The DC‐HIL ligand syndecan‐4 is a negative regulator of T‐cell allo‐reactivity responsible for graft‐versus‐host disease

Acute graft-versus-host disease (GVHD) is the most important cause of mortality after allogeneic haematopoietic stem cell transplantation. Allo-reactive T cells are the major mediators of GVHD and the process is regulated by positive and negative regulators on antigen-presenting cells (APC). Because the significance of negative regulators in GVHD pathogenesis is not fully understood, and having discovered that syndecan-4 (SD-4) on effector T cells mediates the inhibitory function of DC-HIL on APC, we proposed that SD-4 negatively regulates the T-cell response to allo-stimulation in acute GVHD, using SD-4 knockout mice. Although not different from their wild-type counterparts in responsiveness to anti-CD3 stimulation, SD-4^−/− T cells lost the capacity to mediate the inhibitory function of DC-HIL and were hyper-reactive to allogeneic APC. Moreover, infusion of SD-4^−/− T cells into sub-lethally γ-irradiated allogeneic mice worsened mortality, with hyper-proliferation of infused T cells in recipients. Although there my be little or no involvement of regulatory T cells in this model because SD-4 deletion had no deleterious effect on T-cell-suppressive activity compared with SD-4^+/+ regulatory T cells. We conclude that SD-4, as the T-cell ligand of DC-HIL, is a potent inhibitor of allo-reactive T cells responsible for GVHD and a potentially useful target for treating this disease.     

Development and application of a one‐step real‐time RT‐PCR using a minor‐groove‐binding probe for the detection of a novel bunyavirus in clinical specimens

A highly sensitive one‐step real‐time RT‐PCR method using a minor‐groove‐binding (MGB) probe was developed for detection and quantitation of severe febrile with thrombocytopenia syndrome virus (SFTSV). The assay could discriminate SFTSV infection from other related viral diseases in human with a minimum detection limit of 10 viral RNA copies/µl and was 1,000 times more sensitive than the conventional PCR. Strong linear correlations (r² > 0.99) between the C_t values and viral RNA standards over a linear range were obtained. The coefficients of variation of intra‐ and inter‐assay reproducibility were both less than 2%. The RT‐PCR was also shown to be highly specific, as no positive signals were detected for other related viruses. Evaluation of this assay with serum samples from laboratory confirmed cases and healthy donors showed 100% clinical diagnostic sensitivity and over 99% specificity. Clinical application with samples from 287 patients admitted to the hospital with suspected SFTSV infection showed that 15% were infected by SFTSV. This assay was rapid, requiring just over 2 hr, including the nucleic acid extraction step. J. Med. Virol. 85:370–377, 2013. © 2012 Wiley Periodicals, Inc.     

Novel 7‐DHCR mutation in a child with Smith‐Lemli‐Opitz syndrome

Smith‐Lemli‐Opitz syndrome (SLOS) is an autosomal recessive disorder characterized by minor facial anomalies, mental retardation, and multiple congenital abnormalities. Biochemically, the disorder is caused by deficient activity of 7‐dehydrocholesterol reductase, which catalyzes the reduction of the Δ7 double bond of 7‐dehydrocholesterol to produce cholesterol. Recently, mutations in the gene encoding 7‐dehydrocholesterol reductase (7DHCR) were found to cause SLOS. We report the first molecular characterization of an Italian SLOS patient. Interestingly, his paternal 7DHCR allele, of Arab origin, harbored a novel P329L mutation which in combination with a maternal splice‐site (IVS8‐1 G>C) mutation resulted in a relatively milder phenotype. Am. J. Med. Genet. 91:138–140, 2000. © 2000 Wiley‐Liss, Inc.     

Non‐water‐suppressed short‐echo‐time magnetic resonance spectroscopic imaging using a concentric ring k‐space trajectory

Water‐suppressed MRS acquisition techniques have been the standard MRS approach used in research and for clinical scanning to date. The acquisition of a non‐water‐suppressed MRS spectrum is used for artefact correction, reconstruction of phased‐array coil data and metabolite quantification. Here, a two‐scan metabolite‐cycling magnetic resonance spectroscopic imaging (MRSI) scheme that does not use water suppression is demonstrated and evaluated. Specifically, the feasibility of acquiring and quantifying short‐echo (T_E = 14 ms), two‐dimensional stimulated echo acquisition mode (STEAM) MRSI spectra in the motor cortex is demonstrated on a 3 T MRI system. The increase in measurement time from the metabolite‐cycling is counterbalanced by a time‐efficient concentric ring k‐space trajectory. To validate the technique, water‐suppressed MRSI acquisitions were also performed for comparison. The proposed non‐water‐suppressed metabolite‐cycling MRSI technique was tested for detection and correction of resonance frequency drifts due to subject motion and/or hardware instability, and the feasibility of high‐resolution metabolic mapping over a whole brain slice was assessed. Our results show that the metabolite spectra and estimated concentrations are in agreement between non‐water‐suppressed and water‐suppressed techniques. The achieved spectral quality, signal‐to‐noise ratio (SNR) > 20 and linewidth <7 Hz allowed reliable metabolic mapping of five major brain metabolites in the motor cortex with an in‐plane resolution of 10 × 10 mm² in 8 min and with a Cramér‐Rao lower bound of less than 20% using LCModel analysis. In addition, the high SNR of the water peak of the non‐water‐suppressed technique enabled voxel‐wise single‐scan frequency, phase and eddy current correction. These findings demonstrate that our non‐water‐suppressed metabolite‐cycling MRSI technique can perform robustly on 3 T MRI systems and within a clinically feasible acquisition time.     

Assessment of 5‐fluorouracil and 4‐nitroquinoline‐1‐oxide in vivo genotoxicity with Pig‐a mutation and micronucleus endpoints

Genotoxicity assessments were conducted on male Sprague Dawley rats treated with 5‐fluorouracil (5‐FU) and 4‐nitroquinoline‐1–oxide (4NQO) as part of an international validation trial of the Pig‐a mutant phenotype assay. Rats were orally exposed to 0, 11.5, 23, or 46 mg/kg/day 5‐FU for three consecutive days (Days 1–3); blood was sampled on Days ?1, 4, 15, 29, and 45. Pig‐a mutant phenotype reticulocyte (RET^CD59?) and mutant phenotype erythrocyte (RBC^CD59?) frequencies were determined on Days ?1, 15, 29, and 45, and percent micronucleated reticulocytes (%MN‐RET) were measured on Day 4. Rats were treated with 4NQO for 28 consecutive days by oral gavage, at doses of 1.5, 3, or 6 mg/kg/day. RBC^CD59? and RET^CD59? frequencies were determined on Days ?1, 15, and 29, and MN‐RET were quantified on Day 29. Whereas 5‐FU was found to increase %MN‐RET, no significant increases were observed for RBC^CD59? or RET^CD59? at any of the time points studied. The high dose of 4NQO (6 mg/kg/day) was observed to markedly increase RBC^CD59? and RET^CD59? frequencies, and this same dose level caused a weak but significantly elevated increase in MN‐RET (approximately twofold). Collectively, the results provide additional support for the combination of Pig‐a mutation and MN‐RET into acute and 28‐day repeat‐dose studies. Environ. Mol. Mutagen. 55:735–740, 2014. © 2014 Wiley Periodicals, Inc.     

Self‐Assembly of ATRP‐Synthesized PCH‐b‐PtBA‐b‐PCH Triblock Copolymers Observed by Time‐Resolved SAXS

The phase behavior of PCH‐b‐PtBA‐b‐PCH triblock copolymers has been studied. Measurements in the wide‐angle region probed the existence of microphase segregation through variation of block mobility and thermal expansion coefficients. SAXS experiments pointed out that most copolymers present ordered nanostructures, mostly hexagonally packed cylinders, the morphology being confirmed by AFM. An unusual disorder‐to‐order transition is observed in one copolymer synthesized from a macroinitiator with intermediate length and the highest outer‐block molecular weight, whereas none of the copolymers shows an order‐to‐disorder transition upon heating over the temperature range analyzed.

     

Down‐regulation of miR‐301a suppresses pro‐inflammatory cytokines in Toll‐like receptor‐triggered macrophages

In many types of tumours, especially pancreatic adenocarcinoma, miR‐301a is over‐expressed. This over‐expression results in negative regulation of the target gene of miR‐301a, the nuclear factor‐κB (NF‐κB) repressing factor (NKRF), increasing the activation of NF‐κB and production of NF‐κB‐responsive pro‐inflammatory cytokines such as interleukin‐8, interferon‐β, nitric oxide synthase 2A and cytochrome oxidase subunit 2 (COX‐2). However, in immune cells, mechanisms that regulate miR‐301a have not been reported. Similar to tumour cells, Toll‐like receptor (TLR) ‐activated macrophages produce NF‐κB‐responsive pro‐inflammatory cytokines. Therefore, it is of considerable interest to determine whether miR‐301a regulates the secretion of cytokines by immune cells. In the present study, we demonstrate that the expression of miR‐301a was decreased in TLR‐triggered macrophages. Through targeting NKRF, miR‐301a affected the activity of NF‐κB and the expression of pro‐inflammatory genes downstream of NF‐κB such as COX‐2, prostaglandin E₂ and interleukin‐6. In addition, when lipopolysaccharide‐treated macrophages were simultaneously stimulated with trichostatin A, an inhibitor of histone deacetylases, the expression of miR‐301a increased, whereas NKRF and pro‐inflammatory cytokine expression decreased. However, further investigation revealed that there was no correlation between the induction of miR‐301a and the inhibitory effect of trichostatin A on lipopolysaccharide‐induced gene expression in macrophages. In summary, our study indicates a new mechanism by which miR‐301a regulates inflammatory cytokine expression in macrophages, which may clarify the regulatory role of microRNAs in immune‐mediated inflammatory responses.     

Fluorene‐Based Single‐Chain Copolymers for Color‐Stable White Light‐Emitting Diodes

Fluorene‐based single‐chain copolymers with a white light emitter consisting of a blue and an orange chromophore have been synthesized and their photophysical and electroluminescent properties are investigated. The experimental results suggest that only a relatively small fraction of the orange‐emitting units incorporated into the fluorene is needed to achieve efficient white light emission by controlled incomplete energy transfer. A device from a copolymer with 0.02% DDQ content showed the highest external quantum efficiency of 2.64% with a luminance efficiency of 4.06 cd · A^?1 with CIE coordinates (0.28, 0.24). The EL emissions are extremely stable over a wide range of current densities.

     

Encapsulating Hydrophilic Solution by PU‐PMF Double‐Component Capsule Based on Water‐In‐Oil‐In‐Oil Emulsion Template

This study demonstrates an effective method to encapsulate a hydrophilic payload through the use of polyurethane‐poly(melamine‐formaldehyde) (PU‐PMF) dual‐component capsules based upon the water‐in‐oil‐in‐oil (W/O/O) emulsion template. This emulsion has a middle oil layer that hosts the PU (outer shell) forming reaction while the internal PMF skeleton, fabricated concurrently by polymer precipitation in the aqueous dispersive phase, provides additional mechanical support. The resultant capsules exhibit dense and spherical shape, low permeability, and diameter of ≈50 µm. Remarkably, interfacial tension is the driving factor in the formation of the W/O/O template. This microencapsulation system and the methods used for its fabrication have a great technical potential for use in industrial applications.     

Comparing P300 modulations: Target‐to‐target interval versus infrequent nontarget‐to‐nontarget interval in a three‐stimulus task

This study examined temporal determinants of the P300 component of the ERP in a three‐stimulus visual oddball task. Frequent standards, with equiprobable targets and infrequent nontargets, were utilized. We tested whether the infrequent nontarget‐to‐nontarget interval (infrequent NNI) influences P300 amplitudes and latencies analogously to the target‐to‐target interval (TTI). EEG was recorded from 27 participants, and response time and P300 effects of TTIs and infrequent NNIs were assessed. Increases in TTI augmented target P300 amplitudes and decreased latencies and response times. However, this modulation of P300 amplitude was weak for manipulations of infrequent NNI. P300 latencies increased initially before decreasing across infrequent NNI levels. Together, these findings support the notion that the P300 has an underlying temporal mechanism that is modulated by motivationally significant events. Theoretical implications are discussed.     

Bacillus‐derived poly‐γ‐glutamic acid attenuates allergic airway inflammation through a Toll‐like receptor‐4‐dependent pathway in a murine model of asthma

Background Asthma is an inflammatory disease of the airways that is mediated by Th2 responses. Poly‐γ‐glutamic acid (γ‐PGA) is an extracellular polymeric compound that is synthesized by Bacillus cells. Previously, we found that γ‐PGA promoted Th1 cell development in a manner dependent on antigen‐presenting cells, but inhibited Th2 cell development. Objective To investigate the effect of γ‐PGA on dendritic cells (DCs), and its potential for treating Th2‐mediated allergic asthma. Methods Wild‐type, Toll‐like receptor (TLR)‐2 deficient, and TLR‐4‐defective mice were used. DCs derived from the bone marrow and extracted from the lung were stimulated with γ‐PGA and assayed for the expression of signalling molecules, costimulatory molecules, and cytokines. Mice were sensitized and challenged with ovalbumin (OVA) to induce asthma. They were repeatedly injected intranasally with γ‐PGA before and during the challenge period, and inflammation and structural remodelling of the airways were examined. Results γ‐PGA selectively signalled conventional DCs to activate NF‐κB and mitogen‐activated protein kinase, leading to the up‐regulation of CD86, CD40, and IL‐12, but not IL‐10 and IL‐6. These effects of γ‐PGA were dependent on TLR‐4 and independent of TLR‐2. Importantly, the intranasal administration of γ‐PGA to OVA‐sensitized/challenged mice reduced the airway hyperresponsiveness and allergic inflammation such as leucocyte influx, goblet cell hyperplasia, eosinophilia, and Th2 cytokine production. In addition to lowered IgE titres, the treatment of mice with γ‐PGA significantly reduced the multiplication and Th2 polarization of mediastinal lymph node T cells upon allergen‐specific restimulation. These anti‐asthmatic effects of γ‐PGA were also abolished in TLR‐4‐defective mice. Conclusions and Clinical Relevance Our data indicate that γ‐PGA activates DCs to favour Th1 cell induction through a TLR‐4‐dependent pathway and alleviates pathologic symptoms in a Th2‐biased asthmatic model. These findings highlight the potential of γ‐PGA for the treatment of asthma and other allergic disease in which Th2 polarization plays an important role. Cite this as: K. Lee, S.‐H. Kim, H. J. Yoon, D. J. Paik, J. M. Kim and J. Youn, Clinical & Experimental Allergy, 2011 (41) 1143–1156.     

Polyelectrolyte‐in‐Ionic‐Liquid Electrolytes

Novel polymer electrolyte materials based on a polyelectrolyte‐in‐ionic‐liquid principle are described. A combination of a lithium 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPSLi) and N,N′‐dimethylacrylamide (DMMA) are miscible with the ionic liquid, 1‐ethyl‐3‐methylimidazolium dicyanamide (EMIDCA). EMIDCA has remarkably high conductivity (≥ 2 · 10^?2 S · cm^?1) at room temperature and acts as a good solvating medium for the polyelectrolyte. At compositions of AMPSLi less than or equal to 75 mol‐% in the copolymer (P(AMPSLi‐co‐DMAA)), the polyelectrolytes in EMIDCA are homogeneous, flexible elastomeric gel materials at 10 ? 15 wt.‐% of total polyelectrolyte. Conductivities higher than 8 · 10^?3 S · cm^?1 at 30 °C have been achieved. The effects of the monomer composition, polyelectrolyte concentration, temperature and lithium concentration on the ionic conductivity have been studied using thermal and conductivity analysis, and pulsed field gradient nuclear magnetic resonance techniques.

Comparison of the measured and calculated lithium conductivity at 30 °C.     

Synthesis and Properties of pH‐ and Temperature‐Sensitive Poly[(N‐isopropylacrylamide)‐co‐(2‐methylenebutane‐1,4‐dioic acid)] Hydrogels

Summary: Hydrogels of NIPA and MBDA were synthesized by free‐radical crosslinking copolymerization with different monomer ratios and with two concentrations of the crosslinking agent. The aim of this work was to study the swelling behavior of these gels that are both temperature and pH sensitive. PNIPA hydrogels are typical examples of thermo‐shrinking hydrogels with a LCST, T_C, around 31–34 °C. MBDA is a weakly ionizable monomer which imparts a pH sensitiveness to the copolymer hydrogels. The pH influence on the swelling behavior of the studied hydrogels was analyzed using deionized water and aqueous HCl and NaOH as swelling media. According to the results found in deionized water, the swelling processes of P(NIPA‐MBDA) hydrogels follow second‐order kinetics at 22 and 37 °C. The equilibrium water content, W_∞, and the rate constant, K, increased at greater concentrations of MBDA and decreased as the crosslinking agent concentration increased. As the MBDA content in the hydrogel increased, the collapsing of the hydrogels at higher temperatures than the LCST became of less importance. The degree of swelling of pure PNIPA hydrogels was not influenced by the pH of the swelling medium. However, this influence increased as the MBDA content increased. This was due to the fact that at low pH most of the MBDA units are in the protonated (neutral) form and at high pH in the ionized one.

Swelling isotherms of hydrogels with different copolymer compositions and with 1.5 wt.‐% of BIS at 22 °C in deionized water.     

Synthesis and Characterization of a Red‐Emitting Copolymer Containing 5,8‐Quinoline Units

A novel nitrogen‐containing electroluminescent copolymer, PQV‐alt‐MOPPV has been designed and synthesized by Wittig‐Horner polymerization. Structure, thermal stability, and optical and electrochemical properties of the resulting copolymer were characterized by FT‐IR, ¹H NMR, elemental analysis, GPC, DSC, TGA, UV‐vis, PL, EL, and CV. The copolymer possesses excellent solubility in common organic solvents and good thermal stability. The absorption maxima of the copolymer in solution and a thin film are 490 and 516 nm, and the photoluminescence maxima in solution and thin film are 571 and 629 nm, respectively. The PLED (ITO/PEDOT: PSS (40 nm)/PQV‐alt‐MOPPV (80 nm)/Ca (30 nm)/Al (150 nm) shows a very pure red light emission with maximum peaks around 618 nm.

     

Synthesis,Characterization, and Intramolecular End‐to‐End Ring Closure of α‐Isopropylidene‐1,1‐dihydroxymethyl‐ω‐diethylacetal Polystyrene‐block‐polyisoprene Block Copolymers

Cyclic polystyrene‐block‐polyisoprenes of controlled dimensions have been synthesized for the first time by the direct coupling of α‐isopropylidene‐1,1‐dihydroxymethyl‐ω‐diethylacetal‐heterodifunctional linear polystyrene‐block‐polyisoprene precursors previously prepared by living anionic polymerization. Cyclization is achieved under high dilution by intramolecular coupling of the polymer ends under acid catalyst conditions. Using this strategy polystyrene‐block‐polyisoprene macrocycles of controlled chain dimensions are prepared in high yield (> 90%). Pure cycles were finally recovered by flash chromatography. The synthesis and characterization of both the linear α,ω‐heterodifunctional polystyrene‐block‐polyisoprenes block copolymers precursors and of the corresponding cyclized chain architectures are reported.

200 MHz ¹H NMR spectrum (CDCl₃) of cyclized polystyrene‐block‐polyisoprene copolymer (M _n = 12 000).     

Gamma‐Cyclodextrin‐Recognition‐Responsive Characteristics of Poly(N‐isopropylacrylamide)‐Based Hydrogels with Benzo‐12‐crown‐4 Units as Signal Receptors

Molecular‐recognition‐responsive characteristics of a novel poly(N‐isopropylacrylamide‐co‐benzo‐12‐crown‐4‐acrylamide) (PNB12C4) hydrogel have been investigated. In the prepared PNB12C4 hydrogel, benzo‐12‐crown‐4 (B12C4) groups act as guest molecules and γ‐cyclodextrin (γ‐CD)‐receptors, and poly(N‐isopropylacrylamide) (PNIPAM) networks act as phase‐transition actuators. The formation of stable γ‐CD/B12C4 complexes enhances the hydrophilicity of the PNB12C4 hydrogel networks, and induces positive shift of the volume phase transition temperature (VPTT) of PNB12C4 hydrogel. Moreover, the PNB12C4 hydrogel also shows thermoresponsive adsorption property selectively towards γ‐CD. The γ‐CD‐recognition sensitivity of PNB12C4 hydrogel can be dramatically improved by increasing γ‐CD concentration in solution or B12C4 content in PNB12C4 copolymer networks. The results in this study provide valuable information for developing crown ether‐based smart materials in various applications.