98 research outputs found

    A Near-Infrared Cell Tracker Reagent for Multiscopic In Vivo Imaging and Quantification of Leukocyte Immune Responses

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    The complexity of the tumor microenvironment necessitates that cell behavior is studied in a broad, multi-scale context. Although tomographic and microscopy-based far and near infrared fluorescence (NIRF, >650 nm) imaging methods offer high resolution, sensitivity, and depth penetration, there has been a lack of optimized NIRF agents to label and track cells in their native environments at different scales. In this study we labeled mammalian leukocytes with VivoTag 680 (VT680), an amine reactive N-hydroxysuccinimide (NHS) ester of a (benz) indolium-derived far red fluorescent probe. We show that VT680 diffuses into leukocytes within minutes, covalently binds to cellular components, remains internalized for days in vitro and in vivo, and does not transfer fluorescence to adjacent cells. It is biocompatible, keeps cells fully functional, and fluoresces at high intensities. In a tumor model of cytotoxic T lymphocyte (CTL) immunotherapy, we track and quantify VT680-labeled cells longitudinally at the whole-body level with fluorescence-mediated molecular tomography (FMT), within tissues at single cell resolutions by multiphoton and confocal intravital microscopy, and ex vivo by flow cytometry. Thus, this approach is suitable to monitor cells at multiple resolutions in real time in their native environments by NIR-based fluorescence imaging

    Properties of Graphene: A Theoretical Perspective

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    In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

    A Customized Pigmentation SNP Array Identifies a Novel SNP Associated with Melanoma Predisposition in the SLC45A2 Gene

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    As the incidence of Malignant Melanoma (MM) reflects an interaction between skin colour and UV exposure, variations in genes implicated in pigmentation and tanning response to UV may be associated with susceptibility to MM. In this study, 363 SNPs in 65 gene regions belonging to the pigmentation pathway have been successfully genotyped using a SNP array. Five hundred and ninety MM cases and 507 controls were analyzed in a discovery phase I. Ten candidate SNPs based on a p-value threshold of 0.01 were identified. Two of them, rs35414 (SLC45A2) and rs2069398 (SILV/CKD2), were statistically significant after conservative Bonferroni correction. The best six SNPs were further tested in an independent Spanish series (624 MM cases and 789 controls). A novel SNP located on the SLC45A2 gene (rs35414) was found to be significantly associated with melanoma in both phase I and phase II (P<0.0001). None of the other five SNPs were replicated in this second phase of the study. However, three SNPs in TYR, SILV/CDK2 and ADAMTS20 genes (rs17793678, rs2069398 and rs1510521 respectively) had an overall p-value<0.05 when considering the whole DNA collection (1214 MM cases and 1296 controls). Both the SLC45A2 and the SILV/CDK2 variants behave as protective alleles, while the TYR and ADAMTS20 variants seem to function as risk alleles. Cumulative effects were detected when these four variants were considered together. Furthermore, individuals carrying two or more mutations in MC1R, a well-known low penetrance melanoma-predisposing gene, had a decreased MM risk if concurrently bearing the SLC45A2 protective variant. To our knowledge, this is the largest study on Spanish sporadic MM cases to date

    A polymorphism at the 3'-UTR region of the aromatase gene defines a subgroup of postmenopausal breast cancer patients with poor response to neoadjuvant letrozole

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    <p>Abstract</p> <p>Background</p> <p>Aromatase (<it>CYP19A1</it>) regulates estrogen biosynthesis. Polymorphisms in <it>CYP19A1 </it>have been related to the pathogenesis of breast cancer (BC). Inhibition of aromatase with letrozole constitutes the best option for treating estrogen-dependent BC in postmenopausal women. We evaluate a series of polymorphisms of <it>CYP19A1 </it>and their effect on response to neoadjuvant letrozole in early BC.</p> <p>Methods</p> <p>We analyzed 95 consecutive postmenopausal women with stage II-III ER/PgR [+] BC treated with neoadjuvant letrozole. Response to treatment was measured by radiology at 4<sup>th </sup>month by World Health Organization (WHO) criteria. Three polymorphisms of <it>CYP19A1</it>, one in exon 7 (rs700519) and two in the 3'-UTR region (rs10046 and rs4646) were evaluated on DNA obtained from peripheral blood.</p> <p>Results</p> <p>Thirty-five women (36.8%) achieved a radiological response to letrozole. The histopathological and immunohistochemical parameters, including hormonal receptor status, were not associated with the response to letrozole. Only the genetic variants (AC/AA) of the rs4646 polymorphism were associated with poor response to letrozole (p = 0.03). Eighteen patients (18.9%) reported a progression of the disease. Those patients carrying the genetic variants (AC/AA) of rs4646 presented a lower progression-free survival than the patients homozygous for the reference variant (p = 0.0686). This effect was especially significant in the group of elderly patients not operated after letrozole induction (p = 0.009).</p> <p>Conclusions</p> <p>Our study reveals that the rs4646 polymorphism identifies a subgroup of stage II-III ER/PgR [+] BC patients with poor response to neoadjuvant letrozole and poor prognosis. Testing for the rs4646 polymorphism could be a useful tool in order to orientate the treatment in elderly BC patients.</p

    Use of functional feeding strategies to protect Atlantic salmon from virally-induced inflammatory diseases- mechanistic insights revealed by transcriptomic analysis

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    Over the past few years one of the major concerns in the Atlantic salmon (Salmo salar) farming industry has been the increasing incidence and severity of inflammatory viral diseases. Heart and skeletal muscle inflammation (HSMI) and cardiomyopathy syndrome (CMS) are currently two of the most prevalent viral diseases in commercial Atlantic salmon farms in Norway. Mortality levels in both diseases are generally low but morbidity can be very high with the associated chronic inflammatory response lasting for several months. The consequent reduced growth performance is causing considerable financial impact as HSMI has become increasingly widespread in recent years. The impact of CMS is further exacerbated as it generally affects large fish close to harvest. HSMI lesions occur in the atrium and ventricle in the heart including inflammation and necrosis in epi- endo- and myocardium along with myositis of red skeletal muscle. CMS lesions are commonly observed in the spongy myocardium in the atrium and ventricle of the heart with severe mononuclear inflammation and necrosis. Furthermore, circulatory disturbances associated with reduced cardiac function cause multifocal liver steatosis and necrosis in both diseases. Currently there are no vaccines or any other effective treatments for these diseases and so alternative therapies that could potentially modulate the intensity of the inflammatory response could be crucial to improve the clinical manifestation of the diseases. Therefore, the overall aim of the present study was to evaluate the concept of “clinical nutrition” to improve the clinical symptoms of both viral diseases, HSMI and CMS, through the use of functional feeds formulated with reduced lipid content and increased proportions of anti-inflammatory fatty acids to moderate the apparently uncontrolled inflammatory response in the heart tissue associated with both diseases and also alleviate the secondary hepatic lesions. The experimental work consisted of three major dietary trials in Atlantic salmon in seawater. Two large trials investigated the effects of functional feeds in Atlantic salmon challenged with Atlantic salmon piscine reovirus (ASRV) and piscine myocarditis virus (PMCV), the causal agents of HSMI and CMS, respectively. In both trials, heart transcriptome, heart and liver histopathology and tissue lipid and fatty acid compositions and metabolism were determined post-infection in fish fed with the functional feeds in comparison with fish fed with a standard commercial feed formulation considered as a reference diet. All the functional feeds were formulated to have reduced digestible energy through lower dietary lipid and higher protein contents, and increased levels and proportions of anti-inflammatory long-chain polyunsaturated fatty acids (LC-PUFA), particularly eicosapentaenoic acid (EPA) compared with the reference diets. Histopathology, fatty acid composition and gene expression of heart were assessed over a long time-period of 16 weeks and 14 weeks post-challenge with ASRV and PMCV, respectively. Viral load in heart tissue, hepatic histopathology and fatty acid composition of liver and head kidney along with expression of the genes involved in the eicosanoid and LC-PUFA and eicosanoid biosynthesis pathways were also determined in the HSMI trial. The third trial was a nutritional trial evaluating the effects of dietary digestible energy content on lipid and fatty acid metabolism in salmon fed diets containing graded amounts of lipid. Fatty acid composition of liver and heart were assessed over 12 weeks, along with the hepatic expression of genes of lipid and fatty acid metabolism. The results of this research are presented in four chapters (Chapters 2-5) as four paper manuscripts. The manuscripts/Papers are either published (Chapter 2), in review (Chapter 3 and 4) or drafted for submission (Chapter 5) in appropriate peer-reviewed international journals. Chapter 2 and 3 correspond to the HSMI trial, Chapter 4 to the nutritional trial, and Chapter 5 to the CMS trial. Chapter 2 showed that viral load and histopathology scores were lower in fish fed the functional feeds, especially diet FF1, which displayed better performance. Diet strongly influenced the expression of genes related with the immune and inflammatory responses, with delayed expression in fish fed the functional feeds. Up-regulation of pro-inflammatory genes was correlated with the higher viral load observed at early-mid stages of the disease in fish fed the reference diet (ST). Expression of genes related with the immune response at 16-weeks post challenge reflected the differences in immunomodulation between the functional feeds, with fish fed diet FF1 showing lower expression. Therefore, severity of the heart lesions was correlated with the intensity of the immune response and could be associated with tissue anti-inflammatory LC-PUFA levels. Chapter 3 was focused on liver histopathology, fatty acid composition and LC-PUFA biosynthesis, along with phospholipid fatty acid composition and eicosanoid production in head kidney and heart tissue at early and late stages of ASRV infection. Liver was severely affected by the virus at the beginning of the infection in fish fed the reference ST diet, but the level of lesions were similar in all dietary groups at the end of the trial. Hepatic expression of fatty acyl desaturases was significantly depressed in fish fed the ST diet compare with fish fed the functional feeds despite the lower levels of dietary LC-PUFA in that feed. Thus endogenous production and bioavailability of anti-inflammatory LC-PUFA was potentially enhanced in fish fed the functional feeds. Changes in tissue lipid content, mobilization of fatty acids involved in inflammatory responses and changes in expression of transcription factors and genes involved in eicosanoid biosynthesis were more prominent in head kidney, confirming the important role of this organ in dietary immunomodulation after viral infection. To a lesser extent similar changes were observed in heart tissue, suggesting in situ production of eicosanoids could also be important. The unexpected effects of diet on expression of genes of LC-PUFA biosynthesis were specifically investigated in the trial described in Chapter 4. One aim of this study was to clarify whether dietary lipid content or viral infection was the cause of altered expression of desaturase genes between the different diets. Hepatic expression of other genes of lipid and fatty acid metabolism were also determined to evaluate metabolic changes associated with dietary lipid/energy level. In general, reduction of dietary energy and lipid contents while maintaining similar proportions of dietary fatty acids, led to a general up-regulation of genes involved in lipid biosynthetic pathways. Thus salmon fed lower energy diet showed increased liver expression of fatty acyl desaturases in comparison with fish fed higher energy levels. Heart transcriptomic data in Chapter 5 showed a similar delay in the inflammatory response in fish fed the functional feeds after PCMV infection as observed in the HSMI study. Modulation of inflammatory responses, similar to that previously described after ASRV infection, was also observed in fish fed the functional feeds. However, the differences in the expression of immune related genes and the level of heart lesions were not as prominent at mid-late stages of the disease as in fish fed FF1 in the HSMI trial. The present study demonstrated the beneficial effects of a clinical nutrition approach via functional feeds in two viral inflammatory diseases, HSMI and CMS, currently affecting farmed Atlantic salmon. Dietary immunomodulation increased the availability of anti-inflammatory LC-PUFA and significantly influenced the expression of the genes related with the immune/inflammatory response reducing the level and severity of cardiac and liver lesions and therefore improving the performance of fish suffering the diseases

    International entrepreneurship in SMEs: a study of influencing factors in the textile industry

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s11365-012-0242-3International entrepreneurship is an incipient research area with a rapidly increasing body of knowledge and contributions. An important part of this literature has focused on the analysis of the contributing factors to IE development. From these studies, this work attempts to analyse and validate through an integrative model the effect on this construct in SME of some of the main factors proposed by the literature such as Skills and Competences, Attitude and Proactiveness, Creativity and Innovation, Networking, Employees and Activity. To proceed with this aim, we conducted an empirical research focused on 174 textile SME in Spain. The results obtained confirm a positive relationship between the studied factors and the IE development. 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    Modulation of the endocannabinoids N-Arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) on Executive Functions in Humans

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    Animal studies point to an implication of the endocannabinoid system on executive functions. In humans, several studies have suggested an association between acute or chronic use of exogenous cannabinoids (Δ9-tetrahydrocannabinol) and executive impairments. However, to date, no published reports establish the relationship between endocannabinoids, as biomarkers of the cannabinoid neurotransmission system, and executive functioning in humans. The aim of the present study was to explore the association between circulating levels of plasma endocannabinoids N-arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) and executive functions (decision making, response inhibition and cognitive flexibility) in healthy subjects. One hundred and fifty seven subjects were included and assessed with the Wisconsin Card Sorting Test; Stroop Color and Word Test; and Iowa Gambling Task. All participants were female, aged between 18 and 60 years and spoke Spanish as their first language. Results showed a negative correlation between 2-AG and cognitive flexibility performance (r = −.37; p<.05). A positive correlation was found between AEA concentrations and both cognitive flexibility (r = .59; p<.05) and decision making performance (r = .23; P<.05). There was no significant correlation between either 2-AG (r = −.17) or AEA (r = −.08) concentrations and inhibition response. These results show, in humans, a relevant modulation of the endocannabinoid system on prefrontal-dependent cognitive functioning. The present study might have significant implications for the underlying executive alterations described in some psychiatric disorders currently associated with endocannabinoids deregulation (namely drug abuse/dependence, depression, obesity and eating disorders). Understanding the neurobiology of their dysexecutive profile might certainly contribute to the development of new treatments and pharmacological approaches

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    Cohort Profile: Post-Hospitalisation COVID-19 (PHOSP-COVID) study

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