Non-osteogenic muscle hypertrophy in children with McArdle disease.

INTRODUCTION: McArdle disease is an inborn disorder of muscle glycogen metabolism that produces exercise intolerance, and has been recently associated with low values ​​of lean mass (LM) and bone mineral content (BMC) and density (BMD) in affected adults. Here we aimed to study whether this bone health problem begins in childhood. METHODS: Forty children and adolescents were evaluated: 10 McArdle disease and 30 control children (mean age of both groups, 13 ± 2y). Body composition was evaluated by dual-energy X-ray absorptiometry and creatine kinase (CK) levels were determined in the patients as an estimate of muscle damage. RESULTS: Legs bone mass was significantly lower in patients than in controls (-36% for BMC and -22% for BMD). Moreover, patients had significantly higher LM values in the legs than controls, whereas no difference was found for fat mass. CK levels were positively associated with LM in McArdle patients. A correlation was found between LM and BMD variables in the control group but not in McArdle patients. CONCLUSION: We have identified a 'non-osteogenic muscle hypertrophy' in children with McArdle disease. This phenomenon warrants special attention since low osteogenesis at an early age predicts a high risk for osteoporosis later in life.

Sleep disturbance, obesity, physical fitness and quality of life in older women: EXERNET study group.

OBJECTIVES: To investigate the association between physical fitness, obesity, health related quality of life (HRQoL) and sleep disturbance in 463 community-dwelling older Spanish women (66-91 years of age). STUDY DESIGN: Cross-sectional study. METHOD: Sleep disturbance was assessed with the Jenkins Sleep Scale. Active and sedentary behaviors were recorded by standardized questionnaires. HRQoL was assessed with the EuroQoL-5D. Anthropometric measurements were obtained using standardized techniques. Body fat was measured using bioelectrical impedance. Physical fitness was evaluated by a set of eight tests. RESULTS: Sleep disturbance was reported by 45.1% of women, being associated with higher body mass index (p < 0.05) and waist circumference (p < 0.01). Presence of insomnia was inversely associated with physical fitness. Women in the upper tertile of fitness index had 92.0% lower risk of sleep disturbance as compared to the lower tertile (p = 0.08), while women in the highest tertile of upper body strength had 76.4% lower risk of sleep disturbance as compared to the lower tertile (p < 0.05). Women without sleep disturbance showed better HRQoL. CONCLUSION: Sleep disturbance was associated with central obesity, lower physical fitness and reduced HRQoL. Interventions involving weight management and improvement of physical fitness may contribute to better sleep quality in older women.

Sex differences in kinetic and neuromuscular control during jumping and landing.

In the present study, we analysed the kinetic profile together with the lower limb EMG activation pattern during a countermovement jump and its respective landing phase in males and females. Twenty subjects (10 males and 10 females) took part in the study. One experimental session was conducted in order to record kinetic and electromyographic (EMG) parameters during a countermovement jump (CMJ) and the subsequent landing phase. During the CMJ, males recorded a higher (p<0.001) performance than females in terms of jump height and power production. Stiffness values were lower in males than females due to greater centre of mass displacement during the countermovement (p<0.01). According to the EMG activity, males demonstrated greater (p<0.05) activation during the concentric phase of the jump. However, females revealed a higher co-contraction ratio in the plantar flexors during the push-off phase. During landings males showed higher (p<0.01) peak ground reaction forces (Fpeak), greater (p<0.05) stiffness and a higher maximal displacement of the CoM (p<0.05) than females. EMG analysis revealed greater EMG activity in the tibialis anterior (p<0.05) and rectus femoris (p=0.05) muscles in males. Higher plantar flexor co-activation during landing has also been found in males. Our findings demonstrated different neuromuscular control in males and females during jumping and landing.

Severe hidradenitis suppurativa complicated by renal AA amyloidosis.

Hidradenitis suppurativa (HS) is a chronic, recurrent inflammatory disease affecting the skin folds. Multiple therapeutic options have been proposed for severe cases, but persistent responses are rarely seen. Important complications of HS are uncommon, and usually seen only in severe and unresponsive disease. Amyloid A (AA) amyloidosis is secondary to inflammatory chronic diseases, and is an uncommon complication of dermatological diseases. Only a few cases related with HS have been reported. We report the case of a 37-year-old patient who developed AA amyloidosis secondary to severe HS.

Effects of resistance training with moderate vs heavy loads on muscle mass and strength in the elderly: A meta-analysis.

The purpose of the present study was to perform a meta-analysis to compare the efficacy of heavy (∼80% of one repetition maximum, 1RM) vs light-moderate load (∼45% 1RM) resistance training (RT) programs in inducing strength gains and skeletal muscle hypertrophy in elderly people. To assess the role of training volumes, studies in which training protocols were matched for mechanical work were independently analyzed. In all 15 studies included (448 subjects, age 67.8 years), when comparing heavy with light-moderate loads, strength gains tended to be larger following RT with higher intensities of load, with the resulting total population effect being µ = 0.430 (P = 0.060). Effect sizes were substantially smaller in "work-matched" studies (µ = 0.297, P = 0.003). Training with higher loads also provoked marginally larger gains in muscle size, although the degree of training-induced muscle hypertrophy was generally small (0.056 < µ < 0.136). To conclude, provided a sufficient number of repetitions is performed, RT at lower than traditionally recommended intensities of load may suffice to induce substantial gains in muscle strength in elderly cohorts.

Changes in footprint with resistance exercise.

We aimed to describe the changes in footprint characteristics after 2 types of resistance training sessions performed at different intensities. 18 young subjects (8 men and 10 women) volunteered for the study. All of them performed 2 different resistance training sessions, one with light loads (LS) and the other with heavy loads (HS). Their footprint was recorded and analysed before and after exercise. Lengths, widths, and areas of the footprint (rearfoot, midfoot, and forefoot) were measured. Almost all the variables significantly increased after both sessions. The greatest changes were found in the midfoot (area, LS: 10.4%; HS: 8.1%, P<0.0005; width, LS: 7.5%, P=0.002, and HS: 8%, P<0.0005). However, there were no significant differences between post-exercise data from both sessions. The variable that showed the smallest changes was the foot length (LS: 0.3%, P=0.023; HS: -0.4%, P=0.549). A resistance training session led to increases in most of the dimensions of the footprint, regardless of the magnitude of the loads handled. The greatest changes were found in the midfoot, indicating that the foot was flatter after exercise, and the foot changed more in width than in length.

Muscle morphology and jump performance: gender and intermuscular variability.

AIM: The present study aimed 1) to investigate the gender differences in jump performance and muscle architecture between men and women; and 2) to determine whether the differences in jump performance could be attributed to gender differences in the muscle architecture of the leg extensor muscles. METHODS: Sixty-two subjects volunteered for the study (34 women and 28 men): 19 club-level volleyball players, 20 physical education students, and 23 sedentary individuals. They performed trials of countermovement jumps (CMJ) and the muscle architecture of the vastus lateralis (VL), gastrocnemius medialis (GM), and lateralis (GL) were analyzed at rest by ultrasonography. RESULTS: There were significant differences in jump performance between men and women (CMJ height: 0.388 + or - 0.056 m in men and 0.279 + or - 0.060 m in women, P<0.001). There were also significant gender differences in the VL muscle thickness, while the relative fascicle length was significantly different in the three muscles studied, with longer fascicles in the VL muscle in men and longer fascicles in the gastrocnemii in women. There were significant associations between the VL muscle size and jump performance (r=0.49-0.50, P<0.001), and non linear relationships between muscle size parameters and pennation angles (R(2)=0.67-0.77, P<0.001). CONCLUSIONS: These results confirm that there are gender differences in the muscle architecture of people with a wide physical activity background. The gender differences found in the VL muscle size partially explained the differences in jump performance.

Landing differences between men and women in a maximal vertical jump aptitude test.

AIM: The aim of this study was to analyze the gender differences in the vertical ground reaction forces and the position of the center of gravity during the landing phase of a maximal vertical jump aptitude test. METHODS: The push-off, flight and landing phases of the jumps of 291 males (age = 19.6+/-2.8 years) and 92 females (age = 19.2+/-2.6 years), applicants to a Spanish faculty of sports sciences, were analyzed with a force platform. RESULTS: The greatest differences between men and women were found in the jump performance (women = 25.6+/-3.5 cm; men = 35.5+/-4.5 cm) and second peak vertical force value of the landing phase (women = 5.89+/-2.06 times body weight; men = 7.51 +/-2.38 times body weight), the values being greater in the men's group (P < 0.001). Correlation coefficients showed that the women utilized a different landing pattern than the one utilized by the men. CONCLUSION: Contrary to the authors' expectations, women showed lower second peak vertical force values during the landing. Taking into account only a kinetic point of view, they would have a lower risk of injury during the landing movement of maximal jumps. The lower values in the peak force, the delay of the impact of the calcaneus and the longer path of the center of gravity during the landing phase found in the women's group were related to a landing technique that is different from that of men.

Assessment of power output in jump tests for applicants to a sports sciences degree.

AIM: Our study aimed: 1) to describe the jump performance in a population of male applicants to a Faculty of Sports Sciences, 2) to apply different power equations from the literature to assess their accuracy, and 3) to develop a new regression equation from this population. METHODS: The push off phases of the counter-movement jumps (CMJ) on a force platform of 161 applicants (age: 19+/-2.9 years; weight: 70.4+/-8.3 kg) to a Spanish Faculty of Sports Sciences were recorded and subsequently analyzed. Their hands had to be placed on the hips and the knee angle during the counter movement was not controlled. Each subject had 2 trials to reach a minimum of 29 cm of jump height, and when 2 jumps were performed the best trial was analyzed. Multiple regression analysis was performed to develop a new regression equation. RESULTS: Mean jump height was 34.6+/-4.3 cm, peak vertical force 1 663.9+/-291.1 N and peak power 3524.4+/-562 W. All the equations underestimated power, from 74% (Lewis) to 8% (Sayers). However, there were high and significant correlations between peak power measured on the force platform, and those assessed by the equations. CONCLUSIONS: The results of the present study support the development of power equations for specific populations, to achieve more accurate assessments. The power equation from this study [Power = (62.5 x jump height (cm)) + (50.3 x body mass (kg)) 2184.7] can be used accurately in populations of male physical education students.

Enhanced Formation of alpha-Tocopherol and Highly Oxidized Abietane Diterpenes in Water-Stressed Rosemary Plants.

The lipid-soluble antioxidants alpha-tocopherol and carnosic acid were studied in field-grown rosemary (Rosmarinus officinalis L.) plants subjected to drought. During summer in the Mediterranean region, the predawn water potential decreased to -3 MPa and the relative water content to 42%, which caused a depletion of the maximum diurnal CO(2) assimilation rate by 80%. Meanwhile, the maximum efficiency of photosystem II photochemistry and the chlorophyll content of leaves remained unaltered, indicative of the absence of photooxidative damage. The concentration of alpha-tocopherol increased by 15-fold and that of carotenoids by approximately 26% in response to water stress. Enhanced formation of the highly oxidized abietane diterpenes isorosmanol (by 25%) and dimethyl isorosmanol (by 40%) was observed during the summer as result of the oxidation of carnosic acid, which decreased by 22%. The large amounts of carnosic acid, alpha-tocopherol, and carotenoids present in rosemary leaves might contribute to the prevention of oxidative damage in plants exposed to drought.

Response of abietane diterpenes to stress in Rosmarinus officinalis L.: new insights into the function of diterpenes in plants.

Abietane diterpenes were measured in field-grown rosemary (Rosmarinus officinalis L.) plants throughout the year. Carnosic acid and carnosol, which were present in high amounts (5 and 1 mg/gDW respectively) in rosemary leaves, decreased by ca. 50% during the Mediterranean summer in response to low precipitation, high radiation and high temperature. In contrast, the highly oxidised diterpenes rosmanol, isorosmanol and dimethyl isorosmanol, which are formed from carnosic acid by enzymatic dehydrogenation and the action of activated oxygen, increased in response to such environmental constraints. Collectively, these data support the contention that abietane diterpenes from R. officinalis function as antioxidants that protect biological membranes from oxidative stress. This is especially important during the Mediterranean summer when there is low precipitation, high light and high temperature.

Daily time course of whole-shoot gas exchange rates in two drought-exposed Mediterranean shrubs.

Effects of drought on water relations, whole-shoot gas-exchange characteristics, and pigment and zeatin concentrations were investigated in the Mediterranean shrubs rosemary (Rosmarinus officinalis L.) and lavender (Lavandula stoechas L.). Two-year-old, greenhouse-grown plants were placed in a whole-shoot gas-exchange measurement system and subjected to 10 days of drought, resulting in severe water stress, and then re-watered for 5 days in order to study their recovery. Water stress resulted in a significant decline in maximum whole-shoot net CO2 assimilation rates (An) for both species that was associated with reductions in leaf area and stomatal conductance. Because shoot dark respiration rate (Rd) was less sensitive to water stress than An, shoot Rd/An ratio increased from about 15 to 95% during water stress. No major changes in chlorophyll and carotenoid concentrations of rosemary leaves were observed during the experiments, but chlorophyll and carotenoid concentrations fell significantly in water-stressed lavender leaves. Zeatin concentrations were higher in rosemary leaves than in lavender leaves during water stress. After re-watering, whole-shoot An and Rd rapidly recovered to their pre-drought rates.

A preliminary microbiological assessment of process hygiene of traditional outdoor camel slaughter in Sahrawi refugee camps.

The aim of this study was to investigate the hygiene performance of a camel (Camelus dromedarius) slaughtering process as carried out with the traditional method in the Sahrawi refugee camps located in southwestern Algeria. The camel slaughtering process in this region differs significantly from that carried out in commercial abattoirs. Slaughtering is performed outdoors in desert areas, and dehiding of the carcass is approached via the dorsoventral route rather than the classic ventrodorsal route. Samples were taken from 10 camel carcasses from three different areas: the hide, the carcass meat immediately after dehiding, and the meat after final cutting. Enterobacteriaceae counts (EC) were enumerated employing conventional laboratory techniques. Carcass meat samples resulted in EC below the detection limit more frequently if the hide samples from the same carcass had also EC counts below the detection limit. Because of the low number of trials, the calculation of statistical significance of the results was not possible. Further experimental research is needed in order to validate the results presented in this study. The comparison of the microbiological hygiene performance between dorsal dehiding and traditional ventral dehiding of slaughtered animals could serve to validate the hypothesis of the potential positive impact of the dorsal dehiding method in carcass meat hygiene.

Redox regulation of water stress responses in field-grown plants. Role of hydrogen peroxide and ascorbate.

Abiotic stresses, such as drought, can increase the production of reactive oxygen species (ROS) in plants. An increase in ROS levels can provoke a partial or severe oxidation of cellular components inducing redox status changes, so continuous control of ROS and therefore of their metabolism is decisive under stress conditions. The present work focuses on the contribution of one pro-oxidant, hydrogen peroxide (H(2)O(2)) and one antioxidant, ascorbate (AA) and its redox status, in the control of plant responses to drought-oxidative stress in resistant plants growing in field conditions. After a general introduction to the concept of drought and oxidative stress and its relationship, we describe the role of H(2)O(2) in drought stress responses, emphasizing the importance of studies in H(2)O(2) subcellular localization, needed for a better understanding of its role in plant responses to stress. Although more studies are needed in the study of changes of redox status in plants subjected to stress, the AA pools and its redox status can be indicative of its involvement as a part of cellular mechanisms by which the plant respond to drought-induced oxidative stress. The mechanism of resistance and/or tolerance to drought-oxidative stress is complex, especially when studies are carried out in plants growing in field conditions, where an interaction of stresses occurs. This study sheds light on the mechanisms of plant responses to water-oxidative stress in plants growing in the field.

Kinematics of ankle taping after a training session.

This study aimed to test the effectiveness of ankle taping on the limitation of forced supination during a change of direction, as well as the losses of effectiveness after a 30-minute training session. Fifteen young men with no ankle injury volunteered for the study. The static and dynamic ranges of movement (ROM) were measured before and after a training session. The dynamic measurements were recorded using high-speed 3D photogrammetry. The differences between static and dynamic measures of ankle supination and plantar flexion were significant. The losses of effectiveness during supination and ankle plantar flexion restriction were 42.3 % and 47.6 %, respectively. Ankle taping was effective in restricting the maximal static ROMs before a training session, but the effectiveness decreased after 30 min of training. The present study shows the necessity of performing dynamic ROM analysis of sports techniques involved in the ankle sprain mechanism in order to determine the degree of tape restriction after a training session, because there were differences between static and dynamic ankle ROMs. The lack of effects on the restriction of the dynamic plantar flexion would bring into question the necessity of ankle taping in subjects without previous injuries.

Subcellular compartmentation of the diterpene carnosic acid and its derivatives in the leaves of rosemary.

The potent antioxidant properties of rosemary (Rosmarinus officinalis) extracts have been attributed to its major diterpene, carnosic acid. Carnosic acid has received considerable attention in food science and biomedicine, but little is known about its function in the plant in vivo. We recently found that highly oxidized diterpenes increase in rosemary plants exposed to drought and high light stress as a result of the antioxidant activity of carnosic acid (S. Munné-Bosch, K. Schwarz, L. Alegre [1999] Plant Physiol 121: 1047-1052). To elucidate the significance of the antioxidant function of carnosic acid in vivo we measured the relative amounts of carnosic acid and its metabolites in different compartments of rosemary leaves. Subcellular localization studies show that carnosic acid protects chloroplasts from oxidative stress in vivo by following a highly regulated compartmentation of oxidation products. Carnosic acid scavenges free radicals within the chloroplasts, giving rise to diterpene alcohols, mainly isorosmanol. This oxidation product is O-methylated within the chloroplasts, and the resulting form, 11,12-di-O-methylisorosmanol, is transferred to the plasma membrane. This appears to represent a mechanism of a way out for free radicals from chloroplasts. Carnosic acid also undergoes direct O-methylation within the chloroplasts, and its derived product, 12-O-methylcarnosic acid, accumulates in the plasma membrane. O-methylated diterpenes do not display antioxidant activity, but they may influence the stability of the plasma membrane. This study shows the relevance of the compartmentation of carnosic acid metabolism to the protection of rosemary plants from oxidative stress in vivo.

Changes in carotenoids, tocopherols and diterpenes during drought and recovery, and the biological significance of chlorophyll loss in Rosmarinus officinalis plants.

Two-year-old rosemary (Rosmarinus officinalis L.) plants were subjected to severe stress by exposure to prolonged drought during a Mediterranean summer. Severely stressed plants recovered completely after the autumn rainfalls although the relative water content remained below 35% for 3 months and the chlorophyll content of leaves was reduced by up to 85% during the drought. In severe stress: (i) alpha-tocopherol increased 9-fold per g dry weight and 20-fold per unit of chlorophyll; (ii) lutein and beta-carotene contents decreased on a dry-weight basis, but an 80% increase in lutein and constant levels of beta-carotene were observed on a chlorophyll basis; (iii) there were transient and sustained increases in the de-epoxidation state of the xanthophyll cycle; and (iv) the highly oxidised abietane diterpene isorosmanol increased 8-fold as a result of the oxidation of carnosic acid. With the autumn rainfalls, water status, alpha-tocopherol and violaxanthin recovered first and the levels of photosynthetic pigments and abietane diterpenes increased later. The photoprotection conferred by the xanthophyll cycle and the antioxidant function of tocopherols, lutein and diterpenes may help to avoid irreversible damage in severe drought, making possible the recovery of functional membranes after the autumn rainfalls. Besides, chlorophyll loss reduces the amount of photons absorbed by leaves, which enhances the photoprotective and antioxidant capacity of leaves per amount of photons absorbed, since the ratios of xanthophylls, alpha-tocopherol and abietane diterpenes to chlorophyll increase.

Plant aging increases oxidative stress in chloroplasts.

Aging has received considerable attention in biomedicine, but little is known about the regulatory mechanisms responsible for the aging not associated with senescence in plants. This study provides new insights into the relationship between oxidative stress and plant aging, and points out chloroplasts as one of the target organelles of age-associated oxidative stress in plants. We simultaneously analyzed lipid oxidation, photosynthesis, chlorophyll content, de-epoxidation state of the xanthophyll cycle, and levels of chloroplastic antioxidant defenses such as beta-carotene and alpha-tocopherol in leaves of the same age in 1-, 3- and 7-year-old Cistus clusii Dunal plants growing under Mediterranean field conditions. Enhanced formation of malondialdehyde in leaves (2.7-fold) and chloroplasts (2.8-fold), decreased photosynthetic activity (25%), and lower chlorophyll (ca. 20%) and chloroplastic antioxidant defense levels (ca. 25%-85%) were observed in 7-year-old plants, when compared with 1- and 3-year-old plants. The differences observed, which were associated with plant aging, were only noticeable in mature nonsenescing plants (7-year-old plants). No differences were observed between pre-reproductive (1-year-old plants) and young plants (3-year-old plants). This study shows that from a certain age, oxidative stress increases progressively in chloroplasts as plants age, whereas photosynthesis is reduced. The results indicate that the oxidative stress associated with the aging in plants accumulates progressively in chloroplasts, and that the contribution of oxidative stress to aging increases as plants age.