A Single Amino Acid Substitution in an ORANGE Protein Promotes Carotenoid Overaccumulation in Arabidopsis.

Carotenoids are crucial for plant growth and human health. The finding of ORANGE (OR) protein as a pivotal regulator of carotenogenesis offers a unique opportunity to comprehensively understand the regulatory mechanisms of carotenoid accumulation and develop crops with enhanced nutritional quality. Here, we demonstrated that alteration of a single amino acid in a wild-type OR greatly enhanced its ability to promote carotenoid accumulation. Whereas overexpression of OR from Arabidopsis (Arabidopsis thaliana; AtOR) or from the agronomically important crop sorghum (Sorghum bicolor; SbOR) increased carotenoid levels up to 2-fold, expression of AtOR(His) (R90H) or SbOR(His) (R104H) variants dramatically enhanced carotenoid accumulation by up to 7-fold in the Arabidopsis calli. Moreover, we found that AtOR(Ala) (R90A) functioned similarly to AtOR(His) to promote carotenoid overproduction. Neither AtOR nor AtOR(His) greatly affected carotenogenic gene expression. AtOR(His) exhibited similar interactions with phytoene synthase (PSY) as AtOR in posttranscriptionally regulating PSY protein abundance. AtOR(His) triggered biogenesis of membranous chromoplasts in the Arabidopsis calli, which shared structures similar to chromoplasts found in the curd of the orange cauliflower (Brassica oleracea) mutant. By contrast, AtOR did not cause plastid-type changes in comparison with the controls, but produced plastids containing larger and electron-dense plastoglobuli. The unique ability of AtOR(His) in mediating chromoplast biogenesis is responsible for its induced carotenoid overproduction. Our study demonstrates OR(His/Ala) as powerful tools for carotenoid enrichment in plants, and provides insights into the mechanisms underlying OR(His)-regulated carotenoid accumulation.

Desperdício de materiais assistenciais na percepção de trabalhadores de enfermagem de um hospital universitário / Desperdicio de materiales asistenciales en la percepcion de trabajadores de enfermería de un hospital universitario / Waste of patient care material in the perception of nursing personnel at a university hospital

Objetiva-se identificar a percepção de trabalhadores de enfermagem de um hospital universitário do sul do Brasil acerca das causas do desperdício de materiais assistenciais em seu cotidiano. Estudo descritivo e exploratório em que foram entrevistados 45 sujeitos de quatro unidades do hospital, entre agosto de 2009 e dezembro de 2010. Os dados foram organizados, analisados e interpretados através da análise temática. Os fatores estruturais, organizacionais e gerenciais, que incluem o desconhecimento sobre materiais assistenciais por parte dos responsáveis pela compra, a má qualidade dos materiais adquiridos e a falta de materiais foram identificados como causadores do desperdício. Os trabalhadores entendem o desperdício como uma prática inevitável e não intencional. Indicam a inclusão de trabalhadores de enfermagem na equipe de compras, sua instrumentalização para a função e a construção de rotinas, para a substituição racional dos materiais quando da falta e da má qualidade dos mesmos, para minimizar o desperdício.

The aim was to identify perceptions among nursing personnel at a university hospital in southern Brazil of the causes of waste of patient care material in their daily routine. In this descriptive exploratory study, 45 subjects at four hospital units were interviewed between August 2009 and December 2010. Data were organized, analyzed and interpreted through thematic analysis. Structural, organizational and management factors including lack of knowledge of patient care material among those responsible for procurement, poor quality of materials purchased, and lack of materials were identified as causes of waste. Nursing personnel understand waste as an inevitable and unintentional practice. They suggest including nursing personnel in the procurement team, equipping them for that function, and constructing routines, so as to rationalize replacement of materials in short supply or of poor quality, so as to minimize waste.

Se pretende identificar la percepción de los trabajadores de enfermería de un hospital universitário del sur de Brasil en relación a las causas del desperdicio de materiales asistenciales en su cotidiano. Estudio descriptivo y exploratorio en que fueron entrevistados 45 sujetos de cuatro unidades del hospital, entre agosto de 2009 y diciembre de 2010. Los datos fueron organizados, analizados e interpretados por medio del análisis temático. Los factores estructurales, organizacionales y gerenciales, que incluyen el desconocimento sobre materiales asistenciales por parte de los responsables por la compra, la mala cualidad de los materiales adquiridos y la falta de materiales fueron identificados como las causas del desperdicio. Los trabajadores entienden el desperdicio como una práctica inevitable y no intencional. Indican la inclusión de trabajadores de enfermería en el equipo de compras, su instrumentalización para la función y la construcción de rutinas, para la substitución racional de los materiales cuando faltan y de la mala cualidad de los mismos para minimizar el desperdicio.

Stabilization of alpha-chymotrypsin at the CH2Cl2/water interface and upon water-in-oil-in-water encapsulation in PLGA microspheres.

Protein inactivation and aggregation are serious drawbacks in the encapsulation of proteins in bioerodible polymers by water-in-oil-in-water (w/o/w) encapsulation. The model protein alpha-chymotrypsin was employed to investigate whether its stabilization towards the major stress factors in the w/o/w encapsulation procedure would allow for the encapsulation and release of non-aggregated and active protein. Due to the formation of amorphous aggregates alpha-chymotrypsin is an excellent sensor to probe unfolding events. Furthermore, its enzymatic activity is highly sensitive towards the presence of organic solvents. alpha-Chymotrypsin in aqueous solution showed substantial aggregation and activity loss when it was homogenized with CH(2)Cl(2) due to adsorption to the interface. Its w/o/w encapsulation in poly(lactic-co-glycolic)acid (PLGA) microspheres caused formation of 35% non-covalent aggregates and reduced the specific activity by 14%. Screening for efficient excipients revealed that co-dissolving the protein with maltose and polyethylene glycol (PEG, M(w) 5000) in the first aqueous phase reduced interface-induced protein aggregation and inactivation. Employing these excipients during encapsulation led to a reduction in alpha-chymotrypsin inactivation (10%) and aggregation (12%). Optimizing the effect of PEG by also dissolving the excipient in the organic phase prior to encapsulation further decreased the amount of non-covalent aggregates to 7% and loss in activity to 5%. The data obtained demonstrate that the w/o emulsification step is the main stress-factor in the w/o/w encapsulation procedure but subsequent encapsulation steps also cause some protein aggregation.