bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uptake and Efflux of [35S] Sulfite by Protoplasts and their Chloroplasts of Oat (Avena sativa L.)
Authors: Miszalski Z. , Ziegler H. 
Published: September 2017

Abstract
Processes of 35S-labelled sulfite uptake and efflux by oat protoplasts and their chloroplasts are very rapid: during the first minutes (or perhaps even seconds) after sulfite supply a state of equilibrium is established between the protoplasts and their chloroplasts and the incubation medium. Bicarbonate concentrations ranging from 1 to 5 mᴍ in the medium had no significant effect on sulfite uptake. At pH 7.0 sulfite uptake is much greater than at pH 7.6. Light of low intensity (9 W m-2) had no significant effect on this uptake. The 35S concentration in chloroplasts was always much higher than in the whole protoplasts. One hour's incubation at sulfite concentra­ tions of 0.1 and 0.5 mᴍ in the medium, concentrations slightly stimulating or inhibiting photosyn­ thesis, results in sulfite concentrations of 0.004 to 0.230 mᴍ in chloroplasts. At a sulfite concentration photosynthesis, these values are 0.120 to 0.551 and 2.045 to 3.531, respectively.
Photoinhibitory Damage to Chloroplasts under Phosphate Deficiency and Alleviation of Deficiency and Damage by Photorespiratory Reactions
Authors: Heber U. , Viil J. , Neimanis S. , Mimura T. , Dietz K.-J. 
Published: September 2017

Abstract
Effects of Pi deficiency on photosynthesis ot isolated spinach chloroplasts were examined. The following observations were made: (1) Chloroplasts isolated in Pi-free media evolved oxygen in the light in the absence of added Pi until acid-extractable Pi in the chloroplasts had decreased to 1 to 2.5 m M . This Pi was unavailable for photophosphorylation as shown by the inability of the chloroplasts to respond by oxygen evolution to the addition of PGA. In the state of Pi-deficiency, stromal ATP to A DP ratios were in the light close to or below ratios observed in the dark. In the presence of 2 mᴍ PGA, addition of 20 μm Pi was insufficient to increase ATP to ADP ratios, but sufficient for appreciable oxygen evolution. (2) More Pi was available for oxygen evolution of phosphate-deficient chloroplasts at low levels of C02 than at high levels. This was due mainly to the suppression of oxygenation of RuBP by high C02 levels which prevented formation of phosphoglycolate and the subsequent release of Pi into the chloroplast stroma. (3) More oxygen was produced by phosphate-deficient chloroplasts at a low light intensity than at a high light intensity. This was due to increased availability of endogenous Pi under low light and to photoinhibition of the chloroplasts by high light. The main product of photosynthesis of phosphate-deficient chloroplasts in the presence of a high bicarbonate concentration was starch, and the main soluble product was PGA. (4) After phosphate-deficient chloroplasts had ceased to evolve oxygen in the light, they be­ came photosensitive. Part of the loss of the capacity for oxygen evolution is attributed to leakage of PGA, but the main reason for loss of function is photoinactivation of electron transport. Both photosystems of the electron transport chain were damaged by light. (5) Protection against photoinactivation was provided by coupled electron transport. Photo­ inactivation of phosphate-deficient chloroplasts was less extensive in the presence of low C02 concentrations which permitted oxygenation of RuBP than at high CO2 concentrations. Electron transport to C02 and other physiological electron acceptors and to the herbicide methylviologen was also protective. However, electron transport to oxygen in the Mehler reaction failed to provide appreciable protection against high light intensities, because oxygen reduction is slow and reactive oxygen species produced in the light contribute to photoinactivation.
Histidyl Residues Mediate Electron Transport in Plant Mitochondria
Authors: Arora Jaspreet , Sane P. V. 
Published: September 2017

Abstract
Plant The effect of chemical modification of histidyl residues using diethyl pyrocarbonate (DEP) on plant mitochondrial electron transport was studied. Mitochondrial membranes from potato tubers were isolated and electron flow from NADH to oxygen, NADH to ferricyanide and ascorbate to oxygen were monitored in pro», nee and/or absence of DEP. Measurements were made at various concentrations of DEP and at different pHs either by using an oxygen electrode or spectro-photometrically. The results show that DEP inhibits flow of electrons from NADH to oxygen, however partial electron transport from NADH to ferricyanide and ascorbate to oxygen was unaffected. Maximum inhibition was observed at pH 6.5. The time course of the DEP action revealed a biphasic nature of inhibition. Effects on the levels of reduction of cytochromes b and c by DEP during electron transport indicated that histidyl residues may be present before or at cytochrome b , which are being modified.
Mitochondrial DNA Double-Strand Breaks in Oligodendrocytes Cause Demyelination, Axonal Injury, and CNS Inflammation
Authors: Madsen Pernille M. , Pinto Milena , Patel Shreyans , McCarthy Stephanie , Gao Han , Taherian Mehran , Karmally Shaffiat , Pereira Claudia V. , Dvoriantchikova Galina , Ivanov Dmitry , Tanaka Kenji F. , Moraes Carlos T. , Brambilla Roberta 
Published: September 2017

Mitochondrial dysfunction has been implicated in the pathophysiology of neurodegenerative disorders, including multiple sclerosis (MS). To date, the investigation of mitochondrial dysfunction in MS has focused exclusively on neurons, with no studies exploring whether dysregulation of mitochondrial bioenergetics and/or genetics in oligodendrocytes might be associated with the etiopathogenesis of MS and other demyelinating syndromes. To address this question, we established a mouse model where mitochondrial DNA (mtDNA) double-strand breaks (DSBs) were specifically induced in myelinating oligodendrocytes (PLP:mtPstI mice) by expressing a mitochondrial-targeted endonuclease, mtPstI, starting at 3 weeks of age. In both female and male mice, DSBs of oligodendroglial mtDNA caused impairment of locomotor function, chronic demyelination, glial activation, and axonal degeneration, which became more severe with time of induction. In addition, after short transient induction of mtDNA DSBs, PLP:mtPstI mice showed an exacerbated response to experimental autoimmune encephalomyelitis. Together, our data demonstrate that mtDNA damage can cause primary oligodendropathy, which in turn triggers demyelination, proving PLP:mtPstI mice to be a useful tool to study the pathological consequences of mitochondrial dysfunction in oligodendrocytes. In addition, the demyelination and axonal loss displayed by PLP:mtPstI mice recapitulate some of the key features of chronic demyelinating syndromes, including progressive MS forms, which are not accurately reproduced in the models currently available. For this reason, the PLP:mtPstI mouse represents a unique and much needed platform for testing remyelinating therapies.SIGNIFICANCE STATEMENTIn this study, we show that oligodendrocyte-specific mitochondrial DNA double-strand breaks in PLP:mtPstI mice cause oligodendrocyte death and demyelination associated with axonal damage and glial activation. Hence, PLP:mtPstI mice represent a unique tool to study the pathological consequences of mitochondrial dysfunction in oligodendrocytes, as well as an ideal platform to test remyelinating and neuroprotective agents.
A Cross Talk between Neuronal Urokinase-type Plasminogen Activator (uPA) and Astrocytic uPA Receptor (uPAR) Promotes Astrocytic Activation and Synaptic Recovery in the Ischemic Brain
Authors: Diaz Ariel , Merino Paola , Manrique Luis Guillermo , Ospina Juan Pablo , Cheng Lihong , Wu Fang , Jeanneret Valerie , Yepes Manuel 
Published: September 2017

Urokinase-type plasminogen activator (uPA) is a serine proteinase that, upon binding to its receptor (uPAR), catalyzes the conversion of plasminogen into plasmin on the cell surface. Our previous studies indicate that uPA and uPAR expression increase in the ischemic brain during the recovery phase from an acute ischemic injury and that uPA binding to uPAR promotes neurological recovery after an acute ischemic stroke. Here, we used male mice genetically deficient on either uPA (uPA−/−) or uPAR (uPAR−/−) or with a four-amino acid substitution into the growth factor domain of uPA that abrogates its binding to uPAR (PlatGFDhu/GFDhu) to investigate the mechanism whereby uPA promotes neurorepair in the ischemic brain. We found that neurons release uPA and astrocytes recruit uPAR to their plasma membrane during the recovery phase from a hypoxic injury and that binding of neuronal uPA to astrocytic uPAR induces astrocytic activation by a mechanism that does not require plasmin generation, but instead is mediated by extracellular signal-regulated kinase 1/2 (ERK1/2)-regulated phosphorylation of the signal transducer and activator of transcription 3 (STAT3). We report that uPA/uPAR binding is necessary and sufficient to induce astrocytic activation in the ischemic brain and that astrocytes activated by neuronal uPA promote synaptic recovery in neurons that have suffered an acute hypoxic injury via a mechanism mediated by astrocytic thrombospondin-1 (TSP1) and synaptic low-density lipoprotein receptor-related protein-1 (LRP1). In summary, we show that uPA/uPAR-induced astrocytic activation mediates a cross talk between astrocytes and injured neurons that promotes synaptic recovery in the ischemic brain.SIGNIFICANCE STATEMENTTo date, there is no therapeutic strategy to promote synaptic recovery in the injured brain. Here, we show that neurons release urokinase-type plasminogen activator (uPA) and astrocytes recruit the uPA receptor (uPAR) to their plasma membrane during the recovery phase from a hypoxic injury. We found that binding of neuronal uPA to astrocytic uPAR promotes astrocytic activation and that astrocytes activated by uPA–uPAR binding promote synaptic recovery in neurons that have suffered a hypoxic injury by a mechanism that does not require plasmin generation, but instead is mediated by ERK1/2-regulated STAT3 phosphorylation, astrocytic thrombospondin-1 (TSP1) and synaptic low-density lipoprotein receptor-related protein-1 (LRP1). Our work unveils a new biological function for uPA–uPAR as mediator of a neuron–astrocyte cross talk that promotes synaptic recovery in the ischemic brain.
DrosophilaNeprilysin 1 Rescues Memory Deficits Caused by Amyloid-β Peptide
Authors: Turrel Oriane , Goguel Valérie , Preat Thomas 
Published: September 2017

Neprilysins are Type II metalloproteinases known to degrade and inactivate a number of small peptides, in particular the mammalian amyloid-β peptide (Aβ). InDrosophila, several neprilysins expressed in the brain are required for middle-term (MTM) and long-term memory (LTM) in the dorsal paired medial (DPM) neurons, a pair of large neurons that broadly innervate the mushroom bodies (MB), the center of olfactory memory. These data indicate that one or several peptides need to be degraded for MTM and LTM. We have previously shown that the fly amyloid precursor protein (APPL) is required for memory in the MB. We show here that APPL is also required in adult DPM neurons for MTM and LTM formation. This finding prompted us to search for an interaction between neprilysins andDrosophilaAβ (dAβ), a cleavage product of APPL. To find out whether dAβ was a neprilysin's target, we used inducible drivers to modulate neprilysin 1 (Nep1) and dAβ expression in adult DPM neurons. Experiments were conducted either in both sexes or in females. We show that Nep1 inhibition makes dAβ expression detrimental to both MTM and LTM. Conversely, memory deficits displayed by dAβ-expressing flies are rescued by Nep1 overexpression. Consistent with behavioral data, biochemical analyses confirmed that Nep1 degrades dAβ. Together, our findings establish that Nep1 and dAβ expressed in DPM neurons are functionally linked for memory processes, suggesting that dAβ is a physiological target for Nep1.SIGNIFICANCE STATEMENTNeprilysins are endopeptidases known to degrade a number of small peptides and in particular the amyloid peptide. We previously showed that all four neprilysins expressed in theDrosophilabrain are involved in specific phases of olfactory memory. Here we show that an increase in the level of the neprilysin 1 peptidase overcomes memory deficits induced by amyloid peptide in young flies. Together, the data reveal a functional interaction between neprilysin 1 and amyloid peptide, suggesting that neprilysin 1 degrades amyloid peptide. These findings raise the possibility that, under nonpathological conditions, mammalian neprilysins degrade amyloid peptide to ensure memory formation.
Employer-Sponsored Plan Expenditures for Infants Born Preterm
Authors: Grosse Scott D. , Waitzman Norman J. , Yang Ninee , Abe Karon , Barfield Wanda D. 
Published: September 2017

BACKGROUND:
Care for infants born preterm or with major birth defects is costly. Specific estimates of financial burden for different payers are lacking, in part because use of administrative data to identify preterm infants and costs is challenging.

METHODS:
We used private health insurance claims data and billing codes to identify live births during 2013 and calculated first-year expenditures for employer-sponsored health plans for infants born preterm, both overall and stratified by major birth defects.

RESULTS:
We conservatively estimated that 7.7% of insured infants born preterm accounted for 37% of $2.0 billion spent by participating plans on the care of infants born during 2013. With a mean difference in plan expenditures of ∼$47 100 per infant, preterm births cost the included plans an extra $600 million during the first year of life. Extrapolating to the national level, we projected aggregate employer-sponsored plan expenditures of $6 billion for infants born preterm during 2013. Infants with major birth defects accounted for 5.8% of preterm births but 24.5% of expenditures during infancy. By using an alternative algorithm to identify preterm infants, it was revealed that incremental expenditures were higher: $78 000 per preterm infant and $14 billion nationally.

CONCLUSION
Preterm births (especially in conjunction with major birth defects) represent a substantial burden on payers, and efforts to mitigate this burden are needed. In addition, researchers need to conduct studies using linked vital records, birth defects surveillance, and administrative data to accurately and longitudinally assess per-infant costs attributable to preterm birth and the interaction of preterm birth with major birth defects.
La educación para la salud en la salud pública: un análisis pedagógico
Authors: Peñaranda Correa Fernando , López Ríos Jennifer Marcela , Molina Berrío Diana Patricia 
Published: September 2017

Introducción: En la literatura sobre educación para la salud (EpS) se plantea la existencia de dos modelos pedagógicos en tensión, una contradicción entre la teoría y la práctica en aquellas experiencias que buscan promover propuestas críticas, y debilidad en la fundamentación pedagógica, que estarían explicadas por problemas en la formación del talento humano. Esta investigación se propone Objetivos: Cuestionar dichos planteamientos para ampliar la comprensión de los supuestos y perspectivas pedagógicas de la EpS en el campo de la salud pública. Materiales y métodos: Se realizó investigación documental de orientación cualitativa. Con base en tres criterios de inclusión, se tomaron 40 artículos de Brasil, Colombia, México y Cuba. Como producto de un proceso emergente se construyeron seis categorías para hacer el análisis. Resultados: Con la utilización de las categorías emergentes, se identificaron cuatro tendencias en los 17 estudios de "sistematización, análisis o evaluación de programas o proyectos" encontrados, y 3 tendencias en los estudios de revisión que abordaron las concepciones, modelos pedagógicos y los propósitos de la EpS. Conclusiones: Con base en las tendencias identificadas se plantea una situación más compleja y diversa que la dicotomía educación tradicional/crítica, y como reduccionista la idea de atribuir a la falta de formación del talento humano los problemas en la EpS y la contradicción entre la teoría y la práctica. La discusión de la EpS en la salud pública es un asunto más complejo que requiere abordar sus fundamentos pedagógicos y la teoría de la salud pública como disciplina.
Regulación del uso de marihuana en Colombia con fines medicinales
Authors: Calderón Vallejo Gustavo Adolfo , Pareja Hincapié Lina María , Caicedo Cano Catalina , Chica Ríos Rubiel Alberto 
Published: September 2017

Objetivo: Interpretar el proceso de regulación del uso de marihuana con fines medicinales. Materiales y métodos: Cualitativo con enfoque hermenéutico, utiliza la técnica de entrevista, se aplicó a 15 expertos en octubre de 2015. Se hizo triangulación: expertos, artículos científicos e investigadores. Se realizó interpretación a partir de sistema categorial y de apoyo de programa Atlas. Ti. Resultados: El debate sobre la regulación de la marihuana con fines terapéuticos se continúa dando en el mundo, en especial en relación a los beneficios para la salud. Con el uso de algunos cannabinoides ya existen evidencias, pero expertos consultados reconocen que no son suficientes; en estos casos se recomienda más investigación. Los expertos de diversas disciplinas entrevistados respaldan el argumento que con la prohibición poco se ha conseguido y que los enfoques de salud pública traen una apertura científica no represiva a la situación, situando el debate en los posibles beneficios que puede traer para el tratamiento de algunas enfermedades. Estos procesos regulatorios deben considerar un control sobre la producción, fabricación, exportación, distribución, comercio y uso del cannabis con fines médicos e investigativos; proceso distinto al de la legalización del consumo con fines recreativos. Conclusión: Para el caso colombiano, la regulación del cannabis con fines medicinales hasta hace unos meses era solo una discusión con posiciones radicalizadas a favor y en contra. Hoy es una realidad en términos de legislación pues fue aprobada por decreto, pero con escaso debate y acción pedagógica de lo que implica la ley para población.
El prácticum: eje formador de la práctica reflexiva en enfermería
Authors: Rivera Álvarez Luz Nelly , Medina Moya José Luís 
Published: September 2017

Objetivo: Caracterizar el papel que juegan las pedagogías de contextualización en la tutoría clínica y describir algunas estrategias didácticas que favorecen la práctica reflexiva del estudiante de enfermería en su prácticum. Materiales y métodos: Investigación cualitativa, etnográfica, desarrollada en el marco de las asignaturas prácticum hospitalario II y estancias clínicas II durante la formación de once estudiantes de enfermería en un Hospital Universitario de Barcelona (España) entre el 2011 y 2012. Los datos fueron recolectados por medio de observación participante y no participante, conversación informal, entrevista en profundidad y materiales escritos. Para el análisis se empleó el método de comparaciones constantes de Glaser y Strauss. Resultados: Emergieron ejes cualitativos como las pedagogías de contextualización y estrategias didácticas que favorecen el desarrollo del raciocinio y juicio clínico y la planificación de los cuidados de enfermería en la práctica hospitalaria, allí se hacen evidentes algunas estrategias de educación didácticas como el diálogo reflexivo y la interrogación didáctica, con las que las estudiantes verbalizan las razones de sus acciones, evitando así acciones mecánicas. Conclusión: las pedagogías de contextualización empleadas por las enfermeras favorecen el desarrollo del razonamiento y juicio clínico, llevando a las estudiantes a desarrollar un sentido de saliencia.
Estrés y sobrecarga laboral durante el embarazo: experiencias de médicas vinculadas al sector asistencial en Bogotá
Authors: Antolínez Ruiz Patricia , Lafaurie Villamil María Mercedes 
Published: September 2017

Objetivo: Explorar cómo fueron sus embarazos desde las experiencias de médicas que trabajan en el sector asistencial en Bogotá. Materiales y Métodos: estudio cualitativo fenomenológico, realizado mediante entrevistas a profundidad entre noviembre y diciembre de 2015; para el análisis se utilizó el software Atlas.ti 7. Resultados: Las entrevistadas consideran que trabajaron en exceso en sus embarazos. El estrés causado por su actividad y la carga de trabajo son mencionados como situaciones de riesgo laboral para sus embarazos por parte de las entrevistadas, quienes en siete casos presentaron complicaciones (amenaza de parto pretérmino, amenaza de aborto, parto pretérmino, preeclampsia, eclampsia e hipertensión gestacional). Las condiciones de contratación, con frecuencia por prestación de servicios, son valoradas como difíciles por varias de las participantes; recomiendan reducir los tiempos laborales y, a las organizaciones, que las profesionales cuenten con condiciones para atender sus necesidades de salud. Conclusiones: Es imperioso avanzar en el estudio de la posible relación entre carga laboral y complicaciones del embarazo en las profesionales de la medicina; insistir en la importancia del cuidado en el embarazo de las mujeres de la profesión médica y lograr avances normativos para la protección especial a las trabajadoras de la salud durante sus embarazos.
Nivel de actividad física y grado de discapacidad en pacientes con dolor lumbar crónico
Authors: Duque Vera Iván Leonardo , Urrutia Illera Isabella María 
Published: September 2017

Objetivo: Determinar, en una población colombiana, el nivel de actividad física y el nivel de discapacidad en pacientes con dolor lumbar crónico y establecer la eventual existencia de asociación entre estas variables. Materiales y Métodos: En una unidad externa de rehabilitación en Manizales (Colombia), pacientes con dolor lumbar crónico completaron tanto el cuestionario de actividad física de Baecke como el de incapacidad de dolor lumbar de Oswestry. Resultados: Un total de 125 pacientes participaron en el estudio. El valor promedio del índice de Baecke fue de 7,9±0,9 con valores para hombres y mujeres de 7,8±0,1 y 8,0±0,7 respectivamente, sin que lograra demostrar una diferencia estadísticamente significativa entre los sexos. El valor promedio del índice de Oswestry fue de 40,7±18,3 con valores para hombres y mujeres de 38,4±18,8 y 42,4±17,7 respectivamente, sin que tampoco se lograra demostrar una diferencia estadísticamente significativa entre los sexos. Un valor del coeficiente de correlación de Pearson >0,05 demostró la inexistencia de relación entre el nivel de actividad física y el grado de discapacidad en los pacientes. Conclusiones: Los resultados describen una población de pacientes con dolor lumbar crónico que, comparada con lo reportado en otros estudios en estos pacientes, puede ser considerada como más activa y menos discapacitada, pero en la cual no existe correlación entre el nivel de actividad física y el grado de discapacidad. Así las cosas, los pacientes con dolor lumbar crónico parecen variar los niveles de actividad independientemente del grado de discapacidad.