901 research outputs found

    Optimal Control Realizations of Lagrangian Systems with Symmetry

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    A new relation among a class of optimal control systems and Lagrangian systems with symmetry is discussed. It will be shown that a family of solutions of optimal control systems whose control equation are obtained by means of a group action are in correspondence with the solutions of a mechanical Lagrangian system with symmetry. This result also explains the equivalence of the class of Lagrangian systems with symmetry and optimal control problems discussed in \cite{Bl98}, \cite{Bl00}. The explicit realization of this correspondence is obtained by a judicious use of Clebsch variables and Lin constraints, a technique originally developed to provide simple realizations of Lagrangian systems with symmetry. It is noteworthy to point out that this correspondence exchanges the role of state and control variables for control systems with the configuration and Clebsch variables for the corresponding Lagrangian system. These results are illustrated with various simple applications

    ΔNp63α silences a microRNA program to aberrantly initiate a wound healing program that promotes TGFβ-induced metastasis.

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    Primary cancer cell dissemination is a key event during the metastatic cascade, but context-specific determinants of this process remain largely undefined. Multiple reports have suggested that the p53 (TP53) family member p63 (TP63) plays an anti-metastatic role through its minor epithelial isoform containing the N-terminal transactivation domain (TAp63). However, the role and contribution of the major p63 isoform lacking this domain, ΔNp63α, remain largely undefined. Here, we report a distinct and TAp63-independent mechanism by which ΔNp63α-expressing cells within a TGFβ-rich microenvironment become positively selected for metastatic dissemination. Orthotopic transplantation of ΔNp63α-expressing human osteosarcoma cells into athymic mice resulted in larger and more frequent lung metastases than transplantation of control cells. Mechanistic investigations revealed that ΔNp63α repressed miR-527 and miR-665, leading to the upregulation of two TGFβ effectors, SMAD4 and TβRII (TGFBR2). Furthermore, we provide evidence that this mechanism reflects a fundamental role for ΔNp63α in the normal wound healing response. We show that ΔNp63α-mediated repression of miR-527/665 controls a TGFβ-dependent signaling node that switches off anti-migratory miR-198 by suppressing the expression of the regulatory factor, KSRP (KHSRP). Collectively, these findings reveal that a novel microRNA network involved in the regulation of physiological wound healing responses is hijacked and suppressed by tumor cells to promote metastatic dissemination

    Insulin Resistance and Obesity in Mexican Youth

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    Purpose: Although research shows that prevalence rates of insulin resistance (IR) is increasing in children, little is known about the impact of obesity in IR in Mexican youth. This study investigated the association between overweight, obesity, and insulin resistance in Mexican adolescents. Methods: Data were collected from 448 adolescents aged 12 to 18 years from a random sample of a high school student population in Durango, Mexico. After fasting overnight, blood samples were obtained from participants. Glucose, insulin, lipid profile, leptin, insulin growth factor, growth hormone, cortisol, TNF-alpha, and C-reactive protein were determined in serum. Body Mass Index (BMI) was calculated using CDC parameters. Fat mass was determined using a bioelectrical impedance analyzer. THE HOMA index was used to calculate IR and a Keskin diagnosis value of 3.1 was considered. Statistical analyses were conducted. Results: The mean age of the sample was 15.44 years and a majority was female (61.4%). Prevalence of overweight and obesity was 31.9%. The BMI mean was slightly higher in females (65.5) than in males (61.1) (p \u3e0.05). Females had a greater mean of body fat percentage (31.9) than males (20.2) (p\u3c 0.05). Prevalence of resistance to insulin by HOMA-IR was 14.4% with no statistically significant gender differences. The IR mean was higher in adolescents with greater BMI (≥85th percentile) than those with low and normal BMI (\u3c85th percentile) (p \u3c0.05). Adolescents with high IR levels (≥3.1) had higher mean values of corporal fat (37.69%) and BMI (89.76) than those with lower IR levels (\u3c3.1) and lower corporal fat and BMI values (26.4%3 and 61.67, respectively). Conclusions: The significant association found between obesity and insulin resistance in Mexican adolescents suggests a greater risk for the development of degenerative disease in this young population during adulthood. Public health programs among Mexican adolescents are essential to prevent obesity and IR related consequences

    Weaker HLA footprints on HIV in the unique and highly genetically admixed host population of Mexico

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    HIV circumvents HLA class I-restricted CD8+ T-cell responses through selection of escape mutations that leave characteristic mutational “footprints,” also known as HLA-associated polymorphisms (HAPs), on HIV sequences at the population level. While many HLA footprints are universal across HIV subtypes and human populations, others can be region specific as a result of the unique immunogenetic background of each host population. Using a published probabilistic phylogenetically informed model, we compared HAPs in HIV Gag and Pol (PR-RT) in 1,612 subtype B-infected, antiretroviral treatment-naive individuals from Mexico and 1,641 individuals from Canada/United States. A total of 252 HLA class I allele subtypes were represented, including 140 observed in both cohorts, 67 unique to Mexico, and 45 unique to Canada/United States. At the predefined statistical threshold of a q value of <0.2, 358 HAPs (201 in Gag, 157 in PR-RT) were identified in Mexico, while 905 (534 in Gag and 371 in PR-RT) were identified in Canada/United States. HAPs identified in Mexico included both canonical HLA-associated escape pathways and novel associations, in particular with HLA alleles enriched in Amerindian and mestizo populations. Remarkably, HLA footprints on HIV in Mexico were not only fewer but also, on average, significantly weaker than those in Canada/United States, although some exceptions were noted. Moreover, exploratory analyses suggested that the weaker HLA footprint on HIV in Mexico may be due, at least in part, to weaker and/or less reproducible HLA-mediated immune pressures on HIV in this population. The implications of these differences for natural and vaccine-induced anti-HIV immunity merit further investigation

    Application f ionized reactive oxygen species for desinfection of carcasses, table eggs and fertile eggs

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    Primary Audience: Processing Plant Managers, Hatchery Managers SUMMARY We evaluated the effect of ionized reactive oxygen species created using Binary Ionization Technology (BIT) for disinfection of broiler carcasses, table eggs, and treatment of fertile eggs. Previous research has indicated that BIT creates a high concentration of reactive oxygen species (ROS) that lyse bacterial cells on contact. Application of BIT to broiler carcasses that had been intentionally inoculated with 1.58 × 10 6 Salmonella enterica Enteritidis (SE) caused a 1 to 3 log reduction in recoverable SE, depending on the duration of the treatment. Additionally, after inoculation of table eggs with 6.8 × 10 8 cfu of SE, we recovered SE from 95% fewer eggs following enrichment and found significantly fewer (7.77 and 7.41 log reduction) colony-forming units recovered from eggs treated with BIT compared with nontreated control eggs. We also evaluated whether application of the BIT treatment had any effect on hatchability of broiler breeder eggs to determine whether use of this technology could be feasible in a hatchery environment for disinfection of eggs. There were no significant effects of BIT on the hatchability (of total set) of treated eggs as compared with nontreated control eggs; however, there was a slight numerical increase in hatchability, between 5 and 10% in 2 trials. These data suggest that application of BIT technology to carcasses and table eggs could reduce contamination with pathogens and that the application to fertile eggs may not have effects on hatchability of eggs set

    Gene-environment interaction analysis of redox-related metals and genetic variants with plasma metabolic patterns in a general population from Spain: The Hortega Study

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    Background: Limited studies have evaluated the joint influence of redox-related metals and genetic variation on metabolic pathways. We analyzed the association of 11 metals with metabolic patterns, and the interacting role of candidate genetic variants, in 1145 participants from the Hortega Study, a population-based sample from Spain. Methods: Urine antimony (Sb), arsenic, barium (Ba), cadmium (Cd), chromium (Cr), cobalt (Co), molybdenum (Mo) and vanadium (V), and plasma copper (Cu), selenium (Se) and zinc (Zn) were measured by ICP-MS and AAS, respectively. We summarized 54 plasma metabolites, measured with targeted NMR, by estimating metabolic principal components (mPC). Redox-related SNPs (N = 291) were measured by oligo-ligation assay. Results: In our study, the association with metabolic principal component (mPC) 1 (reflecting non-essential and essential amino acids, including branched chain, and bacterial co-metabolism versus fatty acids and VLDL subclasses) was positive for Se and Zn, but inverse for Cu, arsenobetaine-corrected arsenic (As) and Sb. The association with mPC2 (reflecting essential amino acids, including aromatic, and bacterial co-metabolism) was inverse for Se, Zn and Cd. The association with mPC3 (reflecting LDL subclasses) was positive for Cu, Se and Zn, but inverse for Co. The association for mPC4 (reflecting HDL subclasses) was positive for Sb, but inverse for plasma Zn. These associations were mainly driven by Cu and Sb for mPC1; Se, Zn and Cd for mPC2; Co, Se and Zn for mPC3; and Zn for mPC4. The most SNP-metal interacting genes were NOX1, GSR, GCLC, AGT and REN. Co and Zn showed the highest number of interactions with genetic variants associated to enriched endocrine, cardiovascular and neurological pathways. Conclusions: Exposures to Co, Cu, Se, Zn, As, Cd and Sb were associated with several metabolic patterns involved in chronic disease. Carriers of redox-related variants may have differential susceptibility to metabolic alterations associated to excessive exposure to metals.This work was supported by the Strategic Action for Research in Health sciences [CP12/03080, PI15/00071, PI10/0082, PI13/01848, PI14/00874, PI16/01402, PI21/00506 and PI11/00726], CIBER Fisio patología Obesidad y Nutrición (CIBEROBN) (CIBER-02-08-2009, CB06/03 and CB12/03/30,016), the State Agency for Research (PID2019-108973RB- C21 and C22), the Valencia Government (GRUPOS 03/101; PROMETEO/2009/029 and ACOMP/2013/039, IDI FEDER/2021/072 and GRISOLIAP/2021/119), the Castilla-Leon Government (GRS/279/A/08) and European Network of Excellence Ingenious Hypercare (EPSS-037093) from the European Commission. The Strategic Action for Research in Health sciences, CIBERDEM and CIBEROBN are initiatives from Carlos III Health Institute Madrid and cofunded with European Funds for Regional Development (FEDER). The State Agency for Research and Carlos III Health Institute belong to the Spanish Ministry of Science and Innovation. ADR received the support of a fellowship from “la Caixa” Foundation (ID 100010434) (fellowship code “LCF/BQ/DR19/11740016”). MGP received the support of a fellowship from “la Caixa” Foundation (ID 100010434, fellowship code LCFLCF/BQ/DI18/11660001). The funding bodies had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.S

    Deletion Mutants of VPg Reveal New Cytopathology Determinants in a Picornavirus

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    BACKGROUND: Success of a viral infection requires that each infected cell delivers a sufficient number of infectious particles to allow new rounds of infection. In picornaviruses, viral replication is initiated by the viral polymerase and a viral-coded protein, termed VPg, that primes RNA synthesis. Foot-and-mouth disease virus (FMDV) is exceptional among picornaviruses in that its genome encodes 3 copies of VPg. Why FMDV encodes three VPgs is unknown. METHODOLOGY AND PRINCIPAL FINDINGS: we have constructed four mutant FMDVS that encode only one VPG: either VPg(1), VPg(3), or two chimeric versions containing part of VPg(1) and VPg(3). All mutants, except that encoding only VPg(1), were replication-competent. Unexpectedly, despite being replication-competent, the mutants did not form plaques on BHK-21 cell monolayers. The one-VPg mutant FMDVs released lower amounts of encapsidated viral RNA to the extracellular environment than wild type FMDV, suggesting that deficient plaque formation was associated with insufficient release of infectious progeny. Mutant FMDVs subjected to serial passages in BHK-21 cells regained plaque-forming capacity without modification of the number of copies of VPg. Substitutions in non-structural proteins 2C, 3A and VPg were associated with restoration of plaque formation. Specifically, replacement R55W in 2C was repeatedly found in several mutant viruses that had regained competence in plaque development. The effect of R55W in 2C was to mediate an increase in the extracellular viral RNA release without a detectable increase of total viral RNA that correlated with an enhanced capacity to alter and detach BHK-21 cells from the monolayer, the first stage of cell killing. CONCLUSIONS: The results link the VPg copies in the FMDV genome with the cytopathology capacity of the virus, and have unveiled yet another function of 2C: modulation of picornavirus cell-to-cell transmission. Implications for picornaviruses pathogenesis are discussed

    The use of digital pathology and image analysis in clinical trials

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    Digital pathology and image analysis potentially provide greater accuracy, reproducibility and standardisation of pathology‐based trial entry criteria and endpoints, alongside extracting new insights from both existing and novel features. Image analysis has great potential to identify, extract and quantify features in greater detail in comparison to pathologist assessment, which may produce improved prediction models or perform tasks beyond manual capability. In this article, we provide an overview of the utility of such technologies in clinical trials and provide a discussion of the potential applications, current challenges, limitations and remaining unanswered questions that require addressing prior to routine adoption in such studies. We reiterate the value of central review of pathology in clinical trials, and discuss inherent logistical, cost and performance advantages of using a digital approach. The current and emerging regulatory landscape is outlined. The role of digital platforms and remote learning to improve the training and performance of clinical trial pathologists is discussed. The impact of image analysis on quantitative tissue morphometrics in key areas such as standardisation of immunohistochemical stain interpretation, assessment of tumour cellularity prior to molecular analytical applications and the assessment of novel histological features is described. The standardisation of digital image production, establishment of criteria for digital pathology use in pre‐clinical and clinical studies, establishment of performance criteria for image analysis algorithms and liaison with regulatory bodies to facilitate incorporation of image analysis applications into clinical practice are key issues to be addressed to improve digital pathology incorporation into clinical trials

    Early mobilization in the critical care unit: A review of adult and pediatric literature.

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    Early mobilization of critically ill patients is beneficial, suggesting that it should be incorporated into daily clinical practice. Early passive, active, and combined progressive mobilizations can be safely initiated in intensive care units (ICUs). Adult patients receiving early mobilization have fewer ventilator-dependent days, shorter ICU and hospital stays, and better functional outcomes. Pediatric ICU data are limited, but recent studies also suggest that early mobilization is achievable without increasing patient risk. In this review, we provide a current and comprehensive appraisal of ICU mobilization techniques in both adult and pediatric critically ill patients. Contraindications and perceived barriers to early mobilization, including cost and health care provider views, are identified. Methods of overcoming barriers to early mobilization and enhancing sustainability of mobilization programs are discussed. Optimization of patient outcomes will require further studies on mobilization timing and intensity, particularly within specific ICU populations
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