UVB pretreatment of ß-lactoglobulin affects the temperature-induced formation of functional amyloid-like aggregates and promotes oxidative degradation.

Unfolding in combination with or without acid hydrolysis is crucial for the formation of functional amyloid (fibrillar) or amyloid-like (worm-like) ß-lactoglobulin (BLG) aggregates, which can be induced through temperature treatment for several hours at pH 2-4. A preceding conformational destabilization of BLG might affect its aggregation. We investigated ultraviolet (UV) B radiation as conformational perturbing treatment to facilitate temperature-induced protein aggregation. 2-h UVB pretreated BLG (UV-BLG) exhibited an accelerated worm-like aggregation at pH 3.5, while at pH 2 the formation of fibrils was decelerated. The UV-induced conformational destabilization lowered the thermal stability and thus facilitates unfolding during thermal treatment. Thereby, the formation of covalent and non-covalent intermolecular interactions was favored, which promoted assembly of intact proteins resulting in worm-like aggregates. The oxidative degradation of UV-BLG was suggested to alter fibrillation-prone protein regions and thereby impede peptide assembly.

Normobaric Hypoxia Exposure on Substrate Oxidation Pattern: Sex Differences.

CONTEXT: Hypoxic exposure has been associated with a metabolic perturbation that might affect basal energy expenditure (BEE). OBJECTIVE: The aim was to examine the metabolic response during hypoxic exposure of men and women adults. DESIGN: Crossover design with two experimental trials: normoxic and hypoxic exposure. SUBJECTS AND METHODS: Twenty-nine healthy subjects (14 women) participated in (1) control study (NOR), subjected first to normoxic exposure (FiO2 = 20.9%) and (2) after that, to passive normobaric hypoxic exposure study (HYP) (FiO2 = 15%). Respiratory gases and blood glucose samples were recorded every hour in hypoxia chamber (8 points in total), and blood lactate samples were collected at baseline, at 4 and 7 h to exposure. RESULTS: In females, basal energy expenditure was significantly higher at 2h, 4h, 6h and 7h compared with NOR group. Also, BEE was lower in females compared with men from 2h of hypoxia exposure. In the HYP group the blood lactate concentration increased significantly at 4h and 7 h relative to NOR group (P < 0.05) in males. CONCLUSION: An exposure to moderate normobaric hypoxia did not alter metabolic response, but induced a different response on substrate oxidation in adults men and women.

Toxic Metamorphosis-How Changes from Lysosomal to Cytosolic pH Modify the Alpha-Synuclein Aggregation Pattern.

Alpha-synuclein (aSyn) is a cytosolic, aggregation-prone protein that is associated with neurodegenerative disorders like Parkinson's disease. Interestingly, the protein can appear in different conformations, including monomeric and oligomeric forms as well as amyloid fibrils. Its individual structural constituents seem to be dependent on various factors and the composition of the respective cellular surroundings. Although under physiological conditions, most aSyn is found in the cytosol and synapses of neurons, aSyn can also be found in lysosomal compartments, where it gets degraded. We here compare the assembly speed, morphology, folding state, and spreading of aSyn at cytosolic pH (pH 7.4) and lysosomal pH (pH 5) using Thioflavin T, transmission electron microscopy, circular dichroism, and Fourier transform infrared spectroscopy. Interestingly, we found substantial differences between aSyn aggregation under neutral and acidic pH conditions, like those present in cytosolic and lysosomal cellular compartments. Also, lysosomal aSyn enriched from an aSyn-overexpressing cell line was able to seed aggregation in a concentration-dependent manner. Moreover, we observed that aSyn aggregates formed under in vitro lysosomal pH (pH 5) conditions were not stable at neutral pH and collapsed into partly soluble aggregates with changed structural characteristics. Our findings have meaningful implications in intracellular toxicity events as well as in lysis procedures for molecular and structural characterization of intracellular aSyn conformers.

Measurement of length distribution of beta-lactoglobulin fibrils by multiwavelength analytical ultracentrifugation.

The whey protein beta-lactoglobulin is the building block of amyloid fibrils which exhibit a great potential in various applications. These include stabilization of gels or emulsions. During biotechnological processing, high shear forces lead to fragmentation of fibrils and therefore to smaller fibril lengths. To provide insight into such processes, pure straight amyloid fibril dispersions (prepared at pH 2) were produced and sheared using the rotor stator setup of an Ultra Turrax. In the first part of this work, the sedimentation properties of fragmented amyloid fibrils sheared at different stress levels were analyzed with mulitwavelength analytical ultracentrifugation (AUC). Sedimentation data analysis was carried out with the boundary condition that fragmented fibrils were of cylindrical shape, for which frictional properties are known. These results were compared with complementary atomic force microscopy (AFM) measurements. We demonstrate how the sedimentation coefficient distribution from AUC experiments is influenced by the underlying length and diameter distribution of amyloid fibrils.In the second part of this work, we show how to correlate the fibril size reduction kinetics with the applied rotor revolution and the resulting energy density, respectively, using modal values of the sedimentation coefficients obtained from AUC. Remarkably, the determined scaling laws for the size reduction are in agreement with the results for other material systems, such as emulsification processes or the size reduction of graphene oxide sheets.

Protein oxidation during temperature-induced amyloid aggregation of beta-lactoglobulin.

Although the connection between protein oxidation, amyloid aggregation and diseases such as Alzheimer's is well known there is no information on such effects during preparation of beta-lactoglobulin fibrils. Different morphologies of amyloid aggregates of beta-lactoglobulin were prepared by incubation at pH 2 or pH 3.5 for up to 72 h. After 5 h, amyloid aggregates at pH 2 formed typical fibrils, which consisted of peptides. At pH 3.5, the amyloid aggregates were worm-like and consisted of intact protein. After 72 h, the building blocks at both pH values changed towards smaller peptides. The apparent tyrosine oxidation reached a maximum after 5 h at both pH values, whereas N-formylkynurenine and carbonyls increased continuously during 72 h. In case amyloid structures are used as edible material, the health related effects caused by protein oxidation needs to be considered.

Efecto ergogénico de la ingesta de fosfato sódico en sujetos físicamente activos / Ergogenic effect of sodium phosphate intake in physically active subjects

Este estudio pretende evaluar los efectos de la ingesta de fosfato sódico a corto plazo, sobre la composición corporal, serie roja y parámetros ergoespirométricos máximos y submáximos. A una muestra de 20 sujetos físicamente activos, separados en dos grupos, se les suministró fosfato sódico durante 7 días (50 mg/kg masa magra) o placebo. Ambos grupos realizaron una prueba de esfuerzo incremental máxima en cicloergómetro, siguiendo el protocolo Fatmax, se les determinó la composición corporal y se les realizó un hemograma antes y después de la suplementación. En el grupo experimental, se observó una disminución en el peso e índice de masa corporal (IMC), un aumento en la potencia máxima alcanzada y una mejor eficiencia energética en la zona Fatmax. No se observaron cambios en parámetros hematológicos. Estos resultados pueden atribuir un efecto ergogénico al fosfato sódico en actividades aeróbicas y aquellas donde el peso corporal influya en el rendimiento (AU)

This study aims to evaluate the effects of short-term sodium phosphate intake upon body composition, haemogram, maximal ergospirometer parameters and submaximal ones in the maximal fat oxidation zone (Fatmax). 20 active subjects participated in this study randomly divided into two groups: The experimental group which ingested sodium phosphate for 7 days (50 mg/kg lean mass) and the placebo group. Both performed an incremental maximal cycle ergo meter test following the Fatmax protocol, body composition assessment and blood analysis (CBC) before and after the supplementation period. In the experimental group, phosphate supplementation produced a decrease in weight and body mass index (BMI), an increase in maximal power output and it also improved energy efficiency in the Fatmax zone. No changes were observed in the parameters listed in the CBC. These results may attribute an ergogenic effect of sodium phosphate in aerobic activities and sports where body weight is considered to be an important factor for performance (AU)

Effects of regular and abusive intake of alcohol at weekends on physiological parameters in Spanish young.

OBJECTIVES: The aim of this study was to evaluate the effects of excessive intake at weekends, on different parameters in young university students. STUDY DESIGN: Cross sectional, descriptive study. METHODS: A group of 180 subjects were selected (young males between 18 and 22 years old) and were classified into three groups by their alcohol consumption habits: The control group of non-drinkers (ND; n = 60), the group of one day/weekend drinkers (1D/W, n = 60) and the group of two day/weekend drinkers (2D/W, n = 60). An evaluation of the body composition, a spirometry test (FVC, PEF and MVV), a maximal cycle ergometer test (Heart rate, blood pressure, VO2 max, total watts and time test until exhaustion), a blood sample (GOT, Triglycerides, Total Cholesterol, HDL cholesterol, LDL cholesterol and Glucose) were performed. RESULTS: It was observed that 2D/W group presented significantly higher levels than ND in the following parameters: total cholesterol [185.66 (16.06) compared to 154.28 (25.53) mg/dl]; triglycerides [113.66 (22.47) compared to 45.75 (12.76) mg/dl]; systolic blood pressure [130 (9.50) compared to 115 (5.77) mmHg] and waist to hip ratio [0.92 (0.08) compared to 0.84 (0.05)], and 1D/W group also showed significantly higher levels of triglycerides [71.04 (24.31) compared to 45.75 (12.76) mg/dl] than ND. Moreover, it was confirmed that the accumulation of triglycerides in weekend drinkers is influenced by smoking and the lack of physical activity, and that the relationship between alcohol drinking and systolic blood pressure could be modified by smoking. CONCLUSIONS: Young people's abusive intake of alcohol at weekends can cause negative changes in various health parameters, similar to those observed in alcoholics that drink regularly during the week.

Effects of aerobic exercise on urinary estrogens and progestagens in pre and postmenopausal women.

The purpose of this study was to elucidate the effect of 6 months of aerobic exercise on urinary excretion of female steroid hormones in pre and postmenopausal women and to check the basal values of urinary steroid. To this end, 20 premenopausal (age 45.56 ± 4.06 years) and 20 postmenopausal (age 52.27 ± 3.80 years) women, all sedentary, were studied before and after a supervised 6-month exercise training program (at 60-70% of maximal heart rate, 60 min/day, 3 days/week), based on aerobic dance. The exercise included standing on one leg, squatting, walking, and touching their heels. Before and after the program, anthropometric data and VO(2max) were measured and urine samples were collected and analyzed by gas chromatography/mass spectrometry (GC/Q-MS). Both, pre and postmenopausal women, improved their VO(2max) after the aerobic exercise program. Regarding the urinary steroids, on the one hand, important differences were observed between urinary estrogens and progestagens in pre and postmenopausal women in basal values. Estrone (P < 0.05), pregnanediol (P < 0.01), pregnanetriol (P < 0.05), and estriol (P < 0.01) levels were lower in postmenopausal women than in premenopausal women. On the other hand, the aerobic exercise program did not affect postmenopausal women in the same way as premenopausal women. After the exercise program, no changes in urinary steroid levels were observed in premenopausal women. However, the aerobic exercise program caused an increase in urinary excretion of pregnanediol (P < 0.05) and pregnanetriol (P < 0.05) in postmenopausal women.

The effect of high level tennis matches on urine steroid profiles in professional tennis players.

AIM: Modern day, tennis matches are characterized by shorter and more intense efforts with players enduring great physical and psychological stress. The aim of this study was to evaluate acute changes in the urinary steroid profile of elite tennis players following professional tournament matches. METHODS: Eight professional male tennis players participated in this study. Urine samples were collected before and after tennis matches corresponding to the quarter finals of the Spanish Tennis Masters. RESULTS: After the match, there was a significant fall (P<0.05) in testosterone, androsterone, etiocholanolone, and dehydroepiandrosterone (DHEA). Cortisone increased whereas tetrahydrocortisone (THE) decreased. The anabolic/catabolic hormone ratio also decreased, although only the fall in total suprarenal androgen (TSA)/total corticosteroid (TC) and DHEA/(THE+THF) ratios had a significant decrease (P<0.05). CONCLUSION: These results indicate that a professional tennis match modifies the urine steroid profiles of players, increasing corticosteroid and decreasing androgen excretion in urine, suggesting an important adrenal activation.

Effect of different exercise intensities on oxidative stress markers and antioxidant response in trained cyclists.

Traditionally, physical activity has been associated with beneficial effects on the organism. However, exercise has been shown to increase the production of reactive oxygen species (ROS) to a point that can exceed antioxidant defences, causing oxidative stress. Characteristics of exercise such as the intensity or duration seem to be associated with oxidative damage. The aim of this study was to evaluate the effect of exercise of two different cycling intensities on oxidative stress and antioxidant response in trained males. Twenty male trained cyclists participated in this study. The maximal exercise test consisted of an incremental cycling test until voluntary exhaustion, and the submaximal test was a steady state at 75% VO(2max) for 30 min on a cycloergometer. In maximal exercise test (16+/-4 min of cycling), the results showed an increase in malondialdehyde (MDA) from 40.6+/-2.0 to 45.4+/- 18.4 microM (p<0.05) in plasma and from 0.21+/-0.10 to 0.23+/-0.12 micromol/g Hb (P<0.05) in erythrocytes, also vitamin C increased in plasma from 3.80+/-1.60 to 5.20+/-2.16 mg/mL (P<0.05) and it decreased from 130.5+/-34.7 to 83.4+/-30.0 mg/g hemoglobin (P<0.05) in erythrocytes, whereas there were no changes in vitamin E concentrations. In submaximal exercise, no significant differences were obtained in MDA, vitamin C or vitamin E. In conclusion, short time of high intensity cycling leads to oxidative stress increasing plasma and decreasing erythrocyte vitamin C levels.

Urinary steroid profile after the completion of concentric and concentric/eccentric trials with the same total workload.

High intensity strength training causes changes in steroid hormone concentrations. This could be altered by the muscular contraction type: eccentric or concentric. The aim of this study was to compare the effect of the completion of a short concentric (CON) and concentric/eccentric (CON/ECC) trial on the urinary steroid profile, both with the same total work. 18 males performed the trials on an isokinetic dynamometer (BIODEX III) exercising quadriceps muscles, right and left, on different days. Trial 1 (CON): 4 x 10 Concentric knee extension + relax knee flexion, speed 600/second; rest 90 seconds between each series and 4 minutes between each leg exercise. Trial 2 (CON/ECC): 4 x 5 concentric knee extension + Eccentric knee flexion under similar conditions. Urine samples were taken before the exercise and one hour after finishing it. Androsterone, Etiocholanolone, DHEA, Androstenedione, Testosterone, Epitestosterone, Dehydrotestosterone, Estrone, B-Estradiol, Tetrahydrocortisone, Tetrahydrocortisol, Cortisone and Cortisol (free, glucoconjugated and sulfoconjugated) urinary values were determined using gas chromatography/mass spectrometry techniques. No significant differences were noted in Total Work and Average Peak Torque, although Maximum Peak Torque in the CON/ECC trial was higher than in the CON trial. These results demonstrate no changes in the steroid profile before and after trials, or when comparing CON to CON/ECC trials. The data suggest that eccentric contractions do not cause hormonal changes different to the ones produced by concentric contractions, when they are performed in strength short trials with the same total workload.

Perfil esteroideo urinario tras la realización de una sesión de ejercicio concéntrico y otra concéntrico/excéntrico con similar carga de trabajo total / Urinary steroid profile after the completion of concentric and concentric/eccentric trials with the same total workload

High intensity strength training causes changes in steroid hormone concentrations.This could be altered by the muscular contraction type: eccentric or concentric.The aim of this study was to compare the effect of the completion of a short concentric(CON) and concentric/eccentric (CON/ECC) trial on the urinary steroidprofile, both with the same total work. 18 males performed the trials on an isokineticdynamometer (BIODEX III) exercising quadriceps muscles, right and left, on differentdays. Trial 1(CON): 4x10 Concentric knee extension + relax knee flexion,speed 60º/second; rest 90 seconds between each series and 4 minutes between each legexercise. Trial 2(CON/ECC): 4x5 concentric knee extension + Eccentric knee flexionunder similar conditions. Urine samples were taken before the exercise and onehour after finishing it. Androsterone, Etiocholanolone, DHEA, Androstenedione,Testosterone, Epitestosterone, Dehydrotestosterone, Estrone, B-Estradiol, Tetrahydrocortisone,Tetrahydrocortisol, Cortisone and Cortisol (free, glucoconjugated andsulfoconjugated) urinary values were determined using gas chromatography/massspectrometry techniques. No significant differences were noted in Total Work andAverage Peak Torque, although Maximum Peak Torque in the CON/ECC trial washigher than in the CON trial. These results demonstrate no changes in the steroidprofile before and after trials, or when comparing CON to CON/ECC trials. Thedata suggest that eccentric contractions do not cause hormonal changes different tothe ones produced by concentric contractions, when they are performed in strengthshort trials with the same total workload(AU)

El entrenamiento de fuerza de alta intensidad provoca variaciones en la concentración de esteroides. El tipo de contracción muscular, excéntrica o concéntrica, podría ser un factor que la alterase. El objetivo de este estudio fue comparar el efecto de la realización de una sesión corta de ejercicio concéntrico (CON) y otra concéntrica/excéntrica (CON/EXC), con la misma carga de trabajo total, sobre el perfil esteroideo urinario. 18 hombres realizaron dos sesiones de ejercicio de corta duración utilizando una máquina isocinética (BIODEX III) en días diferentes y trabajando los músculos cuádriceps de ambas piernas. La sesión de ejercicio 1 (CON) fue un 4 x 10 rep de extensión concéntrica de rodilla más relajación en el movimiento de flexión, a una velocidad de 60º/segundo y con una recuperación de 90 seg. entre cada serie y 4 minutos entre cada una de las piernas. La sesión de ejercicio 2 (CON/EXC) fue un 4x 5 rep. de extensión concéntrica de rodilla más flexión excéntrica de rodilla, con las mismas condiciones de velocidad y recuperación. Muestras de orina fueron se tomaron antes del ejercicio y una hora después de finalizarlo. Los niveles urinarios (fracción libre, glucoconjugada y sulfoconjugada) de Androsterona, Etiocolanolona, DHEA, Androstenodiona, Testosterona, Epitestosterona, Dehidrotestosterona, Estrona, β-estradiol, Tetrahidrocortisona, Tetrahidrocortisol, Cortisona y Cortisol, se determinaron usando técnicas de cromatografía de gases espectrometría de masas. No se encontraron diferencias significativas en los valores de Trabajo Total y de Pico Torque Medio, aunque los valores de Pico Torque Máximo fueron más alto en el CON/EXC ejercicio que en el CON(AU)

Tampoco se observó ningún cambio en el perfil esteroideo urinario entre antes y después de las sesiones de ejercicio, o comparando las sesiones CON/EXC con la CON. Por tanto, los datos sugieren que las contracciones excéntricas no producen alteraciones hormonales diferentes a las producidas por las contracciones concéntricas, cuando se trata de sesiones de ejercicio de fuerza de corta duración con similar carga de trabajo total(AU)

Evaluation of urinary steroid profile in highly trained cyclists.

AIM: A regular and intense physical exercise significantly modifies hormonal metabolism and there are many reports of a change in urine steroid levels accompanying the practice of sport. The aim of this study was to compare the urinary steroid profile between highly trained cyclists and untrained subjects. METHODS: Urine levels of testosterone (T), epitestosterone (Epit), androstenedione, dehydroepiandrosterone (DHEA), androsterone (A), etiocholanolone (E), beta-estradiol (E2), estrone (E1) and the most abundant urine metabolites of cortisol and cortisone, tetrahydrocortisone (THE) and tetrahydrocortisol (THF) were determined by gas chromatography-mass spectrometry in urine samples from a group of professional cyclists (n=15) submitted to maximum level training for several years and compared with urine samples from sedentary subjects (n=15). The relationships between T/Epit, A+E/ THE, A+E/ THF, DHEA/THE and DHEA/THF were also studied. RESULTS: Cyclists showed lower urine levels of T, A, E and E2 and higher urine levels of androstenedione and E1 than sedentary individuals. A+E/THE and A+E/ THF ratios were higher in sedentary subjects than in cyclists. CONCLUSION: We conclude that cyclists showed a urinary steroid profile different from sedentary individuals, probably due to an adaptation to regular and intense physical training .

El ejercicio físico en agua caliente reduce el dolor pero no el número de puntos sensibles de mujeres con fibromialgia: un ensayo clínico randomizado / Exercise in warm water decreases pain but no the number of tender points in women with fibromyalgia: a randomized controlled trial

Introducción: el propósito de este estudio fue evaluar los efectos de 8 meses de ejercicio físico en agua caliente sobre el dolor de mujeres con fibromialgia (FM). Métodos: treinta y tres pacientes fueron distribuidas aleatoriamente en dos grupos: un grupo de ejercicio (n=17), que realizó 3 sesiones semanales de 60 minutos de ejercicio físico; y un grupo de control (n=16), que continuó realizando sus actividades habituales de la vida diaria. El dolor fue evaluado usando las dimensiones de dolor del Fibromyalgia Impact Questionnarie (FIQ) y Short Form 36 (SF-36). También se evaluó el número de puntos gatillo. Resultados: después de 8 meses de ejercicio físico fueron observadas mejoras significativas en el grupo experimental respecto al grupo de control en las dimensiones de “dolor” del FIQ (9%; p=0.040) y “dolor corporal” del SF-36 (58%; p=0.001). El número de puntos sensibles no mostró ningún cambio significativo. Conclusión: ocho meses de ejercicio físico en agua caliente fue un tratamiento efectivo para reducir el dolor en mujeres con FM. Sin embargo, el programa de ejercicio físico no tuvo efectos positivos en la reducción del número de puntos sensibles (AU)

Introduction: the purpose of this study was to evaluate the effects of 8 months of physical exercise in warm water on pain in female with fibromialgia (FM). Methods: thirty three patients with FM were randomly assigned into two groups: an exercise group (n = 17), who performed 3 weekly sessions for 60 minutes of physical exercise; and a control group (n=16), who continued their habitual daily activities without exercising. The pain was assessed by means of the Fibromyalgia Impact Questionnarie (FIQ) and the Short Form 36 (SF-36). The number of tender points were also assessed. Results: after 8 months of physical exercise significant improvements in the exercise group were observed compared to the control group in the dimensions of “pain” (FIQ) (9%; p=0.040) and “body pain” (SF-36) (58%; p=0.001). The number tender points did not show any significant change. Conclusion: eight months of physical exercise in warm water was an effective treatment to decrease the pain in women with FM. However, the physical exercise program was not effective in decreasing the number of tender points (AU)

Alteración en la excreción urinaria dehormonas esteroideas como consecuencia de larealización de una rutina de ejercicios defuerza / Alteration in the urine excretion of steroids hormones as consequence of the performance of strength session

La producción y excreción de hormonas esteroideas en el organismo se puede ver alterada por múltiples factores, uno de ellos es la realización de ejercicio físico de alta intensidad. En el presente estudio se propone a un grupo de universitarios (n=15), no deportistas, la realización de una rutina de ejercicios de fuerza (al 70-75 por ciento de la fuerza máxima). Se trata de ver la variación del perfil esteroideo urinario (andrógenos, estrógenos y corticosteroides) entre antes y después de la sesión de ejercicio.La cuantificación de la concentración urinaria de las diferentes hormonas se llevó a cabo a través de técnicas cromatográficas y la detección se realizó por espectrometría de masas o de masas/masas. Se analizaron, tras finalizar la sesión, una serie de parámetros hormonales de interés para valorar el estado anabólico o catabólico de los sujetos de estudio. Se observó que la excreción urinaria de Testosterona y Dehidroepiandrosterona descendió significativamente (p<0.05) y la de Tetrahidrocortisol aumentó de forma significativa (p<0.05). Por otro lado, todas las relaciones andrógenos/corticosteroides estudiadas también descendieron de forma significativa. Estos resultados podrían ser reflejo del estado catabólico y de cansancio en el que se encuentran los sujetos una vez finalizada la rutina de ejercicios (AU)