWf in plasma from healthy human beings, and indicated that the mean von Willebrand factor antigen (vWf:Ag) content in platelets from healthy human being was 526 +/- 87 human U/10(12) platelets. Radioelectroimmunoassay for vWf in platelet lysates from 17 healthy dogs with normal plasma. vWf:Ag concentration produced precipitin rockets that looked different from those produced from canine plasma and indicated vWf:Ag content of 59 +/- 35 canine U/10(12) platelets. Inclusion of protease inhibitors in the lysing solution did not normalize the appearance of the precipitin rockets or substantially alter the measured platelet content of vWf:Ag. The array of vWf multimers revealed by sodium dodecyl sulfate-agarose gel electrophoresis of canine platelet lysates had a distinct appearance that differed from that of vWf in canine or human plasma and platelets; the intensity of the canine platelet vWf multimer bands was skewed, with relatively greater density in the lower molecular weight region and faint or undetectable multimer bands in the higher molecular weight region. Electrophoretograms with visible multimers in the high molecular weight region had vWf components that had higher molecular weight than did any vWf components in canine plasma. Radioelectroimmunoassay for fibronectin in these same canine platelet lysates indicated that the fibronectin content in platelets was 2.89 +/- 1.10 mg/10(12) platelets.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Prohibitin is an antiproliferative protein that is a product of a putative tumor suppressor gene. However, there is little information on prohibitins in companion animals. In this study, we cloned canine prohibitin mRNA using RT-PCR and 3′-RACE (Rapid Amplification of cDNA Ends). The sequence was well conserved compared with those of other mammals, including human. The deduced amino acid sequence translated from the open reading frame completely corresponded to the human sequence. Canine prohibitin mRNA was expressed in all normal mammary and tumor samples examined. These results suggest that this protein plays a vital role in cell growth mechanisms and may be related to the occurrence of canine mammary tumors.  相似文献   

11.
BACKGROUND: Cyclooxygenase-2 (COX-2) expression has been documented in human and canine prostate carcinoma (PCA). Canine PCA is a histologically heterogeneous tumor, sometimes including inflammatory infiltrates. However, it is unknown whether COX-2 expression in canine PCA is related to the histologic type of tumor, to the presence of inflammation, or to both. Moreover, little is known about the mechanisms regulating COX-2 expression in neoplastic tissue. HYPOTHESIS: COX-2 expression is related to the presence of inflammation in canine PCA and correlates with the degree of tumor differentiation. METHODS: The expression of COX-2 was examined in 28 cases of canine PCA by immunohistochemistry. In addition, a neoplastic and a nonneoplastic canine prostatic cell line were used to investigate the effects of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), phorbol 12-myristate 13-acetate (PMA), epithelial growth factor (EGF), and specific signal transduction pathway inhibitors on COX-2 expression. RESULTS: Twenty-four of the 28 prostate tumors showed COX-2 expression. The presence of inflammatory infiltrates in tumor tissue was associated with lower COX-2 expression scores. In vitro, TNF-alpha, IL-6, and EGF increased COX-2 expression in nonneoplastic cells but not in PCA cells, where baseline expression was high. COX-2 expression in PCA cells could be suppressed by means of specific phosphatidyl inositol-3 kinase (PI3K), protein kinase C (PKC), or inhibitor of extracellular signal-related kinase (ERK/MAPK) inhibitors. CONCLUSIONS AND CLINICAL IMPORTANCE: COX-2 is expressed in canine PCA; however, expression is not related to the presence of inflammatory infiltrates. This conclusion is further supported by the finding that the cytokines TNF-alpha and IL-6 and their involved signaling pathways do not stimulate COX-2 expression in malignant canine prostate cells.  相似文献   

12.
Nonsteroidal anti-inflammatory drug (NSAID)-activated gene (NAG-1), a divergent member of the transforming growth factor beta superfamily, was previously identified as a gene induced by several anti-tumorigenic compounds, including NSAIDs and peroxisome proliferator-activated receptor gamma (PPARgamma) ligands in humans. In this study, canine NAG-1 was characterised from a canine genomic database. Gene induction by some NSAIDs and PPARgamma ligands was demonstrated in canine osteosarcoma cell lines. Phylogenetic analysis indicates that canine NAG-1 is more homologous with the corresponding mouse and rat genes than with human NAG-1. Expression of canine NAG-1 was increased by treatment with piroxicam and SC-560 (NSAIDs) and the PPARgamma ligand rosiglitazone. This study demonstrates that canine NAG-1 is up-regulated by some anti-tumorigenic compounds in osteosarcoma cell lines and may provide an important target of chemotherapy in canine cancer.  相似文献   

13.
Cyclooxygenase (COX)-2 is involved in several physiologic and pathologic processes. COX-2 is overexpressed in human and canine prostate cancer, but little is known about COX-2 inducers in the prostate. Our objective was to investigate the effect of sex steroid hormones on COX-2 expression in the canine prostate in vivo. COX-2 expression was evaluated by immunohistochemistry in intact and castrated dogs treated with exogenous androgen or estrogen. Results showed that no COX-2 staining was observed in prostates of untreated or androgen-treated castrated or intact dogs. However, treatment of intact and castrated dogs with estrogen resulted in squamous metaplasia with intense COX-2 expression observed in both squamous epithelial cells and in cells of acini without metaplasia. This is the first report to demonstrate the induction of COX-2 by estrogen in the prostate in vivo.  相似文献   

14.
Canine herpesvirus 1 (CHV-1) has a relatively narrow host cell range when compared to other alphaherpesviruses. The early events of CHV-1 infection in a permissive Madin-Darby canine kidney (MDCK) and non-permissive cell lines. In order to quantify attachment and penetration, were investigated quantitative competitive PCR (QCPCR) method was established for quantitation of CHV-1 DNA. In all non-permissive cells tested, no significant decrease in viral attachment was observed. When CHV-1 was treated with heparin, viral attachment to MDCK cells was reduced by 25% of the input CHV-1 attached to MDCK cells even in the presence of 50 microg/ml heparin. However, the attachment of CHV-1 to non-permissive cells was severely impaired by heparin treatment. In permissive MDCK cells, about 80% of attached CHV-1 penetrated into cells. However, only 4-10% of CHV-1 attached to non-permissive cells penetrated into cells. Our data indicated that CHV-1, like other herpesviruses, attached to permissive MDCK cells through two mechanisms: the first one is through the interaction mediated by heparan sulfate (HS) on the cell surface and the second involves unidentified viral component and the cellular receptor. In contrast, the non-permissive cells lacked the cellular receptor for the second attachment mechanism and the defect in viral penetration into non-permissive cell might be related to the lack of the cellular receptor.  相似文献   

15.
OBJECTIVE: To determine potency and selectivity of nonsteroidal anti-inflammatory drugs (NSAID) and cyclooxygenase- (COX-) specific inhibitors in whole blood from horses, dogs, and cats. SAMPLE POPULATION: Blood samples from 30 healthy horses, 48 healthy dogs, and 9 healthy cats. PROCEDURE: Activities of COX-1 and COX-2 were determined by measuring coagulation-induced thromboxane and lipopolysaccharide-induced prostaglandin E2 concentrations, respectively, in whole blood with and without the addition of various concentrations of phenylbutazone, flunixin meglumine, ketoprofen, diclofenac, indomethacin, meloxicam, carprofen, 5-bromo-2[4-fluorophenyl]-3-14-methylsulfonylphenyl]-thiophene (DuP 697), 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl) phenyl-2(5H)-furan one (DFU), 3-(3,4-difluorophenyl)-4-(4-(methylsulfonyl)phenyl)-2-(5H)-furanone (MF-tricyclic), and celecoxib. Potency of each test compound was determined by calculating the concentration that resulted in inhibition of 50% of COX activity (IC50). Selectivity was determined by calculating the ratio of IC50 for COX-1 to IC50 for COX-2 (COX-1/COX-2 ratio). RESULTS: The novel compound DFU was the most selective COX-2 inhibitor in equine, canine, and feline blood; COX-1/COX-2 ratios were 775, 74, and 69, respectively. Carprofen was the weakest inhibitor of COX-2, compared with the other COX-2 selective inhibitors, and did not inhibit COX-2 activity in equine blood. In contrast, NSAID such as phenylbutazone and flunixin meglumine were more potent inhibitors of COX-1 than COX-2 in canine and equine blood. CONCLUSIONS AND CLINICAL RELEVANCE: The novel COX-2 inhibitor DFU was more potent and selective in canine, equine, and feline blood, compared with phenylbutazone, flunixin meglumine, and carprofen. Compounds that specifically inhibit COX-2 may result in a lower incidence of adverse effects, compared with NSAID, when administered at therapeutic dosages to horses, dogs, and cats.  相似文献   

16.
Cyclooxygenase (COX) inhibitors, already widely used to reduce fever, inflammation and pain, are under increasing consideration as potential agents for the prevention and treatment of neoplasia. As COX-2 was detected in human and canine osteosarcomas, we have evaluated the effect of the preferential COX-2 inhibitor meloxicam on an established D-17 canine osteosarcoma cell line, which expressed, as well as COX-1 and COX-2 also COX-3 (as demonstrated by Western blot). An XTT proliferation kit was used to assess surviving cells after drug treatment. At low concentrations (1, 2, 4 and 10 microm) meloxicam caused an increase in cell numbers while a marked anti-proliferative effect was observed at higher concentrations (100, 200 microm) after 3 days and also 3 weeks of incubation. The chemotherapeutic drug doxorubicin showed a cytotoxic effect at all concentrations (60-1920 nm). Exposure of tumour cells to combinations of meloxicam and doxorubicin revealed synergistic effects (with 240 nm doxorubicin), as well as sub-additive and antagonistic results, especially if combined with concentrations of meloxicam typically found in serum. Care should be taken in concluding, on the basis of one in vitro study, that meloxicam does not have a role in the treatment of canine osteosarcomas given that the results from in vivo studies may differ.  相似文献   

17.
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18.
The inducible inflammatory enzyme cyclooxygenase‐2 (COX‐2) and its product prostaglandin E2 (PGE2) are prominent tumour promoters, and expression of COX‐2 is elevated in a number of tumours of both humans and canines. Targeting COX‐2 in cancer is an attractive option because of readily available non‐steroidal anti‐inflammatory drugs (NSAIDs), and there is a clear epidemiological link between NSAID use and cancer risk. In this study, we aim to establish the anti‐tumourigenic effects of the selective, long‐acting COX‐2 inhibitor mavacoxib. We show here that mavacoxib is cytotoxic to a panel of human and canine osteosarcoma, mammary and bladder carcinoma cancer cell lines; that it can induce apoptosis and inhibit the migration of these cells. Interestingly, we establish that mavacoxib can exert these effects independently of elevated COX‐2 expression. This study highlights the potential novel use of mavacoxib as a cancer therapeutic, suggesting that mavacoxib may be an effective anti‐cancer agent independent of tumour COX‐2 expression.  相似文献   

19.
A panel of 380 commercially available monoclonal antibodies (mAbs) against human CD molecules from various sources was tested during the 8th Human Leukocyte Differentiation Antigen Workshop (HLDA8) for cross-reactivity on canine peripheral blood leukocytes by flow cytometry. In addition, all mAbs were used to label a 50:50 mixture of platelets and erythrocytes of the same dogs. This testing resulted in 51 cross-reacting mAbs. mAbs with specificity for CD9, CD29, CD42a, CD61, and CD41/CD61 showed cross-reactivity with canine platelets in a non-polymorphic and one mAb with the erythrocyte antigen CD235a in a polymorphic reaction pattern. Canine leukocyte-reactive mAbs included those with specificity for CD11a, CD11b, CD14, CD18, CD21, CD22, CD47, CD49d, CD49e, CD56, CD62L, CD91, CD94, and CD172a. In addition, several mAbs resulted in a staining pattern of canine cells which suggest that the canine epitope equivalents have an alternate expression pattern from that expected for humans (CD1a, CD35, CD44, CD45, CD75s, CD81). In summary, this study confirmed the reactivity of previously described cross-reactive mAbs with canine cells and resulted in the characterization of mAbs recognizing so far undetectable canine CD molecules.  相似文献   

20.
This communication reports the cloning of cDNAs encoding two canine IL-13 receptor alpha chains (caIL-13Ralpha1 and caIL-13Ralpha2). As described for the members of type-I cytokine receptors, both caIL-13Ralpha1 and caIL-13Ralpha2 were found to contain the highly conserved motifs, such as cysteine and tryptophan residues in their N-terminal portion and the WSXWS at C-terminus. The isolated caIL-13Ralpha1 cDNA contains 1547 nucleotides with an open reading frame that encodes 405 amino acid residues. Canine IL-13Ralpha1 is 82.0 and 69.3% identical to human and mouse IL-13Ralpha1s, respectively, at the amino acid level. Canine IL-13Ralpha1 has an almost identical cytoplasmic domain to its human and mouse counterparts. The isolated caIL-13Ralpha2 cDNA contains 1454 nucleotides and encodes an open reading frame of 386 amino acid residues. Canine IL-13Ralpha2 is 62.6 and 47.5% identical to its human and mouse counterparts, respectively, at the amino acid level. Using RT-PCR with caIL-13Ralpha1 and caIL-13Ralpha2 specific primers, mRNAs of caIL-13Ralpha1 and caIL-13Ralpha2 were detected in most dog tissues. In addition, RT-PCR detected caIL-13Ralpha1 mRNA in one of two canine mastocytoma (C2 but not Br) cell lines and in a canine macrophage-derived cell line (DH82). CaIL-13Ralpha2 mRNA was detected in all three canine cell lines.  相似文献   

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