Search

The present study aimed at investigating whether the neuromuscular system behaves differently (in terms of force and muscle activity generation) as a function of the task being performed (i.e. maximal voluntary efforts vs stair negotiation) and the presence of patellofemoral pain (PFP) and possible influences of pain intensity. Thirty-eight women with (n = 19) and without PFP (n = 19) had their knee strength (extension joint torque) measured during maximal voluntary isometric contractions (MVIC) and electromyography (EMG) data recorded during both MVIC and stair ascent tasks, which were performed before and after a loading protocol designed to exacerbate pain symptoms. Women with PFP displayed lower levels of vastus medialis (p = 0.002) and vastus lateralis (p = 0.032) EMG activation during MVIC assessments. Conversely, the PFP group showed higher levels of vastus medialis muscle activity during stair climbing (p = 0.007), which happened exclusively after the loading protocol. Similarly, women with PFP displayed lower knee extensor torque only during the MVIC tests performed after the loading protocol, which was moderately correlated with the increase in self-reported pain (p = 0.041, r = 0.37), whereas the changes in EMG activity during stair ascent were not correlated with changes in pain intensity (p = 0.215, r = 0.12). These results suggest that, in comparison to pain-free controls, women with PFP display lower levels of quadriceps EMG activation during maximal contractions, but higher activation during dynamic tasks (stair ascent). In addition, the moderate association between the decrease in knee extensor torque and increase in self-reported pain indicates that care should be taken by clinicians during quadriceps strength evaluation in women with PFP, as misleading outcomes may emerge if the intensity of knee pain is not considered during screening. Additionally, rehabilitation strategies should focus on both restoring neuromuscular control and increasing muscle strength. [ABSTRACT FROM AUTHOR]

LdtR is a master regulator of gene expression in Liberibacter asiaticus, one of the causative agents of citrus greening disease. LdtR belongs to the MarR-family of transcriptional regulators and it has been linked to the regulation of more than 180 genes in Liberibacter species, most of them gathered in the following Clusters of Orthologous Groups: cell motility, cell wall envelope, energy production, and transcription. Our previous transcriptomic evidence suggested that LdtR is directly involved in the modulation of the zinc uptake system genes (znu) in the closely related L. crescens. In this report, we show that LdtR is involved in the regulation of one of the two encoded zinc uptake mechanisms in L. asiaticus, named znu2. We also show that LdtR binds zinc with higher affinity than benzbromarone, a synthetic effector inhibitory molecule, resulting in the disruption of the LdtR:promoter interactions. Using site-directed mutagenesis, electrophoretic mobility shift assays (EMSAs), and isothermal titration calorimetry, we identified that residues C28 and T43 in LdtR, located in close proximity to the Benz1 pocket, are involved in the interaction with zinc. These results provided new evidence of a high-affinity effector molecule targeting a key player in L. asiaticus’ physiology and complemented our previous findings about the mechanisms of signal transduction in members of the MarR-family. [ABSTRACT FROM AUTHOR]

Sickle cell disease (SCD) is an inherited hemolytic anemia whose pathophysiology is driven by polymerization of the hemoglobin S (Hb S), leading to hemolysis and vaso-occlusive events. Inflammation is a fundamental component in these processes and a continuous inflammatory stimulus can lead to tissue damages. Thus, pro-resolving pathways emerge in order to restore the homeostasis. For example there is the annexin A1 (ANXA1), an endogenous anti-inflammatory protein involved in reducing neutrophil-endothelial interactions, accelerating neutrophil apoptosis and stimulating macrophage efferocytosis. We investigated the expression of ANXA1 in plasma of SCD patients and its relation with anemic, hemolytic and inflammatory parameters of the disease. Three SCD genotypes were considered: the homozygous inheritance for Hb S (Hb SS) and the association between Hb S and the hemoglobin variants D-Punjab (Hb SD) and C (Hb SC). ANXA1 and proinflammatory cytokines were quantified by ELISA in plasma of SCD patients and control individuals without hemoglobinopathies. Hematological and biochemical parameters were analyzed by flow cytometry and spectrophotometer. The plasma levels of ANXA1 were about three-fold lesser in SCD patients compared to the control group, and within the SCD genotypes the most elevated levels were found in Hb SS individuals (approximately three-fold higher). Proinflammatory cytokines were higher in SCD groups than in the control individuals. Anemic and hemolytic markers were higher in Hb SS and Hb SD genotypes compared to Hb SC patients. White blood cells and platelets count were higher in Hb SS genotype and were positively correlated to ANXA1 levels. We found that ANXA1 is down-regulated and differentially expressed within the SCD genotypes. Its expression seems to depend on the inflammatory, hemolytic and vaso-occlusive characteristics of the diseased. These data may lead to new biological targets for therapeutic intervention in SCD. [ABSTRACT FROM AUTHOR]

Background: High-intensity functional training (HIFT) has become more popular, and the number of practitioners has increased; however, it remains unclear whether perturbations in the immune parameters occur, even after one single bout. Our aim was to examine acute leucocyte, muscle damage, and stress marker responses following a single 'Cindy' workout session, and compare the results between novice and experienced participants. Material and methods: Twenty-three HIFT practitioners (age 31.0 ± 1.0 years) completed the 'Cindy' workout. They were categorized as novice (3–8 months of experience; n = 10) and experienced (≥18 months; n = 13). White blood cell (WBC) count, plasma creatine kinase (CK) activity, blood cortisol level, and lactate concentration were measured. Blood analysis was performed before (pre-ex), immediately after (post-ex), 30 min after (post-30 min), and 24 h after (post-24 h) a single 'Cindy' workout session. Results: WBC count was higher post-ex (6.8 to 11.8x103/μL) and returned to baseline values within post-30 min (p<0.01). Neutrophil (3.3 to 4.5x103/μL) and lymphocyte levels (2.8 to 5.9x103/μL) were higher post-ex and returned to baseline values after post-24 h, yet lymphocytopoenia (2.2x103/μL) was observed at post-30 min (p<0.01). CK increased post-ex (174.9 to 226.7 U.L-1) and remained elevated post-24 h. Cortisol (14.7 to 17.0 μg/dL) and lactate (1.9 to 13.5 mmol.l-1) responses increased post-ex, but only the lactate level was reduced at post-30 min (p<0.01). The experienced participants had higher WBC, lymphocyte, and cortisol concentrations post-ex than the novice ones (p<0.01). Conclusions: A single HIFT session elicited significant acute perturbations in WBC count, stress markers, and muscle tissue, which is like other similar regimens. Importantly, the experienced participants showed greater lymphocyte and cortisol responses than the novice ones. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of different levels of crude cottonseed oil in isoenergetic diets, with or without supplementation of ferrous sulfate, on performance variables, relative weight of organs, and blood parameters of broilers, and on the economic viability of diets in the periods from 1 to 7 and 1 to 21 days of age. A total of 600 male birds of the Ross line were distributed in a completely randomized design in a (4×2) factorial arrangement with eight treatments (0, 2, 4, and 6% cottonseed oil with and without ferrous sulfate), and five replicates. The following variables were studied: feed intake, weight gain, feed conversion, weight of organs, blood parameters, and yield of carcass and cuts at 21 days. No effects of the levels of cottonseed oil were found on the performance of animals aged 1 to 7 days, or on the relative weights of the organs. In this same period, the weight gain, and the relative weights of heart, liver, and intestine of the animals that received ferrous sulfate were decreased, and feed conversion was worsened. In the period from 1 to 21 days, weight gain increased linearly with the increase in the levels of cottonseed oil. Blood parameters were not influenced by the diets. Crude cottonseed oil can be utilized in diets for broilers in the periods from 1 to 7 and 1 to 21 days of age at up to 6% of inclusion, and supplementation with ferrous sulfate is unnecessary if the differences in metabolization of the cottonseed oil are considered, with and without, it during the diet formulation process. [ABSTRACT FROM AUTHOR]