Characterization of autochthonal yeasts isolated from Spanish soft raw ewe milk protected designation of origin cheeses for technological application.

The yeasts involved in the ripening process of artisanal soft raw ewe milk Protected Designation of Origin (PDO) Torta del Casar and Queso de la Serena cheeses produced in Extremadura, Spain, were isolated throughout their ripening process, strain typed, and characterized for some important technological properties. A total of 508 yeast isolates were obtained and identified by inter-single sequence repeat anchored PCR amplification analysis and subsequent sequencing of the internal transcribed spacer ITS1/ITS2 5.8S rRNA. A total of 19 yeast species representing 8 genera were identified. Debaryomyces hansenii, Pichia kudriavzevii, Kluyveromyces lactis, and Yarrowia lipolytica were the predominant species. We selected 157 isolates, by genotyping and origin, for technological characterization. The evaluation of yeast isolates' growth under stress conditions of cheese ripening showed that 87 presented better performance. Among them, 71 isolates were not able to catabolize tyrosine to produce a brown pigment. Principal component analysis of the biochemical features of these isolates showed that 9 strains stood out, 3 K. lactis strains (2287, 2725, and 1507), 2 Pichia jadinii (1731 and 433), 2 Yarrowia alimentaria (1204 and 2150), Y. lipolytica 2495 and P. kudriavzevii 373. These strains displayed strong extracellular proteolytic activity on skim milk agar as well as an adequate enzymatic profile (strong aminopeptidase and weak protease activity), suggesting their great potential for cheese proteolysis. Extracellular lipolytic activity was mainly restricted to Yarrowia spp. isolates and weakly present in P. kudriavzevii 373 and K. lactis 2725, although enzymatic characterization by API-ZYM (bioMérieux SA) evidenced that all may contribute, at least in part, to the lipolysis process. Moreover, these strains were able to assimilate lactose, galactose, and glucose at NaCl concentrations higher than that usually found in cheese. However, lactate and citrate assimilation were limited to Y. lipolytica 2495, P. kudriavzevii 373, and P. jadinii 433, and may contribute to the alkalinizing process relevant to biochemical processes that take place in the last stages of ripening. By contrast, K. lactis strains showed acidifying capacity and ß-galactosidase activity and may take part in the initial stages of ripening, together with lactic acid bacteria. Thus, considering the technological characteristics studied, the 9 selected strains presented biochemical features well suited to their potential use as adjunct cultures, alone or in combination with autochthonous starter bacteria in the cheesemaking process, to overcome the heterogeneity of these PDO cheeses, preserving their unique sensory characteristics.

The Effect of Ethanol Treatment on the Quality of a New Table Grape Cultivar It 681-30 Stored at Low Temperature and after a 7-Day Shelf-Life Period at 20 °C: A Molecular Approach.

Despite the fact that many studies have examined the effectiveness of different gaseous postharvest treatments applied at low temperature to maintain table grape quality, the use of ethanol vapor has hardly been investigated. Thus, this work has studied the effectiveness of ethanol vapor-generating sachets in the maintenance of It 681-30 table grape quality, a new cultivar, during storage at low temperature and after the shelf-life period at 20 °C. To this end, various quality assessments have been carried out and the effect of the ethanol treatment on the expression of different genes (phenylpropanoids, transcription factors, PRs, and aquaporins) was determined. The results indicated that the application of ethanol vapor reduced the total decay incidence, weight loss, and the rachis browning index in It 681-30 grapes stored at 0 °C and after the shelf-life period at 20 °C, as compared to non-treated samples. Moreover, the modulation of STS7 and the different PR genes analyzed seems to play a part in the molecular mechanisms activated to cope with fungal attacks during the postharvest of It 681-30 grapes, and particularly during the shelf-life period at 20 °C. Furthermore, the expression of aquaporin transcripts was activated in samples showing higher weight loss. Although further work is needed to elucidate the role of ethanol in table grape quality, the results obtained in this work provide new insight into the transcriptional regulation triggered by ethanol treatment.

Functional characterization of VviDHN2 and VviDHN4 dehydrin isoforms from Vitis vinifera (L.): An in silico and in vitro approach.

Dehydrins, a family of hydrophilic and intrinsically disordered proteins, are a subgroup of late embryogenesis abundant proteins that perform different protective roles in plants. Although the transition from a disordered to an ordered state has been associated with dehydrin function or interactions with specific partner molecules, the question of how the primary and secondary dehydrin protein structure is related to specific functions or target molecule preferences remains unresolved. This work addresses the in silico sequencing analysis and in vitro functional characterization of two dehydrin isoforms, VviDHN2 and VviDHN4, from Vitis vinifera. Conformational changes suggest potential interactions with a broad range of molecules and could point to more than one function. The in silico analysis showed differences in conserved segments, specific amino acid binding sequences, heterogeneity of structural properties and predicted sites accessible for various post-translational modifications between the sequence of both dehydrins. Moreover, in vitro functional analysis revealed that although they both showed slight antifungal activity, only VviDHN4 acts as a molecular shield that protects proteins from freezing and dehydration. VviDHN4 also demonstrated high potential as a chaperone and reactive oxygen species scavenger, in addition to presenting antifreeze activity, all of which confirms its multifunctional nature. Our findings highlight the significant role of Y-segments and the differential and specific amino acid composition of less conserved segments that are rich in polar/charged residues between S- and K-segments, coupled with post-translational modifications, in modulating and switching dehydrin biological function.

Control of Penicillium glabrum by Indigenous Antagonistic Yeast from Vineyards.

Biocontrol is one of the most promising alternatives to synthetic fungicides for food preservation. Botrytis cinerea, Alternaria alternata, and Aspergillus section Nigri are the most concerning pathogens for grape development. However, frequently, other species, such as Penicillium glabrum in this study, are predominant in spoiled bunches. In this work, 54 native yeasts from vineyards were screened by direct confrontation in potato dextrose agar plates as antagonists against P. glabrum. Isolates of Pichia terricola, Aureobasidium pullulans, and Zygoascus meyerae were selected for their antagonist activity in vitro, plus isolates of Pichia kudriavzevii, Hormonema viticola, and Hanseniaspora uvarum were used as negative controls. However, in vivo, confrontations in wounded grapes showed disagreement with direct confrontation in vitro. P. terricola, P. kudriavzevii, H. viticola, Z. meyerae, and H. uvarum significantly reduced the incidence of P. glabrum on grapes. Nevertheless, P. terricola, H. viticola, and H. uvarum themselves spoiled the wounded grapes. Inhibitions were associated with different mechanisms such as the production of volatile organic compounds (VOCs), lytic enzymes, biofilm formation, and competition for nutrients. The isolates of P. kudriavzevii L18 (a producer of antifungal VOCs which completely inhibited the incidence of P. glabrum) and Z. meyerae L29 (with pectinase, chitinase and ß-glucanase activity and biofilm formation which reduced 70% of the incidence of P. glabrum) are proposed as suitable biocontrol agents against P. glabrum.

Table Grapes during Postharvest Storage: A Review of the Mechanisms Implicated in the Beneficial Effects of Treatments Applied for Quality Retention.

Table grape is a fruit with increasing interest due to its attributes and nutritional compounds. During recent years, new cultivars such as those without seeds and with new flavors have reached countries around the world. For this reason, postharvest treatments that retain fruit quality need to be improved. However, little is known to date about the biochemical and molecular mechanisms related with observed quality improvements. This review aims to examine existing literature on the different mechanisms. Special attention will be placed on molecular mechanisms which activate and regulate the different postharvest treatments applied in order to improve table grape quality.

Deciphering the Role of CBF/DREB Transcription Factors and Dehydrins in Maintaining the Quality of Table Grapes cv. Autumn Royal Treated with High CO2 Levels and Stored at 0°C.

C-repeat/dehydration-responsive element binding factors (CBF/DREB) are transcription factors which play a role in improving plant cold stress resistance and recognize the DRE/CRT element in the promoter of a set of cold regulated genes. Dehydrins (DHNs) are proteins that accumulate in plants in response to cold stress, which present, in some cases, CBF/DREB recognition sequences in their promoters and are activated by members of this transcription factor family. The application of a 3-day gaseous treatment with 20 kPa CO2 at 0°C to table grapes cv. Autumn Royal maintained the quality of the bunches during postharvest storage at 0°C, reducing weight loss and rachis browning. In order to determine the role of CBF/DREB genes in the beneficial effect of the gaseous treatment by regulating DHNs, we have analyzed the gene expression pattern of three VviDREBA1s (VviDREBA1-1, VviDREBA1-6, and VviDREBA1-7) as well as three VviDHNs (VviDHN1a, VviDHN2, and VviDHN4), in both alternative splicing forms. Results showed that the differences in VviDREBA1s expression were tissue and atmosphere composition dependent, although the application of high levels of CO2 caused a greater increase of VviDREBA1-1 in the skin, VviDREBA1-6 in the pulp and VviDREBA1-7 in the skin and pulp. Likewise, the application of high levels of CO2 regulated the retention of introns in the transcripts of the dehydrins studied in the different tissues analyzed. The DHNs promoter analysis showed that VviDHN2 presented the cis-acting DRE and CRT elements, whereas VviDHN1a presented only the DRE motif. Our electrophoretic mobility shift assays (EMSA) showed that VviDREBA1-1 was the only transcription factor that had in vitro binding capacity to the CRT element of the VviDHN2 promoter region, indicating that the transcriptional regulation of VviDHN1a and VviDHN4 would be carried out by activating other independent routes of these transcription factors. Our results suggest that the application of high CO2 levels to maintain table grape quality during storage at 0°C, leads to an activation of CBF/DREBs transcription factors. Among these factors, VviDREBA1-1 seems to participate in the transcriptional activation of VviDHN2 via CRT binding, with the unspliced form of this DHN being activated by high CO2 levels in all the tissues analyzed.

Consumo actual de edulcorantes naturales (beneficios y problemática): Stevia / Current consumption of natural sweeteners (benefits and problems): Stevia

La estevia [Stevia rebaudiana (Bertoni)] es un arbusto de tipo perenne de la familia de las Asteraceas que crece en áreas tropicales y subtropicales de Suramérica. Hoy en día, su cultivo se ha extendido a otras regiones del mundo, incluyendo Canadá y algunas partes de Asia, Europa y México, donde sus hojas se han utilizado tradicionalmente como edulcorante natural durante cientos de años. En la actualidad, el uso potencial y las implicaciones prácticas de la estevia como un edulcorante se muestran en una serie de alimentos procesados, ya que contiene glucósidos de esteviol como ingrediente activo, que puede ser bajo o no calórico, y hasta 100-300 veces más dulce que la sacarosa. Además, las hojas secas de estevia contienen también minerales, vitaminas, compuestos fenólicos, flavonoides y otros compuestos antioxidantes, con propiedades antimicrobianas y antioxidantes. Stevia acumula hasta un 30 % de los glucósidos de esteviol (SGs por su sigla en inglés) del peso seco de las hojas. El esteviósido y el rebaudiósido A son las principales SGs. Desde diciembre de 2011, los SGs (E 960) se han autorizado como aditivo alimentario y edulcorante en Estados Unidos. Su uso en diversas categorías de alimentos está regulado como por ejemplo en suplementos alimenticios y alimentos dietéticos para propósitos médicos especiales y control de peso. Sin embargo, la información ofrecida al consumidor es engañosa y dista de ser confiable. Este artículo ofrece al público interesado, datos que deben de ser evaluados al comprar productos adicionados con estevia (AU).

Stevia [Stevia rebaudiana (Bertoni)] is a perennial shrub belonging to the Asteraceae family that grows in tropical and subtropical areas of South America. Today its cultivation has spread to other regions of the world, including Canada and some parts of Asia, Europe and México, where its leaves have been used traditionally as a natural sweetener for hundreds of years. Nowadays, the potential use and practical implications of Stevia as a sweetener are shown in a number of processed foods, because it contains steviol-glycosides, which are low- or non-caloric ingredients, up to 100­300 times sweeter than sucrose. In addition, dry Stevia leaves also contain minerals, vitamins, phenolic compounds, flavonoids and other antioxidant compounds, with antimicrobial and antioxidant properties. Stevia accumulates up to 30% of diterpenoid steviol glycosides (SGs) of the leaf dry weight. Stevioside and rebaudioside A are the major SGs. Since December 2011, SGs (E 960) have been permitted for use as food additive and a sweetener in the United States. Its use in various food categories is regulated, e.g. food supplements and dietary foods for special medical purposes and weight control. However, the information offered to the consumers is misleading and far from reliable. This article offers the interested public, data that should be evaluated when buying products added with Stevia (AU).

Consumo actual de edulcorantes naturales (beneficios y problemática): Stevia / Current consumption of natural sweeteners (benefits and problems): Stevia

La estevia [Stevia rebaudiana (Bertoni)] es un arbusto de tipo perenne de la familia de las Asteraceas que crece en áreas tropicales y subtropicales de Suramérica. Hoy en día, su cultivo se ha extendido a otras regiones del mundo, incluyendo Canadá y algunas partes de Asia, Europa y México, donde sus hojas se han utilizado tradicionalmente como edulcorante natural durante cientos de años. En la actualidad, el uso potencial y las implicaciones prácticas de la estevia como un edulcorante se muestran en una serie de alimentos procesados, ya que contiene glucósidos de esteviol como ingrediente activo, que puede ser bajo o no calórico, y hasta 100-300 veces más dulce que la sacarosa. Además, las hojas secas de estevia contienen también minerales, vitaminas, compuestos fenólicos, flavonoides y otros compuestos antioxidantes, con propiedades antimicrobianas y antioxidantes. Stevia acumula hasta un 30 % de los glucósidos de esteviol (SGs por su sigla en inglés) del peso seco de las hojas. El esteviósido y el rebaudiósido A son las principales SGs. Desde diciembre de 2011, los SGs (E 960) se han autorizado como aditivo alimentario y edulcorante en Estados Unidos. Su uso en diversas categorías de alimentos está regulado como por ejemplo en suplementos alimenticios y alimentos dietéticos para propósitos médicos especiales y control de peso. Sin embargo, la información ofrecida al consumidor es engañosa y dista de ser confiable. Este artículo ofrece al público interesado, datos que deben de ser evaluados al comprar productos adicionados con estevia (AU).

Stevia [Stevia rebaudiana (Bertoni)] is a perennial shrub belonging to the Asteraceae family that grows in tropical and subtropical areas of South America. Today its cultivation has spread to other regions of the world, including Canada and some parts of Asia, Europe and México, where its leaves have been used traditionally as a natural sweetener for hundreds of years. Nowadays, the potential use and practical implications of Stevia as a sweetener are shown in a number of processed foods, because it contains steviol-glycosides, which are low- or non-caloric ingredients, up to 100­300 times sweeter than sucrose. In addition, dry Stevia leaves also contain minerals, vitamins, phenolic compounds, flavonoids and other antioxidant compounds, with antimicrobial and antioxidant properties. Stevia accumulates up to 30% of diterpenoid steviol glycosides (SGs) of the leaf dry weight. Stevioside and rebaudioside A are the major SGs. Since December 2011, SGs (E 960) have been permitted for use as food additive and a sweetener in the United States. Its use in various food categories is regulated, e.g. food supplements and dietary foods for special medical purposes and weight control. However, the information offered to the consumers is misleading and far from reliable. This article offers the interested public, data that should be evaluated when buying products added with Stevia (AU).

Panorama general y programas de protección de seguridad alimentaria en México / Overview and Protection Programs of Food Security in Mexico

Proporcionar seguridad alimentaria a la población representa un desafío global, especialmente para los países en vías de desarrollo debido a su insostenible crecimiento poblacional, bajo nivel de ingresos y tasa acelerada de urbanización. En México, un alto porcentaje de la población no tiene acceso a una canasta básica y por ende posee algún grado de inseguridad nutricional. Existen programas gubernamentales que han procurado mitigar este problema al proveer una cantidad suficiente de alimentos, sobretodo en poblaciones vulnerables como comunidades indígenas, rurales, niños y mujeres. Por otra parte, los alarmantes índices de obesidad y sobrepeso que han elevado la morbilidad de enfermedades crónicas como hipertensión y diabetes en la población, reflejan un problema relacionado con el hambre oculta, aquella donde hay una deficiencia de micronutrientes al enfocarse en una dieta alta en contenido energético, evidenciando la falta de calidad nutritiva en los alimentos y desinformación en la población mexicana. El presente artículo muestra la situación de seguridad alimentaria en México y algunos programas gubernamentales que procuran mitigar este problema, de los cuales solo algunos prestan poca atención a los aspectos nutricionales, restringiendo el derecho a una alimentación de calidad (AU).

Providing food security to the population represents a global challenge, especially for developing countries due to the unsustainable population growth, low incomes and accelerated urbanization rate. In México, a high percentage of the population does not have access to a basic basket and therefore has some degree of food insecurity. Government programs have tried to mitigate this problem by providing sufficient food, especially in vulnerable populations such as indigenous communities, rural communities, children and women. On the other hand, the alarming rates of obesity and overweight that have raised the morbidity of chronic diseases such as hypertension and diabetes in the population, reflect a problem related to hidden hunger, the one where there is a deficiency of micronutrients, focusing on a diet high in energy content, evidencing the lack of nutritional quality in foods and disinformation among Mexican population. This article shows the situation of food security in Mexico and some government programs intending to mitigate this problem, but only a few of them pay little attention to nutritional aspects, restricting the right to a qualitative nutrition (AU).

Panorama general y programas de protección de seguridad alimentaria en México / Overview and Protection Programs of Food Security in Mexico

Proporcionar seguridad alimentaria a la población representa un desafío global, especialmente para los países en vías de desarrollo debido a su insostenible crecimiento poblacional, bajo nivel de ingresos y tasa acelerada de urbanización. En México, un alto porcentaje de la población no tiene acceso a una canasta básica y por ende posee algún grado de inseguridad nutricional. Existen programas gubernamentales que han procurado mitigar este problema al proveer una cantidad suficiente de alimentos, sobretodo en poblaciones vulnerables como comunidades indígenas, rurales, niños y mujeres. Por otra parte, los alarmantes índices de obesidad y sobrepeso que han elevado la morbilidad de enfermedades crónicas como hipertensión y diabetes en la población, reflejan un problema relacionado con el hambre oculta, aquella donde hay una deficiencia de micronutrientes al enfocarse en una dieta alta en contenido energético, evidenciando la falta de calidad nutritiva en los alimentos y desinformación en la población mexicana. El presente artículo muestra la situación de seguridad alimentaria en México y algunos programas gubernamentales que procuran mitigar este problema, de los cuales solo algunos prestan poca atención a los aspectos nutricionales, restringiendo el derecho a una alimentación de calidad (AU).

Providing food security to the population represents a global challenge, especially for developing countries due to the unsustainable population growth, low incomes and accelerated urbanization rate. In México, a high percentage of the population does not have access to a basic basket and therefore has some degree of food insecurity. Government programs have tried to mitigate this problem by providing sufficient food, especially in vulnerable populations such as indigenous communities, rural communities, children and women. On the other hand, the alarming rates of obesity and overweight that have raised the morbidity of chronic diseases such as hypertension and diabetes in the population, reflect a problem related to hidden hunger, the one where there is a deficiency of micronutrients, focusing on a diet high in energy content, evidencing the lack of nutritional quality in foods and disinformation among Mexican population. This article shows the situation of food security in Mexico and some government programs intending to mitigate this problem, but only a few of them pay little attention to nutritional aspects, restricting the right to a qualitative nutrition (AU).

Expression Profiles and DNA-Binding Affinity of Five ERF Genes in Bunches of Vitis vinifera cv. Cardinal Treated with High Levels of CO2 at Low Temperature.

Ethylene response factors (ERFs) play an important role in plants by regulating defense response through interaction with various stress pathways. After harvest, table grapes (Vitis vinifera L.) are subject to a range of problems associated with postharvest storage at 0°C, such as fungal attack, water loss and rachis browning. The application of a 3-day high CO2 treatment maintained fruit quality and activated the induction of transcription factors belonging to different families such as ERF. In this paper, we have isolated five VviERFs from table grapes cv. Cardinal, whose deduced amino acid sequence contained the conserved apetalous (AP2)/ERF domain. The phylogeny and putative conserved motifs in VviERFs were analyzed and compared with those previously reported in Vitis. VviERFs-c gene expression was studied by quantitative real-time RT-PCR in the different tissues of bunches stored at low temperature and treated with high levels of CO2. The results showed that in most of the tissues analyzed, VviERFs-c gene expression was induced by the storage under normal atmosphere although the application of high levels of CO2 caused a greater increase in the VviERFs-c transcript accumulation. The promoter regions of two PRs (pathogenesis related proteins), Vcchit1b and Vcgns1, were obtained and the in silico analysis revealed the presence of a cis-acting ethylene response element (GCC box). In addition, expression of these two PR genes was analyzed in the pulp and rachis of CO2-treated and non-treated table grapes stored at 0°C and results showed significant correlations with VviERF2-c and VviERF6L7-c gene expression in rachis, and between VviERF11-c and Vcchit1b in pulp. Finally by using electro mobility shift assays, we denoted differences in binding of VviERFs to the GCC sequences present in the promoters of both PRs, with VviERF6L7-c being the only member which did not bind to any tested probe. Overall, our results suggest that the beneficial effect of high CO2 treatment maintaining table grape quality seems to be mediated by the regulation of ERFs and in particular VviERF2-c might play an important role by modulating the expression of PR genes.

Inhibition of PMCA activity by tau as a function of aging and Alzheimer's neuropathology.

Ca2+-ATPases are plasma membrane and intracellular membrane transporters that use the energy of ATP hydrolysis to pump cytosolic Ca2+ out of the cell (PMCA) or into internal stores. These pumps are the main high-affinity Ca2+ systems involved in the maintenance of intracellular free Ca2+ at the properly low level in eukaryotic cells. The failure of neurons to keep optimal intracellular Ca2+ concentrations is a common feature of neurodegeneration by aging and aging-linked neuropathologies, such as Alzheimer's disease (AD). This disease is characterized by the accumulation of ß-amyloid senile plaques and neurofibrillary tangles of tau, a protein that plays a key role in axonal transport. Here we show a novel inhibition of PMCA activity by tau which is concentration-dependent. The extent of inhibition significantly decreases with aging in mice and control human brain membranes, but inhibition profiles were similar in AD-affected brain membrane preparations, independently of age. No significant changes in PMCA expression and localization with aging or neuropathology were found. These results point out a link between Ca2+-transporters, aging and neurodegeneration mediated by tau protein.

Differential regulation of dehydrin expression and trehalose levels in Cardinal table grape skin by low temperature and high CO2.

Dehydrins and trehalose are multifunctional protective biomolecules that play a role in counteracting cellular damage during dehydrative stresses. In this paper, we studied dehydrin isoform patterns, dehydrin gene expression and trehalose levels in the skin of Cardinal (Vitis vinifera L.) table grapes, along with their regulation by different cold postharvest storage conditions. Immunoanalysis with K-segment antibody recognizes four constitutive dehydrins (from 17 to 44 kDa) that are tightly regulated by low temperature and high CO2. Phosphatase treatment showed that DHN44 and DHN22 isoforms are phosphorylated polypeptides, while MALDI-TOF MS and MS/MS analysis suggested that 44 kDa polypeptide may be a dehydrin homodimer. At the transcriptional level, dehydrins are also regulated by low temperature and high CO2, showing a fairly good correlation with their mRNA levels. Trehalose was quantified by high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD), revealing a progressive increase of this metabolite throughout storage at 0 °C and the sudden transitory increases in short-term high CO2-treated fruit. We propose that the constitutive presence and up-regulation of dehydrins and trehalose during low temperature postharvest storage could be positively correlated with the relative chilling tolerance of table grapes and the adaptive responses activated by high CO2 levels to preserve cell water status and to counteract the disruption of physiological processes during cold storage.

Calmodulin antagonizes amyloid-ß peptides-mediated inhibition of brain plasma membrane Ca(2+)-ATPase.

The synaptosomal plasma membrane Ca(2+)-ATPase (PMCA) plays an essential role in regulating intracellular Ca(2+) concentration in brain. We have recently found that PMCA is the only Ca(2+) pump in brain which is inhibited by amyloid-ß peptide (Aß), a neurotoxic peptide implicated in the pathology of Alzheimer's disease (AD) [1], but the mechanism of inhibition is lacking. In the present study we have characterized the inhibition of PMCA by Aß. Results from kinetic assays indicate that Aß aggregates are more potent inhibitors of PMCA activity than monomers. The inhibitory effect of Aß could be blocked by pretreating the purified protein with Ca(2+)-calmodulin, the main endogenous activator of PMCA, and the activity of truncated PMCA lacking the calmodulin binding domain was not affected by Aß. Dot-overlay experiments indicated a physical association of Aß with PMCA and also with calmodulin. Thus, calmodulin could protect PMCA from inhibition by Aß by burying exposed sites on PMCA, making them inaccessible to Aß, and also by direct binding to the peptide. These results suggest a protective role of calmodulin against neuronal Ca(2+) dysregulation by PMCA inhibition induced by Aß.

Metformin and improvement of the hepatic insulin resistance index independent of anthropometric changes.

OBJECTIVE: To determine the change in the hepatic insulin resistance index (HIRI) after metformin treatment. METHODS: In this retrospective cohort study, Mexican mestizo patients with a body mass index (BMI) of 25 kg/m(2) or greater were evaluated. Participants were classified into 2 groups: patients who received metformin and patients who did not. Both groups were followed up for a median of 6 months (range, 4-10 months). The HIRI was calculated at baseline and at follow-up in both groups. We evaluated the independent effect of metformin on HIRI after adjustment for the difference in basal and final values (DELTA) of BMI, waist circumference, glucose, and insulin. RESULTS: A total of 71 patients were enrolled (51 [72%] female). Forty-one patients received metformin and 30 patients did not. Mean age was 36.3 ± 12.2 years and mean BMI was 42.2 ± 10.7 kg/m(2). After metformin treatment, HIRI significantly decreased from 38 ± 10.7 to 34.7 ± 9.5 (P = .03). In contrast, the control group had a nonsignificant increase in HIRI (37.6 ± 11.7 to 40.0 ± 14.0, P = .22). Weight significantly decreased in both groups (group 1: 114.6 ± 33.8 kg to 107.6 ± 28.9 kg, P<.01; group 2: 104.8 ± 28.5 kg to 98.9 ± 26.0 kg, P<.01). After BMI adjustment, the total metformin dosage correlated negatively with HIRI (r = -0.36, P = .03). Using a linear regression model (F = 6.0, r2 = 0.37, P = .002) adjusted for DELTA BMI and DELTA waist circumference, the administration of metformin resulted in independent improvement in the HIRI level (standardized ß = -0.29, t = -2.0, P = .04). CONCLUSIONS: Metformin improves HIRI independently of anthropometric changes. In persons with elevated HIRI levels, metformin may be considered among the treatment options.

Fuentes de actualización utilizadas por el personal de enfermería del IMSS / The most used sources for update in nursing

Resumen

Introducción: la actualización en las competencias laborales en enfermería es una necesidad constante y su calidad depende de la fuente consultada.

Objetivo: determinar las fuentes de consulta bibliográfica para la actualización en temas pediátricos mas utilizados por el personal de enfermería en algunos hospitales pediátricos del IMSS.

Metodología: encuesta descriptiva, con un cuestionario autoaplicado en cuatro hospitales de atención pediátrica. Se exploraron la frecuencia y tipo de documentos consultados para actualizarse, los temas o tópicos más comúnmente buscados en cada fuente, información sobre revistas nacionales e internacionales en pediatría, capacitación en lectura crítica de revistas y dominio de lectura en inglés.

Resultados: 142 enfermeras de180 invitadas participaron en la encuesta. En la actualización el Internet fue la fuente más consultada para: adelantos de enfermedades o medicamentos (37.3 %), nuevas técnicas de enfermería (30.3 %) y temas educacionales (33.8 %); para temas administrativos y psicosociales, los libros (35.9 % y 33.8 %); y para los cuidados de enfermería los manuales de procedimientos (32.4 %). 90 % conocían algunas revistas en enfermería nacionales, pero 95 % desconocían internacionales. El 75.2 % reconocieron deficiencias en la búsqueda y capacidad de crítica de artículos científicos de enfermería. El 95 % manifestó conflictos para leer en inglés.

Conclusiones: la actualización del personal en enfermería se realiza principalmente por Internet en páginas generales. Es necesario establecer programas de capacitación en la búsqueda y lectura crítica de revistas científicas, así como lectura en documentos en inglés.

Summary

Introduction: the continuing nursing education is a need and its quality depends on the information sources consulted.

Objective: to determine the sources of bibliographical consultation for the update in pediatric topics used by the nurses in a pediatric hospital.

Methodology: a descriptive survey with a autoapplied questionnaire in four pediatric hospital was done. The frequency and type of papers consulted to be updated and the most requeriment were explored. Topics lockheed in every source, information about national and international journals in pediatrics, training in critical of papers and authority on redding in English were investigated.

Results: A hundred forty two of the 180 invited nurses took part in the survey. The internet was the source more consulted In the update in advances of disease or drug therapy (37.3 %), new technologies (0.3 %), and educational topics (33.8 %); for administrative and psychosocial topics, (35.9 % and 33.8 %) the source most consulted was the book; and for nursing care in the manuals of procedures (32.4 %). The 90 % of the nurses knew little about the national nursing journals, but 95 % unknown or look for the International nursing journals. 75 % recognized deficiencies in their capacity to search and critique the scientific information. The 95 % of the nurses demonstrated difficulties to manage english.

Conclusions: the principal source for updating in the nursing staff is the Internet web pages. It is necessary to establish programs of training in the search and scientific reading.

Nivel crítico de oxígeno disponible en pacientes graves con falla pulmonar aguda / Critical level of oxygen delivery in critically ill patients with acute pulmonary failure

Introducción: La función celular normal depende de un aporte adecuado de O2 para satisfacer sus necesidades metabólicas. Objetivo. Encontrar el nivel crítico de O2 disponible (DO2) en pacientes graves con falla pulmonar aguda en la ciudad de México. Pacientes y métodos. Estudiamos retrospectivamente 25 pacientes con falla pulmonar aguda (14 mujeres, 11 hombres, edad media 46 ñ 177 años) en una UCI multidisciplinaria de un hopsital de tercer nivel de atención. Se efectuaron 140 mediciones de 20 variables hemodinámicas. El análisis estadístico incluyó t de Student y análisis de regresión lineal simple. Resultados. El nivel crítico de DO2 fue 386 ñ 149 mL/min.m² cuando el consumo de oxígeno (VO2) fue 80 ñ 22.4 mL/min.m², a un nivel mayor a 110 mL/min.m² de VO2, la DO2 fue e 530 ñ 179 mL/min.m². Hubo una correlación baja entre VO2 y DO2 (r² = 0.2952, p = 0.0424) pero la correlación entre DO2 y oxígeno residual (RO2) a un nivel de VO2 menor a 110 mL/min.m² fue alta (r² = 0.9187, p< 0.001). La DO2 se puede expresar en función de RO2 así: DO2 = 1.24 x RO2 (r² = 0.9235, p < 0.001). Conclusión. Un decremento del VO2 a un nivel de DO2 menor a 386 mL/min.m² sugiere deprivación tisular de O2 y utilización inadecuada del oxígeno residual

Ascenso inadvertido de mdio de contraste no iónico al sistema nervioso central durante un estudio mielotomográfico / Inadverted rise of nonionic contrast medium to central nervous system during a myelotomographic study

Introducción. El uso de medios de contraste no iónicos tiene efectos colaterales. Objetivo. Reportar un caso de aracnoiditis química y neuritis óptica después del empleo de medio de contraste no iónico (MCNI). Reporte del caso. Una paciente de 28 años de edad con historia de paraperesia postraumática fue enviada a una UCI después de presentar súbitamente convulsiones tónico-clónicas, mientras se le efectuaban una mielotomografía con MCNI. A su ingreso se encontró: TA 70/40 mmHg, 4 puntos en la escala de coma de Glasgow, postura de descerebración, rigidez de nuca y papiledema. La TAC cerebral mostró la presencia de medio de contraste en el espacio subaracnoideo y en las cisternas. Al 5o. días de estancia se encontró estable y había buena recuperación neurológica, excepto que tenia amaurosis (se diagnosticó neuropatía óptica retrobulbar). Conclusión. La aracnoiditis química y la neuropatía óptica retrobulbar pueden ocurrir después del ascenso inadvertido de MCNI

Comparación de los efectos entre la ranitidina y el sucralfato sobre el pH gástrico y el desarrollo bacteriano intragástrico / Comparison of between ranitidine and sucralfate effects on gastric pH and intragastric colonization

Introducción. La profilaxis de las úlceras de estrés con antiácidos y bloqueadores H2 produce colonización gástrica en los pacientes en estado crítico. Objetivo Comparar los efectos entre ranitidina y sucralfato sobre el pH gástrico y colonización intragástrica. Pacientes y métodos. Estudiamos prospectivamente 64 pacientes que ingresaron a una UCI. Se compararon los efectos entre el tratamiento con ranitidina (32 pacientes, grupo A) y sucralfato (32 pacientes, grupo B) durante 72 horas. Resultados. El pH gástrico fue a las 0, 24, 48 y 72 horas después del tratamiento 2.9 ñ 0.68; 4.3 ñ 0.73, 4.1 ñ 0.68, 4.5 ñ 0.86 y 2.75 ñ 0.61, 6.16 ñ 0.97, 6.5 ñ 0.87, 6.56 ñ 0.79, respectivamente entre los grupos A y B (p < 0.05). La colonización gástrica fue más alta en el grupo B, once pacientes, que en el grupo A, tres pacientes (p= 0.034). Conclusión. La ranitidina incrementa el riesgo de colonización bacteriana del estómago en el paciente crítico

Beneficios del lavado peritoneal en pancreatitis grave / Benefits of peritoneal lavage in severe pancreatitis

Introducción. El tratamiento de la pancreatitis aguda grave es aún controversial. Objetivo. Evaluar la utilidad del lavado peritoneal en el tratamiento de la pancreatitis aguda severa. Pacientes y métodos. Estudiamos prospectivamente en una UCI de un hospital de tercer nivel, 23 pacientes con pancreatitis aguda grave. Se estableció una comparación entre el lavado peritoneal en once pacientes (grupo A) y el tratamiento quirúrgico en doce pacientes (grupo B). El lavado peritoneal se inició al ingreso, utilizando un catéter rígido y solución dializante, que se mantuvo por 48-72 horas. El tratamiento quirúrgico se efectuó a las 24.48 hosas después del ingreso. Resultados. Los signos pronósticos de Ranson fueron 5.7 ñ 1 y 4.6 ñ 1 en los grupos A y B, respectivamente (p< 0.05); la mortalidad fue 27.27 por ciento en el grupo A, 58.33 por ciento en el grupo B, p< 0.05. Conclusiones. El lavado peritoneal puede ser un buen método de tratamiento en la pancreatitis aguda severa