984 resultados para Eva


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Spatial variability of bias-dependent electrochemical processes on a (La0.5Sr0.5)(2)CoO4 +/- modified (LaxSr1-x)CoO3- surface is studied using first-order reversal curve method in electrochemical strain microscopy (ESM). The oxygen reduction/evolution reaction (ORR/OER) is activated at voltages as low as 3-4 V with respect to bottom electrode. The degree of bias-induced transformation as quantified by ESM hysteresis loop area increases with applied bias. The variability of electrochemical activity is explored using correlation analysis and the ORR/OER is shown to be activated in grains at relatively low biases, but the final reaction rate is relatively small. At the same time, at grain boundaries, the onset of reaction process corresponds to larger voltages, but limiting reactivity is much higher. The reaction mechanism in ESM of mixed electronic-ionic conductor is further analyzed. These studies both establish the framework for probing bias-dependent electrochemical processes in solids and demonstrate rich spectrum of electrochemical transformations underpinning catalytic activity in cobaltites.

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Haematological malignancies (HM) represent over 6% of the total cancer incidence in Europe and affect all ages, ranging between 45% of all cancers in children and 7% in the elderly. Thirty per cent of childhood cancer deaths are due to HM, 8% in the elderly. Their registration presents specific challenges, mainly because HM may transform or progress in the course of the disease into other types of HM. In the context of cancer registration decisions have to be made about classifying subsequent notifications on the same patient as the same tumour (progression), a transformation or a new tumour registration. Allocation of incidence date and method of diagnosis must also be standardised. We developed European Network of Cancer Registries (ENCR) recommendations providing specific advice for cancer registries to use haematology and molecular laboratories as data sources, conserve the original date of incidence in case of change of diagnosis, make provision for recording both the original as well as transformed tumour and to apply precise rules for recording and counting multiple diagnoses. A reference table advising on codes which reflect a potential transformation or a new tumour is included. This work will help to improve comparability of data produced by population-based cancer registries, which are indispensable for aetiological research, health care planning and clinical research, an increasing important area with the application of targeted therapies.

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YKL-40 regulates vascular endothelial growth factors and induces tumor proliferation. We investigated YKL-40 before and after treatment with vorinostat in 31 polycythemia vera (PV) and 16 essential thrombocythemia (ET) patients. Baseline PV patient levels were 2 times higher than in healthy controls (P < 0.0001) and 1.7 times higher than in ET (P = 0.02). A significant correlation between YKL-40 at baseline and neutrophils, CRP, LDH, JAK2V617F and platelets in PV patients was observed, as well as a significantly greater reduction of YKL-40 levels in PV patients responding to therapy. YKL-40 might be a novel marker of disease burden and progression in myeloproliferative neoplasms.

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We describe, for the first time, quantification of in-skin swelling and fluid uptake by hydrogel-forming microneedle (MN) arrays and skin barrier recovery in human volunteers. Such MN arrays, prepared from aqueous blends of hydrolyzed poly(methylvinylether/maleic anhydride) (15%, w/w) and the cross-linker poly(ethyleneglycol) 10,000 Da (7.5%, w/w), were inserted into the skin of human volunteers (n = 15) to depths of approximately 300 μm by gentle hand pressure. The MN arrays swelled in skin, taking up skin interstitial fluid, such that their mass had increased by approximately 30% after 6 h in skin. Importantly, however, skin barrier function recovered within 24 h after MN removal, regardless of how long the MN had been in skin or how much their volume had increased with swelling. Further research on closure of MN-induced micropores is required because transepidermal water loss measurements suggested micropore closure, whereas optical coherence tomography indicated that MN-induced micropores had not closed over, even 24 h after MN had been removed. There were no complaints of skin reactions, adverse events, or strong views against MN use by any of the volunteers. Only some minor erythema was noted after patch removal, although this always resolved within 48 h, and no adverse events were present on follow-up.

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Purpose: To investigate, for the first time, the influence of pharmacist intervention and the use of a patient information leaflet on self-application of hydrogel-forming microneedle arrays by human volunteers without the aid of an applicator device.
Methods: A patient information leaflet was drafted and pharmacist counselling strategy devised. Twenty human volunteers applied 11 × 11 arrays of 400 μm hydrogel-forming microneedle arrays to their own skin following the instructions provided. Skin barrier function disruption was assessed using transepidermal water loss measurements and optical coherence tomography and results compared to those obtained when more experienced researchers applied the microneedles to the volunteers or themselves.
Results: Volunteer self-application of the 400 μm microneedle design resulted in an approximately 30% increase in skin transepidermal water loss, which was not significantly different from that seen with self-application by the more experienced researchers or application to the volunteers. Use of optical coherence tomography showed that self-application of microneedles of the same density (400 μm, 600 μm and 900 μm) led to percentage penetration depths of approximately 75%, 70% and 60%, respectively, though the diameter of the micropores created remained quite constant at approximately 200 μm. Transepidermal water loss progressively increased with increasing height of the applied microneedles and this data, like that for penetration depth, was consistent, regardless of applicant.
Conclusion: We have shown that hydrogel-forming microneedle arrays can be successfully and reproducibly applied by human volunteers given appropriate instruction. If these outcomes were able to be extrapolated to the general patient population, then use of bespoke MN applicator devices may not be necessary, thus possibly enhancing patient compliance.

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Objective: To assess the seasonality of cardiovascular risk factors (CVRF) in a large set of population-based studies.

Methods: Cross-sectional data from 24 population-based studies from 15 countries, with a total sample size of 237 979 subjects. CVRFs included Body Mass Index (BMI) and waist circumference; systolic (SBP) and diastolic (DBP) blood pressure; total, high (HDL) and low (LDL) density lipoprotein cholesterol; triglycerides and glucose levels. Within each study, all data were adjusted for age, gender and current smoking. For blood pressure, lipids and glucose levels, further adjustments on BMI and drug treatment were performed.

Results: In the Northern and Southern Hemispheres, CVRFs levels tended to be higher in winter and lower in summer months. These patterns were observed for most studies. In the Northern Hemisphere, the estimated seasonal variations were 0.26 kg/m2 for BMI, 0.6 cm for waist circumference, 2.9 mm Hg for SBP, 1.4 mm Hg for DBP, 0.02 mmol/L for triglycerides, 0.10 mmol/L for total cholesterol, 0.01 mmol/L for HDL cholesterol, 0.11 mmol/L for LDL cholesterol, and 0.07 mmol/L for glycaemia. Similar results were obtained when the analysis was restricted to studies collecting fasting blood samples. Similar seasonal variations were found for most CVRFs in the Southern Hemisphere, with the exception of waist circumference, HDL, and LDL cholesterol.

Conclusions: CVRFs show a seasonal pattern characterised by higher levels in winter, and lower levels in summer. This pattern could contribute to the seasonality of CV mortality.

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Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.

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ARTD1 (PARP1) is a key enzyme involved in DNA repair through the synthesis of poly(ADP-ribose) (PAR) in response to strand breaks, and it plays an important role in cell death following excessive DNA damage. ARTD1-induced cell death is associated with NAD(+) depletion and ATP loss; however, the molecular mechanism of ARTD1-mediated energy collapse remains elusive. Using real-time metabolic measurements, we compared the effects of ARTD1 activation and direct NAD(+) depletion. We found that ARTD1-mediated PAR synthesis, but not direct NAD(+) depletion, resulted in a block to glycolysis and ATP loss. We then established a proteomics-based PAR interactome after DNA damage and identified hexokinase 1 (HK1) as a PAR binding protein. HK1 activity is suppressed following nuclear ARTD1 activation and binding by PAR. These findings help explain how prolonged activation of ARTD1 triggers energy collapse and cell death, revealing insight into the importance of nucleus-to-mitochondria communication via ARTD1 activation.

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In wetland-adapted plants, such as rice, it is typically root apexes, sites of rapid entry for water/nutrients, where radial oxygen losses (ROLs) are highest. Nutrient/toxic metal uptake therefore largely occurs through oxidized zones and pH microgradients. However, the processes controlling the acquisition of trace elements in rice have been difficult to explore experimentally because of a lack of techniques for simultaneously measuring labile trace elements and O2/pH. Here, we use new diffusive gradients in thin films (DGT)/planar optode sandwich sensors deployed in situ on rice roots to demonstrate a new geochemical niche of greatly enhanced As, Pb, and Fe(II) mobilization into solution immediately adjacent to the root tips characterized by O2 enrichment and low pH. Fe(II) mobilization was congruent to that of the peripheral edge of the aerobic root zone, demonstrating that the Fe(II) mobilization maximum only developed in a narrow O2 range as the oxidation front penetrates the reducing soil. The Fe flux to the DGT resin at the root apexes was 3-fold higher than the anaerobic bulk soil and 27 times greater than the aerobic rooting zone. These results provide new evidence for the importance of coupled diffusion and oxidation of Fe in modulating trace metal solubilization, dispersion, and plant uptake.

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Cathelicidin is an antimicrobial peptide (AMP) and signaling molecule in innate immunity and a direct target of 1,25-dihydroxyvitamin D3 (1,25D3) in primary human keratinocytes (NHEK). The expression of cathelicidin is dysregulated in various skin diseases and its regulation differs depending on the epithelial cell type. The secondary bile acid lithocholic acid (LCA) is a ligand of the vitamin D receptor (VDR) and can carry out in vivo functions of vitamin D3. Therefore we analyzed cathelicidin mRNA- and peptide expression levels in NHEK and colonic epithelial cells (Caco-2) after stimulation with LCA. We found increased expression of cathelicidin mRNA and peptide in NHEK, in Caco-2 colon cells no effect was observed after LCA stimulation. The VDR as well as MEK-ERK signaled the upregulation of cathelicidin in NHEK induced by LCA. Collectively, our data indicate that cathelicidin induction upon LCA treatment differs in keratinocytes and colonic epithelial cells. Based on these observations LCA-like molecules targeting cathelicidin could be designed for the treatment of cutaneous diseases that are characterized by disturbed cathelicidin expression.

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Antimicrobial peptides (AMPs) are strongly expressed in lesional skin in psoriasis and play an important role as proinflammatory "alarmins" in this chronic skin disease. Vitamin D analogs like calcipotriol have antipsoriatic effects and might mediate this effect by changing AMP expression. In this study, keratinocytes in lesional psoriatic plaques showed decreased expression of the AMPs beta-defensin (HBD) 2 and HBD3 after topical treatment with calcipotriol. At the same time, calcipotriol normalized the proinflammatory cytokine milieu and decreased interleukin (IL)-17A, IL-17F and IL-8 transcript abundance in lesional psoriatic skin. In contrast, cathelicidin antimicrobial peptide expression was increased by calcipotriol while psoriasin expression remained unchanged. In cultured human epidermal keratinocytes the effect of different vitamin D analogs on the expression of AMPs was further analyzed. All vitamin D analogs tested blocked IL-17A induced HBD2 expression by increasing IkappaB-alpha protein and inhibition of NF-kappaB signaling. At the same time vitamin D analogs induced cathelicidin through activation of the vitamin D receptor and MEK/ERK signaling. These studies suggest that vitamin D analogs differentially alter AMP expression in lesional psoriatic skin and cultured keratinocytes. Balancing AMP "alarmin" expression might be a novel goal in treatment of chronic inflammatory skin diseases.

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Reports from individual centres suggest a preponderance of females with chronic cough. Females also have heightened cough reflex sensitivity. Here we have reviewed the age and sex of unselected referrals to 11 cough clinics. To investigate the cause of any observed sex dimorphism, functional magnetic resonance imaging of putative cough centres was analysed in normal volunteers. The demographic profile of consecutive patients presenting with chronic cough was evaluated. Cough challenge with capsaicin was undertaken in normal volunteers to construct a concentration-response curve. Subsequent functional magnetic resonance imaging during repeated inhalation of sub-tussive concentrations of capsaicin observed areas of activation within the brain and differences in the sexes identified. Of the 10 032 patients presenting with chronic cough, two-thirds (6591) were female (mean age 55 years). The patient profile was largely uniform across centres. The most common age for presentation was 60-69 years. The maximum tolerable dose of inhaled capsaicin was lower in females; however, a significantly greater activation of the somatosensory cortex was observed. Patients presenting with chronic cough from diverse racial and geographic backgrounds have a strikingly homogeneous demographic profile, suggesting a distinct clinical entity. The preponderance of females may be explained by sex-related differences in the central processing of cough sensation.

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In 2011, a European Respiratory Society Task Force embarked on a process to determine the position and clinical relevance of the cough hypersensitivity syndrome, a disorder characterised by troublesome coughing often triggered by low levels of thermal, mechanical or chemical exposure, in the management of patients with chronic cough. A 21-component questionnaire was developed by an iterative process supported by a literature review. 44 key opinion leaders in respiratory medicine were selected and interviewed as to their opinions. There was a high degree of unanimity in the responses obtained, with all opinion leaders supporting the concept of cough hypersensitivity as a clinically useful paradigm. The classic stratification of cough into asthmatic, rhinitic and reflux-related phenotypes was supported. Significant disparity of opinion was seen in the response to two questions concerning the therapy of chronic cough. First, the role of acid suppression in reflux cough was questioned. Secondly, the opinion leaders were split as to whether a trial of oral steroids was indicated to establish a diagnosis of eosinophilic cough. The cough hypersensitivity syndrome was clearly endorsed by the opinion leaders as a valid and useful concept. They considered that support of patients with chronic cough was inadequate and the Task Force recommends that further work is urgently required in this neglected area.

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A commercial polymeric film (Parafilm M (R), a blend of a hydrocarbon wax and a polyolefin) was evaluated as a model membrane for microneedle (MN) insertion studies. Polymeric MN arrays were inserted into Parafilm M (R) (PF) and also into excised neonatal porcine skin. Parafilm M (R) was folded before the insertions to closely approximate thickness of the excised skin. Insertion depths were evaluated using optical coherence tomography (OCT) using either a force applied by a Texture Analyser or by a group of human volunteers. The obtained insertion depths were, in general, slightly lower, especially for higher forces, for PF than for skin. However, this difference was not a large, being less than the 10% of the needle length. Therefore, all these data indicate that this model membrane could be a good alternative to biological tissue for MN insertion studies. As an alternative method to OCT, light microscopy was used to evaluate the insertion depths of MN in the model membrane. This provided a rapid, simple method to compare different MN formulations. The use of Parafilm M (R), in conjunction with a standardised force/time profile applied by a Texture Analyser, could provide the basis for a rapid MN quality control test suitable for in-process use. It could also be used as a comparative test of insertion efficiency between candidate MN formulations.