Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 298
Filtrar
1.
Sci Rep ; 11(1): 8981, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33903692

RESUMO

Mebendazole is used extensively for treatment of local gut helminthic and invasive echinococcus infections. Anticancer effects of mebendazole have been shown in experimental cancer models and in case studies in patients with advanced cancer. Given these observations, the aims of this study were to investigate safety and efficacy of individualized dosed mebendazole in the cancer indication. Patients with treatment refractory gastrointestinal cancer were treated with individualized dose adjusted mebendazole up to 4 g/day to target a serum concentration of 300 ng/ml. Efficacy and safety were assessed by CT-scans, clinical surveillance and blood sampling. Eleven patients were included in the study and 10 started the treatment phase. Two patients stopped treatment prior to and the remaining eight after tumour evaluation by CT-scan at 8 weeks, all due to progressive disease. Four patients also fulfilled criteria suggested for hyperprogression. Only five patients reached the target serum-mebendazole concentration. No severe adverse effects were observed. Individualized dose adjusted mebendazole is safe and well tolerated in patients with advanced cancer but all patients experienced rapid progressive disease. New approaches such as prodrug development and combination with other anticancer drugs seem needed for further exploration of mebendazole as an anticancer drug.


Assuntos
Antineoplásicos , Neoplasias Gastrointestinais , Mebendazol , Tomografia Computadorizada por Raios X , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Feminino , Neoplasias Gastrointestinais/diagnóstico por imagem , Neoplasias Gastrointestinais/tratamento farmacológico , Humanos , Masculino , Mebendazol/administração & dosagem , Mebendazol/farmacocinética , Pessoa de Meia-Idade
2.
J Environ Manage ; 240: 47-56, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30928794

RESUMO

This study focuses on drivers for changing urban flood risk. We suggest a framework for guiding climate change adaptation action concerning flood risk and manageability in cities. The identified key drivers of changing flood hazard and vulnerability are used to provide an overview of each driver's impact on flood risk and manageability at the city level. We find that identified drivers for urban flood risk can be grouped in three different priority areas with different time horizon. The first group has high impact but is manageable at city level. Typical drivers in this group are related to the physical environment such as decreasing permeability and unresponsive engineering. The second group of drivers is represented by public awareness and individual willingness to participate and urbanization and urban sprawl. These drivers may be important and are manageable for the cities and they involve both short-term and long-term measures. The third group of drivers is related to policy and long-term changes. This group is represented by economic growth and increasing values at risk, climate change, and increasing complexity of society. They have all high impact but low manageability. Managing these drivers needs to be done in a longer time perspective, e.g., by developing long-term policies and exchange of ideas.


Assuntos
Mudança Climática , Inundações , Cidades , Meio Ambiente , Urbanização
3.
Biochem Pharmacol ; 118: 40-49, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27565890

RESUMO

Cytogenetic lesions often alter kinase signaling in acute myeloid leukemia (AML) and the addition of kinase inhibitors to the treatment arsenal is of interest. We have screened a kinase inhibitor library and performed combination testing to find promising drug-combinations for synergistic killing of AML cells. Cytotoxicity of 160 compounds in the library InhibitorSelect™ 384-Well Protein Kinase Inhibitor I was measured using the fluorometric microculture cytotoxicity assay (FMCA) in three AML cell lines. The 15 most potent substances were evaluated for dose-response. The 6 most cytotoxic compounds underwent combination synergy analysis based on the FMCA readouts after either simultaneous or sequential drug addition in AML cell lines. The 4 combinations showing the highest level of synergy were evaluated in 5 primary AML samples. Synergistic calculations were performed using the combination interaction analysis package COMBIA, written in R, using the Bliss independence model. Based on obtained results, an iterative combination search was performed using the therapeutic algorithmic combinatorial screen (TACS) algorithm. Of 160 substances, cell survival was ⩽50% at <0.5µM for Cdk/Crk inhibitor, KP372-1, synthetic fascaplysin, herbimycin A, PDGF receptor tyrosine kinase inhibitor IV and reference-drug cytarabine. KP372-1, synthetic fascaplysin or herbimycin A obtained synergy when combined with cytarabine in AML cell lines MV4-11 and HL-60. KP372-1 added 24h before cytarabine gave similar results in patient cells. The iterative search gave further improved synergy between cytarabine and KP372-1. In conclusion, our in vitro studies suggest that combining KP372-1 and cytarabine is a potent and synergistic drug combination in AML.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Citarabina/agonistas , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Tetrazóis/farmacologia , Adulto , Antimetabólitos Antineoplásicos/química , Antimetabólitos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citarabina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Fluoresceína/metabolismo , Corantes Fluorescentes/metabolismo , Ensaios de Triagem em Larga Escala , Humanos , Concentração Inibidora 50 , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Masculino , Proteínas Proto-Oncogênicas c-akt/metabolismo , Bibliotecas de Moléculas Pequenas , Espectrometria de Fluorescência , Células Tumorais Cultivadas
4.
Sci Rep ; 5: 14118, 2015 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-26392291

RESUMO

In vitro-based search for promising anti-cancer drug combinations may provide important leads to improved cancer therapies. Currently there are no integrated computational-experimental methods specifically designed to search for combinations, maximizing a predefined therapeutic index (TI) defined in terms of appropriate model systems. Here, such a pipeline is presented allowing the search for optimal combinations among an arbitrary number of drugs while also taking experimental variability into account. The TI optimized is the cytotoxicity difference (in vitro) between a target model and an adverse side effect model. Focusing on colorectal carcinoma (CRC), the pipeline provided several combinations that are effective in six different CRC models with limited cytotoxicity in normal cell models. Herein we describe the identification of the combination (Trichostatin A, Afungin, 17-AAG) and present results from subsequent characterisations, including efficacy in primary cultures of tumour cells from CRC patients. We hypothesize that its effect derives from potentiation of the proteotoxic action of 17-AAG by Trichostatin A and Afungin. The discovered drug combinations against CRC are significant findings themselves and also indicate that the proposed strategy has great potential for suggesting drug combination treatments suitable for other cancer types as well as for other complex diseases.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Algoritmos , Automação Laboratorial , Linhagem Celular Tumoral , Análise por Conglomerados , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Quimioterapia Combinada , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Esferoides Celulares , Células Tumorais Cultivadas
5.
Blood Cancer J ; 5: e307, 2015 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-25885427

RESUMO

To find drugs suitable for repositioning for use against leukemia, samples from patients with chronic lymphocytic, acute myeloid and lymphocytic leukemias as well as peripheral blood mononuclear cells (PBMC) were tested in response to 1266 compounds from the LOPAC(1280) library (Sigma). Twenty-five compounds were defined as hits with activity in all leukemia subgroups (<50% cell survival compared with control) at 10 µM drug concentration. Only one of these compounds, quinacrine, showed low activity in normal PBMCs and was therefore selected for further preclinical evaluation. Mining the NCI-60 and the NextBio databases demonstrated leukemia sensitivity and the ability of quinacrine to reverse myeloid leukemia gene expression. Mechanistic exploration was performed using the NextBio bioinformatic software using gene expression analysis of drug exposed acute myeloid leukemia cultures (HL-60) in the database. Analysis of gene enrichment and drug correlations revealed strong connections to ribosomal biogenesis nucleoli and translation initiation. The highest drug-drug correlation was to ellipticine, a known RNA polymerase I inhibitor. These results were validated by additional gene expression analysis performed in-house. Quinacrine induced early inhibition of protein synthesis supporting these predictions. The results suggest that quinacrine have repositioning potential for treatment of acute myeloid leukemia by targeting of ribosomal biogenesis.


Assuntos
Ensaios de Seleção de Medicamentos Antitumorais , Leucemia Mieloide Aguda/tratamento farmacológico , Leucócitos Mononucleares/efeitos dos fármacos , Quinacrina/isolamento & purificação , Antineoplásicos/isolamento & purificação , Antineoplásicos/uso terapêutico , Células HL-60 , Humanos , Leucemia Mieloide Aguda/patologia , Quinacrina/uso terapêutico
6.
Case Rep Oncol ; 6(1): 84-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23569442

RESUMO

Inflammatory pseudotumour is a rare condition that can affect various organs. The clinical and histologic appearance of the pseudotumour may mimic haematological, lymphoproliferative, paraneoplastic or malignant processes. A previously healthy 39-year-old man presented with nephrotic syndrome. He had a history of headaches, nausea and swollen ankles. Computed tomography of the abdomen revealed a 6-cm mass in the spleen. Following a renal biopsy, a diagnosis of membranoproliferative glomerulonephritis (MPGN) type I was made. Splenectomy was performed and the examination revealed a mixed population of lymphocytes with predominantly T-cells, B-cells and lymphoplasmacytoid cells. Immunostaining confirmed that the small cells were mostly T-cells positive for all T-cell markers including CD2, CD3, CD4, CD5, CD7 and CD8. A diagnosis of inflammatory pseudotumour was established. The removal of the spleen was followed by remission of glomerulonephritis, but it was complicated by a subphrenic abscess and pneumonia. This association between an inflammatory pseudotumour of the spleen and MPGN has not been previously described. Abnormal immune response due to the inflammation leading to secondary glomerulonephritis might be the main pathogenic mechanism.

7.
Blood Cancer J ; 2: e81, 2012 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-22864397

RESUMO

Aberrantly expressed tyrosine kinases have emerged as promising targets for drug development in acute myeloid leukemia (AML). We report that AKN-028, a novel tyrosine kinase inhibitor (TKI), is a potent FMS-like receptor tyrosine kinase 3 (FLT3) inhibitor (IC(50)=6 nM), causing dose-dependent inhibition of FLT3 autophosphorylation. Inhibition of KIT autophosphorylation was shown in a human megakaryoblastic leukemia cell line overexpressing KIT. In a panel of 17 cell lines, AKN-028 showed cytotoxic activity in all five AML cell lines included. AKN-028 triggered apoptosis in MV4-11 by activation of caspase 3. In primary AML samples (n=15), AKN-028 induced a clear dose-dependent cytotoxic response (mean IC(50) 1 µM). However, no correlation between antileukemic activity and FLT3 mutation status, or to the quantitative expression of FLT3, was observed. Combination studies showed synergistic activity when cytarabine or daunorubicin was added simultaneously or 24 h before AKN-028. In mice, AKN-028 demonstrated high oral bioavailability and antileukemic effect in primary AML and MV4-11 cells, with no major toxicity observed in the experiment. In conclusion, AKN-028 is a novel TKI with significant preclinical antileukemic activity in AML. Possible sequence-dependent synergy with standard AML drugs and good oral bioavailability has made it a candidate drug for clinical trials (ongoing).

8.
Curr Med Chem ; 18(29): 4440-53, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21864277

RESUMO

Recurrent prostate cancer (PCa) remains a major clinical challenge. Invasive and metastatic PCa lesions often exhibit a partial and time-limited response to therapy before the cancer progresses and the patient succumbs to the disease. Despite recent advances in early diagnosis and treatment, approximately one-third of treated patients will relapse and become resistant to currently available treatments. In this review we evaluate current treatment practices and recent advances in therapy for localized prostate malignancy and advanced, metastatic prostate cancer. Some of the promising new drugs for PCa treatment include MDV3100, an androgen receptor (AR) antagonist that prevents androgens from binding to the AR and nuclear translocation and co-activator recruitment of the ligand-receptor complex; abiraterone, an orally administered drug that irreversibly inhibits a rate-limiting enzyme in androgen biosynthesis, CYP17; and several newer cytotoxic drugs (epothilones, satraplatin). Key new insights are that cancer stem cells play a role in PCa and that PCa cells are dependent on the AR for proliferation, even in the hormone refractory state of the disease. We also discuss potential molecular targets for new drug candidates for the treatment of metastatic PCa.


Assuntos
Antineoplásicos/uso terapêutico , Próstata/efeitos dos fármacos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/secundário , Antagonistas de Receptores de Andrógenos/química , Antagonistas de Receptores de Andrógenos/farmacologia , Antagonistas de Receptores de Andrógenos/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Ensaios Clínicos como Assunto , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Transdução de Sinais/efeitos dos fármacos
9.
Scanning ; 32(5): 294-303, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20973091

RESUMO

Functional additives, particularly extreme pressure and antiwear additives, in formulated oil will compete to adsorb and function in tribological contacts. A low-polarity commercial base oil, poly-α-olefin (PAO), blended with zinc dialkyl dithiophosphates (ZDDP) has been studied. The tribological performance was evaluated using a ball-on-disk test rig under mixed rolling-sliding conditions in the boundary lubrication regime at 90°C. An adapted in situ interferometry technique was used to monitor the additive-derived reaction layer formation. The thickness of the reaction layer evolves with rubbing until reaching a limiting thickness value of approximately 70 nm. The evolution of the topography and mechanical properties of the ZDDP-derived reaction layer with rubbing time were studied using Atomic Force Microscopy. A constant roughening and hardening of the additive-derived layer with rubbing time is observed and related to the different tribological performance of the layer at different rubbing times.

10.
Lab Anim ; 43(3): 249-54, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19246503

RESUMO

Streptozotocin (STZ) given intravenously destroys pancreatic beta cells and is widely used in animal models to mimic type 1 diabetes. The effects of STZ on the clinical state of health and metabolism were studied in six high health certified domestic pigs weighing 19+/-1.3 kg at the start of the experiment. A single STZ dose of 150 mg/kg of body weight successfully induced hyperglycaemia and alterations in amino acid metabolism. Within 9 h after STZ administration, the blood glucose values fell from 5.4-7.5 mmol/L to 0.8-2.2 mmol/L. Hypoglycaemia was treated with 0.5 g glucose/kg body weight. In all pigs, hyperglycaemia was produced 24 h after STZ treatment, and 3 days after STZ injection, the glucose concentration was >25 mmol/L. Mean C-peptide concentration was 0.25+/-0.16 microg/L since 2 days after STZ injection until the end of the study. The serum concentration of the branched-chain amino acids (BCAA) increased four-fold, and alanine and taurine decreased by approximately 70% and 50%, respectively, after STZ treatment. All but one pig remained brisk and the physical examination was normal except for a retarded growth rate and a reduction of the skeletal muscle. At the end of the study, the pigs were moderately emaciated. Postmortem examination confirmed muscle wasting and a reduction of abdominal and subcutaneous fat. In conclusion, STZ-induced diabetes in pigs fulfils the requirements for a good animal model for type 1 diabetes with respect to clinical signs of the disease and alterations in the carbohydrate and amino acid metabolism.


Assuntos
Aminoácidos/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Alanina/sangue , Aminoácidos de Cadeia Ramificada/sangue , Animais , Glicemia/análise , Peso Corporal/efeitos dos fármacos , Peptídeo C/sangue , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/patologia , Hiperglicemia , Insulina/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Suínos , Taurina/sangue
12.
Thromb Res ; 122(2): 257-63, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18177925

RESUMO

INTRODUCTION: This study was designed to investigate whether fibrinogen, soluble desAA-fibrin, and insoluble desAABB-fibrin are able to induce clotting by triggering the plasma contact activation system when adsorbed to polystyrene. MATERIALS AND METHODS: The above-mentioned substances were individually prepared on polystyrene meshwork squares, and then exposed to a purified FXII solution or non-calcium containing plasma (citrated and dialyzed normal pooled plasma) in polystyrene cuvettes coated with surface-immobilized heparin, to completely block contact activation and the coagulation mechanism that might be induced by the cuvette surfaces. Sodium glass beads were used as the reference material. RESULTS: On exposure to purified FXII solution and plasma, all the tested materials adsorbed and activated FXII to varying degrees. This activation led to the formation of FXIa in the exposed plasma, with the highest activation occurring upon exposure to glass, desAA-fibrin and desAABB-fibrin and the lowest upon exposure to fibrinogen-adsorbed or unmodified polystyrene meshwork squares. Following recalcification, in cuvettes with surface-immobilized heparin, a spectrophotometric assay showed that the surface-exposed plasma aliquots clotted within 5 min after contact with glass, within 10 to 15 min after contact with the two forms of fibrin, and somewhat longer after contact with adsorbed fibrinogen. The longest lag phase, close to 20 min, occurred in plasma exposed to unmodified polystyrene meshwork. Whole blood deposited in surface heparinized cuvettes directly from the cubital vein did not clot during the observation time (2 h). CONCLUSIONS: These results indicate that domains induced by conformational changes in adsorbed fibrinogen and fibrin are capable of activating adsorbed proenzymes and that various forms of fibrin are considerably stronger activators of the contact activation system than are adsorbed fibrinogen or a polystyrene meshwork. The delayed coagulation in plasma exposed to the unmodified polystyrene meshwork can be explained by a two-step process: first, adsorption of fibrinogen, and second, activation of FXII. Under our experimental conditions, the adsorption and activation of FXII on fibrinogen and fibrin seems to be an important mechanism for triggering coagulation.


Assuntos
Fibrina/química , Fibrinogênio/química , Fragmentos de Peptídeos/química , Adsorção , Coagulação Sanguínea , Fator XII/química , Vidro , Heparina/química , Humanos , Poliestirenos/química , Pré-Calicreína/química , Sódio/química , Propriedades de Superfície , Trombina/antagonistas & inibidores
13.
Eur J Surg Oncol ; 34(5): 547-52, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17574369

RESUMO

AIMS: To investigate if the pattern of cytotoxic drug sensitivity in vitro in patient samples of peritoneal carcinomatosis (PC) is supportive to the current standardized approach for drug selection for perioperative intraperitoneal chemotherapy (IPC). METHODS: The cytotoxic effect of cisplatin, oxaliplatin, irinotecan, 5-fluorouracil, mitomycin-C, doxorubicin and melphalan was investigated in vitro on tumour cells from 223 patient tumour samples of different PC origins. RESULTS: Considerable differences in cytotoxic drug sensitivity between tumour types of the PC entity and within each tumour type were observed. Cisplatin showed high cross-resistance with oxaliplatin but low cross-resistance with doxorubicin and irinotecan. No cross-resistance was found between irinotecan and doxorubicin. The dose-response relationships for melphalan and irinotecan in individual samples showed great variability. CONCLUSIONS: The activity in vitro of cytotoxic drugs commonly used in IPC for PC is very heterogeneous. Efforts for individualizing drug selection for PC patients undergoing IPC seem justified.


Assuntos
Citotoxinas/farmacologia , Neoplasias Peritoneais/tratamento farmacológico , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Cisplatino/farmacologia , Citotoxinas/uso terapêutico , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Feminino , Fluoruracila/farmacologia , Humanos , Irinotecano , Masculino , Melfalan/farmacologia , Mitomicina/farmacologia , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Assistência Perioperatória , Células Tumorais Cultivadas
14.
Toxicol In Vitro ; 21(6): 1174-81, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17481850

RESUMO

Several in vitro methods have been suggested to predict drug-induced haematotoxicity and species differences; the most commonly used being the clonogenic CFU-GM assay. The aim of the current study was to evaluate whether primary lymphocytes from peripheral blood, assayed with a short-term non-clonogenic assay, could be used to detect species differences in drug sensitivity, and offer an alternative to the CFU-GM assay. The effect of 17 different cytotoxic drugs on lymphocytes from human, dog, rat and mouse was evaluated. A higher sensitivity of human than mouse lymphocytes was seen for topotecan and for 3 of 5 antimetabolites tested. Clear species specificity was also seen for the proteasome inhibitor bortezomib where rodent cells were 50-300 times less sensitive than human cells. Good agreement between our data and published CFU-GM data was observed, suggesting that primary lymphocytes may be a useful model for species difference screening in drug development.


Assuntos
Antineoplásicos/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cães , Feminino , Fluorometria , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos Endogâmicos , Especificidade da Espécie , Testes de Toxicidade/métodos
15.
J Chem Inf Model ; 47(1): 239-48, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17238270

RESUMO

A major concern of chemogenomics is to associate drug activity with biological variables. Several reports have clustered cell line drug activity profiles as well as drug activity-gene expression correlation profiles and noted that the resulting groupings differ but still reflect mechanism of action. The present paper shows that these discrepancies can be viewed as a weighting of drug-drug distances, the weights depending on which cell lines the two drugs differ in.


Assuntos
Células/efeitos dos fármacos , Farmacogenética , Animais , Linhagem Celular , Análise por Conglomerados , Gráficos por Computador , Humanos
16.
Clin Exp Allergy ; 37(2): 208-18, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17250693

RESUMO

BACKGROUND: The eosinophil is a cytotoxic cell and takes part in parasite killing and tissue-destructive processes by secretion of proteins such as eosinophil cationic protein (ECP). A polymorphism was demonstrated in the ECP gene, giving rise to a substitution of arginine at position 97 with threonine. This polymorphism is related to disease development. OBJECTIVE: To investigate the functional and molecular heterogeneity of native ECP and the functional consequences of the replacement of arginine with a threonine. METHODS: ECP was purified from healthy blood donors by gel filtration, ion-exchange chromatography and reversed-phase chromatography. Recombinant ECPs i.e. rECP 97(arg) and rECP 97(thr) were produced by the pFASTBAC baculovirus expression system. The cytotoxic activity was determined against an erythroleukaemia or a small cell lung cancer cell line. RESULTS: Native ECP was purified to apparent homogeneity and showed a considerable molecular heterogeneity and a corresponding functional heterogeneity with respect to cytotoxic activity. After reduction, the native cytotoxic ECP showed three bands on sodium dodecylsulphate polyacrylamide gel electrophoresis : one major band at 18-20 kDa and two minor bands at about 10 and 5 kDa, respectively. The 5 kDa contained two masses differing with 56.2 Da, which corresponds to the difference in molecular masses of arginine and threonine. rECP 97(arg) was cytotoxic in contrast to rECP97(thr). Deglycosylation with N-glycosidase F did not affect the cytotoxic activity of native ECP to any measurable extent nor the activity of rECP 97(arg), whereas rECP 97(thr) achieved cytotoxic activity. The RNase activities of the recombinant and native ECPs were similar. CONCLUSION: We conclude that ECP is present in several molecular forms with varying biological activities. Some of this functional heterogeneity is based on the genetic polymorphism of the ECP gene and some on post-translational modifications. In subjects carrying the ECP 97(thr) variant, the cytotoxic activity may be disguised by N-linked glycosylation of the active site.


Assuntos
Proteínas Sanguíneas/genética , Proteína Catiônica de Eosinófilo/genética , Hipersensibilidade/genética , Polimorfismo Genético/genética , Processamento de Proteína Pós-Traducional/genética , Animais , Proteína Catiônica de Eosinófilo/metabolismo , Cobaias , Humanos , Imunoensaio/métodos , Coelhos , Suécia/epidemiologia , Suécia/etnologia
17.
Colloids Surf B Biointerfaces ; 49(1): 1-7, 2006 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16567083

RESUMO

The durability and functionality of a heparin coating on artificial heart valve leaflets were evaluated with X-ray photoelectron spectroscopy (XPS) and by the coatings' capacity to bind antithrombin. Current methods for accelerated life-time testing are based on exposing leaflets to water solutions. In this paper a method is explored, in which heart valve leaflets were exposed to a continuous high shear rate (4 L/min) of human citrated plasma. It was found that the heparin coating was stable and wear resistant enough to still be present after 3 weeks and to have about the same antithrombin uptake as coatings not exposed to circulating plasma. It was, however, partly destroyed by the test as found using XPS. We suggest that heparin chains from the upper layer of heparin have been torn off from the carrier chain, in combination with loss of heparin conjugate and plasma deposition in patches. This study showed that XPS provides additional information to biological measurements such as antithrombin uptake. XPS is therefore a valuable technique not only to characterize biomaterials but also to evaluate the effect of a performance test.


Assuntos
Antitrombinas/química , Antitrombinas/metabolismo , Materiais Biocompatíveis/química , Valvas Cardíacas/química , Valvas Cardíacas/metabolismo , Heparina/química , Configuração de Carboidratos , Sequência de Carboidratos , Elétrons , Humanos , Teste de Materiais , Dados de Sequência Molecular , Sensibilidade e Especificidade , Análise Espectral , Propriedades de Superfície , Raios X
18.
Biosens Bioelectron ; 21(10): 1973-80, 2006 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16289605

RESUMO

Real time interactions of antithrombin (AT) with Corline Heparin Surfaces (CHS) with one and two layers of heparin conjugate have been examined using a multi-wavelength TIRF spectroscopy technique with continuous flow. Fluorescently labeled AT, adsorbed from citrated human blood plasma, showed significantly higher signals on CHS compared to the cationic surface used to attach the heparin conjugate. The AT binding to CHS was very stable, also after exposure to soluble heparin at a concentration of 1.5 IU/mL. Only a few percent of the bound AT were displaced from the surfaces by AT present in plasma after long-term exposure to plasma. In contrast, larger amounts of the freshly added AT had adsorbed to the surfaces, especially to the surface with two layers of heparin conjugate, indicating the presence of unsaturated AT binding sites. The amount of AT bound to the different surfaces was quantified after elution using an enzyme immunoassay (EIA). Characteristic emission spectra of proteins and fluorophores of labeled proteins, obtained at the surfaces after a long-term exposure to plasma, confirmed their presence at the surfaces. The multi-wavelength TIRF technique proved to be a useful tool when combined with other techniques to study the time course of interactions of fluorescently labeled proteins with biomaterials, even in a complex environment such as plasma.


Assuntos
Antitrombinas/metabolismo , Heparina/metabolismo , Espectrometria de Fluorescência/métodos , Antitrombinas/química , Técnicas Biossensoriais , Heparina/química , Humanos
19.
Br J Cancer ; 93(4): 483-92, 2005 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-16012520

RESUMO

Acquired drug resistance is a major problem in cancer treatment. To explore the genes involved in chemosensitivity and resistance, 10 human tumour cell lines, including parental cells and resistant subtypes selected for resistance against doxorubicin, melphalan, teniposide and vincristine, were profiled for mRNA expression of 7400 genes using cDNA microarray technology. The drug activity of 66 cancer agents was evaluated on the cell lines, and correlations between drug activity and gene expression were calculated and ranked. Hierarchical clustering of drugs based on their drug-gene correlations yielded clusters of drugs with similar mechanism of action. Genes correlated with drug sensitivity and resistance were imported into the PathwayAssist software to identify putative molecular pathways involved. A substantial number of both proapoptotic and antiapoptotic genes such as signal transducer and activator of transcription 1, mitogen-activated protein kinase 1 and focal adhesion kinase were found to be associated to drug resistance, whereas genes linked to cell cycle control and proliferation, such as cell division cycle 25A and signal transducer of activator of transcription 5A, were associated to general drug sensitivity. The results indicate that combined information from drug activity and gene expression in a resistance-based cell line panel may provide new knowledge of the genes involved in anticancer drug resistance and become a useful tool in drug development.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Perfilação da Expressão Gênica , Apoptose/efeitos dos fármacos , Apoptose/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de Sinais , Software
20.
Br J Haematol ; 129(2): 189-98, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15813846

RESUMO

Rearrangements in the 11q23 region, the site of the mixed lineage leukaemia (MLL) gene, are found in both childhood acute myeloid (AML) and lymphoblastic (ALL) leukaemia. We studied the in vitro drug resistance by the fluorometric microculture cytotoxicity assay (FMCA) in 132 children with AML and 178 children with ALL (aged 0-17 years). In AML, children with t(9;11) (n = 10) were significantly more sensitive to cytarabine (P < 0.001) and doxorubicin (P = 0.005) than non-11q23 rearranged patients (n = 108). Children with other 11q23 rearrangements (n = 14) differed less from non-rearranged children. The 'AML-profile' common to all three groups included relative resistance to glucocorticoids and vincristine. In ALL, children with 11q23 rearrangement (n = 22) were significantly more sensitive to cytarabine (P = 0.026) than children without 11q23 rearrangement (n = 156), also after stratification for white blood cell count. In conclusion, the findings indicate that the cellular drug resistance is correlated to both the cell lineage and the type of 11q23 rearrangement. High cellular sensitivity to cytarabine and doxorubicin might explain the excellent treatment results in children with AML and t(9;11). The present study supports the strategy of contemporary protocols to include high-dose cytarabine in the treatment of 11q23-positive patients both in AML and ALL.


Assuntos
Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Rearranjo Gênico , Leucemia Mieloide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proto-Oncogenes/genética , Fatores de Transcrição/genética , Doença Aguda , Adolescente , Antineoplásicos/farmacologia , Linhagem da Célula , Criança , Pré-Escolar , Cromossomos Humanos Par 11 , Cromossomos Humanos Par 9 , Citarabina/farmacologia , Testes Imunológicos de Citotoxicidade , Doxorrubicina/farmacologia , Feminino , Fluorometria , Glucocorticoides/farmacologia , Histona-Lisina N-Metiltransferase , Humanos , Lactente , Recém-Nascido , Leucemia Mieloide/imunologia , Masculino , Proteína de Leucina Linfoide-Mieloide , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Estudos Prospectivos , Estatísticas não Paramétricas , Translocação Genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...