| 1. |
- Christensen, Kjeld, et al.
(författare)
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Effects on blood compatibility in vitro by combining a direct P2Y(12) receptor inhibitor and heparin coating of stents
- 2006
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Ingår i: Platelets. - : Informa UK Limited. - 0953-7104 .- 1369-1635. ; 17:5, s. 318-327
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Tidskriftsartikel (refereegranskat)abstract
- The effect of the direct platelet P2Y12 receptor inhibitor, AR-C69931MX, on activation of blood induced by stents with and without heparin coating was investigated using a whole blood Chandler loop model in vitro . Stents were deployed in Chandler loops. Fresh human blood with heparin and AR-C69931MX was rotated for 1 h at 37°C and used for measurements of platelets, microparticles, thrombin-antithrombin complex (TAT), fibrinogen binding to platelets, P-selectin expression by platelets, CD11b, Prothrombin Fragment F1+2, FXIa-AT, FXIIa-AT, C3a, sC5b-9 and stent score. In the first experiment there were four study groups with unmodified stents: 1a, no AR-C69931MX; 1b, 250 nmol/L; 1c, 750 nmol/L; 1d, 2250 nmol/L of AR-C69931MX. In the second experiment the concentration of AR-C69931MX was 500 nmol/L: 2a; tubings without stent; 2b; tubings with heparin-coated stent; 2c; tubings with unmodified stents. Heparin-coated stents were used in the third experiment: 3a; no AR-C69931MX; 3b; 500 nmol/L of AR-C69931MX. In the first experiment there were significant differences in all parameters analysed except for C3a, and stent score when the group with no AR-C69931MX was compared to all the groups with AR-C69931MX. In the second experiment there were significant differences in platelet count, TAT, FXIa-AT, FXIIa-AT and stent score when unmodified stents were compared to loops with no stents and partly to loops with heparin-coated stents. In the third experiment there was a significant reduction in generation of TAT, stent score and better preservation of platelet number by combining the platelet inhibitor and heparin-coated stents as compared to heparin-coated stents alone. The conclusion is that the direct P2Y12 receptor inhibitor AR-C69931MX reduced the different aspects of activation of blood induced by both unmodified and heparin-coated stents.
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| 4. |
- Gullbo, Joachim, et al.
(författare)
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Antitumor activity of the novel melphalan containing tripeptide J3 (L-prolyl-melphalanyl-p-L-fluorophenylalanine ethyl ester) : Comparison with its m-L-sarcolysin analogue P2
- 2003
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Ingår i: Molecular Cancer Therapeutics. - 1535-7163 .- 1538-8514. ; 2:12, s. 1331-1339
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Tidskriftsartikel (refereegranskat)abstract
- Peptichemio (PTC), a mixture of six oligopeptides all containing m-L-sarcolysin, has previously shown impressive results in clinical trials. The tripeptide P2 (L-prolyl-m-L-sarcolysyl-p-L-fluorophenylalanine ethyl ester) has been suggested as the main contributor to PTC activity. In contrast to its analogue melphalan, m-L-sarcolysin never reached clinical use. To allow a direct comparison, the corresponding melphalan containing tripeptide J3 (L-prolyl-L-melphalanyl-p-L-fluorophenylalanine ethyl ester) was synthesized and its activity was compared with that of P2; the activities of melphalan and m-L-sarcolysin were studied in parallel. Cytotoxic activity in human tumor cell lines and some fresh human tumor specimens were analyzed as well as effects on cellular metabolism, macromolecular synthesis, and preliminary evaluation of the cell death characteristics. The results show that melphalan and m-L-sarcolysin display similar activity in these systems and that the tripeptides were more active than their parent monomers. Surprisingly however, the melphalan containing tripeptide J3 demonstrated a significantly more rapid and stronger activity than the m-L-sarcolysin analogue P2. Finally, the in vivo toxicity and activity of melphalan and J3 were investigated in mice bearing human leukemia cells in s.c. fibers. The in vitro results seem translatable into the in vivo situation, demonstrating better antileukemic effect of J3 but similar side effects as melphalan.
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| 5. |
- Gullbo, Joachim, et al.
(författare)
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Antitumor efficacy and acute toxicity of the novel dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) in vivo.
- 2004
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Ingår i: Investigational new drugs. - 0167-6997. ; 22:4, s. 411-20
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Tidskriftsartikel (refereegranskat)abstract
- The novel alkylating dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) was evaluated for acute toxicity and antitumor activity in mice, with melphalan as a reference. To determine a safe and tolerable dose for efficacy studies the acute toxicity following intravenous injection in the tail vein was monitored using a 14-day schedule with up to four doses. The highest tested dose, 25 micromoles/kg, was considered close to this level, with minor effects on body weight gain but significant effects on hematological parameters. Melphalan and J1 appeared equitoxic with no statistically significant differences. Subsequently a mouse hollow fiber model was employed with subcutaneous implantation of fibers containing human tumor cells. Three different human tumor cell lines as well as two samples of primary human tumor cells (ovarian carcinoma and chronic lymphatic leukemia) were used as tumor models. At the dose level tested there was a marked and statistically significant decrease in both T-cell leukemia CCRF-CEM and small cell lung cancer NCI-H69 tumor cell growth and viability in response to J1 as compared with both placebo and melphalan treated groups. In primary ovarian carcinoma cells only J1 treatment resulted in significant tumor regression (net cell kill). In summary the results indicate that, despite an expected short half time in the blood circulation, the promising in vitro data from the previous studies of J1 seems translatable into the in vivo situation. At equal doses of alkylating units J1, compared to melphalan, was more active in the mouse hollow-fiber model, but showed similar general toxicity.
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| 6. |
- Gullbo, Joachim, et al.
(författare)
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Structure activity relationship for alkylating dipeptide nitrogen mustard derivatives
- 2003
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Ingår i: Oncology Research. - : Computers, Materials and Continua (Tech Science Press). - 0965-0407 .- 1555-3906. ; 14:3, s. 113-132
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Tidskriftsartikel (refereegranskat)abstract
- The strategy of using small peptides for effective targeting of tumor cells in chemotherapy has proven beneficial. Recently we showed that J1 (L-melphalanyl-p-L-fluorophenylalanine ethyl ester), an alkylating nitrogen mustard-containing dipeptide, exhibited strong cytotoxic activity in fresh human tumor samples in addition to rapid and pronounced inhibition of macromolecular syntheses and cellular respiration in the human tumor lymphoma cell line U-937 GTB. In this study, an additional series of 17 nitrogen mustard-containing dipeptides has been synthesized and analyzed for cytotoxic activity in a panel of 10 human tumor cell lines. The results were compared to the single amino acid mustard derivative melphalan and its ethyl and isopropyl esters. Also P2 (L-prolyl-m-L-sarcolysyl-p-L-fluorophenylalanine ethyl ester), a tripeptide that previously has shown impressive effects in human tumor cells, was used as reference. The tested compounds displayed various activities in the different cell lines but also showed a high correlation, indicating a similar mechanism of action. Factors like amino acid composition, amino acid sequence, modifications of the C- and N-termini, and to a minor extent the lipophilicity of the dipeptide derivatives appear to influence the in vitro activity. The results indicate that the activity of these compounds not only relies on their chemical reactivity, but also on active biological interactions such as transport across membranes and/or enzymatic liberation of reactive molecular entities.
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| 8. |
- Johnell, Matilda, et al.
(författare)
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Coagulation, fibrinolysis and cell activation in patients and shed mediastinal blood during coronary artery bypass grafting using a new heparin-coated surface
- 2002
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier BV. - 0022-5223 .- 1097-685X. ; 124:2, s. 321-332
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Heparin coating of the cardiopulmonary bypass circuit is shown to improve the biocompatibility of the surface. We have studied a new heparin surface, the Corline Heparin Surface, applied to a complete set of an extracorporeal device used during coronary artery bypass grafting in terms of activation of inflammation, coagulation, and fibrinolysis in patients and in shed mediastinal blood. METHODS: Sixty patients scheduled for coronary artery bypass grafting were randomized to one of 3 groups with heparin-coated devices receiving either a standard, high, or low dose of systemic heparin or to an uncoated but otherwise identical circuit receiving a standard dose of systemic heparin. Samples were drawn before, during, and after the operation from the pericardial cavity and in shed mediastinal blood. No autotransfusion of shed mediastinal blood was performed. RESULTS: The Corline Heparin Surface significantly reduced the activation of coagulation, fibrinolysis, platelets, and inflammation compared with that seen with the uncoated surface in combination with a standard dose of systemic heparin during cardiac surgery with cardiopulmonary bypass. Both a decrease and an increase of systemic heparin in combination with the coated heparin surface resulted in higher activation of these processes. A significantly higher expression of all studied parameters was found in the shed mediastinal blood compared with in systemic blood at the same time. CONCLUSIONS: The Corline Heparin Surface used in cardiopulmonary bypass proved to be more biocompatible than an uncoated surface when using a standard systemic heparin dose. The low dose of systemic heparin might not be sufficient to maintain the antithrombotic activity, and the high dose resulted in direct cell activation rather than a further anti-inflammatory and anticoagulatory effect.
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| 9. |
- Larsson, Dhana E., et al.
(författare)
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Combination analyses of anti-cancer drugs on human neuroendocrine tumor cell lines
- 2009
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Ingår i: Cancer Chemotherapy and Pharmacology. - : Springer Science and Business Media LLC. - 0344-5704 .- 1432-0843. ; 65:1, s. 5-12
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: There is a large need for better pharmacological treatment of neuroendocrine tumors. The aim of this study was to investigate and quantify the cytotoxic potentiating effects resulting from a combination of five substances, NSC 95397, emetine, CGP-74514A hydrochloride, Brefeldin A and sanguinarine chloride, chosen from a previous screening of 1,280 pharmacologically active agents on neuroendocrine tumor cells, with standard cytotoxic agents currently used in the treatment of neuroendocrine tumors. METHOD: The human pancreatic carcinoid cell line BON-1, human typical bronchial carcinoid cell line NCI-H727 and the human atypical bronchial carcinoid cell line NCI-H720 were used. Combinations between doxorubicin, etoposide, oxaliplatin, docetaxel, and each one of the five agents were studied and simultaneous exposures were explored using the median-effect method. RESULTS: Most of the combinations of NSC-95397 and emetine with doxorubicin, etoposide, docetaxel, and oxaliplatin showed synergism, and their remaining combinations were additive. Almost all of the CGP-74514A hydrochloride interactions were additive, while brefeldin A and sanguinarine displayed less synergy but more additive and antagonistic interactions in combination with the standard drugs. CONCLUSION: The synergistic and additive interactions make NSC-95397, emetine, and CGP-74514A hydrochloride potential candidates for incorporation into combination chemotherapy regimens and these drugs might be the suitable candidates for further clinical studies in patients with bronchial carcinoids and pancreatic endocrine tumors.
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| 10. |
- Larsson, Dhana E., et al.
(författare)
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Identification and evaluation of potential anti-cancer drugs on human neuroendocrine tumor cell lines
- 2006
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 26:6B, s. 4125-4129
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate drug sensitivity in neuroendocrine tumor cell lines. Materials and Methods: In vitro drug sensitivity screening was performed using the fluorometric microculture cytotoxicity assay in one human pancreatic carcinoid and two human bronchial carcinoid cell lines. In addition, a normal human retinal pigment epithelial cell line was used for comparison. A total of 18 drugs with different mechanisms of action were tested. Results: The most active agents were brefeldin A, emetine, bortezomib and idarubicin, having IC50 values < 1 μM in all four cell lines. In addition, the three tumor cell lines showed sensitivity for sanguinarine, Bay11-7085, mitoxantrone, doxorubicin, β-lapachone, NSC 95397 and CGP-74514A. Conclusion: The cell lines were sensitive for several drugs acting in different ways, covering a broad spectrum of mechanisms of action. Some of these compounds may possibly be used in clinical trials and show therapeutic effect in patients with neuroendocrine tumors.
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