Recent Progress of Nano-drug Combined with Chimeric Antigen Receptor T Cell Therapy in the Treatment of Soild Tumors / 中国肺癌杂志

Chimeric antigen receptor T cell (CAR-T) therapy has shown remarkable success in treating hematological malignancies. However, CAR-T therapy for solid tumors is still limited due to the unique solid-tumor microenvironment and heterogeneous target antigen expression, which leads to an urgent need of combining other therapies. At present, nano delivery system has become one of the most promising directions for the development of anti-tumor drugs. Based on the background of CAR-T and tumor treatment, we focus on the research progress of nanomedicine combined with CAR-T therapy, and systematically review the strategies and examples in recent years in the aspects of in vivo delivery of mRNA, regulation of tumor microenvironment, combination with photothermal therapy. And we also look forward to the future direction of this filed.
.

The production of the first functional antibody mimetic in higher plants: the chloroplast makes the DARPin G3 for HER2 imaging in oncology

BACKGROUND: Designed mimetic molecules are attractive tools in biopharmaceuticals and synthetic biology. They require mass and functional production for the assessment of upcoming challenges in the near future. The DARPin family is considered a mimetic pharmaceutical peptide group with high affinity binding to specific targets. DARPin G3 is designed to bind to the HER2 (human epidermal growth factor receptor 2) tyrosine kinase receptor. Overexpression of HER2 is common in some cancers, including breast cancer, and can be used as a prognostic and predictive tool for cancer. The chloroplasts are cost-effective alternatives, equal to, and sometimes better than, bacterial, yeast, or mammalian expression systems. This research examined the possibility of the production of the first antibody mimetic, DARPin G3, in tobacco chloroplasts for HER2 imaging in oncology. RESULTS: The chloroplast specific DARPin G3 expression cassette was constructed and transformed into N. tabacum chloroplasts. PCR and Southern blot analysis confirmed integration of transgenes as well as chloroplastic and cellular homoplasmy. The Western blot analysis and ELISA confirmed the production of DARPin G3 at the commercial scale and high dose with the rate of 20.2% in leaf TSP and 33.7% in chloroplast TSP. The functional analysis by ELISA confirmed the binding of IMAC purified chloroplast-made DARPin G3 to the extracellular domain of the HER2 receptor with highly effective picomolar affinities. The carcinoma cellular studies by flow cytometry and immunofluorescence microscopy confirmed the correct functioning by the specific binding of the chloroplast-made DARPin G3 to the HER2 receptor on the surface of HER2-positive cancer cell lines. CONCLUSION: The efficient functional bioactive production of DARPin G3 in chloroplasts led us to introduce plant chloroplasts as the site of efficient production of the first antibody mimetic molecules. This report, as the first case of the cost-effective production of mimetic molecules, enables researchers in pharmaceuticals, synthetic biology, and bio-molecular engineering to develop tool boxes by producing new molecular substitutes for diverse purposes.

Estudio de las variantes alélicas CYP2C9*2 y CYP2C9*3 en muestras de población mestiza peruana / Study of the allelic variants CYP2C9*2 and CYP2C9*3 in samples of the Peruvian mestizo population

Resumen Introducción. El citocromo CYP2C9 metaboliza, aproximadamente, el 15 % de los fármacos prescritos. Su gen presenta alelos cuyas frecuencias difieren entre grupos étnicos y poblaciones. Los alelos CYP2C9*2 y CYP2C9*3 dan cuenta de una enzima con actividad disminuida cuya frecuencia no ha sido determinada en la población mestiza peruana. Objetivo. Caracterizar la frecuencia de las variantes *2 (rs1799853) y *3 (rs1057910) del gen CYP2C9 en muestras de población mestiza peruana provenientes de Lima, Tacna y Junín. Materiales y métodos. Se hizo un estudio descriptivo, observacional y prospectivo, con muestreo no probabilístico, por conveniencia e incidental. Se incluyeron 218 sujetos según los criterios de inclusión y exclusión; todos los participantes otorgaron su consentimiento informado. El ADN genómico se obtuvo mediante hisopado de mucosa oral, y la detección de los genotipos para los alelos CYP2C9*2 y CYP2C9*3 se hizo mediante reacción en cadena de la polimerasa (PCR) en tiempo real, utilizando sondas TaqMan™. Resultados. Las variantes de CYP2C9*2 y CYP2C9*3 están presentes en la población mestiza peruana con frecuencias de 0,046 y 0,062, respectivamente. El análisis de las frecuencias genotípicas observadas permitió predecir que la frecuencia de fenotipos metabolismo intermedio sería del 15,13 % (CYP2C9*1/*2: 5,96 %; CYP2C9*1/*3: 9,17 %), y la de fenotipos de metabolismo lento, del 3,22 % (CYP2C9*2/*2: 1,38 %; CYP2C9*3/*3: 1,38 %; CYP2C9*2/*3: 0,46 %). Conclusiones. Se lograron determinar las frecuencias genotípicas y alélicas para las variantes *2 y *3 del gen CYP2C9 en una muestra no probabilística de población mestiza peruana. Las frecuencias obtenidas (0,046 y 0,062, respectivamente) están entre las esperadas para una población mestiza sudamericana con ascendencia amerindia, europea, africana y asiática.

Abstract Introduction: CYP2C9 metabolizes approximately 15% of the prescribed drugs. Its gene has alleles whose frequencies differ between ethnic groups and populations. The alleles CYP2C9*2 and CYP2C9*3 account for an enzyme with decreased activity and their frequencies have not been determined in the Peruvian mestizo population. Objective: To characterize the frequencies of the allelic variants *2 (rs1799853) and *3 (rs1057910) of CYP2C9 gen in the Peruvian mestizo population from Lima, Tacna y Junín. Materials and methods: We conducted an observational, prospective cross-sectional study with non-probabilistic, by convenience, and incidental sampling. We included 218 subjects according to the inclusion and exclusion criteria, all of whom had signed the informed consent. We obtained the genomic DNA from oral mucosa swab. For the detection of the CYP2C9*2 and CYP2C9*3 genotypes, we used real-time-polymerase chain reaction with TaqMan® probes. Results: The genotyping revealed that CYP2C9*2 and CYP2C9*3 variants have low frequencies (0.046 and 0.062, respectively). The frequency of intermediate metabolizers was 15.13% (CYP2C9*1/*2: 5.96%; CYP2C9*1/*3: 9.17%) and that of slow metabolizers was 3.22% (CYP2C9*2/*2: 1.38%; CYP2C9*3/*3: 1.38%; CYP2C9*2/*3: 0.46%). Conclusions: It was possible to determine the genotypic and allelic frequencies for the variants *2 and *3 of the CYP2C9 gene in a non-probabilistic sample of the Peruvian mestizo population. The frequencies obtained (0.046 and 0.062, respectively) corresponded to those expected for a South American mestizo population with Amerindian, European, African and Asian ancestry.

Rapid identification of microbial contaminants in pharmaceutical products / Identificação rápida de contaminantes microbianos em produtos farmacêuticos

A qualidade microbiológica de medicamentos é fundamental para garantir sua eficácia e segurança. Os métodos convencionais para identificação microbiana em produtos não estéreis são amplamente utilizados, entretanto são demorados e trabalhosos. O objetivo deste trabalho é desenvolver método microbiológico rápido (MMR) para a identificação de contaminantes em produtos farmacêuticos utilizando a espectrofotometria de infravermelho com transformada de Fourier com reflectância total atenuada (FTIR-ATR). Análise de componentes principais (PCA) e análise de discriminantes (LDA) foram utilizadas para obter um modelo de predição com a capacidade de diferenciar o crescimento de oriundo de contaminação por Bacillus subtilis (ATCC 6633), Candida albicans (ATCC 10231), Enterococcus faecium (ATCC 8459), Escherichia coli (ATCC 8739), Micrococcus luteus (ATCC 10240), Pseudomonas aeruginosa (ATCC 9027), Salmonella Typhimurium (ATCC 14028), Staphylococcus aureus (ATCC 6538) e Staphylococcus epidermidis (ATCC 12228). Os espectros de FTIR-ATR forneceram informações quanto à composição de proteínas, DNA/RNA, lipídeos e carboidratos provenientes do crescimento microbiano. As identificações microbianas fornecidas pelo modelo PCA/LDA baseado no método FTIR-ATR foram compatíveis com aquelas obtidas pelos métodos microbiológicos convencionais. O método de identificação microbiana rápida por FTIR-ATR foi validado quanto à sensibilidade (93,5%), especificidade (83,3%) e limite de detecção (17-23 UFC/mL de amostra). Portanto, o MMR proposto neste trabalho pode ser usado para fornecer uma identificação rápida de contaminantes microbianos em produtos farmacêuticos

Microbiological quality of pharmaceuticals is fundamental in ensuring efficacy and safety of medicines. Conventional methods for microbial identification in non-sterile drugs are widely used, however are time-consuming and laborious. The aim of this paper was to develop a rapid microbiological method (RMM) for identification of contaminants in pharmaceutical products using Fourier transform infrared with attenuated total reflectance spectrometry (FTIR-ATR). Principal components analysis (PCA) and linear discriminant analysis (LDA) were used to obtain a predictive model with capable to distinguish Bacillus subtilis (ATCC 6633), Candida albicans (ATCC 10231), Enterococcus faecium (ATCC 8459), Escherichia coli (ATCC 8739), Micrococcus luteus (ATCC 10240), Pseudomonas aeruginosa (ATCC 9027), Salmonella Typhimurium (ATCC 14028), Staphylococcus aureus (ATCC 6538), and Staphylococcus epidermidis (ATCC 12228) microbial growth. FTIR-ATR spectra provide information of protein, DNA/RNA, lipids, and carbohydrates constitution of microbial growth. Microbial identification provided by PCA/LDA based on FTIR-ATR method were compatible to those obtained using conventional microbiological methods. FTIR-ATR method for rapid identification of microbial contaminants in pharmaceutical products was validated by assessing the sensitivity (93.5%), specificity (83.3%), and limit of detection (17-23 CFU/mL of sample). Therefore, the RMM proposed in this work may be used to provide a rapid identification of microbial contaminants in pharmaceutical products

Comparison among ACR1997, SLICC and the new EULAR/ACR classification criteria in childhood-onset systemic lupus erythematosus

Abstract Background: To date there are no specific classification criteria for childhood-onset systemic lupus erythematosus (cSLE). This study aims to compare the performance among the American College of Rheumatology (ACR) 1997, the Systemic Lupus International Collaborating Clinics criteria (SLICC) and the new European League Against Rheumatism (EULAR)/ACR criteria, in a cSLE cohort. Methods: We conducted a medical chart review study of cSLE cases and controls with defined rheumatic diseases, both ANA positive, to establish each ACR1997, SLICC and EULAR/ACR criterion fulfilled, at first visit and 1-year-follow-up. Results: Study population included 122 cSLE cases and 89 controls. At first visit, SLICC criteria had higher sensitivity than ACR 1997 (89.3% versus 70.5%, p < 0.001), but similar specificity (80.9% versus 83.2%, p = 0.791), however performance was not statistically different at 1-year-follow-up. SLICC better scored in specificity compared to EULAR/ACR score ≥ 10 at first visit (80.9% versus 67.4%, p = 0.008) and at 1-year (76.4% versus 58.4%, p = 0.001), although sensitivities were similar. EULAR/ACR criteria score ≥ 10 exhibited higher sensitivity than ACR 1997 (87.7% versus 70.5%, p < 0.001) at first visit, but comparable at 1-year, whereas specificity was lower at first visit (67.4% versus 83.2%, p = 0.004) and 1-year (58.4% versus 76.4%, p = 0.002). A EULAR/ACR score ≥ 13 against a score ≥ 10, resulted in higher specificity, positive predictive value, and cut-off point accuracy. Compared to SLICC, a EULAR/ACR score ≥ 13 resulted in lower sensitivity at first visit (76.2% versus 89.3%, p < 0.001) and 1-year (91% versus 97.5%, p = 0.008), but similar specificities at both assessments. When compared to ACR 1997, a EULAR/ACR total score ≥ 13, resulted in no differences in sensitivity and specificity at both observation periods. Conclusions: In this cSLE population, SLICC criteria better scored at first visit and 1-year-follow-up. The adoption of a EULAR/ACR total score ≥ 13 in this study, against the initially proposed ≥10 score, was most appropriate to classify cSLE. Further studies are necessary to address if SLICC criteria might allow fulfillment of cSLE classification earlier in disease course and may be more inclusive of cSLE subjects for clinical studies.

An HPLC-UV method for the measurement of permeability of marker drugs in the Caco-2 cell assay

The Caco-2 cell line has been used as a model to predict the in vitro permeability of the human intestinal barrier. The predictive potential of the assay relies on an appropriate in-house validation of the method. The objective of the present study was to develop a single HPLC-UV method for the identification and quantitation of marker drugs and to determine the suitability of the Caco-2 cell permeability assay. A simple chromatographic method was developed for the simultaneous determination of both passively (propranolol, carbamazepine, acyclovir, and hydrochlorothiazide) and actively transported drugs (vinblastine and verapamil). Separation was achieved on a C18 column with step-gradient elution (acetonitrile and aqueous solution of ammonium acetate, pH 3.0) at a flow rate of 1.0 mL/min and UV detection at 275 nm during the total run time of 35 min. The method was validated and found to be specific, linear, precise, and accurate. This chromatographic system can be readily used on a routine basis and its utilization can be extended to other permeability models. The results obtained in the Caco-2 bi-directional transport experiments confirmed the validity of the assay, given that high and low permeability profiles were identified, and P-glycoprotein functionality was established.

Genetic variation in genes involved in folate and drug metabolism in a south Indian population.

BACKGROUND: Genetic variations represented as single nucleotide polymorphisms (SNPs) vary across the world population. This genetic polymorphism (such as SNPs) plays an important role in pharmacogenomics. SNPs that affects cellular metabolism, by altering the enzyme activity, have an important role in therapeutic outcome. Allele frequencies in number of clinically relevant SNPs within south Indian populations are not yet known. Hence, we genotyped randomly selected unrelated south Indian subjects from different locations of south India representing the heterogeneous ethnic background of the population. MATERIALS AND METHODS: Common variants of MTHFD1, TYMS, SHMT1, MTR, MTRR, CBS and SULT1A1 gene polymorphisms were screened from healthy unrelated south Indian volunteers. Genotypes were determined using RFLP analysis of polymerase chain reaction-amplified products and confirmed by DNA sequencing. Chi-square test was performed to test for deviation from the Hardy-Weinberg equilibrium for each locus. RESULTS: Gene allele frequency for several polymorphisms in our study differed significantly between the populations of other nations reported for several of the SNPs. These results demonstrate that the populations in different geographic regions may have widely varying genetic allele frequencies for clinically relevant SNPs. CONCLUSION: The present study reports, for the first time, the frequency distribution of MTHFD1, TYMS, SHMT1, MTR, MTRR, CBS and SULTIA1 gene polymorphisms in a south Indian population. Population-specific genetic polymorphism studies will help in practicing pharmacogenomic principles in the clinics.

Indução do sistema citocromo P450 em linhagens de hepatoma humano para utilização como modelo in vitro no desenvolvimento de fármacos / Induction of cytochrome P450 system in human hepatoma cell lines for using as in vitro model in drug development

Na etapa inicial do desenvolvimento de novos fármacos, a avaliação do metabolismo e da toxicidade é fundamental para definir seu potencial emprego como candidato a fármaco. Nestes estudos, diversos modelos in vitro são empregados, dentre eles linhagens de hepatoma humano. Entretanto, uma grande limitação ao uso deste modelo in vitro é a baixa expressão das enzimas do sistema citocromo P450. O carotenóide bixina, componente majoritário do anato (urucum), apresentou em estudos in vivo, a capacidade de induzir algumas isoformas do sistema citocromo P450, com a vantagem de apresentar baixa toxicidade. Neste trabalho, a fração lipossolúvel do anato (bixina) e hidrossolúvel (norbixina) foram avaliadas como indutores do sistema citocromo P450 em linhagens de hepatoma humano. Ensaios de MTT, empregando as linhagens HepG2, C3A e SK-HEP-1 indicaram que bixina e norbixina em concentrações abaixo de 0,22 mM são seguras quanto à citotoxicidade. A expressão dos genes CYP 1A1, 1A2, 2C9, 2B6, 2E1 e 3A4 foi avaliada, através de ensaios de RT-PCR em tempo real, em linhagens de hepatoma humano submetidas a tratamento com os compostos bixina e norbixina. Os resultados mostraram que células HepG2 e C3A tratadas com bixina nas concentrações de 0,05 e 0,1 mM, por períodos de 24 e 48 horas, apresentaram aumento de expressão da CYP 1A1 e CYP 1A2. Porém, a exposição de células HepG2 e C3A ao composto norbixina não resultou em aumento de expressão das isoformas avaliadas neste estudo. Os resultados deste trabalho indicaram o potencial emprego de bixina como agente indutor das CYPs 1A1 e 1A2, em linhagens de hepatoma humano utilizadas como modelo in vitro, para estudo de compostos cuja metabolização envolva uma destas vias, entretanto, estudos adicionais são fundamentais, a fim de avaliar a ação deste composto sobre outras isoformas do sistema citocromo P-450, bem como outros sistemas enzimáticos.

In the early development stage of the new drugs, the pharmacological and toxicological properties are critical to define the potential use of the candidate drug. During this stage, several in vitro models systems are employed, including human hepatoma cell lines. However, the main limitation of the use of cell lines as in vitro model is the low expression level of cytochrome P450 enzymes. A carotenoid knowed as bixin, the main pigment in the annatto (urucum), it has been reported to induce some isoforms of cytochrome P450 in rats, with the advantage of its low toxicity. In this work, the oil-soluble (bixin) and aqueous soluble extracts (norbixin) were evaluated as inducers of the cytochrome P450 system in human hepatoma cell lines (HepG2, C3A, SK-HEP-1). The results of MTT assays showed that bixin concentrations below 0.22 mM were not cytotoxic in HepG2, C3A and SK-HEP-1 cell lines. Expression changes in CYP 1A1, 1A2, 2C9, 2B6, 2E1 and 3A4 were evaluated, by real time RT-PCR and the results showed that the exposition to 0,05 mM and 0,1 mM bixin, for 24 and 48 hours of treatment, lead to an increase in CYP 1A1 and CYP 1A2 expression level. By contrast, the cytochrome P450 isoforms were not affected by the exposition to norbixin. In conclusion, this work indicated the potential use of bixin induced hepatoma cell lines as in vitro model for studies of biotransformation and toxicity of drugs involving CYP 1A, however, further studies are necessary to evaluate the effect of bixin on the other cytochrome P450 isoforms as well as other enzymatic systems.

Modulação da atividade das enzimas de biotransformação de xenobióticos na malária murina letal e não-letal / Modulation of the activity of enzymes of biotransformation of xenobiotics in the lethal and not-lethal murina malaria

Durante as últimas três décadas, um expressivo número de estudos experimentais e clínicos mostrou que várias infecções e inflamações assépticas modulam a expressão e a atividade de enzimas citocromo P450 (CYP). Nesta linha de investigação, alguns estudos sugeriram que as atividades de CYP e a cinética de xenobióticos são alteradas também na malária. Não é claro, entretanto, que enzimas do metabolismo de fármacos são alteradas e se as modificações ocorrem apenas no estágio terminal da malária grave. Faltam dados também sobre os mecanismos pelos quais a malária altera o metabolismo de xenobióticos. Este estudo foi conduzido como um esforço para preencher algumas dessas lacunas de pesquisa. Na primeira parte do estudo, verificamos que a malária letal (estágio eritrocítico) causada pelo Plasmodium berghei ANKA em camundongos C57BL/6 e DBA-2 (fêmeas) deprimiu as atividades de CYP1A e 2B (EROD e BROD) e induziu a atividade mediada por 2A5 (COH) no fígado. Uma diminuição dos níveis de apoproteínas CYP1A também foi encontrada em camundongos infectados. As enzimas hepáticas de conjugação, quer na fração microssoma1 (UGT e GST), quer na citosólica (GST), não foram alteradas pela malária. Os níveis de glutationa reduzida (GSH), todavia, foram diminuídos nos camundongos C57BL/6 infectados. Além disso, constatamos que a genotoxidade (micronúcleos em células de medula óssea) da ciclofosfamida (ativada por CYP2B e 3A) e do DMBA (ativado por CYP1A) foi atenuada, enquanto a de um clastógeno de ação direta (EMS) foi exacerbada nos camundongos infectados com P. berghei. Na segunda parte, investigamos o curso temporal das alterações das atividades de CYP1A, 2B e 2A5 nos C57BL/6 e DBA-2 infectados com um parasita letal (P. berghei), ou com um não letal (P. chabaudi). Na malária não letal, a depressão de CYP1A e 2B(C57BL/6) e a indução de CYP2A5 (DBA-2) ocorreram apenas nos dias pós-infecção (5 e 6) em que foram registradas as taxas mais elevadas de parasitemia. Em...

Reportes y entrevistas del American College of Cardiology: New Orleans 2007 / Report and interviews of the American College of Cardiology: New Orleans 2007

Este documento es publicación de la Canadian Medical Association y revisado por el Dr. Andreas Wieldosz del Hospita de Ottawa. Su contenido tiene propósitos educativos e informativos, sobre las investigaciones más recientes, Está dirigido primordialmente a médicos en atención primaria y se le sugiere al lector consultar las respectivas publicaciones originales e información relacinada, antes de tomar las acciones mencionadas en este reporte.

Cytochrome P450's pharmacogenetics in drug development and clinical aspects [review]

cytochrome P450s [CYPs] are members associated heme protein and hepatic microsomal enzymes, which play important role in drugs metabolism and detoxification. Seven of the 57 known human isoforms of P450s responsible for metabolism of more than 90% of the currently used drugs, CYP1A2, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1 and CYP3A4. Some. of them, CYP2D6, CYP2C9 and CYP2C19, have been shown to be polymorphic as a result of single nuclcotide polymorphisms [SNPs], gene deletions, and gene duplications. The effect of the polymorphisms ranges from a complete loss of functional protein to an increase in enzyme activity and can impact the drug development and clinical application. Most pharmaceutical companies have increasingly screened out compounds that are metabolized solely by polymorphic CYPs. Retrospective studies showed that one of the major causes of the new chemical entities [NCE] failure to reach the clinical stage was related to pharmacokinetic and toxicological issues. Therefore the industry has invested in the science and technology of absorption, distribution, metabolism, excretion and toxicity [ADMET] in order to reduce NCE attribution rates.. Drug metabolism is the most important determinant of the ADMET of most compounds and the role CYP450 is predominant. Overall, current trends in the industry have been fueled by increased managed healthcare, the desire to minimize the need for therapeutic drug monitoring and CYP genotyping in medical practice, and a very competitive marketplace

Farmacogenética: medicina personalizada / Pharmacogenetics: personalized medicine

La farmacogenética es la ciencia que permite identificar las bases genéticas de las diferencias interindividuales en la respuesta a drogas. Este artículo de revisión utiliza un número de ejemplos publicados de diferencias heredadas en enzimas metabolizadoras de drogas, para ilustrar la importancia de la herencia en la determinación de la eficacia y la toxicidad de medicamentos en humanos. Aunque tienen un desarrollo incipiente, ya existen pruebas para el diagnóstico molecular mediante las cuales médicos y farmacéuticos pueden seleccionar los fármacos y las dosis para cada paciente de forma individual. El desarrollo de la farmacogenética, provee de, al menos, una vía para hacer prescripciones médicas sin el empirismo corriente e ir hacia una terapia más personalizada

Estudo de alterações no gene da enzima CYP3A4 que influenciam a resposta a atorvastatina em indivíduos hipercolesterolêmicos / Study of alterations in the gene of the CYP3A4 enzyme that influence the response to atorvastatin in hipercolesterolemic individuals

As vastatinas são inibidores da enzima HMG-CoA redutase que revolucionaram o tratamento e prevenção das doenças isquêmicas e coronarianas. A resposta as vastatinas é influenciada por inúmeros fatores, incluindo deterinantes ambientais e genéticos, como proteínas variantes envolvidas no metabolismo lipídico e na biodisponibilidade de fármacos. CYP3A4 é a isoenzima mais abundante do citocromo P450 no fígado de humanos adultos e é de extrema importância no metabolismo de muitos fármacos, incluindo as vastatinas. A grande variabilidade na expressão da CYP3A4 entre os indivíduos pode ter alto impacto na eficácia de tratamentos farmacológicos...

Separação enantiomérica de fármacos em medicamentos por cromatografia líquida com fase estacionária quiral / Enantiomeric separation of drugs in medicine by liquid chromatography with chiral stationary phase

A maioria dos agentes terapêuticos, freqüentemente prescritos, são formulados e comercializados sob a forma racêmica, embora para alguns deles, já tenha sido demonstrado que os efeitos farmacológicos e/ou tóxicos estejam relacionados apenas a um dos enantiômeros. Além disso, é conhecido o fato de que os enantiômeros podem apresentar perfis farmacocinéticos e farmacodinâmicos diferentes. Neste trabalho foram selecionados fármacos que fazem parte de dois grupos importantes no uso clínico. São fármacos freqüentemente prescritos, como os BETA-bloqueadores (atenolol, metoprolol, pindolol, betaxolol e nadolol) e os antiinflamatórios não-esteróides (ibuprofeno e flurbiprofeno)...

Importancia clínica del metabolismo de medicamentos: primera parte / Clinic importance of the metabolism of medicaments: first Part

Este es el primer artículo de una serie de dos artículos sobre el metabolismo de medicamentos. El metabolismo de medicamentos es un tema de mucho importancia en farmacología, porque parte de la farmacocinética y el efecto clínico de los medicamentos dependen de el. Además, el metabolismo de medicamentos es importante para explicar una gran cantidad de interacciones. En este artículo se revisa el papel de las enzimas citocromales P450, en el metabolismo e interacciones de medicamentos. Esta es la razón por la que solo se estudiarán los citocromos de importancia clínica en farmacología. Se revisarán entre otros temas los siguientes: mecanismos de inducción e inhibición, nomenclatura, distribución en el cuerpo humano y polimorfismo genérico. Además, se incluyen tablas con las sustancias inductoras e inhibidoras más importantes así como las sondas utilizadas para la identificación de un citocromo particular. Finalmente se inicia una sección con la discusión de las interacciones de interés clínico más relevantes.

La farmacogenética y su importancia en la clínica / Pharmacogenetics and its clinical Significance

En el uso clínico de medicamentos, se ha observado con frecuencia ineficacia terapéutica o toxicidad farmacológica, las cuales pueden presentarse en algunos individuos quienes reciben tratamiento farmacológico. Debido a la presencia de algunas enzimas metabolizantes de fármacos, los medicamentos pueden participar como sustratos inhibidores o inductores de dichas enzimas, la actividad de éstas varía entre los individuos. Esta variabilidad enzimática puede ser determinada por el análisis del ADN recombinante como son: el análisis de restricción del ADN genómico Fragmentos de Restricción de Longitud Polimórfica (RFLP), y la amplificación enzimática del ADN por la Reacción en Cadena de la Polimerasa (PCR). Esta tecnología se ha empleado en estudios clínicos que permiten conocer los mecanismos de las variaciones heredadas en las respuestas a los fármacos las cuales son reguladas por los genes de cada individuo de las diferentes razas, donde estas diferencias enzimáticas también pueden estar influenciadas por hábitos nutricionales o factores ambientales. Con este trabajo pretendemos presentar la importancia que tiene el conocimiento del metabolismo de los fármacos aplicado al manejo terapéutico de individuos que presentan ineficacia terapéutica o toxicidad farmacológica.

Estudo comparativo "in vitro" das propriedades biofarmacotécnicas de comprimidos de cloridrato de metformina comercializados no Brasil / In vitro comparative study of biopharmaceutics properties of metformin hydrochloride tablets marketed in Brazil

Comprimidos de cloridrato de metformina de 850 mg, dos laboratórios A e B (3 lotes de cada), foram submetidos a ensaios físicos e físico-químicos conforme recomendações da Farmacopéia Britânica (1993). O fármaco foi quantificado por espectrofotometria na região UV a 233nm. Os resultados indicaram que dois lotes do laboratório B estavam em desacordo com as especificações por apresentarem dureza de 2,57ñ0,98 e 2,89ñ0,62 kgf, inferior ao mínimo exigido pela Farmacopéia Brasileira 4ª ed.(parte I), que é de 3 kgf. Todos os lotes do laboratório A mostravam camada de revestimento, dureza bastante irregular (D=22,99ñ1,49, 8,64ñ0,99 e 19,02ñ2,36) e teor de fármaco, aproximadamente, 22 porcento abaixo...