The influence of visual information on multi-muscle control during quiet stance: a spectral analysis approach

Standing upright requires the coordination of neural drives to a large set of muscles involved in controlling human bipedal stance (i.e., postural muscles). The coordination may deteriorate in situations where standing is performed under more challenging circumstances, such as standing on a smaller base of support or not having adequate visual information. The present study investigates the role of common neural inputs in the organization of multi-muscle synergies and the effects of visual input disruption to this mechanism of control. We analyzed the strength and distribution of correlated neural inputs (measured by intermuscular coherence) to six postural muscles previously recognized as components of synergistic groups involved in the maintenance of the body's vertical positioning. Two experimental conditions were studied: quiet bipedal stance performed with opened eyes (OEs) and closed eyes (CEs). Nine participants stood quietly for 30 s while the activity of the soleus, biceps femoris, lumbar erector spinae, tibialis anterior, rectus femoris, and rectus abdominis muscles were recorded using surface electrodes. Intermuscular (EMG-EMG) coherence was estimated for 12 muscle pairs formed by these muscles, including pairs formed solely by either posterior, anterior, or mixed (one posterior and one anterior) muscles. Intermuscular coherence was only found to be significant for muscle pairs formed solely by either posterior or anterior muscles, and no significant coherence was found for mixed muscle pairs. Significant intermuscular coherence was only found within a distinct frequency interval bounded between 1 and 10 Hz when visual input was available (OEs trials). The strength of correlated neural inputs was similar across muscle pairs located in different joints but executing a similar function (pushing body either backward or forward) suggesting that synergistic postural groups are likely formed based on their functional role instead of their anatomical location. Absence of visual information caused a significant decrease in intermuscular coherence. These findings are consistent with the hypothesis that correlated neural inputs are a mechanism used by the CNS to assemble synergistic muscle groups. Further, this mechanism is affected by interruption of visual input

Beneficial effects of the activation of the Angiotensin-(1-7) MAS receptor in a murine model of adriamycin-induced nephropathy

Angiotensin-(1-7) [Ang-(1-7)] is a biologically active heptapeptide that may counterbalance the physiological actions of angiotensin II (Ang II) within the renin-angiotensin system (RAS). Here, we evaluated whether activation of the Mas receptor with the oral agonist, AVE 0991, would have renoprotective effects in a model of adriamycin (ADR)-induced nephropathy. We also evaluated whether the Mas receptor contributed for the protective effects of treatment with AT1 receptor blockers. ADR (10 mg/kg) induced significant renal injury and dysfunction that was maximal at day 14 after injection. Treatment with the Mas receptor agonist AVE 0991 improved renal function parameters, reduced urinary protein loss and attenuated histological changes. Renoprotection was associated with reduction in urinary levels of TGF-{beta}. Similar renoprotection was observed after treatment with the AT1 receptor antagonist, Losartan. AT1 and Mas receptor mRNA levels dropped after ADR administration and treatment with losartan reestablished the expression of Mas receptor and increased the expression of ACE2. ADR-induced nephropathy was similar in wild type (Mas(+/+)) and Mas knockout (Mas (-/-)) mice, suggesting there was no endogenous role for Mas receptor activation. However, treatment with Losartan was able to reduce renal injury only in Mas(+/+) , but not in Mas (-/-) mice. Therefore, these findings suggest that exogenous activation of the Mas receptor protects from ADR-induced nephropathy and contributes to the beneficial effects of AT1 receptor blockade. Medications which target specifically the ACE2/Ang-(1-7)/Mas axis may offer new therapeutic opportunities to treat human nephropathies

In silico analysis of cytochrome p450 genes involved in the metabolism of diterpenes in Coffea.

Brazil is the largest world producer and exporter of coffee, being also the second largest consumer market. Among the main goals of coffee breeders, studies aiming the improvement of cup quality and plant tolerance to biotic and abiotic stresses have extreme importance. Beverage nutraceutical properties and plant defense mechanisms are directly linked to diterpenes present in the lipid fraction of coffee beans, such as cafestol (Caf ) and caveol (Cav). Many members of P 450 gene family are involved in plant secondary metabolism, including diterpenes synthesis. In order to depict biochemical and genetic aspects of diterpenes byosinthesis, we did an in silico characterization of p450 gene family in Coffea spp., and we also quantified Caf and Cav in coffee fruit tissues for further gene expression studies involving diterpens metabolism. Using keyword and Blast search, 1396 ESTs related to Cyt p450 were selected from the Brazilian Coffee Genome Project (http://www.lge.ibi. unicamp.br/cafe). After assembling, we observed 157 putative unigenes, distributed in 92 contigs and 65 singlets. The contigs were analyzed using BLAST X versus public sequences databases (GenBank and Harvest Coffea), confirming their identity to 91 Cyt P450 genes. Expression profiles were inferred by electronic Northern blot of all contigs, allowing the selection of 7 candidate genes for transcriptional analysis based in fruit cDNA library expression. Caf and Cav were measured using HPLC in two different fruit developmental stages: 90 DAF (Days After Flowering) vs 120 DAF and in fruits (120 DAF) treated with 2?M methyl Jasmonate (MJ). Fruits at 120 DAF had an increase of 42% in Cav and 19% in Caf levels in relation to 90DAF fruits. MJ treatment resulted in samples with an average increase of 18% of Cav and 35% of Caf. RNAs were extracted from these samples for future transcriptional analyses. This study establish a platform for expression analysis of cyt P450 candidate genes in RNA samples from tissues with contrasting accumulation of Cav and Caf. (Texte intégral

Resting spontaneous baroreflex sensitivity and cardiac autonomic control in anabolic androgenic steroid users

OBJECTIVES: Misuse of anabolic androgenic steroids in athletes is a strategy used to enhance strength and skeletal muscle hypertrophy. However, its abuse leads to an imbalance in muscle sympathetic nerve activity, increased vascular resistance, and increased blood pressure. However, the mechanisms underlying these alterations are still unknown. Therefore, we tested whether anabolic androgenic steroids could impair resting baroreflex sensitivity and cardiac sympathovagal control. In addition, we evaluate pulse wave velocity to ascertain the arterial stiffness of large vessels. METHODS: Fourteen male anabolic androgenic steroid users and 12 nonusers were studied. Heart rate, blood pressure, and respiratory rate were recorded. Baroreflex sensitivity was estimated by the sequence method, and cardiac autonomic control by analysis of the R-R interval. Pulse wave velocity was measured using a noninvasive automatic device. RESULTS: Mean spontaneous baroreflex sensitivity, baroreflex sensitivity to activation of the baroreceptors, and baroreflex sensitivity to deactivation of the baroreceptors were significantly lower in users than in nonusers. In the spectral analysis of heart rate variability, high frequency activity was lower, while low frequency activity was higher in users than in nonusers. Moreover, the sympathovagal balance was higher in users. Users showed higher pulse wave velocity than nonusers showing arterial stiffness of large vessels. Single linear regression analysis showed significant correlations between mean blood pressure and baroreflex sensitivity and pulse wave velocity. CONCLUSIONS: Our results provide evidence for lower baroreflex sensitivity and sympathovagal imbalance in anabolic androgenic steroid users. Moreover, anabolic androgenic steroid users showed arterial stiffness. Together, these alterations might be the mechanisms triggering the increased blood pressure in this population

Prevalência e tendências temporais de transtornos mentais necessitando de tratamento de internação na cidade de Porto Alegre: Um estudo de toda a cidade incluindo todas as internações por motivo de saúde mental no sistema público de 2013-2017

Objectives: To investigate the 5-year prevalence of patients admitted to public inpatient care units due to a mental disorder, stratifying them by age group and diagnosis, and to assess trends of admissions over this time period in Porto Alegre. Methods: All admissions to the public mental health care system regulated by the city-owned electronic system Administração Geral dos Hospitais (AGHOS) were included in the analysis. The total population size was obtained by estimations of Fundação de Economia e Estatística (FEE). General information about 5-year prevalence of inpatient admissions, time-series trends e prevalence by age groups and diagnosis were presented. Results: There were 32,608 admissions over the 5-year period analyzed. The overall prevalence of patients was 1.62% among the total population, 0.01% among children, 1.12% among adolescents, 2.28% among adults and 0.93% among the elderly. The most common diagnosis was drug-related, followed by mood, alcohol-related and psychotic disorders. There was a linear trend showing an increase in the number of admissions from 2013 to the midst of 2014, which dropped in 2015. Conclusions: Admissions due to mental disorders are relatively common, mainly among adults and related to drug use and mood disorders. Time trends varied slightly over the 5 years. Prevalence rates in real-world settings might be useful for policymakers interested in planning the public mental health system in large Brazilian cities

IKKβ targeting reduces KRAS-induced lung cancer angiogenesis in vitro and in vivo: A potential anti-angiogenic therapeutic target

Objectives: The ability of tumor cells to drive angiogenesis is an important cancer hallmark that positively correlates with metastatic potential and poor prognosis. Therefore, targeting angiogenesis is a rational therapeutic approach and dissecting proangiogenic pathways is important, particularly for malignancies driven by oncogenic KRAS, which are widespread and lack effective targeted therapies. Based on published studies showing that oncogenic RAS promotes angiogenesis by upregulating the proangiogenic NF-κB target genes IL-8 and VEGF, that NF-κB activation by KRAS requires the IKKβ kinase, and that targeting IKKβ reduces KRAS-induced lung tumor growth in vivo, but has limited effects on cell growth in vitro, we hypothesized that IKKβ targeting would reduce lung tumor growth by inhibiting KRAS-induced angiogenesis. Materials and methods: To test this hypothesis, we targeted IKKβ in KRAS-mutant lung cancer cell lines either by siRNA-mediated transfection or by treatment with Compound A (CmpdA), a highly specific IKKβ inhibitor, and used in vitro and in vivo assays to evaluate angiogenesis. Results and conclusions: Both pharmacological and siRNA-mediated IKKβ targeting in lung cells reduced expression and secretion of NF-κB-regulated proangiogenic factors IL-8 and VEGF. Moreover, conditioned media from IKKβ-targeted lung cells reduced human umbilical vein endothelial cell (HUVEC) migration, invasion and tube formation in vitro. Furthermore, siRNA-mediated IKKβ inhibition reduced xenograft tumor growth and vascularity in vivo. Finally, IKKβ inhibition also affects endothelial cell function in a cancer-independent manner, as IKKβ inhibition reduced pathological retinal angiogenesis in a mouse model of oxygen-induced retinopathy. Taken together, these results provide a novel mechanistic understanding of how the IKKβ pathway affects human lung tumorigenesis, indicating that IKKβ promotes KRAS-induced angiogenesis both by cancer cell-intrinsic and cancer cell-independent mechanisms, which strongly suggests IKKβ inhibition as a promising antiangiogenic approach to be explored for KRAS-induced lung cancer therapy

Exciton swapping in a twisted graphene bilayer as a solid-state realization of a two-brane model

It is shown that exciton swapping between two graphene sheets may occur under specific conditions. A magnetically tunable optical filter is described to demonstrate this new effect. Mathematically, it is shown that two turbostratic graphene layers can be described as a "noncommutative" two-sheeted (2+1)-spacetime thanks to a formalism previously introduced for the study of braneworlds in high energy physics. The Hamiltonian of the model contains a coupling term connecting the two layers which is similar to the coupling existing between two braneworlds at a quantum level. In the present case, this term is related to a K-K' intervalley coupling. In addition, the experimental observation of this effect could be a way to assess the relevance of some theoretical concepts of the braneworld hypothesis.Comment: 15 pages, 3 figures, final version published in European Physical Journal