Long-term in vitro 3D hydrogel co-culture model of inflammatory bowel disease

The in vitro study of the pathogenesis of inflammatory bowel disease (IBD) requires a cell model which closely reflects the characteristics of the in vivo intestinal epithelium. This study aimed to investigate the application of L-pNIPAM hydrogel as a scaffold to develop a long-term 3D co-culture model of Caco-2 and HT29-MTX cells under conditions analogous to inflammation, to determine its potential use in studying IBD. Monocultures and co-cultures were layered on L-pNIPAM hydrogel scaffolds and maintained under dynamic culture conditions for up to 12 weeks. Treatments with IL-1β, TNFα, and hypoxia for 1 week were used to create an inflammatory environment. Following prolonged culture, the metabolic activity of Caco-2 monoculture and 90% Caco-2/10% HT29-MTX co-cultures on L-pNIPAM hydrogels were increased, and finger-like structures, similar in appearance to villi were observed. Following treatment with IL-1β, TNFα and hypoxia, ALP and ZO-1 were decreased, MUC2 increased, and MUC5AC remained unchanged. ADAMTS1 was increased in response to hypoxia. Caspase 3 expression was increased in response to TNFα and hypoxic conditions. In conclusion, L-pNIPAM hydrogel supported long-term co-culture within a 3D model. Furthermore, stimulation with factors seen during inflammation recapitulated features seen during IBD

Noncompliance

Among challenging behavior, noncompliance has the unique characteristic of describing the failure to engage in, or the absence of, a specific behavior (i.e., compliance). Recognizing that the term “compliance” has negative connotations for many, we propose an alternative term, “cooperation,” to describe the behavior expected of children with autism who exhibit noncompliance. This chapter initially reviews the functional behavior assessment of noncompliance using indirect assessment, descriptive assessment, and functional analysis. Next, we examine antecedent and consequent interventions for active cooperation (i.e., following an instruction to complete a task), such as implementing the high-probability request sequence, reducing response effort, manipulating the delivery of instructions, and providing reinforcement. The third section focuses on interventions designed for passive cooperation (e.g., tolerating a medical device, remaining in the presence of a feared stimulus), which include exposure, noncontingent reinforcement, differential reinforcement of other behavior, and escape extinction. Overall, this chapter provides an overview of research and practices to support individuals who contend with noncompliance in children with autism

Synthesis and Characterization of Complexes of Schiff Base [1, 2-Diphenyl -2- 2-{[1-(3-Amino-Phenyl)-Ethylidene]-Hydrazono Methyl}-Phenol] with Mn(II), Fe(II), Co(II), Cu(II), Zn(II), Cd(II), Ni(II), and Hg(II) Ions

The new tridentate Schiff base ligand (HL)namely 2-{[1-(3-amino-phenyl)-ethylidene]-hydrazono methyl}-phenol containing (N N O)as donors atoms  was prepared in two steps:Step (1): By the reaction of 3-aminoacetophenone with hydrazine monohydrate under reflux in methanol and drops of glacial acetic acid gave the intermediate compound 3-(1- hydrazono ethyl)-phenol amine.Step (2): By the reaction of 3-(1-hydrazono ethyl)-phenol amine with salicyaldehyde under reflux in methanol, gave the ligand (HL).The prepared ligand was characterized by I.R, U.V-Vis,1H- 13C NMR spectra and melting point and reacted with some metal ions under reflux in methanol with (1:1) ratio gave complexes of the general formula: [MClL]. Where: M= Mn(II), Fe(II), Co(II), Cu(II), Zn(II), Cd(II), Ni(II), and Hg(II).Products were found to be solid crystalline complexes, which have been characterized through the following techniques:Molar conductivity .Spectroscopic Method [FTIR and UV-Vis], additional measurement magnetic suspeliblity and  Chloride  content, The magnetic moment coupled with the electronic spectra suggested an  tetrahedral geometry for all the complexes except[ NiClL] is Square-planar.The nature of the complexes formed were studied by Mole Ratio and  the stability constant of the complexes have also been studied. Key words: spectral studies , tridentate Schiff base, 3-aminoacetophenone, hydrazine monohydrate complexe

Evaluation of the preoperative administration of sildenafil on operative and early postoperative outcome after mitral valve replacement in patients with pulmonary hypertension

Background: Mitral valve diseases are commonly associated with pulmonary hypertension. The aim of this study was to evaluate the effect of preoperative administration of sildenafil on the outcome after mitral valve replacement in patients with pulmonary hypertension. Methods: This prospective randomized study was carried out on 67 patients who had a mitral valve replacement and associated high systolic pulmonary artery pressure more than 50 mmHg. Patients were randomized into three groups: group A (n= 20) received preoperative sildenafil for one week, group B (n=22) received sildenafil for one month, and group C (n= 25) did not receive sildenafil. All patients had transthoracic echocardiography preoperatively, one week and one month postoperatively. Results: There was no difference in preoperative and operative variables among groups. Dobutamine support was required in 15 patients (60%) in group C vs. 6 patients (30%) in group A and 5 patients (22.5%) in group B (p= 0.012). Duration of mechanical ventilation was significantly longer in group C (389.2 ± 48.79 minutes) compared to group A and B (295.5 ± 17.01 and 281.4 ± 39.44 minutes, respectively, p<0.001). ICU stay was longer in group C (61.72 ± 13.69 hours) compared to groups A and B (53.55 ± 14.49 and 45.64 ± 13.43 hours, respectively, p=0001). The hospital stay was longer in group C (8.0 ± 1.80 days) compared to group A and B (6.05 ± 0.94 and 6.27 ± 1.24 days, respectively; p< 0.001). The transthoracic echocardiographic study one month after the operation showed that pulmonary artery systolic pressure significantly lower in groups A and B (28.30 ± 3.3 and 28.2 ± 4.98 mmHg, respectively) compared to group C (43.12 ± 4.99 mmHg) (p <0.001). There was no statistically significant difference between groups A and B regarding PASP after five days  (p= 0.287) or one month (p= 0.939). Conclusion: We found that preoperative administration of oral sildenafil in patients with pulmonary hypertension undergoing mitral valve replacement may reduce pulmonary hypertension postoperatively. We could not find a difference in the administration of sildenafil for either one week or one month preoperatively

Effect of reactant gas flow orientation on the current and temperature distribution in self-heating polymer electrolyte fuel cells

Fuel cell polarisation performance is typically reported under controlled/constant temperature conditions, as a sign of robust metrology. However, in practice, fuel cells self-heat as they generate current; which varies the temperature across the polarisation curve and affects performance. More detail regarding the internal cell operation can be gleaned by current and temperature distribution mapping. For the case of an unheated cell, ‘self-heating’ increases the cell temperature and improves performance, resulting in a ‘voltage recovery’ and a more homogeneous current and water distribution. For actively heated cells, a reduced current is observed in regions of high temperature and low humidity. The positioning of the gas manifolds also has a decisive impact on performance by affecting the reactant concentration, humidity and water distribution. Counter- and cross-flow orientations in a self-heating cell were studied, with a counter-flow orientation with air flowing with gravity producing the most uniform temperature distribution

Regulatory natural killer cell expression in atopic childhood asthma

Introduction: Different subsets of natural killer (NK) cells were found to play a role in pathogenesis of allergy. We sought to investigate the expression of regulatory NK cells (CD56+CD16+CD158+) in atopic children with bronchial asthma in order to outline the value of these cells as biomarkers of disease severity and/or control.Methods: A cross sectional controlled study was carried out in the Pediatric Allergy and Immunology Unit, Ain Shams University. The study included 45 atopic children [mean age(SD)= (2.9) years] with bronchial asthma (BA) and/or allergic rhinitis (AR)as well as 40 healthy matched controls. Enrolled subjects underwent complete blood counting and flow cytometric measurement of NK cell (CD16+ CD56+) and regulatory NK cells (CD16+CD56+CD158+).Results: Patients had significantly higher regulatory NK cell percentages [mean (SD)= 41 (52) %] than controls [mean (SD)=15 (7.1)]; p≤0.001. Regulatory NK cell counts and percentages did not vary with the concomitant presence of AR or the degree of asthma control. Regulatory NK cell counts tended to be higher in children with moderate/severe BA compared to those with mild asthma but the difference did not reach statistical significance (U= -1.8, p=0.06). NK cell counts [mean (SD)= 159 (164) cells/μl] and percentages [mean (SD)= 3.7 (3.2) %] were comparable among patients and controls and did not vary with the presence of AR (p= 0.51, 0.95) or with the degree of asthma control. NK cells absolute counts and percentages tended to be higher among patients with moderate/severe compared to mild asthma but the difference did not reach statistical significance.Conclusions: Regulatory NK cells seem to be increased in childhood asthma. We recommend wider scale prospective studies on steroid-naïve subjects involving measurement of cytokines that are secreted by different types of NK cells.Keywords: Natural killer, regulatory, asthma, children, allerg

Optimising the chick chorioallantoic membrane xenograft model of neuroblastoma for drug delivery

Background Neuroblastoma is a paediatric cancer that despite multimodal therapy still has a poor outcome for many patients with high risk tumours. Retinoic acid (RA) promotes differentiation of some neuroblastoma tumours and cell lines, and is successfully used clinically, supporting the view that differentiation therapy is a promising strategy for treatment of neuroblastoma. To improve treatment of a wider range of tumour types, development and testing of novel differentiation agents is essential. New pre-clinical models are therefore required to test therapies in a rapid cost effective way in order to identify the most useful agents. Methods As a proof of principle, differentiation upon ATRA treatment of two MYCN-amplified neuroblastoma cell lines, IMR32 and BE2C, was measured both in cell cultures and in tumours formed on the chick chorioallantoic membrane (CAM). Differentiation was assessed by 1) change in cell morphology, 2) reduction in cell proliferation using Ki67 staining and 3) changes in differentiation markers (STMN4 and ROBO2) and stem cell marker (KLF4). Results were compared to MLN8237, a classical Aurora Kinase A inhibitor. For the in vivo experiments, cells were implanted on the CAM at embryonic day 7 (E7), ATRA treatment was between E11 and E13 and tumours were analysed at E14. Results Treatment of IMR32 and BE2C cells in vitro with 10 μM ATRA resulted in a change in cell morphology, a 65% decrease in cell proliferation, upregulation of STMN4 and ROBO2 and downregulation of KLF4. ATRA proved more effective than MLN8237 in these assays. In vivo, 100 μM ATRA repetitive treatment at E11, E12 and E13 promoted a change in expression of differentiation markers and reduced proliferation by 43% (p < 0.05). 40 μM ATRA treatment at E11 and E13 reduced proliferation by 37% (p < 0.05) and also changed cell morphology within the tumour. Conclusion Differentiation of neuroblastoma tumours formed on the chick CAM can be analysed by changes in cell morphology, proliferation and gene expression. The well-described effects of ATRA on neuroblastoma differentiation were recapitulated within 3 days in the chick embryo model, which therefore offers a rapid, cost effective model compliant with the 3Rs to select promising drugs for further preclinical analysis

Design of experiments to generate a fuel cell electro-thermal performance map and optimise transitional pathways

The influence of the air cooling flow rate and current density on the temperature, voltage and power density is a challenging issue for air-cooled, open cathode fuel cells. Electro-thermal maps have been generated using large datasets (530 experimental points) to characterise these correlations, which reveal that the amount of cooling, alongside with the load, directly affect the cell temperature. This work uses the design of experiment (DoE) approach to tackle two challenges. Firstly, an S-optimal design plan is used to reduce the number of experiments from 530 to 555 to determine the peak power density in an electro-thermal map. Secondly, the design of experiment approach is used to determine the fastest way to reach the highest power density, yet limiting acute temperature gradients, via three intermediate steps of current density and air cooling rate

Effect of extended short-circuiting in proton exchange membrane fuel cells

Short-circuiting is regularly utilized in Proton Exchange Membrane Fuel Cells (PEMFCs) to reverse short-term reversible catalyst degradation. However, do these improvements in fuel cell performance and durability still exist after extended operation? We provide an answer to this question by comparing the performance and durability of a PEMFC under open-circuit voltage (OCV) and a commercial short-circuiting protocol, against a PEMFC under OCV without short-circuiting for the same extended period (∼144 h). The experimental results demonstrate the detrimental effect of extended short-circuiting on the durability of the catalyst and the performance of the fuel cell. Electrochemically active surface area losses reach ∼46% for the short-circuiting case, compared to only ∼18% losses for the OCV without short-circuiting. TEM and XPS measurements are employed to monitor the morphological changes of the catalyst layer, revealing that Ostwald ripening, carbon corrosion, and Pt migration and precipitation into the polymer membrane are the main degradation mechanisms of the cathode catalyst layer. At the end of PEMFC operation, XPS measurements reveal that only ∼0.1% (atomic) of Pt remains on the surface of the cathode catalyst layer after OCV with short-circuiting, compared to the initial ∼0.4% Pt of the unused cathode MEA and ∼0.3% Pt for the cathode MEA after OCV without short-circuiting. These results show that short-circuiting can cause facile degradation of the catalyst layer and significant decrease in fuel cell performance, rendering this technique non-beneficial for extended operation

Rapid Preparation of Geometrically Optimal Battery Electrode Samples for Nano Scale X-ray Characterisation

Rechargeable lithium-based batteries are one of the key enabling technologies driving the shift to renewable energy, and research into novel technologies has intensified to meet growing demands in applications requiring higher energy and power density. The mechanisms behind battery degradation can be investigated across multiple length-scales with X-ray imaging methods; at the nanoscale severe constraints are imposed on sample size in order to obtain adequate signal to noise. Here, we present a novel lasermilling technique to prepare geometrically optimal samples for X-ray nano-tomography. Advantages of this technique include significantly reduced sample preparation time, and a suitable geometry for mosaic acquisition, enabling a larger field of view to be captured at high spatial resolution, thus improving statistics. The geometry of the resulting electrode remains highly suitable for nano-tomography, and yet permits in situ and operando experiments to be carried out on standard electrode coatings, providing new insights into transient phenomena whilst closely mimicking standard electrochemical cells