Improved diagnostic performance of susceptibility-weighted imaging with compressed sensing-sensitivity encoding and neuromelanin-sensitive MRI for Parkinson's disease and atypical Parkinsonism

AIM

To verify the diagnostic performance of the loss of nigrosome-1 on susceptibility-weighted imaging (SWI) with compressed sensing-sensitivity encoding (CS-SENSE) and neuromelanin on neuromelanin-sensitive (NM) magnetic resonance imaging (MRI) for the diagnosis of Parkinson's disease (PD) and atypical Parkinsonism.

MATERIALS AND METHODS

A total of 195 patients who underwent MRI between October 2019 and February 2020, including SWI, with or without CS-SENSE, and NM-MRI, were reviewed retrospectively. Two neuroradiologists assessed the loss of nigrosome-1 on SWI and neuromelanin on the NM-MRI. The result of N-3-fluoropropyl-2-beta-carbomethoxy-3-beta-(4-iodophenyl) nortropane positron-emission tomography (PET) was set as the reference standard.

RESULTS

When CS-SENSE was applied for nigrosome-1 imaging on SWI, the non-diagnostic scan rate was lowered significantly from 19.3% (17/88) to 5.6% (6/107; p=0.004). Diagnosis of PD and atypical Parkinsonism based on the loss of nigrosome-1 on SWI and based on NM-MRI showed good diagnostic value (area under the curve [AUC] 0.821, 95% confidence interval [CI] = 0.755-0.875: AUC 0.832, 95% CI = 0.771-0.882, respectively) with a substantial inter-reader agreement (κ = 0.791 and 0.681, respectively). Combined SWI and neuromelanin had a similar discriminatory ability (AUC 0.830, 95% CI = 0.770-0.880). Similarly, the diagnosis of PD was excellent.

CONCLUSIONS

CS-SENSE may add value to the diagnostic capability of nigrosome-1 on SWI to reduce the nondiagnostic scan rates. Furthermore, loss of nigrosome-1 on SWI or volume loss of neuromelanin on NM-MRI may be helpful for diagnosing PD.

Silica-Based Platform Decorated with Conjugated Polymer Dots and Prussian Blue for Improved Photodynamic Cancer Therapy

To advance cancer treatment, we have developed a novel composite material consisting of conjugated polymer dots (CPDs) and Prussian blue (PB) particles, which were immobilized on, and encapsulated within, silica particles, respectively. The CPDs functioned as both a photosensitizer and a photodynamic agent, and the PB acted as a photothermal agent. The silica platform provided a biocompatible matrix that brought the two components into close proximity. Under laser irradiation, the fluorescence from the CPDs in the composite material enabled cell imaging and was subsequently converted to thermal energy by PB. This efficient energy transfer was accomplished because of the spectral overlap between the emission of donor CPDs and the absorbance of acceptor PB. The increase in local temperature in the cells resulted in a significant increase in the amount of reactive oxygen species (ROS) generated by CPDs, in which their independent use did not produce sufficient ROS for cancer cell treatment. To assess the impact of the enhanced ROS generation by the composite material, we conducted experiments using cancer cells under 532 nm laser irradiation. The results showed that with the increase in local temperature, the generated ROS increased by 30% compared with the control, which did not contain PB. When the silica-based composite material was positioned at the periphery of the tumor for 120 h, it led to a much slower tumor growth than other materials tested. By using a CPD-based photodynamic therapy platform, a new simplified approach to designing and preparing cancer treatments could be achieved, which included photothermal PB-assisted enhanced ROS generation using a single laser. This advancement opens up an exciting new opportunity for effective cancer treatment.

Eosinophil-derived TGFβ1 controls the new bone formation in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by chronic eosinophilic inflammation and new bone formation (NBF). These processes may be associated with each other in the pathogenesis and influence the severity and prognosis of the disease. However, it is still unclear how eosinophilic inflammation is involved in the NBF.

METHODOLOGY

Sinus bone cells were isolated from ethmoid bone tissues of patients with CRSwNP and controls. Transforming growth factor beta 1 (TGFβ1) and alkaline phosphatase (ALP) expression in sinus bone cells was determined using quantitative RT-PCR, immunoblotting, and immunohistochemistry. The co-localization of TGFβ1 with eosinophils was assessed by immunofluorescence staining. Sinus bone cells were co-cultured with eosinophils (Eol-1 cell line), which were differentiated with butyrate, to measure the osteoblast differentiation activity of sinus bone cells.

RESULTS

TGFβ1 expression was increased in sinus bone tissues and correlated with CT scores in CRSwNP. TGFβ1 was also increased in the submucosa of CRSwNP and co-localized predominantly with eosinophils compared with neutrophils Differentiated Eol-1 cells-derived TGFβ1 increased ALP expression in sinus bone cells. Treatment with a TGFβ inhibitor attenuated TGFβ1-induced ALP expression and staining in sinus bone cells of CRSwNP, leading to loss of bone formation.

CONCLUSIONS

Eosinophil-derived TGFβ1 was enriched in the submucosa of CRSwNP, which induced ALP expression in sinus bone cells and NBF. Therefore, eosinophil-derived TGFβ1 may mediate aberrant bone remodeling in CRSwNP.

Detection rate of MR myelography without intrathecal gadolinium in patients with newly diagnosed spontaneous intracranial hypotension

AIM

To evaluate the detection rate of magnetic resonance (MR) myelography without intrathecal gadolinium for cerebrospinal fluid (CSF) leakage in patients with newly diagnosed spontaneous intracranial hypotension (SIH) and to validate a published scoring system for predicting CSF leakage.

MATERIALS AND METHODS

This retrospective, observational, single-institution study included patients with newly diagnosed SIH between March 2015 and April 2021. Patients were included if they (a) had newly diagnosed SIH and (b) underwent initial brain MR imaging and preprocedural MR myelography with two- and three-dimensional turbo spin-echo sequences. Patients who underwent spine surgery or procedures including epidural injection and acupuncture were excluded. The detection rate was defined as the proportion of patients with a true-positive MR myelography result among all patients with confirmed CSF leakage. The interobserver agreement for the MR myelography results between two radiologists was analysed using weighted kappa statistics.

RESULTS

A total of 136 patients (mean age, 48 years; 70 women) with suspected SIH were included. Of these patients, 120 (88%, 120/136) were confirmed to have CSF leakage. Of the patients with confirmed CSF leakage, 90 (75%, 90/120) had epidural fluid collection. The detection rate of MR myelography for CSF leakage was 88% (105/120). The interobserver agreement between the two readers for detecting CSF leakage (κ = 0.76) or epidural fluid collection (κ = 0.76) on MR myelography was high. Among 24 patients with normal brain MR imaging results, 16 had CSF leakage (67%, 16/24).

CONCLUSIONS

Non-invasive MR myelography without intrathecal gadolinium should be considered to detect CSF leakage in patients with suspected SIH.

Fabrication of a porous polyacrylonitrile nanofiber adsorbent for removing radioactive 60Co

A Co²⁺ adsorbent was prepared using electrospun porous polyacrylonitrile (PAN) nanofibers, featuring easy recovery for reuse compared with a nanoparticle-based adsorbent. As an efficient ligand for Co²⁺, ethylenediaminetetraacetic acid (EDTA) was introduced on the surface of porous PAN nanofibers with the aid of a branched polyethyleneimine (PEI) linker to obtain an adsorbent with carboxylic acid groups. On the adsorbent surface, the carboxylic acid and amine groups from EDTA could adsorb Co²⁺ via ion exchange and chelation, and amine groups from PEI that remained after EDTA functionalization played a role in coordinating Co²⁺. The amine and carboxylic acid groups were simultaneously involved in the adsorption on the surface, making it possible to remove Co²⁺ over a wide pH range. An investigation of the adsorption isotherms and kinetics of the nanofibrous adsorbent indicated that monolayer chemisorption was achieved with a maximum Co²⁺ adsorption capacity of 8.32 mg/g. In addition, radioactive ⁶⁰Co was efficiently removed by the adsorbent with a removal extent of more than 98%. Considering the easy separation from Co²⁺ solution and regeneration of the nanofibrous adsorbent and its availability in a wide pH range, the adsorbent has great advantages in practical applications.

POS0030 CLINICAL AND GENETIC FACTORS ASSOCIATED WITH RADIOGRAPHIC PROGRESSION IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Background

Ankylosing spondylitis (AS) is a heritable inflammatory disease eventually leading to spinal fusion 1. Severity of structural damage is highly variable, some patients develop almost no change in spinal structure for long disease duration, whereas others have total ankylosis even in the early stage of disease.

Objectives

To identify clinical and genetic factors associated with severe radiographic damage in patients with AS.

Methods

We newly generated genome-wide variant data (833K, KoreanChip) of 444 AS patients. The severity of radiographic damage was assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). To identify clinical and genetic factors associated with severe radiographic damage, multiple linear regression analyses were performed. Human AS osteoprogenitor cells were used for functional validation. Pathway analysis was also conducted.

Results

A total 444 AS patients (male 90.3%) were enrolled. The median mSASSS at baseline was 7.7 (5.5-16.8). The patients were observed for 9.6 (7.9-11.3) years. Within this period, the median mSASSS score increased to 14.0 (7.0-36.8). The most influential clinical factor of final mSASSS was baseline mSASSS (β = 0.818, p < 0.001). Peripheral joint involvement was associated with decreased possibility of severe radiographic damage (β = -0.221, p < 0.001). Eye involvement, longer follow up duration, and increased age at enrollment were associated with increased final mSASSS (β = 0.165, p < 0.001; β = 0.039, p < 0.001; β = 0.010, p = 0.002, respectively). Ryanodine receptor 3 (RYR3) gene was associated with severe radiographic damage (β = 1.105, p = 1.97x10-06). Treatment with Rhodamine B, a ligand of RYR3, induced extracellular matrix mineralization of AS osteoprogenitors in vitro. For the pathway analysis, PI3K-Akt signaling pathway and focal adhesion pathway were associated with severe radiographic damage in AS.

Conclusion

This study identified clinical and genetic factors that contributed to better understanding of the pathogenesis and biology associated with radiographic damage in AS.

References

[1]Li Z, Brown MA. Progress of genome-wide association studies of ankylosing spondylitis. Clinical & Translational Immunology. 2017;6(12):e163.

Disclosure of Interests

None declared

Cesium ion adsorption and desorption on electrospun mesoporous silica nanofibers immobilized with Prussian blue

To fabricate an efficient Cs ion adsorbent and prevent unexpected loss of Prussian blue (PB) colloidal particles during use, PB was immobilized on the surface of electrospun mesoporous silica nanofibers (MSFs) via a newly developed method of double exposure to Fe (III) ions. To introduce PB on MSFs, the MSFs were functionalized with ethylenediamine moiety to bind to Fe (III) ions, which would firmly anchor PB. MSFs were pretreated with Fe (III) ions and exposed to K₄ [Fe(II) (CN)₆] to form PB. We found that this process did not provide a sufficient PB amount on the MSFs. To increase the PB amount, after initial PB formation, the MSFs were treated with Fe (III) ions again so that the unreacted K₄ [Fe(II) (CN)₆] remaining on the MSFs could become PB. An investigation of the adsorption isotherms and kinetics of the nanofibrous adsorbent indicated that monolayer chemisorption had occurred. The maximum Cs ion adsorption capacity using the method of double exposure to Fe (III) ions was determined to be 14.66 mg/g, which was higher by a factor of 2.24 than the case that was not prepared by this method. Cs ions were selectively adsorbed over other cations and could be removed in both acidic and basic conditions, presumably because of the robust MSFs.

SOX9+ enthesis cells are associated with spinal ankylosis in ankylosing spondylitis

OBJECTIVE

Although cartilage degeneration and invasion of the subchondral bone plate in entheseal lesion has been considered to consequently lead bony ankylosis in ankylosing spondylitis (AS), no evident mechanisms are known.

DESIGN

To identify histopathological and physiological changes in enthesitis-related ankylosis in AS, we performed molecular characterization of transcription factors and surface markers, and transcriptome analysis with human tissues. Entheseal tissue containing subchondral bone was obtained from the facet joints of 9 patients with AS and 10 disease controls, and assessed by using differential staining techniques. Enthesis cells were isolated, characterized, stimulated with TNF and/or IL-17A, and analysed by cell-based experimental tools.

RESULTS

We found diffusely distributed granular tissue and cartilage in the subchondral bone in AS. Co-expression of SOX9, a specific transcription factor in cartilage, and matrix metalloproteinase 13 (MMP13) was found in the granular tissues within the subchondral bone from AS patients. Intriguingly, SOX9 expression was significantly higher in AS enthesis cells than controls and correlated with TNFR1 and IL-17RA expressions, which is important for high reactivity to TNF and IL-17A cytokines. Co-stimulation by TNF and IL-17A resulted in accelerated mineralization/calcification features, and increased OCN expression in AS enthesis cells. Furthermore, SOX9 overexpression in enthesis leads to promoting mineralization feature by TNF and IL-17A stimuli. Finally, OCN expression is elevated in the destructive enthesis of advanced AS.

CONCLUSION

These findings provide insight into the links between inflammation and the mineralization of entheseal tissue as the initiation of spinal ankylosis, emphasizing the importance of SOX9⁺ enthesis cells.

Fluorescence Modulation of Conjugated Polymer Nanoparticles Embedded in Poly(N-Isopropylacrylamide) Hydrogel

A series of conjugated polymers (CPs) emitting red, green, and blue (RGB) fluorescence were synthesized via the Suzuki coupling polymerization. Polymer dots (Pdots) were fabricated by the reprecipitation method from corresponding CPs, in which the Pdot surface was functionalized to have an allyl moiety. The CP backbones were based on the phenylene group, causing the Pdots to show identical ultraviolet-visible absorption at 350 nm, indicating that the same excitation wavelength could be used. The Pdots were covalently embedded in poly(N-isopropylacrylamide) (PNIPAM) hydrogel for further use as a thermoresponsive moiety in the polymer hydrogel. The polymer hydrogel with RGB emission colors could provide thermally reversible fluorescence changes. The size of the hydrogel varied with temperature change because of the PNIPAM’s shrinking and swelling. The swollen and contracted conformations of the Pdot-embedded PNIPAM enabled on-and-off fluorescence, respectively. Fluorescence modulation with 20 to 80% of the hydrogel was possible via thermoreversibility. The fluorescent hydrogel could be a new fluorescence-tuning hybrid material that changes with temperature.

Visible-Light-Driven Asymmetric TiO2-Based Photocatalytic Micromotor Hybridized with a Conjugated Polyelectrolyte and Glucose Oxidase

We fabricated a TiO₂-based micromotor that was asymmetrically decorated with a water-soluble conjugated polymer (WSP) on one hemisphere and glucose oxidase (GO_x) on the opposite hemisphere. The WSP, which had photocatalytic activity for H₂O₂ decomposition, enabled motion of the micromotor under visible light. The GO_x on the other hemisphere of the micromotor decomposed glucose to produce H₂O₂ and enabled motion of the micromotor without light irradiation. In addition, WSP and GO_x were attached to TiO₂ by chemical bonds, providing stability during use. As a result, the micromotor could move by self-generating H₂O₂ for its own fuel by consuming glucose even without photoirradiation. The micromotor could move faster than without visible light irradiation through the synergistic decomposition of glucose and H₂O₂ under visible light by the diffusiophoretic mechanism with a speed of 7.49 μm/s.

SAT0353 STAT3 PHOSPHORYLATION IS INVOLVED IN THE DEVELOPMENTS OF INFLAMMATORY ARTHRITIS, ENTHESITIS, AND NEW BONE FORMATION IN ANKYLOSING SPONDYLITIS

Background:

Ankylosing Spondylitis (AS) is a chronic inflammatory rheumatic disease, which is characterized by the enthesitis, peripheral arthritis, and chronic inflammation of the spine, leading to bony ankylosis. Signal transducer and activator of transcription (STAT) family proteins are latent cytoplasmic transcription factors that convey signals to the nucleus. It is activated by IL-6, IL-23, and IL-22 through JAK-mediated phosphorylation. Moreover, genetic studies implicate interleukin-23 (IL-23) receptor signal, including STAT3 in the development of AS. IL-17A has recently emerged as a potential target that regulates the extensive inflammation and abnormal bone formation observed in AS. It was reported that STAT3 is a regulatory factor that induces Th17 cell development from naive CD4 T cells.

Objectives:

The aim of this study is to investigate whether the STAT3 phosphorylation (stat3-p) inhibitor has a therapeutic effect on inflammation and new bone formation in AS.

Methods:

Eight weeks after curdlan injection, SKG mice were treated with stat3-p inhibitor or mock as a control. Clinical and histologic scores for arthritis and enthesitis were evaluated. Synovial fluid mononuclear cells (SFMC) samples were obtained from AS patients. Inflammatory cytokine producing cells were analyzed using flow cytometry. Bone tissue samples were obtained from the facet joints of patients with AS at surgery. Primary bone-derived cells (BdCs) were isolated and cultured. The osteogenic differentiation was assessed in vitro for 3 weeks using ALP activity, Alizarin red S (ARS), Type I collagen, von kossa,and hydroxyapatitestains. Statistical analysis was performed using Prism 5.0 Software. A p < 0.05 was considered statistically significant.

Results:

The stat3-p inhibitor significantly suppressed peripheral arthritis and enthesitis in SKG mice (figure 1). Inflammatory infiltration around the tendon–bone insertion site and along the tendon, as well as bony involvement were all reduced in stat3-p inhibitor-treated mice compared to control mice. We found that the levels of IFN-±, IL-17, TNF-± were higher in AS Synovial fluid. A significantly decreased frequencies of IFN-±, IL-17, TNF-± producing cells in AS SFMC were shown after stat3-p inhibitor treatment (P < 0.01).

In vitro experiment of bone formation, the stat3-p inhibitor suppressed ALP activity. In addition, there were significant decrease in Alizarin red S (ARS), Type I collagen, von kossa staining scores due to stat3-p inhibitor at a concentration of 5 μM.Light intensity of hydroxyapatitestaining was also decreased by stat3-p inhibitor in a dose dependent manner (figure 2). Intriguingly, the stat3-p inhibitor suppressed osteogenesis in both early phase and late phase in AS-BdCs, down-regulating osteoblast-involved genes.

Conclusion:

The stat3-p inhibitor had beneficial effects on reducing inflammation and new bone formation in AS animal model. In addition, stat3-p inhibitor suppressed bone formation in vitro experiment. These findings suggest that the stat3-p inhibitor could be a potential therapeutic agent for AS.

References:

[1]Arthritis Res Ther 2018;20:115.

[2]Nat Med 2012;18:1069-76.

[3]Rheumatology (Oxford) 2017;56:488-493.

[4]Nat Rev Immunol. 2011;11:239–50.

[5]J Exp Med 2005;201:949–60.

Acknowledgments:

None

Disclosure of Interests:

None declared

AB0116 DECREASED SERUM LEVEL OF IRISIN IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Irisin, exercise-mediated myokine, is one of the most recently discovered hormones. Irisin has been shown to play multifunctional roles including anti-inflammation by suppressing secretion of NF kß, TNF-α, IL-6, and other pro-inflammatory cytokines from macrophages and adipocytes [1]. Thus, several attempts have been made to investigate irisin in chronic inflammatory rheumatic diseases. And recent evidences show that serum irisin concentration is lower in patients with osteoarthritis, rheumatoid arthritis, and behcet disease than health individuals [2-4]. Furthermore, one study showed that serum irisin level was negatively correlated with radiographic severity of knee osteoarhtiritis [2]. However, no previous study has investigated irisin in patients with ankylosing spondylitis (AS).

Objectives:

To assess the serum level of irisin, and evaluate the possible relationship of irisin with disease activity in patients with AS.

Methods:

Male patients with AS fulfilled the modified New York criteria (n=119), and healthy male controls (n=30) were enrolled. Serum irisin level was measured by ELISA (Cusabio, CSB-EQ027943HU). Disease activity was assessed by acute phase reactants, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Clinical characteristics and serum irisin level of the AS group were compared with those of the control group using Student t-test for normally distributed continuous measures and Mann-Whitney U test for non-normally distributed continuous measures. To evaluate the correlations of serum Irisin level and AS disease activity, Spearman’s correlation test was used. AS patients were grouped into the high BASDAI group (BASDAI ≥ 4, n=45) and the Low BASDAI group (BASDAI < 4, n=74). And serum irisin level was also compared between two groups.

Results:

AS group had lower serum irisin concentration compared with healthy control group (60.50 [23.68-131.15] vs. 124.69 [79.58-192.90], p=0.013), while age and body mass index were not significantly different between groups. There was no significant correlation between irisin level and disease activities. However, High BASDAI group showed significantly lower irisin level than low BASDAI group (44.64 [18.13-85.89] vs. 65.68 [31.81-165.31], p=0.011).

Conclusion:

AS patients have lower serum irisin concentrations than healthy controls. AS patients with severe symptoms tend to have lower serum level of irisin than those with less severe symptoms.

References:

[1]H. Askari, et al. A glance at the therapeutic potential of irisin against diseases involving inflammation, oxidative stress, and apoptosis: an introductory review. Pharmacol Res. 2018

[2]Mao Y, et al. Association of Irisin and CRP Levels with the Radiographic Severity of Knee Osteoarthritis. Genet Test Mol Biomarkers. 2016

[3]Rania M. Gamal, et al. Preliminary study of the association of serum irisin levels with poor sleep quality in rheumatoid arthritis patients. Sleep Med. 2020

[4]A. Icli, et al. Novel myokine: irisin may be an independent predictor for subclinic atherosclerosis in Behcet’s disease. J. Investig. Med. 2016

Disclosure of Interests:

None declared

Unusual fluorescence of o-phenylazonaphthol derivatives with aggregation-induced emission and their use in two-photon cell imaging

Unusual fluorescence of o-phenylazonaphthol derivatives with aggregated-induced emission (AIE) is reported for the first time, which can be used in two-photon cell imaging applications.

Long-term outcomes of cemented versus cementless humeral components in arthroplasty of the shoulder

Aims

In the initial development of total shoulder arthroplasty (TSA), the humeral component was usually fixed with cement. Cementless components were subsequently introduced. The aim of this study was to compare the long-term outcome of cemented and cementless humeral components in arthroplasty of the shoulder.

Patients and Methods

All patients who underwent primary arthroplasty of the shoulder at our institution between 1970 and 2012 were included in the study. There were 4636 patients with 1167 cemented humeral components and 3469 cementless components. Patients with the two types of fixation were matched for nine different covariates using a propensity score analysis. A total of 551 well-balanced pairs of patients with cemented and cementless components were available after matching for comparison of the outcomes. The clinical outcomes which were analysed included loosening of the humeral component determined at revision surgery, periprosthetic fractures, post-operative infection and operating time.

Results

The overall five-, ten-, 15- and 20-year rates of survival were 98.9%, 97.2%, 95.5%, and 94.4%, respectively. Survival without loosening at 20 years was 98% for cemented components and 92.4% for cementless components. After propensity score matching including fixation as determined by the design of the component, humeral loosening was also found to be significantly higher in the cementless group. Survival without humeral loosening at 20 years was 98.7% for cemented components and 91.0% for cementless components. There was no significant difference in the risk of intra- or post-operative fracture. The rate of survival without deep infection and the mean operating time were significantly higher in the cemented group.

Conclusion

Both types of fixation give rates of long-term survival of > 90%. Cemented components have better rates of survival without loosening but this should be weighed against increased operating time and the risk of bony destruction of the proximal humerus at the time of revision of a cemented humeral component. Cite this article: Bone Joint J 2017;99-B:666–73.

Conjugated polymer dots-on-electrospun fibers as a fluorescent nanofibrous sensor for nerve gas stimulant

A novel chemical warfare agent sensor based on conjugated polymer dots (CPdots) immobilized on the surface of poly(vinyl alcohol) (PVA)-silica nanofibers was prepared with a dots-on-fibers (DoF) hybrid nanostructure via simple electrospinning and subsequent immobilization processes. We synthesized a polyquinoxaline (PQ)-based CP as a highly emissive sensing probe and employed PVA-silica as a host polymer for the elctrospun fibers. It was demonstrated that the CPdots and amine-functionalized electrospun PVA-silica nanofibers interacted via an electrostatic interaction, which was stable under prolonged mechanical force. Because the CPdots were located on the surface of the nanofibers, the highly emissive properties of the CPdots could be maintained and even enhanced, leading to a sensitive turn-off detection protocol for chemical warfare agents. The prepared fluorescent DoF hybrid was quenched in the presence of a chemical warfare agent simulant, due to the electron transfer between the quinoxaline group in the polymer and the organophosphorous simulant. The detection time was almost instantaneous, and a very low limit of detection was observed (∼1.25 × 10(-6) M) with selectivity over other organophosphorous compounds. The DoF hybrid nanomaterial can be developed as a rapid, practical, portable, and stable chemical warfare agent-detecting system and, moreover, can find further applications in other sensing systems simply by changing the probe dots immobilized on the surface of nanofibers.

Bupivacaine-induced cellular entry of QX-314 and its contribution to differential nerve block

BACKGROUND AND PURPOSE

Selective nociceptor fibre block is achieved by introducing the cell membrane impermeant sodium channel blocker lidocaine N-ethyl bromide (QX-314) through transient receptor potential V1 (TRPV1) channels into nociceptors. We screened local anaesthetics for their capacity to activate TRP channels, and characterized the nerve block obtained by combination with QX-314.

EXPERIMENTAL APPROACH

We investigated TRP channel activation in dorsal root ganglion (DRG) neurons by calcium imaging and patch-clamp recordings, and cellular QX-314 uptake by MS. To characterize nerve block, compound action potential (CAP) recordings from isolated nerves and behavioural responses were analysed.

KEY RESULTS

Of the 12 compounds tested, bupivacaine was the most potent activator of ruthenium red-sensitive calcium entry in DRG neurons and activated heterologously expressed TRPA1 channels. QX-314 permeated through TRPA1 channels and accumulated intracellularly after activation of these channels. Upon sciatic injections, QX-314 markedly prolonged bupivacaine's nociceptive block and also extended (to a lesser degree) its motor block. Bupivacaine's blockade of C-, but not A-fibre, CAPs in sciatic nerves was extended by co-application of QX-314. Surprisingly, however, this action was the same in wild-type, TRPA1-knockout and TRPV1/TRPA1-double knockout mice, suggesting a TRP-channel independent entry pathway. Consistent with this, high doses of bupivacaine promoted a non-selective, cellular uptake of QX-314.

CONCLUSIONS AND IMPLICATIONS

Bupivacaine, combined with QX-314, produced a long-lasting sensory nerve block. This did not require QX-314 permeation through TRPA1, although bupivacaine activated these channels. Regardless of entry pathway, the greatly extended duration of block produced by QX-314 and bupivacaine may be clinically useful.

Conjugated poly(fluorene-quinoxaline) for fluorescence imaging and chemical detection of nerve agents with its paper-based strip

Conjugated polymer of poly(fluorene-co-quinoxaline) was synthesized via Suzuki coupling polymerization. The emission color of the polymer can be tuned depending on the concentration of the polymer in solution. A low-energy bandgap is observed both in the concentrated solution and in the solid state, caused by aggregation of the polymer chains, resulting in long wavelength emission from the quinoxaline moiety, while short wavelength emission can be seen in diluted, well-dissolved solution. The presence of quinoxaline units enables us to demonstrate fluorescence switching and imaging. Paper-based strips containing the polymer are prepared via simple immersion of filter paper in the polymer solution for practical use in the detection of nerve agents. The emission of the paper-based strip is quenched upon exposure to diethyl chlorophosphate (DCP), a nerve agent simulant, and the initial emission intensity can be almost restored by treatment with aqueous sodium hydroxide solution, making a possible reversible paper-based sensor.

Differences in omega-3 and fatty acid profiles between patients with endometriosis and those with a functional ovarian cyst

Endometriosis is a chronic inflammatory gynaecological disease. Problems associated with endometriosis include dysmenorrhoea, dyspareunia and infertility. We evaluated the omega-3 and fatty acid profiles in erythrocytes and tissues in patients with endometriosis (n = 10) or a functional ovarian cyst (n = 12), using a food frequency questionnaire that included questions about 117 food items typical of Korean meals. Erythrocyte levels of 20:5n3 and 22:6n3, the omega-3 index, and n-3 PUFA were significantly higher, and the n-6:n-3 ratio was significantly lower in the endometriosis group than in the functional ovarian cyst group. The functional ovarian cyst group consumed significantly more fruit than the group with endometriosis.

Simple technique for spatially separated nanofibers/nanobeads by multinozzle electrospinning toward white-light emission

Electrospun, emission color-tunable nanofibrous sheets were fabricated by multinozzle electrospinning equipped with a secondary electrode for the preparation of white-emissive sheets under a single excitation source, manipulating energy transfer between dyes. By control of the concentration of commercially available red, green, and blue dyes in the matrix polymer [poly(methyl methacrylate)], emission color tuning can be easily accomplished because each dye is located in spatially separated fibers to maintain enough distance to prevent or suppress energy transfer, allowing white-light emission. The application of dye separation for the white-light emission upon excitation with a blue light-emitting-diode lamp is demonstrated, indicative of its potential application for the easy and facile tuning of fluorescence color toward flexible illumination.

A novel thermosensitive polymer with pH-dependent degradation for drug delivery

A class of thermosensitive biodegradable multiblock copolymers with acid-labile acetal linkages were synthesized from Pluronic triblock copolymers (Pluronic P85 and P104) and di-(ethylene glycol) divinyl ether. The novel polymers were engineered to form thermogels at body temperature and degrade in an acidic environment. The Pluronic-based acid-labile polymers were characterized using nuclear magnetic resonance, gel permeation chromatography and differential scanning calorimetry. In vitro biocompatibility of the synthesized polymers was evaluated using calorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The polymers showed reverse thermogelling behavior in water around body temperature. The sol-gel transition temperatures of the polymers synthesized from Pluronic P85 and P104 were lowered from 70.3 to 30 degrees C and from 68.5 to 26.9 degrees C, respectively, when the synthesized polymers were compared with corresponding Pluronic block copolymers at a concentration of 25wt.%. The hydrophobic dye solubilization confirmed the formation of polymeric micelles in the aqueous solution. The sizes of the multiblock copolymers increased on a rise in temperature, indicating that thermal gelation was mediated by micellar aggregation. The thermally driven hydrogels showed preferential polymer degradation at acidic pH. At pH 5.0 and 6.5, the release of 40kDa fluorescein isothiocyanate-dextran (FITC-dextran) from the thermally formed hydrogels was completed within 2 and 9 days, respectively. However, FITC-dextran was continuously released up to 30 days at neutral pH. The mechanism of FITC-dextran release at pH 5.0 was mainly an acid-catalyzed degradation, whereas both diffusion and pH-dependent degradation resulted in FITC-dextran release at pH 6.5. The novel polymers hold great potential as a pH-sensitive controlled drug delivery system owing to their interesting phase transition behavior and biocompatibility.

Iron monosulfide as a scavenger for dissolved hexavalent chromium and cadmium

Iron sulfide minerals are common components of soil/sedimentary environments. Reactions near the surfaces of iron sulfides play important roles in metal retention, mobility, and bioavailability. A series of batch experiments was conducted to study the removal of aqueous chromium and cadmium by iron monosulfide. Hexavalent chromium was reduced to Cr(III) by iron monosulfide with simultaneous precipitation of chromium and iron oxyhydroxide. In contrast to chromium, the primary retention mechanism of cadmium by iron monosulfide was lattice exchange. Surface adsorption to iron monosulfide and precipitation with sulfide on the iron monosulfide surface also contributed to the removal of aqueous cadmium. New phases of both chromium and cadmium were confirmed with transmission electron microscopy. The solution pH was an important factor in this research; it can change particle surface charge and metal species, hence affecting the removal of chromium, but not cadmium. Ferrous ions without FeS exhibited less Cr(VI) removal than with FeS, which might be owing to sulfides from FeS and the existence of the solid phase. Iron monosulfide exhibited higher removal efficiency for chromium and cadmium than zero valent iron and other iron oxide minerals, and the synergistic effect of ferrous iron and sulfide appeared to cause this result.