RESUMEN
The relatively large molecular size, diastereoisomeric nature, and complex impurity profiles of therapeutic phosphorothioate oligonucleotides create significant analytical challenges for the quality control laboratory. To overcome the lack of selectivity inherent to traditional chromatographic approaches, an ion pair liquid chromatography-mass spectrometry (LCMS) method combining ultraviolet and mass spectrometry quantification was developed and validated for >35 different oligonucleotide drug substances and products, including several commercialized drugs. The selection of chromatographic and spectrometric conditions, data acquisition and processing, critical aspects of sample and buffer preparation and instrument maintenance, and results from method validation experiments are discussed.
Asunto(s)
Bioensayo , Oligonucleótidos Fosforotioatos , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida/métodos , Espectrometría de Masas/métodos , Oligonucleótidos Fosforotioatos/uso terapéuticoRESUMEN
A novel analytical approach capable of measuring deaminated degradation products of oligonucleotide therapeutics is described. The method employs high-resolution mass spectrometry to assess the shift in isotopic distribution that accompanies deamination. Isotopic Distribution Factors (IDF), derived directly from the peak heights of the isotopic pattern, are employed to measure deamination levels of as little as 0.5%. Results obtained from application of the method to a phosphorothioate diester oligonucleotide exposed to various temperatures were used to determine deamination rates.
Asunto(s)
Espectrometría de Masas/métodos , Oligonucleótidos Fosforotioatos/análisis , Desaminación , Almacenaje de Medicamentos , Oligonucleótidos Fosforotioatos/metabolismo , TemperaturaRESUMEN
OBJECTIVE: Immigrants in the USA are confronted with health disparities, including childhood obesity and obesity-related chronic diseases. We aimed to identify perceptions of childhood body weight, approaches to raising healthy children and desires for supportive programmes of Somali, Latino and Hmong (SLM) parents in the Twin Cities, Minnesota, USA. DESIGN: Using community-based participatory research, ten focus groups (FG) were conducted with sixty-seven parents (n 28 Somali, three FG; n 19 Latino, four FG; n 20 Hmong, three FG) of 3-12-year-old children in their native language. Demographic information was collected. RESULTS: SLM parents perceived that health is not necessarily weight-based; childhood obesity is caused by overeating, eating unhealthy foods and sedentary activities; traditional foods are generally healthy while American foods are generally unhealthy; and healthy children are inherently physically active. Parents identified their goals as feeding children so they would be healthy and happy, helping them be active and safe, and teaching them to cook traditional foods to be self-sufficient and maintain their cultural identity. Parents were challenged by children's unhealthy food and sedentary preferences, their own uncertainties about healthy foods and behaviours, and structural factors. Parents thought interventions could help them with these challenges, including information about healthy foods, age-appropriate portion sizes, safe places to be active and strategies tailored to their cultural norms. CONCLUSIONS: SLM parents are trying to raise healthy-weight children based on their understanding of children's health, weight, diet and physical activity, while dealing with social, economic and environmental challenges and trying to maintain cultural identity and traditions.
Asunto(s)
Emigrantes e Inmigrantes/estadística & datos numéricos , Etnicidad/estadística & datos numéricos , Conocimientos, Actitudes y Práctica en Salud , Sobrepeso/etnología , Responsabilidad Parental/etnología , Adolescente , Adulto , Peso Corporal , Niño , Preescolar , China/etnología , Femenino , Grupos Focales , Humanos , América Latina/etnología , Masculino , Persona de Mediana Edad , Sobrepeso/prevención & control , Somalia/etnología , Adulto JovenRESUMEN
Salinosporamide A (1, NPI-0052) is a potent proteasome inhibitor in development for treating cancer. In this study, a series of analogues was assayed for cytotoxicity, proteasome inhibition, and inhibition of NF-kappaB activation. Marked reductions in potency in cell-based assays accompanied replacement of the chloroethyl group with unhalogenated substituents. Halogen exchange and cyclohexene ring epoxidation were well tolerated, while some stereochemical modifications significantly attenuated activity. These findings provide insights into structure-activity relationships within this novel series.