RESUMO
PURPOSE: Breast cancer patients receiving chemotherapy often experience symptoms such as nausea, vomiting and loss of appetite that potentially affect dietary habits. This study assessed the intake of energy, macronutrients and food groups before and during chemotherapy in breast cancer patients compared with women without cancer, and determined the association between symptoms and energy and macronutrient intake. METHODS: This study included 117 newly diagnosed breast cancer patients scheduled for chemotherapy and 88 women without cancer. Habitual intake before chemotherapy was assessed with a food frequency questionnaire. Two 24-h dietary recalls were completed on random days for each participant during the whole chemotherapy treatment for patients and within 6 months after recruitment for women without cancer. Shortly, after the dietary recall, participants filled out questionnaires on symptoms. RESULTS: Before chemotherapy, habitual energy and macronutrient intake was similar for breast cancer patients and women without cancer. During chemotherapy, breast cancer patients reported a significantly lower total energy, fat, protein and alcohol intake than women without cancer, as shown by a lower intake of pastry and biscuits, cheese, legumes and meat products. A decline in subjective taste perception, appetite and hunger and experiencing a dry mouth, difficulty chewing, lack of energy and nausea were associated with a lower energy intake. CONCLUSIONS: Symptoms induced by chemotherapy are associated with lower dietary intake and manifested by a lower intake of specific food groups. To ensure an optimal dietary intake during chemotherapy, it is important to monitor nutritional status and symptom burden during chemotherapy in breast cancer patients.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/terapia , Dieta/métodos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Humanos , Pessoa de Meia-Idade , Estado Nutricional , Inquéritos e QuestionáriosAssuntos
Neurodermatite , Prurigo , Doença Crônica , França/epidemiologia , Humanos , Prevalência , Prurigo/epidemiologia , Prurigo/terapiaRESUMO
BACKGROUND: This Phase Ib dose-escalating study investigated safety, maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK) and clinical antitumour activity of tosedostat (CHR-2797), an orally bioavailable aminopeptidase inhibitor, in combination with paclitaxel. METHODS: A total of 22 patients received paclitaxel (135-175 mg m(-2)) intravenously, administered once every three weeks for up to six cycles, with oral tosedostat (90-240 mg) daily. RESULTS: One DLT (grade 3 dyspnoea) was observed in one patient with tosedostat 180 mg combined with paclitaxel 175 mg m(-2). A high number of paclitaxel infusion reactions was noted during the second administration (59%) and this prompted interruption of tosedostat dosing for 5 days around every second and subsequent paclitaxel infusion. No formal MTD was determined because of the high frequency of paclitaxel infusion reactions that may have been influenced by tosedostat. Most frequently observed drug-related adverse events were alopecia, fatigue (95% each), peripheral sensory neuropathy (59%), paclitaxel hypersensitivity (59%) and rash (55%). One patient died because of eosinophilic myocarditis, possibly related to study medication. There was no PK interaction between tosedostat and paclitaxel. In all, 3 patients had a partial response and 12 patients had stable disease lasting >3 months. CONCLUSION: The combination of tosedostat with paclitaxel was well tolerated except for the high incidence of paclitaxel-related infusion reactions.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Glicina/análogos & derivados , Ácidos Hidroxâmicos/administração & dosagem , Neoplasias/tratamento farmacológico , Paclitaxel/administração & dosagem , Adulto , Idoso , Aminopeptidases/antagonistas & inibidores , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Esquema de Medicação , Fadiga/induzido quimicamente , Feminino , Glicina/administração & dosagem , Glicina/efeitos adversos , Glicina/farmacocinética , Humanos , Ácidos Hidroxâmicos/efeitos adversos , Ácidos Hidroxâmicos/farmacocinética , Masculino , Dose Máxima Tolerável , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The combination of sorafenib (vascular endothelial growth factor receptor 2 inhibitor) and sirolimus (mammalian target of rapamycin inhibitor) might work synergistically. METHODS: A phase I dose-escalation study with sorafenib twice a day (b.i.d.) and sirolimus once daily (q.d.) was performed to determine the recommended dose of the combination in patients with solid tumours. Secondary objectives were to determine the safety profile and maximum tolerated dose (MTD), and to evaluate the pharmacokinetics (PK) of the combination. RESULTS: Dose-limiting toxicities were transaminitis and cutaneous toxicity. The most frequently reported adverse events were elevated transaminases, hypophosphatemia, fatigue, anorexia, diarrhoea, nausea, rash and palmar-plantar erythrodysaesthesia. Sirolimus did not change the PK of sorafenib; in contrast, sorafenib reduced the AUC(0-96) and C(max) of sirolimus. No objective responses were observed; eight patients showed stable disease for a median of 16.3 weeks (range 8-24). The MTD of the combination was sorafenib 200 mg b.i.d. with sirolimus 1 mg q.d. CONCLUSION: The combination of sorafenib and sirolimus showed enhanced toxicity, which could not be explained by the PK of both drugs. The relative low doses at the MTD, in combination with the PK results, do not warrant further development of this combination.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Benzenossulfonatos/administração & dosagem , Neoplasias/tratamento farmacológico , Piridinas/administração & dosagem , Sirolimo/administração & dosagem , Serina-Treonina Quinases TOR/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Adulto , Benzenossulfonatos/efeitos adversos , Benzenossulfonatos/farmacocinética , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Niacinamida/análogos & derivados , Compostos de Fenilureia , Piridinas/efeitos adversos , Piridinas/farmacocinética , Sirolimo/efeitos adversos , Sirolimo/farmacocinética , SorafenibeRESUMO
BACKGROUND: Chemotherapy (CT)-induced neutropenia and febrile neutropenia (FN) can lead to changes in the treatment plan, potentially worsening the cancer outcome. This study evaluated the effect of the glycopegylated granulocyte-colony stimulating factor lipegfilgrastim, used as primary (PP) or secondary prophylaxis (SP), on treatment modifications in adult patients receiving cytotoxic CT with or without biological/targeted therapy (BT) for solid and haematological tumours. METHODS: This phase 4, prospective, observational study was conducted in eight centres in the Netherlands, in 2015-2017. Other study objectives were to characterise the population of cancer patients receiving lipegfilgrastim, to evaluate the incidence of CT-induced neutropenic events, and to assess safety. RESULTS: Of 142 patients, 73.94% had breast cancer and 55.63% received CT in the adjuvant setting. Most patients received lipegfilgrastim as PP (74.65%) and were at low (34.51%) or high risk (39.44%) of FN. CT dose delays were recorded for 22.64% and 36.11% of patients receiving lipegfilgrastim for PP and SP, respectively. CT dose reductions were recorded for 2.11% of patients; no CT dose omissions and one BT dose omission occurred. FN and grade III/IV neutropenia were reported for 5.63% and 9.86% of patients, respectively; associated hospitalisations were rare. The most frequently lipegfilgrastimrelated adverse events (AE) were myalgia, bone pain, and back pain. Serious AEs (55) were reported for 30 (21.13%) patients. There were two deaths, unrelated to lipegfilgrastim administration. CONCLUSION: Administration of lipegfilgrastim in routine clinical practice in the Netherlands results in limited CT/BT dose modifications and low incidence of neutropenic events, with no new safety concerns.
Assuntos
Antineoplásicos , Filgrastim , Neutropenia , Polietilenoglicóis , Adulto , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica , Filgrastim/uso terapêutico , Humanos , Países Baixos , Neutropenia/induzido quimicamente , Neutropenia/tratamento farmacológico , Polietilenoglicóis/uso terapêutico , Estudos ProspectivosRESUMO
BACKGROUND: Asparagine-glycine-arginine-human tumour necrosis factor (NGR-hTNF) is a vascular targeting agent exploiting a tumour-homing peptide (NGR) that selectively binds to aminopeptidase N/CD13, overexpressed on tumour blood vessels. Significant preclinical synergy was shown between low doses of NGR-TNF and doxorubicin. METHODS: The primary aim of this phase I trial was to verify the safety of low-dose NGR-hTNF combined with doxorubicin in treating refractory/resistant solid tumours. Secondary objectives included pharmacokinetics (PKs), pharmacodynamics, and clinical activity. In all 15 patients received NGR-hTNF (0.2-0.4-0.8-1.6 microg m(-2)) and doxorubicin (60-75 mg m(-2)), both given intravenously every 3 weeks. RESULTS: No dose-limiting toxicity occurred and the combination was well tolerated. Around two cases of neutropenic fevers, lasting 2 days, and two cases of cardiac ejection-fraction drops, one asymptomatic and the other symptomatic, were registered. Only 11% of the adverse events were related to NGR-hTNF and were short-lasting and mild-to-moderate in severity. There was no apparent PK interaction and the shedding of soluble TNF-receptors did not increase to 0.8 microg m(-2). One partial response (7%), at dose level 0.8 microg m(-2), and 10 stable diseases (66%), lasting for a median duration of 5.6 months, were observed. CONCLUSIONS: NGR-hTNF plus doxorubicin was administered safely and showed promising activity in patients pre-treated with anthracyclines. The dose level of 0.8 microg m(-2) NGR-hTNF plus doxorubicin 75 mg m(-2) was selected for phase II development.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Doxorrubicina/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/metabolismo , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/efeitos adversos , Proteínas Recombinantes de Fusão/farmacocinética , Fator de Necrose Tumoral alfa/administração & dosagem , Fator de Necrose Tumoral alfa/efeitos adversos , Fator de Necrose Tumoral alfa/farmacocinéticaRESUMO
In advanced non-small cell lung cancer (NSCLC) the clinical benefit of a platinum-based doublet is only modest, therefore, attenuated dosed three-drug combinations are investigated. We hypothesized that with adequate support a full dosed chemotherapy triplet is feasible. The study was designed as a dose finding study of paclitaxel in chemotherapy-naive patients. Paclitaxel was given as a 3-h infusion on day 1, followed by fixed doses of teniposide (or etoposide) 100mg/m(2) days 1, 3, 5 and cisplatin 80 mg/m(2) day 1 every 3 weeks. As myelotoxicity was expected to be the dose-limiting toxicity, prophylactic G-CSF and antibiotic support was evaluated. Indeed, paclitaxel 120 mg/m(2) resulted in dose-limiting neutropenia, despite G-CSF support. Teniposide/etoposide day 1, 3, 5 was less myelotoxic compared to day 1, 2, 3. G-CSF support allowed paclitaxel dose-escalation to 250 mg/m(2). The addition of prophylactic antibiotics enabled dose-escalation to 275 mg/m(2) without reaching MTD. In conclusion, G-CSF and antibiotics prophylaxis enables the delivery of a full dosed chemotherapy triplet in previously untreated NSCLC patients.
Assuntos
Antibacterianos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Adulto , Idoso , Antibacterianos/efeitos adversos , Medula Óssea/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Feminino , Fator Estimulador de Colônias de Granulócitos/efeitos adversos , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Neutropenia/prevenção & controle , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Teniposídeo/administração & dosagem , Teniposídeo/efeitos adversosRESUMO
Separations of five diastereoisomers of nucleoside phosphoramidate derivatives (pronucleotides) were performed by both HPLC method using derivatized cellulose and amylose chiral stationary phases and CE method using anionic cyclodextrins added in the background electrolyte (BGE). An optimal baseline separation (Rs > 1.5) was readily obtained with all silica-based celluloses and amyloses using in a normal-phase methodology. Capillary electrophoresis was used as an alternative technique to HPLC for the separation of pronucleotides. The diastereoisomers were fully resolved with sulfated cyclodextrins at both BGE pH (2.5 and 6.2). Limits of detection and limits of quantification, calculated for both methods, are up to 200 times higher in CE separations than in HPLC separations. The analytical HPLC method was then applied in a preliminary study for the pronucleotide 1 quantification in cellular extract.
Assuntos
Amidas/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Nucleotídeos/isolamento & purificação , Ácidos Fosfóricos/isolamento & purificação , Linhagem Celular Tumoral , Humanos , Pró-Fármacos/isolamento & purificação , Incerteza , Zidovudina/análogos & derivados , Zidovudina/isolamento & purificaçãoRESUMO
Analytical HPLC methods using derivatized amylose chiral stationary phases, Chiralpak AD-H and Chiralpak AS, were developed for the direct enantioseparation of eight substituted 4-oxo-1,4-dihydroquinoline-3-carboxamide derivatives with one stereogenic center. Baseline separation (Rs>1.5) was always achieved on amylose based Chiralpak AD-H column to the difference with Chiralpak AS. Using UV detection, a linear response was observed within a 180-420 micromol L(-1) concentration range (r2>0.991) for three racemic compounds 1, 3 and 4 with best pharmacological potentials; repeatability, limit of detection (LD) and quantification (LQ) were also determined: LD varied, for the solutes, from 0.36 to 2.56 micromol L(-1). Finally, the enantiopurity of these compounds was determined. Additionally, the effect of temperature variations upon isomer separations was investigated.
Assuntos
Amilose/análogos & derivados , Carbamatos/química , Cromatografia Líquida de Alta Pressão , Fenilcarbamatos/química , Quinolinas/isolamento & purificação , Receptor CB2 de Canabinoide/agonistas , Tecnologia Farmacêutica/métodos , Amilose/química , Cromatografia Líquida de Alta Pressão/normas , Estrutura Molecular , Quinolinas/química , Quinolinas/farmacologia , Reprodutibilidade dos Testes , Solventes/química , Espectrofotometria Ultravioleta , Estereoisomerismo , Tecnologia Farmacêutica/normas , TemperaturaRESUMO
Acidity constants of benzoxa-, benzothia- and benzoselena-zolinone derivatives were determined by capillary electrophoresis, potentiometry and spectrophotometry experiments. These three analytical techniques gave pK(a) results that were in good agreement. A convenient, accurate and precise method for the determination of pK(a) was developed to measure changes in acidity constants induced by heteroatom or 6-benzoyl substituted derivatives. pK(a) values were determined simultaneously for two compounds characterized by different electrophoretic mobility (micro(e)) and pK(a) value and in the presence of an analogous neutral marker.
Assuntos
Benzotiazóis/química , Benzoxazóis/química , Compostos Organosselênicos/química , Oxazolidinonas/química , Ácidos/química , Algoritmos , Soluções Tampão , Eletroforese Capilar , Concentração de Íons de Hidrogênio , Estrutura Molecular , Potenciometria , Espectrofotometria UltravioletaRESUMO
Compounds 1-4 are diastereoisomeric thymine derivatives of isochroman aromatic analogues of stavudine, an approved drug. Both capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) techniques were used to separate these species with high resolution and thus permit the determination of enantiomeric excess. Chiral selectivity was developed using anionic (highly sulfated) cyclodextrins as chiral selectors in CE and amylose, cellulose and cyclodextrin chiral stationary phases by HPLC. The HPLC method was found to be more efficient than the CE method and was applied, after validation (repeatability, limit of detection, limit of quantification) to follow and quantify the kinetics of a stereoselective esterification.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Nucleosídeos/isolamento & purificação , Estavudina/isolamento & purificação , Estrutura Molecular , Nucleosídeos/química , Reprodutibilidade dos Testes , Estavudina/análogos & derivados , Estavudina/química , EstereoisomerismoRESUMO
A stereospecific HPLC methodology has been developed for the diastereoisomeric resolution of a mononucleotide prodrug in cell extracts. This method involves the use of solid phase extraction on a C18 cartridge. Diastereoisomers and internal standard resolutions were performed on a cellulose based chiral column (Chiralcel OD-H) used in the normal phase mode. The method was validated in terms of specificity, recovery, linearity (diasteroisomers mixture concentration: 3-60 micromol L(-1)), precision and accuracy and detection limit (1.67 and 1.33 micromol L(-1) for first and second eluted diastereoisomer). This method was applied to the determination of the apparent rate constants of disappearance and half-lives of each stereoisomers. This permits to conclude to the stereoselectivity of the enzymatic activity involved in the decomposition pathway of 2.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Pró-Fármacos/análise , Zidovudina/análogos & derivados , Zidovudina/análise , Linhagem Celular Tumoral , Humanos , Cinética , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , EstereoisomerismoRESUMO
BACKGROUND: In the past years, interest in patient treatment preferences is growing. Our objectives were: (1) to assess and compare the minimal required benefit for patients with cancer, patients without cancer and healthcare professionals to make chemotherapy acceptable and (2) to obtain insight into attitudes towards societal costs of cancer treatment. PATIENTS AND METHODS: We performed a prospective survey consisting of hypothetical scenarios among patients with cancer, patients without cancer and healthcare professionals. Participants were asked to indicate the minimal desired benefit in terms of chance of cure, life prolongation and symptom relief which would make intensive and mild chemotherapy regimens acceptable. In two other scenarios, attitudes towards monthly costs for chemotherapy treatment were examined. RESULTS: The minimal benefit required to make chemotherapy acceptable did not differ between cancer and non-cancer patients, with respect to chance of cure (mean 57%), life prolongation (median 24 months) and symptom relief (mean 50%); healthcare providers were likely to accept the same chemotherapy regimen at lower thresholds (p < 0.01). Education level was an important explanatory variable and the differences between patients and healthcare professionals disappeared when corrected for education level. Opinions about the maximum acceptable costs for chemotherapy displayed a large spread between the groups. CONCLUSIONS: Minimal benefits to accept chemotherapy were not different between cancer and non-cancer patients, but are beyond what can generally can be achieved. Healthcare professionals were willing to accept chemotherapy for less benefit. This difference may be attributed to a difference in education level between the groups. Healthcare professionals rated the maximum acceptable societal cost for chemotherapy lower than patients.
Assuntos
Antineoplásicos/uso terapêutico , Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Custos de Medicamentos , Neoplasias/tratamento farmacológico , Aceitação pelo Paciente de Cuidados de Saúde , Adulto , Idoso , Antineoplásicos/economia , Atitude , Tomada de Decisões , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Países Baixos , Enfermeiras e Enfermeiros , Preferência do Paciente , Médicos , Estudos Prospectivos , Medição de Risco , Inquéritos e QuestionáriosRESUMO
Raman spectroscopy is a non-destructive analytical technique and previous results have shown that qualitative analysis of the lipid component of human atheromatous arteries is feasible. In this paper, we describe a quantitative analytical method for cholesterol and cholesteryl esters in human atherosclerotic plaques, combined with Raman spectroscopic results, using partial least-squares (PLS) regression, a statistical multivariate method based on factorial analysis. Twenty-nine human atherosclerotic pooled samples were studied and the results of Raman spectroscopy coupled with the PLS method were compared to biochemical results. The standard error of prediction was 16.1, 13.6, 1.9, 3.3 and 3.4 mg/g for total cholesterol, free cholesterol, palmitate cholesteryl, oleate cholesteryl and linoleate cholesteryl, respectively. The repeatability of Raman spectroscopy was found to be excellent. Our results show that Raman spectroscopy is a promising technique to obtain a consistent and non-destructive quantitative analysis of cholesterol and cholesteryl esters in human atherosclerotic lesions. In situ and in vivo analysis is a possibility in the near future.
Assuntos
Arteriosclerose/patologia , Colesterol/análise , Esterol Esterase/análise , Idoso , Idoso de 80 Anos ou mais , Ésteres do Colesterol/análise , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise Espectral RamanRESUMO
ApoAI Milano (AI(M)) and apoAI Paris (AI(P)) are mutant forms of apoAI in which cysteine is substituted for arginine at residues 173 and 151 respectively leading to the formation of homodimers and heterodimers with apoAII. Heterozygous subjects with these mutants are characterized by low levels of plasma HDL cholesterol and apoAI. The present study analyzed the metabolism of the different complexes of apoAI in three subjects, two AI(M) and one AI(P), using a primed-constant infusion of trideuterated leucine. In AI(M) carriers, the mutant form was almost equally distributed in AI(M) dimer, AI(M):AII heterodimer and the monomer, whereas, in the AI(P) subject, the mutant apoAI was essentially in the apoAI(P):AII complex. Normal apoAI was low in the AI(M) subjects (20 and 16 mg/dl) but very low in the AI(P) subject (0.3 mg/dl). In the AI(M) subjects, the low levels of apoAI were due to a rapid catabolism with a normal synthetic rate. However, the apoAI kinetics were heterogeneous with a rapid catabolism of the AI(M):AII complex (FCR of 0.430 and 0.401 day(-1)) and the AI(M) monomer (FCR of 0.570 and 0.406 day(-1)) whereas the AI(M) dimer was catabolized slowly (FCR of 0.114 and 0. 118 day(-1)). In contrast, AI(P) was catabolized relatively slowly with a FCR of 0.263, 0.182 and 0.258 day(-1) for AI(P) homodimer, apoAI(P):AII heterodimer and AI(P) monomer. In the three subjects, normal apoAI was catabolized quickly, with an FCR of 0.805 and 0.601 day(-1) in AI(M) carriers and 0.526 day(-1) in the AI(P) carrier. Therefore, the low level of apoAI in the AI(P) carrier is caused by a low production rate of apoAI, particularly of normal apoAI. In conclusion, apoAI is kinetically heterogeneous in AI(M) and in AI(P) subjects. Moreover, the two mutations lead to significant differences in the kinetic behavior of mutant apoAI depending on its inclusion in its complexes.
Assuntos
Apolipoproteína A-II/metabolismo , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , Mutação , Adulto , Apolipoproteína A-I/sangue , Apolipoproteína A-I/química , Apolipoproteína A-II/sangue , Apolipoproteína A-II/química , Dimerização , Heterozigoto , Humanos , Cinética , Masculino , Pessoa de Meia-IdadeRESUMO
Analytical HPLC methods using derivatized cellulose chiral stationary phases were developed for the separation of the enantiomers of methoxy and ethyl tetrahydronaphthalenic derivatives, new agonist and antagonist ligands for melatonin receptors. The resolution were made using normal-phase methodology with a mobile phase consisting of n-hexane-alcohol (methanol, ethanol, 1-propanol or 2-propanol) in various percentage, and a silica-based cellulose tris-3,5-dimethyl-phenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ). The mobile phase and the chiral stationary phase were varied to achieve the best resolution. The effects of concentration of alcohol, various aliphatic alcohols in the mobile phase were studied. The effects of substitution were analysed. Baseline separation (R(s) > 1.5) was easily obtained in many cases. The resolution results were complementary between the two columns.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Receptores de Superfície Celular/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Tetra-Hidronaftalenos/química , Tetra-Hidronaftalenos/isolamento & purificação , Celulose , Ligantes , Receptores de Melatonina , Dióxido de Silício , Espectrofotometria Ultravioleta , Estereoisomerismo , Tetra-Hidronaftalenos/metabolismoRESUMO
Analytical HPLC methods using derivatized cellulose chiral stationary phases were developed for the direct separation of the stereoisomers of disubstituted tetralin derivatives with two chiral centers, new agonist and antagonist ligands for melatonin receptors. The separations were made using normal-phase methodology with a mobile phase consisting of n-hexane-alcohol (methanol, ethanol, 1-propanol or 2-propanol) in various proportions, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ). The effects of concentration of various aliphatic alcohols in the mobile phase were studied. A better separation was achieved on cellulose carbamate phase compared with the cellulose ester phase. The effects of structural features of the solutes on the discrimination between the stereoisomers were examined. Baseline separation (Rs>1.5) was easily obtained in many cases.
Assuntos
Celulose/química , Cromatografia Líquida de Alta Pressão/métodos , Naftalenos/isolamento & purificação , Receptores de Superfície Celular/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Ligantes , Naftalenos/química , Naftalenos/farmacologia , Receptores de Superfície Celular/agonistas , Receptores de Superfície Celular/antagonistas & inibidores , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Receptores de Melatonina , EstereoisomerismoRESUMO
Capillary electrophoresis (CE) was used as a method to determine the acidity constants of eight aromatase inhibitors. This method was validated by comparison of results obtained with a traditional method, UV spectroscopy, and additionally with computational calculations. We confirmed here, with our series of compounds, that capillary electrophoresis is an attractive method for pKa measurements which is based on migration time or mobilities of the ionic species over a range of pH values. The precision of pKa measurements of N-imidazole derivatives is useful to observe pKa shifts induced by chemical modifications introduced on adjacent aromatic rings such as heterocycle (benzoxa- or benzothiazolinone) or substituted benzyle. The knowledge of these pKa values is a great interest to predict migration of solutes and qualitative interactions with ionized cyclodextrines as chiral selectors in further enantioseparative CE studies.
Assuntos
Inibidores da Aromatase , Inibidores Enzimáticos/análise , Imidazóis/química , Soluções Tampão , Inibidores Enzimáticos/farmacologia , Concentração de Íons de Hidrogênio , Imidazóis/farmacologia , Íons , Osmose , Reprodutibilidade dos TestesRESUMO
Compounds 1-4 are the four stereoisomers of a synthetic new potential antiviral agent (d4T analog) containing two chiral centers and a base (uracil). Both high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) techniques were used to separate and quantify enantiomers with high resolution. The determination of enantiomeric purity of the compounds was developed using both amylose chiral stationary phase by HPLC and anionic cyclodextrins (highly S-CD) as chiral selectors in CE. The HPLC method was found to be superior in sensitivity to the CE method.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Inibidores da Transcriptase Reversa/isolamento & purificação , Estavudina/isolamento & purificação , Reprodutibilidade dos Testes , Inibidores da Transcriptase Reversa/química , Sensibilidade e Especificidade , Estavudina/análogos & derivados , Estavudina/química , EstereoisomerismoRESUMO
The effects of daily Tamoxifen treatment on adult rat uterus weight depend on the degree of estrogenic impregnation of the animal. In intact animals, Tamoxifen caused a decrease of the uterine weight. A weight increase was observed, after castration, which was dose-dependent without reaching saturation even with 500 micrograms of Tamoxifen per day. This uterine weight increase, reaching its peak during the first 24 h after the initial Tamoxifen application, is attributable to water retention. The uterine progesterone receptor (PgR) concentrations are stimulated by daily antiestrogen treatment of intact and castrated animals. This increase in the PgR levels is initially dose-dependent up to 10 micrograms of Tamoxifen per day reaching maximal levels after 4 days of treatment. The results indicate that growth and PgR induction in adult rat uterus are essentially controlled by independent mechanisms, constituting the biological basis of the synergistic effects of anti-estrogens and progestagens.