Determination of Cyclophosphamide Enantiomers in Plasma by LC-MS/MS: Application to Pharmacokinetics in Breast Cancer and Lupus Nephritis Patients

This article describes the enantioseleclive analysis of cyclophosphamide (CPA) in human plasma using LC-MS/MS. CPA enantiomers were extracted from plasma using a mixture of ethyl acetate and chloroform (75:25, v/v). The enantiomers were separated on a Chiralcel(R) OD-R column, with the mobile phase consisting of a mixture of acetonitrile and water (75:25, v/v) plus 0.2% formic acid. The protonaled ions and their respective product ions were monitored using two functions, 261 > 141 for CPA enantiomers and 189 > 104 for the internal standard (antipyrine). Recovery rates were higher than 95% and the quantification limit was 2.5-ng/ml plasma for both enantiomers. The coefficients of variation and the relative errors obtained for the validation of intra- and interassay precision and accuracy were less than 10%. The method was applied for the investigation of the enantioselective pharmacokinetics of CPA in a lupus nephritis patient treated with 1 g CPA infused over 2 h and in a breast cancer patient treated with 0.9 g infused over 1 h. No stereoselectivity in the pharmacokinetic parameters was observed for either patient. Clearance values of 2.63 and 2.93 l/h and of 3.36 and 3.61 l/h for (-)-(S) and (+)-(R)-CPA were obtained for the breast cancer and lupus nephritis patient., respectively. Chirality 21:383-389, 2009. (C) 2008 Wiley-Liss, Inc.

Stereoselective Analysis of Labetalol in Human Plasma by LC-MS/MS: Application to Pharmacokinetics

Labetalol is clinically available as a mixture of two racemates (four stereoisomers). The stereoisomer (R,R) has as main activity the beta(1)-antagonism and the stereoisomer (S,R) is highly selective for the alpha(1) adrenoceptor and is responsible for most of the alpha-blocker activity. In the present investigation, a method for the analysis of labetalol stereoisomers in human plasma was developed and applied to pharmacokinetic studies. Plasma samples (0.5 ml) were extracted with methyl tert-butyl ether at pH 9.5. The four labetalol stereoisomers were analyzed by LC-MS/MS on a Chirobiotic (R) V column using a mobile phase consisting of methanol, acetic acid, and diethylamine, with a recovery of more than 90% for all four. The quantitation limit was 0.5 ng/ml and linearity was observed at 250 ng/ml plasma for each stereoisomer. Studies of precision and accuracy presented coefficients of variation and percentage inaccuracy of less than 15%, indicating that the method is precise and accurate. The method was applied to the study of the kinetic disposition of labetalol over a period of 12 h after oral administration of a single 100 mg dose to a hypertensive pregnant woman. The clinical study revealed stereoselectivity in the pharmacokinetics of labetalol, with a lower plasma proportion for the active stereoisomers (R,R)-labetalol and (S,R)-labetalol. The stereoselectivity observed after oral administration is due to the hepatic metabolism and the first pass effect, with an AUC((R,R))/AUC((S,S)) ratio of 0.5. Chirality 21:738-744, 2009. (C) 2008 Wiley-Liss, Inc.

LC-MS/MS quantitation of plasma progesterone in cattle

Quantitation of progesterone (P(4)) in biological fluids is often performed by radioimmunoassay (RIA), whereas liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been used much less often. Due to its autoconfirmatory nature, LC-MS/MS greatly minimizes false positives and interference. Herein we report and compare with RIA an optimized LC-MS/MS method for rapid, efficient, and cost-effective quantitation of P(4) in plasma of cattle with no sample derivatization. The quantitation of plasma P(4) released from three nonbiodegradable, commercial, intravaginal P(4)-releasing devices (IPRD) over 192 h in six ovariectomized cows was compared in a pairwise study as a test case. Both techniques showed similar P(4) kinetics (P > 0.05) whereas results of P(4) quantitation by RIA were consistently higher compared with LC-MS/MS (P < 0.05) due to interference and matrix effects. The LC-MS/MS method was validated according to the recommended analytical standards and displayed P(4) limits of detection (LOD) and quantitation (LOQ) of 0.08 and a 0.25 ng/mL, respectively. The high selective LC-MS/MS method proposed herein for P(4) quantitation eliminates the risks associated with radioactive handling; it also requires no sample derivatization, which is a common requirement for LC-MS/MS quantitation of steroid hormones. Its application to multisteroid assays is also viable, and it is envisaged that it may provide a gold standard technique for hormone quantitation in animal reproductive science studies. (C) 2011 Elsevier Inc. All rights reserved.

Applications of accurate, high-precision Pb isotope ratio measurement by multi-collector ICP-MS

The isotope composition of Ph is difficult to determine accurately due to the lack of a stable normalisation ratio. Double and triple-spike addition techniques provide one solution and presently yield the most accurate measurements. A number of recent studies have claimed that improved accuracy and precision could also be achieved by multi-collector ICP-MS (MC-ICP-MS) Pb-isotope analysis using the addition of Tl of known isotope composition to Pb samples. In this paper, we verify whether the known isotope composition of Tl can be used for correction of mass discrimination of Pb with an extensive dataset for the NIST standard SRM 981, comparison of MC-ICP-MS with TIMS data, and comparison with three isochrons from different geological environments. When all our NIST SRM 981 data are normalised with one constant Tl-205/Tl-203 of 2.38869, the following averages and reproducibilities were obtained: Pb-207/Pb-206=0.91461+/-18; Pb-208/Ph-206 = 2.1674+/-7; and (PbPh)-Pb-206-Ph-204 = 16.941+/-6. These two sigma standard deviations of the mean correspond to 149, 330, and 374 ppm, respectively. Accuracies relative to triple-spike values are 149, 157, and 52 ppm, respectively, and thus well within uncertainties. The largest component of the uncertainties stems from the Ph data alone and is not caused by differential mass discrimination behaviour of Ph and Tl. In routine operation, variation of sample introduction memory and production of isobaric molecular interferences in the spectrometer's collision cell currently appear to be the ultimate limitation to better reproducibility. Comparative study of five different datasets from actual samples (bullets, international rock standards, carbonates, metamorphic minerals, and sulphide minerals) demonstrates that in most cases geological scatter of the sample exceeds the achieved analytical reproducibility. We observe good agreement between TIMS and MC-ICP-MS data for international rock standards but find that such comparison does not constitute the ultimate. test for the validity of the MC-ICP-MS technique. Two attempted isochrons resulted in geological scatter (in one case small) in excess of analytical reproducibility. However, in one case (leached Great Dyke sulphides) we obtained a true isochron (MSWD = 0.63) age of 2578.3 +/- 0.9 Ma, which is identical to and more precise than a recently published U-Pb zircon age (2579 3 Ma) for a Great Dyke websterite [Earth Planet. Sci. Lett. 180 (2000) 1-12]. Reproducibility of this age by means of an isochron we regard as a robust test of accuracy over a wide dynamic range. We show that reliable and accurate Pb-isotope data can be obtained by careful operation of second-generation MC-ICP magnetic sector mass spectrometers. (C) 2002 Elsevier Science B.V. All rights reserved.

Comparison of an ELISA and an LC/MS/MS method for measuring tacrolimus concentrations and making dosage decisions in transplant recipients

This study compared an enzyme-linked immunosorbent assay (ELISA) to a liquid chromatography-tandem mass spectrometry (LC/MS/MS) technique for measurement of tacrolimus concentrations in adult kidney and liver transplant recipients, and investigated how assay choice influenced pharmacokinetic parameter estimates and drug dosage decisions. Tacrolimus concentrations measured by both ELISA and LC/MS/MS from 29 kidney (n = 98 samples) and 27 liver (n = 97 samples) transplant recipients were used to evaluate the performance of these methods in the clinical setting. Tacrolimus concentrations measured by the two techniques were compared via regression analysis. Population pharmacokinetic models were developed independently using ELISA and LC/MS/MS data from 76 kidney recipients. Derived kinetic parameters were used to formulate typical dosing regimens for concentration targeting. Dosage recommendations for the two assays were compared. The relation between LC/MS/MS and ELISA measurements was best described by the regression equation ELISA = 1.02 . (LC/MS/MS) + 0.14 in kidney recipients, and ELISA = 1.12 . (LC/MS/MS) - 0.87 in liver recipients. ELISA displayed less accuracy than LC/MS/MS at lower tacrolimus concentrations. Population pharmacokinetic models based on ELISA and LC/MS/MS data were similar with residual random errors of 4.1 ng/mL and 3.7 ng/mL, respectively. Assay choice gave rise to dosage prediction differences ranging from 0% to 30%. ELISA measurements of tacrolimus are not automatically interchangeable with LC/MS/MS values. Assay differences were greatest in adult liver recipients, probably reflecting periods of liver dysfunction and impaired biliary secretion of metabolites. While the majority of data collected in this study suggested assay differences in adult kidney recipients were minimal, findings of ELISA dosage underpredictions of up to 25% in the long term must be investigated further.

Identification of slow and fast-acting toxins in a highly ciguatoxic barracuda (Sphyraena barracuda) by HPLC/MS and radiolabelled ligand binding

A barracuda implicated in ciguatera fish poisoning in Guadeloupe was estimated to have an overall flesh toxicity of 15 MUg/g using mouse bioassay. A lipid soluble extract was separated into two toxic fractions, FrA and FrB, on a LH20 Sephadex column eluted with dichloromethane/methanol (1:1). When intraperitoneal injected into mice, FrA provoked symptoms characteristic of slow-acting ciguatoxins, whereas FrB produced symptoms indicative of fast-acting toxins (FAT). High performance liquid chromatography/mass spectrometry/radio-ligand binding (HPLC/MS/RLB) analysis confirmed the two fractions were distinct, because only a weak overlap of some compounds was observed. HPLC/MS/RLB analysis revealed C-CTX-1 as the potent toxin present in FrA, and two coeluting active compounds at m/z 809.43 and 857.42 in FrB, all displaying the characteristic pattern of ion formation for hydroxy-polyethers. Other C-CTX congeners and putative hydroxy-polyether-like compounds were detected in both fractions, however, the RLB found them inactive. C-CTX-1 accounted for >90% of total toxicity in this barracuda and was confirmed to be a competitive inhibitor of brevetoxin binding to voltage-sensitive sodium channels (VSSCs) with a potency two-times lower than P-CTX-1. However, FAT active on VSSCs and

Simula????o de reuni??o com dirigente: prepara????o de informa????es e an??lise sobre programa governamental

A simula????o visa preparar gerentes e assessores para organizarem informa????es e diagn??sticos para tomada de decis??o. Apresenta diversos pontos de vista sobre um programa em andamento e estimula debates entre gestores e atores das ??reas envolvidas. A partir da aprecia????o dos pontos de vista desses atores, os participantes dever??o se preparar, em curto espa??o de tempo, para uma reuni??o com o dirigente rec??m-empossado respons??vel pelo programa em quest??o

Gest??o de condicionalidades e acompanhamento das fam??lias do programa Bolsa Fam??lia

A gest??o das condicionalidades e do acompanhamento das fam??lias do Programa Bolsa Fam??lia consiste em um conjunto de iniciativas, a????es e procedimentos de car??ter intersetorial e intergovernamental para o acompanhamento integral, nominal e massivo de fam??lias em situa????o de vulnerabilidade ou risco social. Atualmente, cerca de 6,5 milh??es de fam??lias s??o acompanhadas em rela????o ?? agenda da sa??de e 14 milh??es de crian??as e adolescentes t??m informa????es sobre sua frequ??ncia escolar registradas. Das fam??lias acompanhadas pela sa??de, 98,3% tiveram cumprimento integral no ??ltimo per??odo. Na educa????o, o percentual foi de 97,3% das crian??as de 6 a 15 anos. As fam??lias em descumprimento s??o prioritariamente inclu??das no acompanhamento familiar realizado pela rede socioassistencial. Tais a????es t??m sua base na institucionaliza????o de inst??ncias e processos de intensa articula????o governamental, envolvendo as ??reas de sa??de, educa????o e assist??ncia social em todos os estados e munic??pios do pa??s

Programa banda larga nas escolas

O Programa Banda Larga nas Escolas tem por objetivo a inclus??o das tecnologias de informa????o e comunica????o (TIC) na realidade das escolas p??blicas urbanas nacionais, sem ??nus para os estados e munic??pios, com dura????o dos servi??os at?? 2025. Para isso foi adotado um modelo de parceria p??blico-privada com reflexo direto na condu????o e na dura????o do programa, que ultrapassa as a????es de um governo para ser reconhecido como a????o de Estado com mais de 20 anos de dura????o e perspectiva para perdurar como obriga????o nas futuras concess??es da explora????o de servi??os de telefonia e transporte multim??dia no pa??s. At?? o segundo trimestre de 2010, j?? estavam conectadas 47.204 escolas, que correspondem a 84% do compromisso inicial (56 mil escolas). Esse n??mero de conex??es beneficia um n??mero aproximado de 30 milh??es de alunos da rede p??blica

Acompanhamento da frequ??ncia escolar de crian??as e adolescentes em vulnerabilidade: condicionalidade em educa????o do Programa Bolsa Fam??lia

Esta iniciativa trata do acompanhamento da frequ??ncia escolar de crian??as e adolescentes em vulnerabilidade social, de fam??lias benefici??rias do Programa Bolsa Fam??lia. Atualmente, o universo de acompanhamento da frequ??ncia escolar ?? de aproximadamente 17 milh??es de crian??as e adolescentes de 6 a 17 anos. No ??ltimo per??odo, alcan??ou-se 97,85% de resultado l??quido de retorno da frequ??ncia, recorde da s??rie hist??rica. A iniciativa consegue resultados expressivos de acompanhamento da frequ??ncia escolar, em uma rede formada por 168 mil escolas que disponibilizam informa????es de aproximadamente 17 milh??es de crian??as e adolescentes de fam??lias pobres ou extremamente pobres, com a participa????o efetiva de todos os munic??pios (5.563 operadores municipais m??ster atuantes) e de operadores estaduais em todas as unidades da federa????o, apoiados por um sistema que possui 22 mil usu??rios

Eco postal: um programa socioambiental com gera????o de emprego e renda

Na Empresa Brasileira de Correios e Tel??grafos (ECT), um grande n??mero de empregados recebe uniformes com periodicidade semestral, o que inclui tamb??m a troca peri??dica dos malotes inutilizados pelo desgaste. Por quest??es de seguran??a, todo esse material inserv??vel era destinado ao aterro sanit??rio. Mas, desde 2004, foi encontrado um novo destino para esses objetos a partir das cooperativas formadas em conv??nio com a Universidade Federal do Paran??, Associa????o Comercial do munic??pio de Toledo e Organiza????es N??o-Governamentais (ONGs). As cooperativas transformam artesanalmente esse material em v??rios produtos que geram emprego e renda, especialmente para as fam??lias que, em muitas situa????es, viviam do subemprego. Isso demonstra a import??ncia que a empresa confere ??s a????es de responsabilidade social que ultrapassam a oferta de servi??os com qualidade ?? comunidade, assegurando que todo o processo de trabalho seja feito de forma socialmente respons??vel. Este programa gera emprego e renda para aproximadamente 50 fam??lias em todo o estado, com projeto de amplia????o para outras regi??es

Programa caminho da escola

O Fundo Nacional de Desenvolvimento da Educa????o (FNDE) concebeu o modelo do Programa Caminho da Escola almejando uma solu????o aos problemas enfrentados no ??mbito do transporte escolar. Desde o princ??pio, o programa procurou alcan??ar resultados concretos e eficientes para transpor as conhecidas dificuldades de ve??culos que trafegam na zona rural e enfrentam condi????es severas de opera????o como vias sem asfaltamento, com poeira, lama, buracos, pontes prec??rias e mata-burros, assim como as embarca????es, que navegam com estiagens e enchentes por rios caudalosos e com grande incid??ncia de troncos e galhos, sem p??er para atraca????o. A fim de facilitar esse processo de melhoria da gest??o de transporte escolar, foi disponibilizada aos munic??pios, estados e Distrito Federal uma linha de cr??dito do Banco Nacional de Desenvolvimento Econ??mico Social (BNDES) com menores juros de mercado e extenso prazo para quita????o, facultando-lhes um modelo de compras que -reduziu expressivamente os custos e lhes isentou do processo licitat??rio para a aquisi????o de ve??culos que atendem rigidamente a especifica????es pr??prias e que contam com chancela de qualidade e conformidade

Programa de apoio ao desenvolvimento de novas empresas de base tecnol??gica agropecu??ria e ?? transfer??ncia de tecnologia (Proeta)

Em dezembro de 2001, o Proeta foi criado pela Empresa Brasileira de Pesquisa Agropecu??ria (Embrapa) com apoio financeiro do Fundo Multilateral de Investimentos do Banco Interamericano de Desenvolvimento (Fumin/BID), por meio de um acordo de coopera????o t??cnica n??o-reembols??vel. O programa tem o objetivo de contribuir para a transfer??ncia de tecnologias e conhecimentos gerados pela Embrapa para empreendimentos de base tecnol??gica, mediante a utiliza????o do processo de incuba????o de empresas. Para concretizar a iniciativa, foram estabelecidas experi??ncias-piloto em cinco unidades de pesquisa da Embrapa, estrategicamente situadas nas regi??es Nordeste, Centro-Oeste e Sudeste. Entre os resultados e avan??os obtidos merecem destaque 21 tecnologias disponibilizadas, 14 conv??nios firmados com incubadoras, 16 propostas de neg??cios apresentadas, 14 empresas pr??-selecionadas e incubadas, e uma empresa graduada. A consolida????o das alian??as e parcerias no processo de incuba????o resultou em um sistema de inova????o que auxilia o desenvolvimento sustent??vel da cadeia produtiva do agroneg??cio, gerando benef??cios para a sociedade em geral