Weights in the balance: jasmonic acid and salicylic acid signaling in root-biotroph interactions.

Work on the interaction of aerial plant parts with pathogens has identified the signaling molecules jasmonic acid (JA) and salicylic acid (SA) as important players in induced defense of the plant against invading organisms. Much less is known about the role of JA and SA signaling in root infection. Recent progress has been made in research on plant interactions with biotrophic mutualists and parasites that exclusively associate with roots, namely arbuscular mycorrhizal and rhizobial symbioses on one hand and nematode and parasitic plant interactions on the other hand. Here, we review these recent advances relating JA and SA signaling to specific stages of root colonization and discuss how both signaling molecules contribute to a balance between compatibility and defense in mutualistic as well as parasitic biotroph-root interactions.

Lack of Smad3 signaling leads to impaired skeletal muscle regeneration.

Smad3 is a key intracellular signaling mediator for both transforming growth factor-β and myostatin, two major regulators of skeletal muscle growth. Previous published work has revealed pronounced muscle atrophy together with impaired satellite cell functionality in Smad3-null muscles. In the present study, we have further validated a role for Smad3 signaling in skeletal muscle regeneration. Here, we show that Smad3-null mice had incomplete recovery of muscle weight and myofiber size after muscle injury. Histological/immunohistochemical analysis suggested impaired inflammatory response and reduced number of activated myoblasts during the early stages of muscle regeneration in the tibialis anterior muscle of Smad3-null mice. Nascent myofibers formed after muscle injury were also reduced in number. Moreover, Smad3-null regenerated muscle had decreased oxidative enzyme activity and impaired mitochondrial biogenesis, evident by the downregulation of the gene encoding mitochondrial transcription factor A, a master regulator of mitochondrial biogenesis. Consistent with known Smad3 function, reduced fibrotic tissue formation was also seen in regenerated Smad3-null muscle. In conclusion, Smad3 deficiency leads to impaired muscle regeneration, which underscores an essential role of Smad3 in postnatal myogenesis. Given the negative role of myostatin during muscle regeneration, the increased expression of myostatin observed in Smad3-null muscle may contribute to the regeneration defects.

Abnormal balance between proliferation and apoptotic cell death in fibroblasts derived from keloid lesions.

A new culture model was developed to study the role of proliferation and apoptosis in the etiology of keloids. Fibroblasts were isolated from the superficial, central, and basal regions of six different keloid lesions by using Dulbecco's Modified Eagle Medium containing 10% fetal calf serum as a culture medium. The growth behavior of each fibroblast fraction was examined in short-term and long-term cultures, and the percentage of apoptotic cells was assessed by in situ end labeling of fragmented DNA. The fibroblasts obtained from the superficial and basal regions of keloid tissue showed population doubling times and saturation densities that were similar to those of age-matched normal fibroblasts. In contrast, the fibroblasts from the center of the keloid lesions showed significantly reduced doubling times (25.9 +/- 6.3 hours versus 43.5 +/- 6.3 hours for normal fibroblasts) and reached higher cell densities. In long-term culture, central keloid fibroblasts formed a stratified three-dimensional structure, contracted the self-produced extracellular matrix, and gave rise to nodular cell aggregates, mimicking the formation of keloid tissue. Apoptotic cells were detected in both normal and keloid-derived fibroblasts, but their numbers were twofold higher in normal cells compared with all keloid fibroblasts. To examine whether apoptosis mediates the therapeutic effect of ionizing radiation on keloids, the cells were exposed to gamma rays at a dose of 8 Gy. Under these conditions, a twofold increase in the population of apoptotic cells was detected. These results indicate that the balance between proliferation and apoptosis is impaired in keloid fibroblasts, which could be responsible for the formation of keloid tumors. The results also suggest that keloids contain at least two different fibroblast fractions that vary in growth behavior and extracellular matrix metabolism.

Balance Between Investment Protection and Sustainable Development in BITs: the Example of Switzerland

The objective of this article is to examine how substantive and procedural rights granted to foreign investors by Swiss bits are gradually being balanced with social and environmental provisions. Switzerland has enjoyed a long bit practice, as it signed its first treaty with Tunisia fifty years ago. Swiss bits rely on the post-establishment model and include usual standards of treatment. From 1981, they also systematically provide for a dispute settlement mechanism for disputes arising between an investor and a host State. Since the Switzerland - El Salvador bit in 1994, sustainable development concerns have been expressly inserted in some Swiss bits, as well as in several recent free trade agreements. Provisions on this theme are however far from being systematic in Switzerland's bit practice and essentially remain declaratory in nature. The trend towards wider inclusion of sustainable development provisions in bits still faces several practical and political challenges.

Respiration, metabolic balance, and attention in affective picture processing

The jointly voluntary and involuntary control of respiration, unique among essential physiological processes, the interconnection of breathing with and its influence on the autonomic nervous system, and disease states associated with the interface between psychology and respiration (e.g., anxiety disorders, hyperventilation syndrome, asthma) make the study of the relationship between respiration and emotion both theoretically and clinically of great relevance. However, the respiratory behavior during affective states is not yet completely understood. We studied breathing pattern responses to 13 picture series varying widely in their affective tone in 37 adults (18 men, 19 women, mean age 26). Time and volume parameters were recorded with the LifeShirt system (VivoMetrics Inc., Ventura, California, USA, see image). We also measured end-tidal pCO2 (EtCO2) with a Microcap Handheld Capnograph (Oridion Medical 1987 Ltd., Jerusalem, Israel) to determine if ventilation is in balance with metabolic demands and spontaneous eye-blinking to investigate the link between respiration and attention. At the end of each picture series, the participants reported their subjective feeling in the affective dimensions of pleasantness and arousal. Increasing self-rated arousal was associated with increasing minute ventilation but not with decreases in EtCO2, suggesting that ventilatory changes during picture viewing paralleled variations in metabolic activity. EtCO2 correlated with pleasantness, and eye-blink rate decreased with increasing unpleasantness in line with a negativity bias in attention. Like MV, inspiratory drive (i.e., mean inspiratory flow) increased with arousal. This relationship reflected increases in inspiratory volume rather than shortening of the time parameters. This study confirms that respiratory responses to affective stimuli are organized to a certain degree along the dimensions of pleasantness and arousal. It shows, for the first time, that during picture viewing, ventilatory increases with increasing arousal are in balance with metabolic activity and that inspiratory volume is modulated by arousal. MV emerges as the most reliable respiratory index of self-perceived arousal. Finally, end-tidal pCO2 is slightly lower during processing of negative as compared to positive picture contents, which is proposed to enhance sensory perception and reflect a negativity bias in attention.

Impact of physical activity on energy balance, food intake and choice in normal weight and obese children in the setting of acute social stress: a randomized controlled trial.

BACKGROUND: Psychological stress negatively influences food intake and food choices, thereby contributing to the development of childhood obesity. Physical activity can also moderate eating behavior and influence calorie intake. However, it is unknown if acute physical activity influences food intake and overall energy balance after acute stress exposure in children. We therefore investigated the impact of acute physical activity on overall energy balance (food intake minus energy expenditure), food intake, and choice in the setting of acute social stress in normal weight (NW) and overweight/obese (OW/OB) children as well as the impact of psychological risk factors. METHOD: After receiving written consent from their parents, 26 NW (BMI < 90(th) percentile) and 24 7-to 11-year-old OW (n = 5)/OB (n = 19, BMI ≥ 90(th) percentile) children were randomly allocated using computer-generated numbers (1:1, after stratification for weight status) to acute moderate physical or to sedentary activity for 30 min. Afterwards, all children were exposed to an acute social stressor. Children and their parents completed self-report questionnaires. At the end of the stressor, children were allowed to eat freely from a range of 12 different foods (6 sweet/6 salty; each of low/high caloric density). Energy balance, food intake/choice and obesity-related psychological risk factors were assessed. RESULTS: Lower overall energy balance (p = 0.019) and a decreased choice of low density salty foods (p < 0.001) in NW children compared with OW/OB children was found after acute moderate physical activity but not sedentary activity. Independent of their allocation, OW/OB children ate more high density salty foods (104 kcal (34 to 173), p = 0.004) following stress. They scored higher on impulsive behavior (p = 0.005), restrained eating (p < 0.001) and parental corporal punishment (p = 0.03), but these psychological factors were not related to stress-induced food intake/choice. Positive parenting tended to be related to lower intake of sweet high density food (-132 kcal, -277 to 2, p = 0.054). CONCLUSIONS: In the setting of stress, acute moderate physical activity can address energy balance in children, a benefit which is especially pronounced in the OW/OB. Positive parenting may act as a protective factor preventing stress-induced eating of comfort food. TRIAL REGISTRATION: clinicaltrials.gov NCT01693926 The study was a pilot study of a project funded by the Swiss National Science Foundation (CRSII3_147673).

Avaliacao dos resultados cirurgicos com a tecnica da resseccao do musculo de Muller-conjuntiva no tratamento da blefaroptose. [Evaluation of the surgery results of Muller's muscle-conjunctival resection in the treatment of blepharoptosis]

OBJECTIVE: To evaluate the results of Muller's muscle-conjunctival resection for correction of blepharoptosis and to discuss the advantages of this procedure. METHODS: 38 patients (39 eyelids) were submitted to Muller's muscle-conjunctival resection. Blepharoptosis varied from 1.0 mm to 3.0 mm (mean: 2.0 mm). The amount of eyelid elevation produced by phenylephrine guided the amount of tissue to be resected. RESULT: 33 eyelids (85%) treated with this procedure were cosmetically acceptable. CONCLUSIONS: Muller's muscle-conjunctival resection procedure is a relatively simple technique for blepharoptosis, with good levator function and positive 10% phenylephrine test. The advantages are: preservation of tarsus and predictable results.

Ubiquitylation and control of renal na+ balance and blood pressure.

Ubiquitylation is crucial for regulating numerous cellular functions. In the kidney, ubiquitylation regulates the epithelial Na(+) channel ENaC. The importance of this process is highlighted in Liddle's syndrome, where mutations interfere with ENaC ubiquitylation, resulting in constitutive Na(+) reabsorption and hypertension. There is emerging evidence that NCC, involved in hypertensive diseases, is also regulated by ubiquitylation. Here, we discuss the current knowledge and recent findings in this field.

Mice carrying ubiquitin-specific protease 2 (Usp2) gene inactivation maintain normal sodium balance and blood pressure.

Ubiquitylation plays an important role in the control of Na⁺ homeostasis by the kidney. It is well established that the epithelial Na⁺ channel ENaC is regulated by the ubiquitin-protein ligase NEDD4-2, limiting ENaC cell surface expression and activity. Ubiquitylation can be reversed by the action of deubiquitylating enzymes (DUBs). One such DUB, USP2-45, was identified previously as an aldosterone-induced protein in the kidney and is also a circadian output gene. In heterologous expression systems, USP2-45 binds to ENaC, deubiquitylates it, and enhances channel density and activity at the cell surface. Because the role of USP2-45 in renal Na⁺ transport had not been studied in vivo, we investigated here the effect of Usp2 gene inactivation in this process. We demonstrate first that USP2-45 protein has a rhythmic expression with a peak at ZT12. Usp2-KO mice did not show any differences from wild-type littermates with respect to the diurnal control of Na⁺ or K⁺ urinary excretion and plasma levels either on a standard diet or after acute and chronic changes to low- and high-Na⁺ diets, respectively. Moreover, they had similar aldosterone levels on either a low- or high-Na⁺ diet. Blood pressure measurements using telemetry did not reveal variations compared with control mice. Usp2-KO mice did not display alterations in expression of genes involved in sodium homeostasis or the ubiquitin system, as evidenced by transcriptome analysis in the kidney. Our data suggest that USP2 does not play a primary role in the control of Na⁺ balance or blood pressure.

Genetic deficiency of tartrate-resistant acid phosphatase associated with skeletal dysplasia, cerebral calcifications and autoimmunity.

Vertebral and metaphyseal dysplasia, spasticity with cerebral calcifications, and strong predisposition to autoimmune diseases are the hallmarks of the genetic disorder spondyloenchondrodysplasia. We mapped a locus in five consanguineous families to chromosome 19p13 and identified mutations in ACP5, which encodes tartrate-resistant phosphatase (TRAP), in 14 affected individuals and showed that these mutations abolish enzyme function in the serum and cells of affected individuals. Phosphorylated osteopontin, a protein involved in bone reabsorption and in immune regulation, accumulates in serum, urine and cells cultured from TRAP-deficient individuals. Case-derived dendritic cells exhibit an altered cytokine profile and are more potent than matched control cells in stimulating allogeneic T cell proliferation in mixed lymphocyte reactions. These findings shed new light on the role of osteopontin and its regulation by TRAP in the pathogenesis of common autoimmune disorders.

Effects of an interleukin-15 antagonist on systemic and skeletal alterations in mice with DSS-induced colitis.

Inflammatory bowel diseases are commonly complicated by weight and bone loss. We hypothesized that IL-15, a pro-inflammatory cytokine expressed in colitis and an osteoclastogenic factor, could play a central role in systemic and skeletal complications of inflammatory bowel diseases. We evaluated the effects of an IL-15 antagonist, CRB-15, in mice with chronic colitis induced by oral 2% dextran sulfate sodium for 1 week, followed by another 1% for 2 weeks. During the last 2 weeks, mice were treated daily with CRB-15 or an IgG2a control antibody. Intestinal inflammation, disease severity, and bone parameters were evaluated at days 14 and 21. CRB-15 improved survival, early weight loss, and colitis clinical score, although colon damage and inflammation were prevented in only half the survivors. CRB-15 also delayed loss of femur bone mineral density and trabecular microarchitecture. Bone loss was characterized by decreased bone formation, but increased bone marrow osteoclast progenitors and osteoclast numbers on bone surfaces. CRB-15 prevented the suppression of osteoblastic markers of bone formation, and reduced osteoclast progenitors at day 14, but not later. However, by day 21, CRB-15 decreased tumor necrosis factor α and increased IL-10 expression in bone, paralleling a reduction of osteoclasts. These results delineate the role of IL-15 on the systemic and skeletal manifestations of chronic colitis and provide a proof-of-concept for future therapeutic developments.

The Smiling Project: development of a new program for gait and balance training

Introduction: The SMILING project, a multicentric project fundedby the European Union, aims to develop a new gait and balance trainingprogram to prevent falls in older persons. The program includes the"SMILING shoe", an innovative device that generates mechanical perturbationwhile walking by changing the soles' inclination. Induced perturbationschallenge subjects' balance and force them to react to avoidfalls. By training specifically the complex motor reactions used to maintainbalance when walking on irregular ground, the program will improvesubjects' ability to react in situation of unsteadiness and reduce theirrisk of falling. Methods: The program will be evaluated in a multicentric,cross-over randomized controlled trial. Overall, 112 subjects (aged≥65 years, ≥1 falls, POMA score 22-26/28) will be enrolled. Subjectswill be randomised in 2 groups: group A begin the training with active"SMILING shoes", group B with inactive dummy shoes. After 4 weeksof training, group A and B will exchange the shoes. Supervised trainingsessions (30 minutes twice a week for 8 weeks) include walkingtasks of progressive difficulties.To avoid a learning effect, "SMILINGshoes" perturbations will be generated in a non-linear and chaotic way.Gait performance, fear of falling, and acceptability of the program willbe assessed. Conclusion: The SMILING program is an innovative interventionfor falls prevention in older persons based on gait and balancetraining using chaotic perturbations. Because of the easy use of the"SMILING shoes", this program could be used in various settings, suchas geriatric clinics or at home.

Role of Na+-K+-ATPase in insulin-induced lactate release by skeletal muscle.

Hyperinsulinemia increases lactate release by various organs and tissues. Whereas it has been shown that aerobic glycolysis is linked to Na+-K+-ATPase activity, we hypothesized that stimulation by insulin of skeletal muscle Na+-K+-ATPase is responsible for increased muscle lactate production. To test this hypothesis, we assessed muscle lactate release in healthy volunteers from the [13C]lactate concentration in the effluent dialysates of microdialysis probes inserted into the tibialis anterior muscles on both sides and infused with solutions containing 5 mmol/l [U-13C]glucose. On one side, the microdialysis probe was intermittently infused with the same solution additioned with 2.10(-5) M ouabain. In the basal state, [13C]lactate concentration in the dialysate was not affected by ouabain. During a euglycemic-hyperinsulinemic clamp, [13C]lactate concentration increased by 135% in the dialysate without ouabain, and this stimulation was nearly entirely reversed by ouabain (56% inhibition compared with values in the dialysate collected from the contralateral probe). These data indicate that insulin stimulates muscle lactate release by activating Na+-K+-ATPase in healthy humans.

The stationary distribution of a continuously varying strategy in a class-structured population under mutation-selection-drift balance.

Many traits and/or strategies expressed by organisms are quantitative phenotypes. Because populations are of finite size and genomes are subject to mutations, these continuously varying phenotypes are under the joint pressure of mutation, natural selection and random genetic drift. This article derives the stationary distribution for such a phenotype under a mutation-selection-drift balance in a class-structured population allowing for demographically varying class sizes and/or changing environmental conditions. The salient feature of the stationary distribution is that it can be entirely characterized in terms of the average size of the gene pool and Hamilton's inclusive fitness effect. The exploration of the phenotypic space varies exponentially with the cumulative inclusive fitness effect over state space, which determines an adaptive landscape. The peaks of the landscapes are those phenotypes that are candidate evolutionary stable strategies and can be determined by standard phenotypic selection gradient methods (e.g. evolutionary game theory, kin selection theory, adaptive dynamics). The curvature of the stationary distribution provides a measure of the stability by convergence of candidate evolutionary stable strategies, and it is evaluated explicitly for two biological scenarios: first, a coordination game, which illustrates that, for a multipeaked adaptive landscape, stochastically stable strategies can be singled out by letting the size of the gene pool grow large; second, a sex-allocation game for diploids and haplo-diploids, which suggests that the equilibrium sex ratio follows a Beta distribution with parameters depending on the features of the genetic system.

Inducing effect of skeletal muscle extracts on the appearance of calbindin-immunoreactive dorsal root ganglion cells in culture.

Calbindin D-28k is a calcium-binding protein which is not expressed by dorsal root ganglion cells cultured from 6-day-old (E6) chick embryos. When soluble muscle extracts from embryos at E11, E18 or chickens 2 weeks after hatching were added immediately after seeding, dorsal root ganglia cells grown at E6 displayed neuronal subpopulations expressing calbindin immunoreactivity with time; the effect of muscle extract on the percentage of calbindin-immunoreactive dorsal root ganglia cells followed a dose-response curve. When muscle extract was added to cultures after a 3 day delay, the percentage of calbindin-expressing neurons was unchanged. The effect produced by muscle extract and, to a lesser degree, skin extract on the appearance of calbindin-positive neurons was not reproduced by brain or liver extracts while all four exerted a trophic action on cultured neurons. Hence it is assumed that muscle extract contains a factor which produces an inductive effect on the initiation of calbindin-expression by uncommitted subpopulations of sensory neurons rather than a trophic influence on the selective survival of covertly committed neuronal subpopulations. The fact that muscle extract promoted calbindin expression by dorsal root ganglia cells in neuron-enriched as well as in mixed dorsal root ganglion cell cultures indicates that the factor would act directly on sensory neurons rather than indirectly through mediation of non-neuronal cells. Since the active muscular factor was non-dialysable, heat-inactivated, trypsin-sensitive and retained by molecular filters with a cut-off of 30 K, this factor is probably a protein.