161 research outputs found

    Non-Invasive Assessment of Arterial Stiffness: Pulse Wave Velocity, Pulse Wave Analysis and Carotid Cross-Sectional Distensibility: Comparison between Methods

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    Background: The stiffening of large elastic arteries is currently estimated in research and clinical practice by propagative and non-propagative models, as well as parameters derived from aortic pulse waveform analysis. Methods: Common carotid compliance and distensibility were measured by simultaneously recording the diameter and pressure changes during the cardiac cycle. The aortic and upper arm arterial distensibility was estimated by measuring carotid-femoral and carotid-radial pulse wave velocity (PWV), respectively. The augmentation index and blood pressure amplification were derived from the analysis of central pulse waveforms, recorded by applanation tonometry directly from the common carotid artery. Results: 75 volunteers were enrolled in this study (50 females, average age 53.5 years). A significant inverse correlation was found between carotid distensibility and carotid-femoral PWV (r = -0.75; p < 0.001), augmentation index (r = -0.63; p < 0.001) and central pulse pressure (r = -0.59; p < 0.001). A strong correlation was found also between the total slope of the diameter/pressure rate carotid curves and aortic distensibility, quantified from the inverse of the square of carotid-femoral PWV (r = 0.67). No correlation was found between carotid distensibility and carotid-radial PWV. Conclusions: This study showed a close correlation between carotid-femoral PWV, evaluating aortic stiffness by using the propagative method, and local carotid cross-sectional distensibility

    Telomere length tracking in children and their parents:Implications for adult onset diseases

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    Adults with comparatively short or long leukocyte telomere length (LTL) typically continue to display comparatively short or long LTL throughout life. This LTL tracking stems from the inability of person-to-person variation in age-dependent LTL shortening during adulthood to offset the wide interindividual LTL variation established prior to adult life. However, LTL tracking in children is unstudied. This study aimed to examine LTL shortening rates and tracking in children and their parents. Longitudinal study in children (n = 67) and their parents (n = 99), whose ages at baseline were 11.4 +/- 0.3 and 43.4 +/- 0.4 yr, respectively. LTL was measured by Southern blotting at baseline and similar to 14 yr thereafter. LTL displayed tracking in both children [intraclass correlation coefficient (ICC) = 0.905, P <0.001] and their parents (ICC = 0.856, P <0.001). The children's rate of LTL shortening was twice that of their parents (40.7 +/- 2.5 bp/yr; 20.3 +/- 2.1 bp/yr, respectively; P <0.0001). LTL tracking applies not only to adulthood but also to the second decade of life. Coupled with previous work showing that the interindividual variation in LTL across newborns is as wide as in their parents, these findings support the thesis that the LTL-adult disease connection is principally determined before the second decade of life, perhaps mainly at birth

    A short leucocyte telomere length is associated with development of insulin resistance

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    International audienceAIMS/HYPOTHESIS:A number of studies have shown that leucocyte telomere length (LTL) is inversely associated with insulin resistance and type 2 diabetes mellitus. The aim of the present longitudinal cohort study, utilising a twin design, was to assess whether shorter LTL predicts insulin resistance or is a consequence thereof.METHODS:Participants were recruited between 1997 and 2000 through the population-based national Danish Twin Registry to participate in the GEMINAKAR study, a longitudinal evaluation of metabolic disorders and cardiovascular risk factors. Baseline and follow-up measurements of LTL and insulin resistance over an average of 12 years were performed in a subset of the Registry consisting of 338 (184 monozygotic and 154 dizygotic) same-sex twin pairs.RESULTS:Age at baseline examination was 37.4 ± 9.6 (mean ± SD) years. Baseline insulin resistance was not associated with age-dependent changes in LTL (attrition) over the follow-up period, whereas baseline LTL was associated with changes in insulin resistance during this period. The shorter the LTL at baseline, the more pronounced was the increase in insulin resistance over the follow-up period (p < 0.001); this effect was additive to that of BMI. The co-twin with the shorter baseline LTL displayed higher insulin resistance at follow-up than the co-twin with the longer LTL.CONCLUSIONS/INTERPRETATION:These findings suggest that individuals with short LTL are more likely to develop insulin resistance later in life. By contrast, presence of insulin resistance does not accelerate LTL attrition

    Alternatives to penoxsulam to control Echinochloa spp. and cyperaceous weeds in rice crop in NE Spain

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    Penoxsulam es un herbicida que se aplica de forma generalizada en los arrozales del nordeste peninsular al resultar eficaz frente a Echinochloa spp. y tener cierto control frente a ciperáceas, pero tiene el inconveniente de pertenecer a un grupo de herbicidas vulnerable a la aparición de resistencias. El objetivo del trabajo fue buscar programas de herbicidas alternativos al penoxsulam para preservar el máximo de tiempo posible las escasas materias activas disponibles. El trabajo constó de 6 ensayos, distribuidos en 3 localidades (Huesca y Zaragoza) durante tres años de cultivo (2011-2013). En cada ensayo se aplicaron 8 programas herbicidas repetidos dos veces y distribuidos al azar. Los resultados mostraron que, efectivamente, penoxsulam aplicado en estado de 1-3 hojas de arroz controla satisfactoriamente Echinochloa spp., con aplicación previa de oxadiazon en presiembra. Los dos mejores programas alternativos fueron: (1) Aplicación en presiembra de oxadiazon, en 1-3 hojas de arroz, profoxidim, y hasta ahijado del arroz, bentazona+ MCPA, o halosulfuron-metil (2) aplicación en 1-3 hojas del arroz: propanil+bispiribac-Na, y hasta ahijado, bentazona+MCPA, controlando además ciperáceas, teniendo como inconveniente este último programa que bispiribac-Na es del mismo modo de acción que penoxsulam (aunque pertenece a otra familia química). Los resultados muestran, por tanto, que existen varias combinaciones eficaces sobre las malas hierbas objetivo para prevenir la aparición de resistencias a los herbicidas.Penoxsulam is commonly-used in rice crop in North eastern Spain with excellent control against Echi - nochloa ssp. and with some effect on Cyperaceae, but it belongs to an herbicide group prone to develop resistant biotypes. The aim of this work was to test herbicide programmes alternative to penoxsulam to preserve the efficacy of the few available active ingredients. The work consisted of 6 trials. Located in three locations during three years (2011-2013). In each trial eight herbicide programmes were applied, in two replicates distributed randomly in the field. The results showed that, effectively, penoxsulam had a good control on Echinochloa spp. after applying oxadiazon presowing. The best two alternative programmes to control Echinochloa ssp. and cyperaceous weeds were: (1) oxadiazon presowing followed by an application of profoxydim at 1-3 leaves stages of the rice and a third treatment until rice tillering of bentazone + MCPA or halosulfuron-metil and (2) propanil + bispyribac-Na at 1-3 leaves stage of the rice, a second treatment until rice tillering of bentazone + MCPA controlling both Echinochloa spp. and cyperaceous weeds. The drawback of this second programme is that bispyribac-Na belongs to the same mode of action group as penoxsulam although to different chemical families. However, the results show that it is possible to control the target weeds with several herbicide combinations to prevent herbicide-resistance appearance.Publishe

    Monitoring Lipase/Esterase Activity by Stopped Flow in a Sequential Injection Analysis System Using p-Nitrophenyl Butyrate

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    Lipases and esterases are biocatalysts used at the laboratory and industrial level.To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05-1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed
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