bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antioxidant kinetics of plant‐derived substances and extracts
Authors: Silva A. R. , Menezes P. F. C. , Martinello T. , Novakovich G. F. L. , Praes C. E. O. , Feferman I. H. S. 
Published: October 2009

SynopsisThe antioxidant activity (AA) of substances present in several plant species has been widely studied which reflects their fundamental role in the protection of skin tissue against the harmful action of reactive oxygen species. Given the importance of effective and long‐lasting protection against ultraviolet radiation, we studied the AA of several plant derivatives and extracts over time. Several chemical in vitro methods may be used to evaluate antioxidant capability, among which the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) method stands out, despite its unspecificity, as the most cited and described method in the literature. In this work the AA was evaluated by measuring their capacity to reduce DPPH in 30 min, which is suggested in the literature, and additionally at different times up to 8 h from the baseline reading. The methodology used to evaluate the AA over time was validated. It is important to emphasize that this study proposes to modify the conventional DPPH method, although considered to be non‐specific, to be used to test new antioxidant agents. This represents a considerable advantage because some substances show no significant activity during the first 30 min of reaction. Among other plant products, we tested a proantocyanidin‐rich grapeseed extract, a hesperidin derivative, a rutin‐containing ginkgo extract, a polyphenol‐containing yerba maté extract and tocopheryl acetate, all of which were properly standardized. As they have different antioxidant profiles, each ingredient showed a specific behaviour over time, which may promote the selection of anti‐radical compounds capable of offering protection against external agents. Combining extracts and plant derivatives that present fast, medium and slow antioxidant kinetic it is possible to create complexes capable of offering an effective protection from the moment of application up to several hours later. It is a perfectly feasible method, and such combinations prove to be more effective and have more durable effect.
RAPA: a novel in vitro method to evaluate anti‐bacterial skin cleansing products
Authors: Ansari S. A. , Gafur R. B. , Jones K. , Espada L. A. , Polefka T. G. 
Published: October 2009

SynopsisDevelopment of efficacious anti‐bacterial skin cleansing products has been limited by the availability of a pre‐clinical (in vitro) method to predict clinical efficacy adequately. We report a simple and rapid method, designated as rapid agar plate assay (RAPA), that uses the bacteriological agar surface as a surrogate substrate for skin and combines elements of two widely used in vivo (clinical) methods (Agar Patch and Cup Scrub). To simulate the washing of the human hand or forearm skin with the test product, trypticase soy agar plates were directly washed with the test product and rinsed under running tap water. After air‐drying the washed plates, test bacteria (Staphylococcus aureus or Escherichia coli) were applied and the plates were incubated at 37°C for 18–24 h. Using S. aureus as the test organism, anti‐bacterial bar soap containing triclocarbanilide showed a strong linear relationship (R2 = 0.97) between bacterial dose and their per cent reduction. A similar dose‐response relationship (R2 = 0.96) was observed for anti‐bacterial liquid hand soap against E. coli. RAPA was able to distinguish between anti‐bacterial products based on the nature and level of actives in them. In limited comparative tests, results obtained by RAPA were comparable with the results obtained by clinical agar patch and clinical cup scrub methods. In conclusion, RAPA provides a simple, rugged and reproducible in vitro method for testing the relative efficacy of anti‐bacterial skin cleansing products with a likelihood of comparable clinical efficacy. Further testing is warranted to improve the clinical predictability of this method.
An analytical method for the determination of betaine (trimethylglycine) from hair
Authors: Pulliainen K. , Nevalainen H. , Väkeväinen H. , Jutila K. , Gummer C. L. 
Published: October 2009

SynopsisHair fibres have no active renewable protective mechanisms yet hair (wool and fur) provides an essential protective function. Therefore, it is possible that hair contains a number of internal components to maintain fibre and protein structure and function through a range of normal environmental conditions. Trimethylglycine (betaine) provides cellular and protein protection during times of high osmotic stress and low water concentrations. These conditions are very pertinent to everyday cosmetic procedures such as shampooing, bleach or perming. Therefore, we have conducted preliminary investigations to establish the presence of natural betaine in hair as a possible ingredient to provide protection and maintain protein function. Using an high performance liquid chromatography (HPLC) technique designed for the analysis of betaine in blood and urine, we have demonstrated, via simple hot water extraction, a measurable level of betaine in blood and human hair. Further, we have demonstrated, in principle, the possibility of adding betaine back to the fibre via cosmetic products such as shampoos.
Effect of konjac glucomannan hydrolysates and probiotics on the growth of the skin bacterium Propionibacterium acnes in vitro
Authors: Al‐Ghazzewi F. H. , Tester R. F. 
Published: October 2009

SynopsisThe synbiotic ability of probiotic bacteria and konjac glucomannan hydrolysates (GMH) to inhibit acne‐inducing bacterium, Propionibacterium acnes growth was studied in vitro. All probiotic bacteria strains tested were able to inhibit the growth of this species of skin bacterium where the inhibition was significantly (P < 0.01) enhanced by the presence of the GMH prebiotic. As the current treatment of acne is based on topical or systemic drugs, it is worth examining further the biotherapeutic activities of the GMH and selected probiotics with a view to future use as prophylactic or therapeutic synbiotics for treating acne infections.
Alzheimer’s β‐amyloid peptide blocks vascular endothelial growth factor mediated signaling via direct interaction with VEGFR‐2
Authors: Patel Nikunj S. , Mathura Venkatarajan S. , Bachmeier Corbin , Beaulieu‐Abdelahad David , Laporte Vincent , Weeks Ophelia , Mullan Michael , Paris Daniel 
Published: October 2009

J. Neurochem. (2010) 112, 66–76.AbstractBeta‐amyloid peptides (Aβ) are the major constituents of senile plaques and cerebrovascular deposits in the brains of Alzheimer’s disease patients. We have shown previously that soluble forms of Aβ are anti‐angiogenic both in vitro and in vivo. However, the mechanism of the anti‐angiogenic activity of Aβ peptides is unclear. In this study, we examined the effects of Aβ1–42 on vascular endothelial growth factor receptor 2 (VEGFR‐2) signaling, which plays a key role in angiogenesis. Aβ inhibited VEGF‐induced migration of endothelial cells, as well as VEGF‐induced permeability of an in vitro model of the blood brain barrier. Consistently, exogenous VEGF dose‐dependently antagonized the anti‐angiogenic activity of Aβ in a capillary network assay. Aβ1–42 also blocked VEGF‐induced tyrosine phosphorylation of VEGFR‐2 in two types of primary endothelial cells, suggesting an antagonistic action of Aβ toward VEGFR‐2 signaling in cells. Moreover, Aβ was able to directly interact with the extracellular domain of VEGFR‐2 and to compete with the binding of VEGF to its receptor in a cell‐free assay. Co‐immunoprecipitation experiments confirmed that Aβ can bind VEGFR‐2 both in vitro and in vivo. Altogether, our data suggest that Aβ acts as an antagonist of VEGFR‐2 and provide a mechanism explaining the anti‐angiogenic activity of Aβ peptides.
Mechanisms involved in the neurotoxic effects of environmental toxicants such as polychlorinated biphenyls and brominated flame retardants
Authors: Fonnum Frode , Mariussen Espen 
Published: October 2009

AbstractMany toxic substances have been distributed to the environment, some of which have properties that promote accumulation and biomagnification in living organisms. Approximately 1.2 million metric tons of polychlorinated biphenyls (PCBs) have been produced and about 30% have been discharged to the environment. Approximately 200 000 metric tons of brominated flame retardants (BFRs) are produced annually, of which considerable amounts have been spread globally, even to the Polar Regions. Behavioral testing of animals has shown that these compounds may affect learning, memory and fine motor functions. Animals are most sensitive during early development. Several epidemiological studies have shown that PCBs and BFRs may be responsible for similar effects in humans. Of especially concern are possible effects of PCBs and BFRs in mixtures containing the highly neurotoxic methyl mercury. The compounds affect several targets in the nervous system that seem to be interconnected, and may be responsible for the observed behavioral deficits. It was shown early that PCBs affect dopamine and serotonin levels in the brain. Later studies showed that transport mechanisms of these neurotransmitters appear to be particularly sensitive to PCBs. Furthermore, PCBs affect intracellular calcium levels and induce formation of reactive oxygen species bothin vivoandin vitro, and reduce cell viabilityin vitro.Neuroendocrine functions, particularly the thyroid hormone system, are also sensitive to disruption by PCBs and BFRs. Their metabolites, such as hydroxy‐metabolites, appear to be particularly potent. We conclude that PCBs are particularly toxic during early development and that the toxic effects are a combination of several factors, including disturbance of calcium homeostasis, oxidative stress, and influence on neurotransmitter transport. Monoaminergic cells appear to be particularly vulnerable.
In vivo neurochemical profiling of rat brain by 1H‐[13C] NMR spectroscopy: cerebral energetics and glutamatergic/GABAergic neurotransmission
Authors: Van Eijsden Pieter , Behar Kevin L. , Mason Graeme F. , Braun Kees P. J. , De Graaf Robin A. 
Published: October 2009

J. Neurochem. (2010) 112, 24–33.AbstractThe quantification of excitatory and inhibitory neurotransmission and the associated energy metabolism is crucial for a proper understanding of brain function. Although the detection of glutamatergic neurotransmission in vivo by 13C NMR spectroscopy is now relatively routine, the detection of GABAergic neurotransmission in vivo has remained elusive because of the low GABA concentration and spectral overlap. Using 1H‐[13C] NMR spectroscopy at high magnetic field in combination with robust spectral modeling and the use of different substrates, [U‐13C6]‐glucose and [2‐13C]‐acetate, it is shown that GABAergic, as well as glutamatergic neurotransmitter fluxes can be detected non‐invasively in rat brain in vivo.
Bilirubin selectively inhibits cytochrome c oxidase activity and induces apoptosis in immature cortical neurons: assessment of the protective effects of glycoursodeoxycholic acid
Authors: Vaz Ana Rita , Delgado‐Esteban Maria , Brito Maria Alexandra , Bolaños Juan P. , Brites Dora , Almeida Angeles 
Published: October 2009

J. Neurochem. (2010) 112, 56–65.AbstractHigh levels of unconjugated bilirubin (UCB) may initiate encephalopathy in neonatal life, mainly in pre‐mature infants. The molecular mechanisms of this bilirubin‐induced neurologic dysfunction (BIND) are not yet clarified and no neuroprotective strategy is currently worldwide accepted. Here, we show that UCB, at conditions mimicking those of hyperbilirubinemic newborns (50 μM UCB in the presence of 100 μM human serum albumin), rapidly (within 1 h) inhibited cytochrome c oxidase activity and ascorbate‐driven oxygen consumption in 3 days in vitro rat cortical neurons. This was accompanied by a bioenergetic and oxidative crisis, and apoptotic cell death, as judged by the collapse of the inner‐mitochondrial membrane potential, increased glycolytic activity, superoxide anion radical production, and ATP release, as well as disruption of glutathione redox status. Furthermore, the antioxidant compound glycoursodeoxycholic acid (GUDCA) fully abrogated UCB‐induced cytochrome c oxidase inhibition and significantly prevented oxidative stress, metabolic alterations, and cell demise. These results suggest that the neurotoxicity associated with neonatal bilirubin‐induced encephalopathy occur through a dysregulation of energy metabolism, and supports the notion that GUDCA may be useful in the treatment of BIND.
Membrane‐initiated estradiol signaling increases tyrosine hydroxylase promoter activity with ERα in PC12 cells
Authors: Maharjan Shreekrishna , Serova Lidia I. , Sabban Esther L. 
Published: October 2009

J. Neurochem. (2010) 112, 42–55.AbstractTyrosine hydroxylase (TH) promoter activity is induced by 17β‐estradiol (E2) in PC12 cells expressing estradiol receptor‐alpha (ERα) requiring a cAMP/calcium response element (CRE/CaRE) at −45. To examine whether membrane‐initiated estradiol signaling is underlying this induction, cells co‐transfected with TH reporter construct and ERα expression vector were exposed to membrane‐impermeant estradiol conjugate (β‐estradiol‐6‐(O‐carboxy‐methyl) oxime‐bovine serum albumin, E2BSA). TH promoter activity was elevated by E2BSA in dose‐ and time‐dependent manner. E2BSA also elicited rapid phosphorylation of CRE binding protein (CREB) and increased CRE‐driven promoter activity. Over‐expression of dominant negative forms of CREB, with mutations in DNA binding or phosphorylation site, prevented TH promoter response to E2BSA. Pre‐treatment with protein kinase A (PKA) and MEK inhibitors reduced E2 dependent phosphorylation of CREB and ERK, and also decreased induction of TH promoter activity by E2 or E2BSA. Blocking S‐palmitoylation of ERα with C451A mutation and/or pre‐treatment with 2‐Bromopalmitate did not prevent but instead enhanced E2 or E2BSA‐elicited induction of TH promoter activity. These findings reveal, for the first time, that estradiol induction of TH gene transcription with ERα in PC12 cells involves membrane‐initiated estradiol signaling, rapid activation of dual PKA/MEK signaling pathways, leading to CREB phosphorylation, acting at CRE/CaRE. The data demonstrate possible mechanism whereby estradiol affects catecholaminergic systems in vivo.
THE COMMON FUND IN THE INTEGRATED PROGRAMME FOR COMMODITIES
Authors: Corea Gamani 
Published: October 2009

Despite the lack of full agreement on all aspects of a Common Fund, negotiations have clarified the issues involved and created conditions in which there is a basis for agreement. The extent of financial resources required for a Common Fund has been established, involving a once‐for‐all contribution of US$500 million, and supporting a Common Fund that would provide 75 per cent of the stock financing requirements under international commodity agreements. Given the changes in the concept of a Common Fund from that envisaged in earlier discussions, there should now be no substantive barrier to the conclusion of an appropriate international agreement.Malgré l'absence d'un consensus sur tous les aspects d'un fonds commun, des pourparlers ont permis d'éclaircir les questions en débat et de créer des conditions favorables à un accord. La portée des ressources financières requises pour la création d'un fonds commun a été établie: celles‐ci comprendraient un versement définitif de 500 millions de dollars des E.U. et alimenteraient un fonds commun qui fournirait 75 pour cent des exigences financières des stocks prévus par les accords internationaux sur les produits de base. Compte tenu des modifications apportées au concept d'un fonds commun depuis les derniers débats, il ne devrait pas exister d'obstacles de fond à la conclusion d'un accord international acceptable.A pesar de que no hay completo acuerdo sobre todos los aspectos del Fondo Común, las negociaciones han aclarado varios de ellos y han creado las condiciones que darían base para un acuerdo. Se ha establecido la magnitud de los recursos financieros para el Fondo Común ‐ se contempla una contribución en una sola vez de US$500 millones que mantendría un Fondo Común capaz de proveer 75 por ciento de las necesidades del financiamiento de existencias bajo acuerdos mercantiles internacionales. En vista de los cambios ocurridos en el concepto de Fondo Común en relación a lo que se proponía inicialmente, no debería haber una dificultad substancial en la conclusión de un acuerdo internacional apropiado.
NON‐FUEL MINERALS AND THE INTEGRATED PROGRAMME FOR COMMODITIES
Authors: Rogers Chirstopher D. 
Published: October 2009

The paper reviews progress in the individual commodity negotiations for non‐fuel minerals covered by the Integrated Programme for Commodities (IPC). Given the minimal progress to date, the author reconsiders the objectives of the IPC to gauge the extent to which they meet the needs of countries engaged in mineral production or trade. It is suggested that the major focus of the IPC be towards price stability, with less attention to other aspects of market instability and other market problems. For this reason, the IPC discussions have failed to focus on such major issues of concern in the mineral sector as measures necessary to guarantee adequate supplies of minerals over the long‐term, the financing of the required investments, the expansion of production by developing countries and the securing of price levels sufficient to generate appropriate returns on capital employed.Cet article est consacré à l'étude des progrès accomplis en matière de négociations individuelles sur les produits de base concernant les minéraux non‐combustibles qui figurent au Programme intégré pour les produits de base. Etant donné les résultats peu concluants qui ont été enregistrés, ‘auteur examine à nouveau les objectifs du programme pour évaluer jusqu’ à quel point ils répondent aux besoins des pays engagés dans la production ou le commerce de minéraux. Selon cet article, ‘accent principal du programme a été mis sur’ instabilité en matière de prix au détriment d'autres aspects de 'instabilité du marché et d'autres problèmes connexes. De telles discussions ont éludé les points d'intérét majeurs du secteur minier, à savoir, les mesures nécessaires à assurer à long terme des approvisionnements suffisants en minéraux, le financement des investissements nécessaires, une participation plus active des pays en développement à 'expansion de la production et le maintien de niveaux de prix susceptibles de créer des profits suffisants sur le capital investi.Este artículo revisa los progresos alcanzados en la negociación individual de minerales no combustibles cubiertos por el programs ‘Integrated Programme for Commodities’ (IPC). Dado el progreso mínimo presente, el autor reconsidera los objectivos de la IPC para apreciar el grado en que estos objectivos se ajustan a las necesidades de los países dedicados a la producción y comercio de minerales. Se sugiero que el IPC enfoca su acción a la estabilidad de precios, con menor atención a otros aspectos de inestabilidad y otros problemas de mercado. Por esta razón las discuciones de IPC no han considerado asuntos de tanta importancia en el sector minero tales como las medidas para garantizar suministros adecuados de minerales por largos plazos, el financimiento de las inversiones requeridas, la expansión de la producción por los países en desarollo y la garantía de niveles de precios suficientes para generar retornos adecuados del capital invertido.
METROPOLITAN GROWTH AND WATER MANAGEMENT IN LATIN AMERICA
Authors: Lee Terence R. 
Published: October 2009

This article discusses some recent developments in water management in Latin America. It is based on research done during the joint CEPAL/UNEP project on Water Development and the Environment. The author discusses the changes in water use occurring in Latin America in general, the contemporary relationship with the water resource in four major metropolitan centres, Bogotá, Colombia, Lima, Peru, and Sāo Paulo and Rio de Janeiro, Brazil. On the basis of the general and specific experiences described, general conclusions are drawn as to styles of water management current in the region and adjustments to the problem posed by the emergence of very large metropolitan concentrations of population and economic activity.Cet article reprend des développements récents en matière de gestion des ressources en eau en Amérique latine. II se base sur des recherches effectuées au cours de l'exécution du projet conjoint CEPAL/PNUE sur la mise en valeur des ressources en eau et de l'environnement. L'auteur discute des modifications intervenues dans l'utilisation des ressources en eau en Amérique latine en général et le rapport qui existe actuellement entre les ressources en eau et quatre centres principaux urbains (Bogota en Colombie, Lima au Pérou, et Sāo Paulo et Rio de Janeiro au Brésil). Sur la base des experiences générales et particulières décrites, des conclusions génèrales sont tirées quant aux modes de gestion actuelle des ressources en eau dans la région et aux améliorations apportées au problème créé par l'apparition d'énormes agglomérations urbaines à activité économique intense.Este artículo trata sobre algunos desarrollos recientes en la administración del uso de recursos de agua en Latinoamérica. El artículo está basado en la investigación realizada en el proyecto conjunto CEPAL/PNUMA sobre Desarrollo de Agua y el Medio Ambiente. El autor analiza los cambios que están ocurriendo en el uso de recursos de ague en Latinoamérica en general y las relaciones entre los recursos de agua y los usos en cuatro centros metropolitanos: Bogotá, Lima, Sāco Paulo y Rio de Janeiro. Basándose en descripciones de experiencias generales y específicas, se extraen conclusiones sobre los estilos de la administración de recursos de agua existentes en la región y sobre la solución a los problemas planteados por la emergencia de grandes concentraciones metropolitanas de población y actividad económica.