How do soil organic carbon stocks change after cropland abandonment in Mediterranean humid mountain areas?

The effects of land use changes on soil carbon stocks are a matter of concern stated in international policy agendas on the mitigation of greenhouse emissions. Afforestation is increasingly viewed as an environmental restorative land use change prescription and is considered one of the most efficient carbon sequestration strategies currently available. Given the large quantity of CO2 that soils release annually, it is important to understand disturbances in vegetation and soil resulting from land use changes. The main objective of this study is to assess the effects of land abandonment, land use change and afforestation practices on soil organic carbon (SOC) dynamics. For this aim, five different land covers (bare soil, permanent pastureland, secondary succession, Pinus sylvestris (PS) and Pinus nigra (PN) afforestation), in the Central Spanish Pyrenees, were analysed. SOC dynamics have been studied in the bulk soil, and in the fractions separated according to two methodologies: (i) aggregate size distribution, and (ii) density fractionation, and rates of carbon mineralization have been determined by measuring CO2 evolution using an automated respirometer. The results showed that: (i) SOC contents were higher in the PN sites in the topsoil (10cm), (ii) when all the profiles were considered no significant differences were observed between pastureland and PN, (iii) SOC accumulation under secondary succession is a slow process, and (iv) pastureland should also be considered due to the relative importance in SOC stocks. The first step of SOC stabilization after afforestation is the formation of macro-aggregates promoted by large inputs of SOC, with a high contribution of labile organic matter. However, our respiration experiments did not show evidence of SOC stabilization. SOC mineralization was higher in the top layers and values decreased with depth. These results gain insights into which type of land management is most appropriate after land abandonment for SOC.

Assessment of Three Alternating Pressure Sequences Applied to a Dynamic Cushion to Relieve Pressure on Seating Areas / Evaluación de tres secuencias de inflado alternantes aplicadas a un cojín dinámico para la liberación de presión en el área de sentado

Pressure ulcers are injuries to the skin and/or underlying tissues caused by prolonged high pressures on supporting body areas, they affect mainly people with poor mobility that have stayed in seating position for a long time. Reducing the amount and duration of pressure has been widely accepted for minimizing the risk of formation of pressure ulcers. Recently, dynamic cushions have been developed to relieve pressure on supporting areas; nevertheless, there is no sufficient information about the adequate characteristics of alternating sequences for pressure ulcers prevention. Therefore, the aim of this work is to explore three sequences of alternating movements designed for an air cell cushion by comparing pressure redistribution on supporting areas when applied on healthy volunteers. The purpose of these sequences is to redistribute the pressure over a larger contact area. To evaluate the effect of the alternating sequences, eight healthy volunteers were asked to sit on the air cell cushion, and to try the three alternating sequences for 12 minutes, 2 minutes on static mode and 10 minutes on alternating mode. A parameter for quantitative assessment of alternating sequences was proposed in this work by determining the coefficient of variation of interface pressure. Furthermore, the percentage of relative change of coefficient of variation was computed for evaluating performance of the alternating sequences comparing to the static mode. It was found that the three proposed strategies maintained values of interface pressure lower than previous work. Additionally, the relative change allowed to differentiate the effects of alternation of each sequence showing the second strategy as the most effective. The results are encouraging for further studies in subjects who require a wheelchair for mobility.

Las úlceras por presión son lesiones en la piel y tejidos subyacentes, causadas por presiones excesivas y prolongadas en las superficies de apoyo del cuerpo. Estas lesiones afectan principalmente a personas con poca movilidad física, como aquellas que permanecen sentados por largos periodos. Para disminuir el riesgo del padecimiento de estas lesiones, se ha recomendado como punto de partida reducir la magnitud y el tiempo de acción de las presiones en las zonas de apoyo. Se han desarrollado cojines dinámicos para sillas de ruedas, los cuales generan movimientos alternantes en las diferentes zonas de apoyo, producido por la inyección de aire, con el fin de disminuir las presiones en esas zonas. Sin embargo, no se han encontrado referencias de las características adecuadas de las secuencias de movimientos alternantes para prevenir la aparición de esas lesiones. El propósito de este trabajo es evaluar tres secuencias de movimientos alternantes diseñadas para un cojín de aire. La evaluación se realizó comparando la distribución de presiones en zonas de apoyo antes y durante la aplicación de estas secuencias alternantes en personas sanas. Las secuencias propuestas se aplican para el inflado y desinflado de celdas que forman el cojín y fueron diseñadas con el objetivo de distribuir las presiones en un área mayor de apoyo. La prueba se realizó en 8 sujetos sanos, con un tiempo de estudio de 12 minutos para cada secuencia diseñada; 2 minutos en modo estático y 10 minutos en modo alternante. Se propuso determinar el coeficiente de variación para evaluar de forma cuantitativa el efecto de las secuencias alternantes sobre la presión de interfaz. Además se calculó el porcentaje de variación relativa del coeficiente de variabilidad entre los modos basal (estático) y alternante como una herramienta para evaluar el desempeño de las secuencias propuestas en relación a la presión de interfaz. Se encontró que las tres estrategias mantuvieron presiones de interfaz por debajo de los valores reportados en trabajos previos. El porcentaje de variación relativa permitió diferenciar el efecto de la alternancia de cada una de las secuencias propuestas, mostrando la segunda estrategia como la más efectiva. Los resultados obtenidos son alentadores para continuar el estudio en sujetos que requieren una silla de ruedas para su movilidad.

In vivo and in situ measurement of electrical impedance for determination of distention in proximal stomach of rats.

We present a non-invasive, in vivo and in situ study of proximal stomach (PS) distention based on electrical impedance measurements that could be used together with distal stomach (DS) motility measurements as a response to different boluses. Stomach motility has been reported in the literature, as a response to different boluses, under in vivo conditions. However, previous studies on stomach motility have been mainly considered clinical parameters of the digestive process. The physiological complexity of the stomach requires the use of biological models when a detailed analysis of stomach function due to bolus ingestion is required. In this work, the determination of the PS distention in rats is presented. It is based on electrical resistive impedance measurements of the external stomach wall, related to different liquid bolus volumes. Trials were performed under in vivo and in situ conditions. A four-point technique with a vacuum-affixed linear electrode array was used for impedance measurements. A pouch was created in the stomach to retain the saline solution bolus in the PS for a longer time. Resulting impedance changes were directly related to the bolus volumes introduced into the PS and dependent on initial conditions and compensation mechanisms of the in vivo system. With the stomach pouch, a direct relationship between resistive impedance and bolus volume was obtained in all measurements. With no stomach pouch, 93% of the cases showed this relationship. Therefore, the obtained relationship will permit new non-invasive studies in the stomach about the effects of different types of bolus on the distention in the PS of rats.

Hypoacusis detector for evaluation of scholars in field.

Hypoacusis on scholars has become not only a problem but also an indicator when attention disorders or misunderstood instructions from teachers are observed. A primary detection of hypoacusis, in particular in speech range, can help scholars, parents and teachers to improve or correct the learning process. A hypoacusis detector has been developed to be applied in field. This device is based on the generation of three tones and three sound level pressures in the speech range. Both the laboratory evaluation and a case of study results are reported in this document.

Serum basic fibroblast growth factor levels in exercise-induced myocardial ischemia more likely a marker of endothelial dysfunction than a marker of ischemia?

Increased levels and activity of fibroblast growth factor (FGF) have been documented in a variety of diseases, including ischemia. Both acute coronary syndromes and exercise are situations that stimulate FGF release. Since experimental studies have demonstrated that FGFs are involved in myocardial preconditioning, it has been suggested that cardiac and circulating FGFs may play a cardioprotective role in ischemic diseases. However, the profile of basic FGF (bFGF) release during transient myocardial ischemia remains uncertain. We sought to determine whether circulating bFGF might be changed in patients with demonstrated coronary artery disease and evidence of ischemia in exercise scintigraphy (Isch +; n = 21). Serum from 22 age-matched patients with no coronary artery disease and no isotopic ischemia (Isch-) were used as controls. Three blood samples were obtained to determine bFGF at different times: baseline (bFGF-A); maximal exercise (bFGF-B), and isotopic redistribution (bFGF-C). An enzyme-linked immunoassay specific for bFGF was used (limit of detection, 1.0 pg/ml). Circulating bFGF was increased at maximal exercise in both Isch + and control patients. However, serum levels of bFGF were elevated up to more than two-fold in Isch-patients compared to Isch+ patients (8.67 +/- 2.10 pg/ml in Isch+ vs 17.83 +/- 2.97 pg/ml in Isch- patients; p<0.01). According to previous data, these findings suggest that bFGF serum levels could be considered more likely a marker of endothelial dysfunction occurring in patients with coronary artery disease, rather than a marker of acute ischemia. This situation could be different in the clinical setting of chronic myocardial ischemia.

[Yield of transthoracic echocardiography with high frequency transducer in the study of the anterior descending coronary artery]. / Rendimiento de la ecocardiografía transtorácica con sonda de alta frecuencia en el estudio de la descendente anterior.

INTRODUCTION AND OBJECTIVES: This study was performed to evaluate the feasibility and utility of a transthoracic high frequency transducer to detect and measure the left anterior descending coronary artery flow in patients with lesions in this artery or anterior myocardial infarction. MATERIALS AND METHODS: We studied 11 subjects with lesions greater than 75% and another 10 with anterior myocardial infarction. We compared the results with a control group of 18 subjects. An ATL HDI 5000 ultrasound unit with a 5-8 MHz transducer was used to identify the left anterior descending in the anterior interventricular sulcus from an apical four chamber window. We considered that left anterior descending was detected when a diastolic predominant flow pattern was obtained with pulse Doppler. RESULTS: Left anterior descending was detected in 37/39 of cases (94.4%). Patients with coronary lesions showed a decrease in the limit of significance in the diastolic/systolic peak velocity ratios: 2.5 (SD 0.7) vs 1.8 (SD 0.3) with a p = 0.024. Patients with anterior myocardial infarction obtained lower diastolic/systolic peak velocity ratios than controls: 2.5 (SD 0.7) vs 1.4 (SD 0.3) with a p = 0.001. CONCLUSIONS: Left anterior descending coronary artery flow can be assessed by transthoracic high frequency echocardiography in greater than 90% of the cases. Patients with coronary lesions and those with anterior myocardial infarction have a decreased diastolic/systolic peak velocity ratio.

Electromagnetic therapeutic angiogenesis: the next step.

Therapeutic angiogenesis, in the form of growth factor protein administration or gene therapy, is a new method of treatment for patients with severe coronary and peripheral artery disease not amenable to conventional methods of revascularization. Furthermore, a new experimental strategy increases endogenous angiogenesis in ischemic tissue to induce local 'angiogens' by means of electromagnetic stimulation. Further studies examining the molecular basis and clinical efficacy of electromagnetic angiogenesis are necessary.

Fibroblast growth factor cardioprotection against ischemia-reperfusion injury may involve K+ ATP channels.

We investigated whether the adenosine triphosphate (ATP)-sensitive K+ (K+ATP) channel that was implicated in the ischemic preconditioning (I-PC) phenomenon, has a role in the cardioprotective effects of fibroblast growth factors (FGFs). For this purpose, we administered glibenclamide, a specific K+ATP channel blocker, before acidic fibroblast growth factor (aFGF, FGF-1) treatment, in rat heart subjected to left ventricular ischemia for 20 minutes followed by reperfusion for 24 hours. Creatine kinase (CK) activity was analyzed in myocardial tissue to assess the degree of cardiac injury. FGF-1 treatment markedly maintains CK activity. This cardioprotective effect of FGF-1 was blocked by glibenclamide. As shown by ultrastructural data, Ca2+ overload and associated cardiomyocyte alterations shown in glibenclamide-treated rats were not observed in specimens from the FGF-1 group. These findings suggest that FGF serves as an effector in I-PC and support a clinical interest of these proteins for increasing myocardial ischemic tolerance.

Cardioprotection from ischemia by fibroblast growth factor: role of inducible nitric oxide synthase.

Growing evidence from both animal experiments and clinical observations indicates that fibroblast growth factor (FGF) plays a protective role in myocardial reperfusion injury. The molecular and cellular mechanisms that lead to this postischemic myocardial protection, however, remain largely unexplored. We studied the cardioprotective effects of human recombinant acidic fibroblast growth factor (aFGF, FGF-1) in a rat model of myocardial reperfusion injury, induced by 20 minutes of left coronary artery occlusion followed by 24 hours of reperfusion. Intravenous FGF-1 administration at the onset of heart reperfusion attenuated both the functional impairment and the histological changes of ischemia/reperfusion injury. FGF-1 increases more than twice the left ventricular contractile function (p <0.005) compared to vehicle-treated rats. As shown by histology, myocardial tissue is better preserved with FGF-1 treatment. The infarct size, normalized for the area at risk, was significantly smaller in the FGF-1 group (p <0.01) than in the vehicle group. Furthermore, FGF-1 administration resulted in expression of inducible nitric oxide synthase (iNOS) in the area at risk. Since increased expression of iNOS could potentiate cardioprotection against myocardial reperfusion injury, our findings support a new non-mitogenic role for FGF and add a clinical interest for this protein in increasing myocardial ischemic tolerance.

[Study of active myocardial damage in children with suspected myocarditis using antimyosin monoclonal antibodies (AMMoAb-111In)]. / Estudio evolutivo del daño miocárdica activo en niños con sospecha de miocarditis mediante anticuerpos monoclonales antimiosina (AbMoAM-111In).

BACKGROUND: The study with monoclonal antimyosin antibody-111In has proved to be useful in the detection of the myocardial damage present in different processes. There is active myocardial damage and specific antimyosin uptake in myocarditis, as both experimental and clinical trials have shown. In experimental models the evolution of myocardial damage has been studied, where a parallelism between the histological changes of the myocardial damage and the evolution on the antimyosin uptake has been found. In clinical myocarditis it is difficult to do an histological follow up of the inflammatory process, and therefore the evolution of myocardial damage present in myocarditis is unknown. The antimyosin antibody images allow a non-invasive study of this evolution. OBJECTIVES: a) to study with monoclonal antimyosin antibody-111In, the myocardial damage present regarding the disease evolution in children with suspected clinical diagnosis of myocarditis; b) to evaluate the evolution of the active myocardial damage reflected on the changes on the monoclonal antimyosin antibody-111In uptake. METHODS: A study with monoclonal antimyosin antibody-111In was carried out on 43 children, 16 males and 27 females with a median age of 39 months (SD 48 m; range: 2-167) with suspected diagnosis of acute myocarditis defined as the presence of congestive cardiac failure or severe ventricular arrhythmia with less than 12 months of evolution. The image evaluation was done visually and through the heart to lung ratio. Twenty of these patients were also followed up with antimyosin antibody scan for a period of 19 +/- 9 months, and 3.8 +/- 1.7 studies were performed on them in this time. RESULTS: The prevalence of positive myocardial uptake was 83.72%. There is a negative correlation (r = -0.352; p < 0.02) between the evolution time of the process and the heart to lung ratio: patients studied before two months, have a higher heart to lung ratio and greater prevalence of positive studies than those studied later (heart to lung ratio 2.09 vs 1.74; p = 0.013; 90% vs 69.2%). Of the patients followed up with antimyosin antibody scans, 6 showed a clinical relapse which increased their heart to lung ratio. The other 14 showed an progressive decrease of the heart to lung ratio reaching normality in 14 +/- 6 months. CONCLUSIONS: a) the uptake intensity of monoclonal antimyosin antibody-111In, as a reflection of the myocardial damage, depends on the disease evolution time, as in the first two months is when the major damage happens; b) the uptake intensity slowly decreases, tending to normality around the 14th month, although this evolution may be altered by the appearance of relapses.

Serum levels of basic fibroblast growth factor in acute myocardial infarction.

As it has been reported that basic fibroblast growth factor (bFGF) is a circulating peptide and bFGF gene expression is increased after myocardial ischemia, this study was designed to investigate the serum levels of bFGF in patients with acute myocardial infarction (AMI). Using a bFGF enzyme-linked immunoassay, bFGF levels were determined in venous blood of 15 patients with AMI on admission, at 10 days, and 30 days after infarction, and of 15 age-matched healthy volunteers who were used as controls. bFGF serum levels on admission were similar to normal values (7.48 +/- 2.3 vs 8.14 +/- 2.9 pg/ml). However, they significantly increased (16.82 +/- 3.4 pg/ml; p <0.05) 10 days after the onset of AMI, and at 30 days they returned to baseline (7.07 +/- 2.9 pg/ml). The increased bFGF levels at the second week post AMI suggest that bFGF plays an important role in mediating the development of coronary collateral circulation after myocardial ischemia in humans.

[Doppler echocardiography in hypertrophic myocardiopathy]. / Ecocardiografía-Doppler en la miocardiopatía hipertrófica.

Hypertrophic cardiomiopathy is a peculiar process with different anatomical and functional abnormalities which are present in different degrees in each case. Echocardiography and Doppler techniques have contributed definitively to the knowledge of this process and these procedures are choices for establishing the diagnosis of hypertrophic cardiomyopathy and to evaluate the clinical and morphological diversity of this process consisting of a spectrum of abnormalities with a variable presence in each case. Disproportionate septal hypertrophy is the most frecuent finding but the hypertrophy can involve other segments and different patterns can be present; concentric hypertrophy, apical, involving right ventricle, inverted asymetric, etc. Anterior mitral valve motion can be produced by the interrelation between anatomic factors of the valve, geometry of the outflow tract and physical forces produced by flow changes. Doppler echocardiography allows us to evaluate subaortic obstruction, to define its site, to demonstrate and measure the degree of mitral regurgitation and to carry out intraoperative studies. In hypertrophy cardiomyopathy the pattern of delayed relaxation is the most frequent but patients with severe obstruction and mitral regurgitation can pseudonormalize this pattern and even show restrictive patterns.

[Diagnostic methods in angina pectoris. The Angina Pectoris Study Group of the Ischemic Cardiopathy Section and Coronary Units of the Spanish Society of Cardiology]. / Métodos diagnósticos en la angina de pecho. Grupo de Estudio de Angina de Pecho de la Sección de Cardioplatía Isquémica y Unidades Coronarias de la Sociedad Espanola de Cardilogía.

Diagnosis and risk stratification in angina pectoris is supported on clinical evaluation, rest electrocardiogram, exercise stress test and coronary angiography. Use and timing application of that diagnostic methods depend on coronary artery disease prevalence and on clinical situation. This review describe diagnostic and prognostic value of the tests in angina pectoris.

[Hypertrophic obstructive myocardiopathy complicated by severe mitral insufficiency secondary to rupture of the chordae tendineae]. / Miocardiopatía hipertrófica obstructiva complicada con insuficiencia mitral severa secundaria a rotura de cuerdas tendinosas.

A case of suddenly increasing dyspnea in a patient with hypertrophic obstructive cardiomyopathy is reported. Transesophageal echocardiography showed severe mitral regurgitation secondary to ruptured chordae tendineae. Mitral valve replacement was done, correcting both mitral regurgitation and subaortic gradient. Utility of transesophageal echocardiography in diagnosis and therapeutic options are discussed.