Analysis of therapeutic proteins and peptides using multiangle light scattering coupled to ultra high performance liquid chromatography.

Analysis of the physical properties of biotherapeutic proteins is crucial throughout all the stages of their lifecycle. Herein, we used size-exclusion ultra high performance liquid chromatography coupled to multiangle light scattering and refractive index detection systems to determine the molar mass, mass-average molar mass, molar-mass dispersity and hydrodynamic radius of two monoclonal antibodies (rituximab and trastuzumab), a fusion protein (etanercept), and a synthetic copolymer (glatiramer acetate) employed as models. A customized instrument configuration was set to diminish band-broadening effects and enhance sensitivity throughout detectors. The customized configuration showed a performance improvement with respect to the high-performance liquid chromatography standard configuration, as observed by a 3 h column conditioning and a higher resolution analysis in 20 min. Analysis of the two monoclonal antibodies showed averaged values of 148.0 kDa for mass-average molar mass and 5.4 nm for hydrodynamic radius, whereas for etanercept these values were 124.2 kDa and 6.9 nm, respectively. Molar-mass dispersity was 1.000 on average for these proteins. Regarding glatiramer acetate, a molar mass range from 3 to 45 kDa and a molar-mass dispersity of 1.304 were consistent with its intrinsic peptide diversity, and its mass-average molar mass was 10.4 kDa. Overall, this method demonstrated an accurate determination of molar mass, overcoming the difficulties of size-exclusion chromatography.

Strengthening families of children with developmental concerns: parent perceptions of developmental screening and services in Head Start.

OBJECTIVE: The authors investigated perceptions of parents with children in the Head Start program about the processes of detection and intervention for developmental concerns. DESIGN: Descriptive, qualitative study. SETTING: A large, urban Head Start agency, operating 14 centers and annually serving more than 1200 predominantly Latino children. During 2008-2009, a collaborative partnership with academicians from UCLA was created to evaluate their model of developmental screening and referrals. PARTICIPANTS AND PROCEDURES: We conducted 5 focus groups with a total of 30 parents of Head Start children with developmental concerns. Parents were asked about where they go for information when they have concerns, how they perceived the developmental screening process and services, and how children and families have changed after being in the Head Start program. Focus groups were recorded, transcribed and translated into English, then coded in ATLAS.ti using the domains above and sorted into themes for analysis. RESULTS: Parents perceived the screening process as both diagnostically and therapeutically important, with multiple benefits ranging from closer parent-teacher relationships to improved parenting and understanding of developmental interventions. Families focused their discussion on the importance of social-emotional and behavioral development, with school readiness and improved expressive language as important but secondary outcomes. CONCLUSIONS: For families of children with developmental and behavioral risks or concerns, a structured developmental screening process in a preschool setting, such as that provided by Head Start, may serve as a vital gateway for identifying and addressing concerns and promoting social-emotional learning, parent engagement, language development and school readiness.

Diagnóstico de ileítis porcina por medio de la reacción en cadena de la polimerasa / Polymerase chain reaction for diagnosis of porcine ileitis

La ileítis porcina es una enfermedad que ocasiona importantes pérdidas económicas a la industria porcina. El agente causal de esta enfermedad es Lawsonia intracellularis, un microorganismo de dificl cultivo. Por esta razón, el diagnóstico, generalmente se realiza sólo al sacrificio. Debido a la dificultad del diagnóstico en animales vivos, se han desarrollado técnicas para detectar el ADN de la L. intracellularis por medio de la reacción en cadena de la polimerasa (PCR). El objetivo de este trabajo fue evaluar la técnica de PCR para el diagnóstico de la ileítis porcina en muestras de mucosa intestinal y heces de cerdos sospechosos de la enfermedad. El ADN fue extraído usando tierras diatomeas y tiocainato de guanidina. Para la amplificación del ADN se utilizaron oligonucleótidos específicos que amplifican un fragmento de ADN de L. intracellularis de 319 pb. La estandarización de la técnica se realizó a partir de mucosa intestinal de un cerdo infectado experimentalmente. La mínima cantidad de ADN de mucosa infectada que se detectó por PCR fue de 3.72 ng. Cuando la mucosa infectada fue adicionada a muestras de heces normales se necesitaron 12.4 ng del ADN extraído, para obtener un producto de amplificación visible. El producto de amplificación esperado de 319 pb fue también obtenido de mucosa intestinal o muestras de heces de cerdos infectados con signos clínicos característicos de ileítis porcina. Se concluyó que la técnica de PCR puede ser muy útil para el diagnóstico de esta enfermedad y para la determinación de la prevalencia de la ileítis porcina en diferentes áreas