Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
Clin Exp Dermatol ; 39(3): 385-90, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24772485

RESUMO

The differences in systemic T-cell responses between patients with psoriatic arthritis (PsA) and patients with cutaneous psoriasis (Ps) are still largely unknown. To determine differential features that could be used to distinguish PsA from Ps, we compared the cytokine secretion profile of circulating T cells in patients with PsA, patients with cutaneous Ps and control subjects. We determined Th1, Th2 and Th17 cytokine secretion of anti-CD3-stimulated peripheral blood mononuclear cells (PBMCs) using a cytokine bead array. Normality of data distribution was assessed by the Shapiro-Wilk test, and statistical significance was calculated by the Mann-Whitney test. Phenotypic characterization of circulating T cells was performed by fluorescence-activated cell sorting analysis. We found that the major systemic differences distinguishing PsA from cutaneous Ps were the increased secretion of interleukin (IL)-2 by α-CD3-stimulated PBMCs and a higher percentage of circulating CD3+ T cells expressing the proliferation marker CD71 in PsA. These results indicate IL-2 as a possible biomarker of PsA, and suggest a role of circulating T cells with high proliferative capacity in the pathogenesis of PsA.


Assuntos
Artrite Psoriásica/metabolismo , Complexo CD3/imunologia , Interleucina-2/metabolismo , Leucócitos Mononucleares/metabolismo , Psoríase/metabolismo , Adolescente , Adulto , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T Auxiliares-Indutores/metabolismo , Adulto Jovem
2.
Curr Alzheimer Res ; 2013 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-23952019

RESUMO

As neuroinflammation is an early event in the pathogenesis of Alzheimer's disease, new selective anti-inflammatory drugs could lead to promising preventive strategies. We evaluated the safety, tolerability, pharmacokinetics and pharmacodynamics of CHF5074, a new microglial modulator, in a 12-week, double-blind, placebo-controlled, parallel groups, ascending dose study involving 96 MCI patients. Subjects were allocated into three successive study cohorts to receive ascending, titrated doses of CHF5074 (200, 400 or 600 mg/day) or placebo. Vital signs, cardiac safety, neuropsychological performance and safety clinical laboratory parameters were assessed on all subjects. Plasma samples were collected throughout the study for measuring drug concentrations, soluble CD40 ligand (sCD40L) and TNF-α. At the end of treatment, cerebrospinal fluid (CSF) samples were optionally collected after the last dose to measure drug levels, ß-amyloid1-42 (Aß42), tau, phospho-tau181, sCD40L and TNF-α. Ten patients did not complete the study: one in the placebo group (consent withdrawn), two in the 200-mg/day treatment group (consent withdrawn and unable to comply) and seven in the 400-mg/day treatment group (five AEs, one consent withdrawn and one unable to comply). The most frequent treatment-emergent adverse events were diarrhea, dizziness and back pain. There were no clinically significant treatment-related clinical laboratory, vital sign or ECG abnormalities. CHF5074 total body clearance depended by gender, age and glomerular filtration rate. CHF5074 CSF concentrations increased in a dose-dependent manner. At the end of treatment, mean sCD40L and TNF-α levels in CSF were found to be inversely related to the CHF5074 dose (p=0.037 and p=0.001, respectively). Plasma levels of sCD40L in the 600-mg/day group were significantly lower than those measured in the placebo group (p=0.010). No significant differences between treatment groups were found in neuropsychological tests but a positive dose-response trend was found on executive function in APOE4 carriers. This study shows that CHF5074 is well tolerated in MCI patients after a 12-week titrated treatment up to 600 mg/day and dose-dependently affects central nervous system biomarkers of neuroinflammation.

3.
Int J Immunopathol Pharmacol ; 22(1): 243-6, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19309573

RESUMO

Amicrobial pustulosis associated with autoimmune diseases (APAD) is a clinical entity which was described only recently and few cases are reported in the literature. This condition is characterized by recurrent acute onset with pustular lesions predominantly involving skin folds, genitals, scalp and external auditory canals of young women. The etiopathogenesis of APAD is unknown and the most effective therapeutic treatment seems to be systemic corticosteroids. We describe the case of a 16-year old female patient suffering from APAD successfully treated with cyclosporine A.


Assuntos
Doenças Autoimunes/tratamento farmacológico , Ciclosporina/uso terapêutico , Imunossupressores/uso terapêutico , Dermatopatias Vesiculobolhosas/tratamento farmacológico , Adolescente , Feminino , Humanos
5.
Int J Immunopathol Pharmacol ; 21(2): 437-45, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18547491

RESUMO

We evaluated the effect of efalizumab on neutrophil and monocyte functions. The in vitro pre-incubation with efalizumab concentrations similar to those reached during in vivo therapy almost completely saturated CD11a binding sites without affecting the membrane expression of CD11b, CD128a or CD128b. There was a significant reduction in the chemotactic activity of the pre-treated cells toward three different chemo-attractants, whereas their phagocytic capacity and production of oxygen radicals remained unchanged. One month after the administration of efalizumab to five patients with psoriasis (T1) circulating neutrophil counts increased by 34% from pre-therapy (T0) with no change in the number of monocytes. In the same patients the CD11a binding sites on phagocytes were >90% saturated, and there was also a significant down-modulation on neutrophils (44% of T0) and monocytes (63% of T0). In line with in vitro results, efalizumab treatment caused a significant deficiency in the chemotactic properties of neutrophils and monocytes, but no changes in phagocytosis, oxidative burst, production of pro-inflammatory cytokines or the membrane expression of CD11b, CD128a and CD128b. Our findings suggest that neutrophils and monocytes may be among the targets of efalizumab activity in patients with psoriasis.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Psoríase/tratamento farmacológico , Psoríase/imunologia , Acridinas/farmacologia , Adulto , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Antígenos CD11/biossíntese , Quimiotaxia/efeitos dos fármacos , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/metabolismo , Fagócitos/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Fenótipo , Espécies Reativas de Oxigênio/metabolismo , Receptores de Interleucina-8A/biossíntese , Receptores de Interleucina-8B/biossíntese , Explosão Respiratória/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia
7.
Br J Dermatol ; 156(2): 372-4, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17223881

RESUMO

Psoriasis is an immune-mediated disease with a chronic relapsing course, and the particularly severe forms that are refractory to traditional therapies are often difficult to manage. Everolimus (Certican; Novartis, Basel, Switzerland) is a new rapamycin-derived macrolide that is used in the prophylaxis of rejection in heart and kidney transplant patients. The mechanism underlying its immunosuppressant and antiproliferative activity is different from, but complementary to, that of calcineurin inhibitors such as ciclosporin. We describe a woman with severe psoriasis treated with everolimus combined with subtherapeutic doses of ciclosporin.


Assuntos
Ciclosporina/uso terapêutico , Imunossupressores/uso terapêutico , Psoríase/tratamento farmacológico , Sirolimo/análogos & derivados , Sinergismo Farmacológico , Quimioterapia Combinada , Everolimo , Feminino , Humanos , Pessoa de Meia-Idade , Sirolimo/uso terapêutico , Resultado do Tratamento
8.
Int J Immunopathol Pharmacol ; 19(2): 433-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16831309

RESUMO

Granuloma annulare is an anatomo-clinical entity that is frequently encountered in everyday dermatological practice. We report our experience regarding 4 patients with disseminated granuloma annulare. Each patient was treated with a cycle of cyclosporine therapy for six weeks. A cycle of systemic cyclosporine therapy was started at a dose of 4 mg/kg/day for four weeks, subsequently reduced by 0.5 mg/kg/day every two weeks. The clinical picture more or less completely resolved within three weeks in all of the patients, and there were no relapses during the dose-tapering period or the following 12 months. Cyclosporine was optimally tolerated by all four patients, none of whom experienced any therapy-related side effects. Cyclosporine is a valid therapeutic option for the treatment of disseminated granuloma annulare, although we recommend its use in a protected hospital environment that facilitates patient monitoring.


Assuntos
Ciclosporina/uso terapêutico , Granuloma Anular/tratamento farmacológico , Imunossupressores/uso terapêutico , Feminino , Granuloma Anular/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Pele/patologia
9.
Int J Immunopathol Pharmacol ; 17(3): 401-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15461875

RESUMO

Psoriasis is a T-lymphocyte mediated autoimmune disease. The response to therapies targeting T-lymphocytes suggest that the latter is a key cell in the pathogenesis of the disease. Cyclosporine (CsA) inhibits the proliferation and the IL-2 dependent expansion of T-lymphocytes. Ultraviolet radiation is an effective treatment for psoriasis. Several studies have demonstrated a significant improvement of the therapeutic response when narrow-band radiation is issued by TL-01 fluorescent lamp compared to broad- band UVB issued by other fluorescent sources. The effects of UVB on the immune system appear to be limited to the cell-mediated compartment of the immune response. In order to reduce the cumulative dose of UVB and limit the toxicity of drugs in the therapy of psoriasis, phototherapy with UVB has been used as treatment in association with other standard therapies. The purpose of the study is to evaluate, in patients with moderate to severe psoriasis a combined therapy with Cyclosporine A and 311 nm UVB phototherapy.


Assuntos
Ciclosporina/uso terapêutico , Imunossupressores/uso terapêutico , Psoríase/terapia , Terapia Ultravioleta , Adulto , Terapia Combinada , Ciclosporina/efeitos adversos , Feminino , Humanos , Imunossupressores/efeitos adversos , Masculino , Pessoa de Meia-Idade , Psoríase/tratamento farmacológico , Psoríase/radioterapia , Pele/patologia , Terapia Ultravioleta/efeitos adversos
10.
J Pharm Biomed Anal ; 35(4): 887-93, 2004 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-15193733

RESUMO

Bioanalysis frequently involves the measurement of very low analyte concentrations in complex and potentially variable matrices. It is not possible to test in validation every possible circumstance that may be encountered when analyzing study samples; logically, therefore, some risk of obtaining erroneous results exists when validated methods are applied to study samples. An initial attempt has been made to apply a risk management tool to the bioanalytical situation, with the hope that this will stimulate further discussion on the idea of more formally addressing "risk" with regards to bioanalytical method validation.


Assuntos
Bioensaio/métodos , Bioensaio/normas , Cromatografia Líquida/métodos , Cromatografia Líquida/normas , Espectrometria de Massas/métodos , Espectrometria de Massas/normas , Fatores de Risco
11.
J Chromatogr A ; 1024(1-2): 87-94, 2004 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-14753710

RESUMO

SU11248 is a potent inhibitor of PDGFR, VEGFR, KIT, and Flt3, and is currently under Phase I clinical evaluation as an anticancer drug. A sensitive and specific analytical method for the quantitation of SU11248 and its metabolite in several monkey tissues (liver, kidney, brain and white fat) using LC-MS-MS following semi-automated liquid-liquid extraction (LLE) was developed and validated. Amounts of 50 mg of tissue were homogenized using an ultrasonic processor. After addition of the stable labelled internal standard (IS) and ammonium hydroxide (0.3%), samples were extracted with 2.5 ml of tert-butyl methyl ether. Following centrifugation, aliquots of 1.8 ml of the organic phase were transferred into a 96-well plate. The Packard Multiprobe II robotic liquid handler was used to perform all steps mentioned above. The organic phase was dried and the residue was reconstituted with 800 microl of 15 mM ammonium formate buffer solution (pH 3.25) using a Tomtec Quadra 96 workstation. Aliquots of 10 microl of the resulting solution were injected into the LC-MS-MS system. A Symmetry Shield C8 column (50 mm x 2.1 mm, 3.5 microm) was used to perform the chromatographic analysis. The mobile phase was 15 mM ammonium formate buffer solution (pH 3.25)-acetonitrile (74:26 (v/v)) with a flow-rate of 0.35 ml/min. Retention times of the metabolite and SU11248 were about 2.5 and 3.5 min, respectively. Total cycle time was 5 min. MS detection used the Applied Biosystems-MDS Sciex API 3000 with TurbolonSpray interface and multiple reaction monitoring (MRM) operated in positive ion mode. The method was validated for both compounds over the calibration range of about 2 and 2000 ng/g. The suitability and robustness of the method for in vivo samples were confirmed by analysis of monkey tissues from animals dosed with SU11248.


Assuntos
Antineoplásicos/análise , Cromatografia Líquida/métodos , Inibidores Enzimáticos/análise , Indóis/análise , Espectrometria de Massas/métodos , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirróis/análise , Animais , Antineoplásicos/metabolismo , Antineoplásicos/farmacocinética , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacocinética , Haplorrinos , Indóis/metabolismo , Indóis/farmacocinética , Pirróis/metabolismo , Pirróis/farmacocinética , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sunitinibe , Distribuição Tecidual
12.
J Chromatogr A ; 987(1-2): 249-56, 2003 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-12613819

RESUMO

A sensitive, specific and high-throughput analytical method for the quantitation of PNU-248686A (I), in human plasma has been developed. I, sodium (2R)-3-[[(4'-chloro(1,1'-biphenyl)-4-yl]sulfonyl]-2-hydroxy-2-[(phenylsulfanyl)methyl] propanoate, is an orally active matrix metalloproteinase (MMP) inhibitor developed for the treatment of solid tumors over-expressing MMPs. Concentrations of I, as free acid, were determined in human plasma by LC-MS-MS after plasma protein precipitation in the 96-well plate format. Aliquots of plasma (50 microl) were placed into the plates and 0.2 ml of methanol was added. The plates were shaken for 5 min and centrifuged at 1500 g for 10 min. Aliquots of 10 microl of the supernatants were then directly injected into the LC-MS-MS system. A Symmetry Shield C. column (50 x 2.1 mm, 3.5 microm) was used to perform the chromatographic analysis. The mobile phase was 5 mM ammonium formate buffer solution pH 5.0-acetonitrile (60:40. v/v) with a flow-rate of 0.3 ml/min. Retention time of I was about 1.2 min. Total cycle time was 2.5 min. MS detection used the Applied Biosystems-MDS Sciex API 3000 with TurbolonSpray interface and single reaction monitoring (461 --> 251 m/z transition) operated in negative ion mode. Calibration curves were constructed by plotting the area of the compound (y) against its concentration (x). A weighed linear regression (weighting factor 1/x(2)) was used to calculate I concentrations in quality control and unknown samples. The method was fully validated over the range of 5.0-5000 ng/ml. The suitability and robustness of the method for in vivo samples was confirmed by analysis of plasma samples from a pilot clinical study.


Assuntos
Compostos de Bifenilo/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Inibidores de Metaloproteinases de Matriz , Inibidores de Proteases/sangue , Sulfonas/sangue , Calibragem , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
J Pharm Biomed Anal ; 30(3): 377-89, 2002 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-12367663

RESUMO

A selective and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for quantitative determination of nemorubicin, (PNU-152243A, 3'-deamino-3'[2(S)-methoxy-4-morpholinyl]doxorubicin) hydrocloride and its reduced metabolite PNU-155051 in human plasma has been developed and validated. The method involved solid phase extraction (SPE) in 96-well plates. Plasma samples (0.5 ml plasma, spiked with doxorubicin as internal standard and diluted with 0.5 ml of 0.01 M borate buffer, pH 8.4) were extracted using Oasis HLB SPE material. The elution of PNU-152243, PNU-155051 and of IS was performed with 1 ml of methanol:0.1 M formic acid mixture (90:10, v/v). The organic phase was reduced to dryness under a stream of nitrogen at 20 degrees C and the residue was reconstituted with 0.25 ml of 10 mM ammonium formate buffer pH 4.15:acetonitrile mixture (90:10, v/v). Aliquots of 60 microl of the resulting solution were injected onto the LC-MS-MS system. A Zorbax SB C18 column (2.1 x 150 mm, 3.5 microm) was used to perform the chromatographic analysis. The mobile phase consisted of ammonium formate buffer 10 mM pH 4.15:acetonitrile (73:27, v/v) with a flow-rate of 0.2 ml/min. Detection was achieved by a PE-SCIEX API 3000 with Turbo IonSpray interface, and multiple reaction monitoring (645 --> 321 for PNU-152243, 647 --> 363 for PNU-155051 and 545 --> 345 m/z for doxorubicin) operated in positive ion mode. A weighted linear regression was used to calculate PNU-152243 and PNU-155051 concentrations in QC and unknown samples. Linearity, precision, accuracy and recovery of the method were evaluated over the concentration range of 0.1-5 ng/ml for both compounds. No interference from blank human plasma was observed. The suitability of the method for in vivo samples was assessed by the analysis of samples obtained from patients who had received a single intrahepatic artery dose of PNU-152243A.


Assuntos
Doxorrubicina/análogos & derivados , Doxorrubicina/sangue , Doxorrubicina/química , Cromatografia Líquida/métodos , Doxorrubicina/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos
14.
J Chromatogr B Biomed Sci Appl ; 763(1-2): 173-83, 2001 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-11710576

RESUMO

A selective HPLC assay is described for the determination of free and total (free plus polymer-bound) camptothecin (CPT) in human plasma after administration of the anti-tumor drug MAG-CPT (polymer bound camptothecin). Total CPT levels were determined after hydrolysis and free CPT was extracted from acidified plasma using Oasis solid-phase extraction material. Extracts were analyzed on a Zorbax SB-C8 analytical column, using a mixture of acetonitrile-25 mM phosphate buffer (pH 4.0) as the eluent. Detection was performed fluorimetrically. Concentrations of polymer-bound CPT were calculated by subtraction of free from total CPT. The lower limits of quantitation of the methods were 100 ng/ml for total and 1.0 ng/ml for free CPT using 50 microl and 250 microl plasma, respectively. Special attention was paid to the stability of the analytes. The presented method was successfully applied in a clinical pharmacokinetic study in our institute.


Assuntos
Antineoplásicos Fitogênicos/sangue , Camptotecina/sangue , Cromatografia Líquida de Alta Pressão/métodos , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacocinética , Calibragem , Camptotecina/química , Camptotecina/farmacocinética , Humanos , Polímeros , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
J Pharm Biomed Anal ; 22(3): 451-60, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10766362

RESUMO

A sensitive, specific and rapid analytical method for the quantitation of exemestane (EXE) in human plasma has been developed. EXE, 6-methylen-androsta-1,4-diene-3,17-dione, is an orally active irreversible steroidal aromatase inhibitor used for the therapy of metastatic postmenopausal breast cancer, with estrogen-dependent pathological conditions. The method involves extraction of EXE from human plasma by solid phase extraction using C2 endcapped sorbent in the 96 well plate format (50 mg/2 ml). After conditioning of the sorbent with 1 ml of acetonitrile (x2) the plates were rinsed with 1 ml of water (x2). The prepared samples (0.5 ml plasma, spiked with [13C3] EXE as internal standard (IS) and diluted with 0.5 ml water) were loaded and drawn through the plate with a minimum of vacuum. The plates were then washed with 1 ml acetonitrile:water (10:90) followed by a drying step for 30 min at full vacuum. Elution was by 0.15 ml of 0.1% trifluoracetic acid in acetonitrile (x2) under a minimum of vacuum. Aliquots of 80 microl were finally injected into the LC-MS-MS system. A Zorbax SB C8 column (4.6 x 150 mm, 5 microm) was used to perform the chromatographic separation; the mobile phase was 100% acetonitrile. MS detection used the heated nebulizer interface, with multiple reaction monitoring (MRM) (297-->121 m/z for EXE and 300-->123 m/z for IS) operated in positive ion mode. A weighed linear regression analysis (weighing factor 1/x2) was used to calculate EXE concentration in standard and unknown samples. The method was fully validated in the concentration range 0.05-25 ng ml(-1).


Assuntos
Androstadienos/sangue , Antineoplásicos/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Cromatografia Líquida/instrumentação , Humanos , Espectrometria de Massas/instrumentação , Reprodutibilidade dos Testes
16.
J Pharm Biomed Anal ; 22(3): 505-14, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10766368

RESUMO

A high throughput. selective and sensitive high-performance liquid chromatographic (HPLC) method for the determination of a water-soluble polymer-bound Camptothecin conjugate (MAG-CPT) and Camptothecin (CPT) in dog plasma has been developed and validated. The method involved the analysis of free and total CPT (free + polymer-bound). Free CPT (intact lactone plus carboxylate) was extracted from acidified plasma using Oasis SPE material in 96-well plates. For the assay of the total CPT, plasma proteins were first precipitated with methanol in a 96-well plate containing a 10-microm melt blown polypropylene membrane. The methanolic supernatant was separated and collected into a second 96-well plate by simply applying vacuum to the plate. After hydrolysis at pH 9.8 for 18 h and re-acidification, samples were injected directly from the collection plate onto the HPLC system. MAG-CPT concentration was then calculated by subtraction of free from total CPT. The LLOQs of the method were 1.17 ng/ml for free CPT and 103.10 ng/ml (as CPT equivalent) for MAG-CPT using 0.1 and 0.05 ml of plasma, respectively. Linearity, precision, accuracy and recovery of the method were evaluated. The stability of MAG-CPT in plasma alone and after its stabilisation was carefully evaluated. No interference from blank dog, mouse and human plasma was observed. The suitability of the method for in vivo samples was assessed by the analysis of samples obtained from dogs that had received a single and 5-day repeated dose of MAG-CPT.


Assuntos
Acrilamidas/sangue , Antineoplásicos Fitogênicos/sangue , Camptotecina/sangue , Cromatografia Líquida de Alta Pressão/métodos , Animais , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Cães , Fluorometria/métodos , Injeções Intravenosas , Irinotecano , Modelos Lineares , Reprodutibilidade dos Testes
17.
J Control Release ; 65(1-2): 105-19, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10699275

RESUMO

Camptothecin (CPT) is a potent, antitumour drug acting mainly through inhibition of topoisomerase I during the S-phase of the cell cycle. Despite its impressive antitumour activity, clinical development was halted for unpredictable toxic events. Two soluble N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers were synthesised to contain CPT (5 wt.% and 10 wt.%). CPT was covalently linked at its alpha-hydroxyl group to the polymers through a Gly-Phe-Leu-Gly- spacer. In-vitro, CPT-conjugates were fairly resistant to hydrolysis in plasma as in buffer at neutral pH (0.2-0. 4% free CPT/h), while elastase and cysteine-proteases were able to release the active drug. Plasma levels in mice after intravenous administration of CPT-conjugates confirmed the modest hydrolysis in plasma. Plasma levels were approximately 5-fold lower than those observed at the highest tolerated dose of CPT administered in classical vehicles. Biodistribution in HT29 human colon carcinoma bearing mice was carried out after i.v. injection of [3H]CPT-conjugate and free [3H]CPT. Radioactivity uptake in tumour was evident only after [3H]CPT-conjugate treatment. Repeated intravenous administration of CPT-conjugates to HT29-bearing mice gave more than 90% tumour inhibition, some complete tumour regressions and no toxic deaths. The improved pharmacological profile on HT29 human colon carcinoma xenografts of the first poly(HPMA)-CPT conjugates might be ascribed to their prolonged intra-tumour retention and sustained release of the active drug.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/farmacocinética , Camptotecina/uso terapêutico , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Autorradiografia , Soluções Tampão , Camptotecina/administração & dosagem , Preparações de Ação Retardada , Células HT29 , Humanos , Hidrólise , Injeções Intravenosas , Cinética , Metacrilatos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Polímeros , Distribuição Tecidual , Transplante Heterólogo
19.
Br J Cancer ; 81(1): 99-107, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10487619

RESUMO

Doxorubicin pharmacokinetics were determined in 33 patients with solid tumours who received intravenous doses of 20-320 mg m(-2) HPMA copolymer bound doxorubicin (PK1) in a phase I study. Since assay constraints limited the data at lower doses, conventional analysis was not feasible and a 'population approach' was used. Bound concentrations were best described by a biexponential model and further analyses revealed a small influence of dose or weight on V1 but no identifiable effects of age, body surface area, renal or hepatic function. The final model was: clearance (Q) 0.194 I h(-1); central compartment volume (V1) 4.48 x (1+0.00074 x dose (mg)) I; peripheral compartment volume (V2) 7.94 I; intercompartmental clearance 0.685 I h(-1). Distribution and elimination half-lives had median estimates of 2.7 h and 49 h respectively. Free doxorubicin was present at most sampling times with concentrations around 1000 times lower than bound doxorubicin values. Data were best described using a biexponential model and the following parameters were estimated: apparent clearance 180 I h-(-1); apparent V1 (I) 1450 x (1+0.0013 x dose (mg)), apparent V2 (I) 21 300 x (1-0.0013 x dose (mg)) x (1+2.95 x height (m)) and apparent Q 6950 I h(-1). Distribution and elimination half-lives were 0.13 h and 85 h respectively.


Assuntos
Antineoplásicos/farmacocinética , Doxorrubicina/análogos & derivados , Neoplasias/metabolismo , Ácidos Polimetacrílicos/farmacocinética , Ácidos Polimetacrílicos/uso terapêutico , Adulto , Idoso , Antineoplásicos/sangue , Antineoplásicos/uso terapêutico , Relação Dose-Resposta a Droga , Doxorrubicina/sangue , Doxorrubicina/metabolismo , Doxorrubicina/farmacocinética , Doxorrubicina/uso terapêutico , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/tratamento farmacológico , Ácidos Polimetacrílicos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...