Self-Regenerative Ni-Doped CaTiO3/CaO for Integrated CO2 Capture and Dry Reforming of Methane

In this work, a new type of multifunctional materials (MFMs) called self-regenerative Ni-doped CaTiO3/CaO is introduced for the integrated CO2 capture and dry reforming of methane (ICCDRM). These materials consist of a catalytically active Ni-doped CaTiO3 and a CO2 sorbent, CaO. The article proposes a concept where the Ni catalyst can be regenerated in situ, which is crucial for ICCDRM. Exsolved Ni nanoparticles are evenly distributed on the surface of CaTiO3 under H2 or CH4, and are re-dispersed back into the CaTiO3 lattice under CO2. The Ni-doped CaTiO3/CaO MFMs show stable CO2 capture capacity and syngas productivity for 30 cycles of ICCDRM. The presence of CaTiO3 between CaO grains prevents CaO/CaCO3 thermal sintering during carbonation and decarbonation. Moreover, the strong interaction of CaTiO3 with exsolved Ni mitigates severe accumulation of coke deposition. This concept can be useful for developing MFMs with improved properties that can advance integrated carbon capture and conversion.

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.

Co-Exsolution of Ni-Based Alloy Catalysts for the Valorization of Carbon Dioxide and Methane

ConspectusThe reversible coexsolution mechanism of perovskite oxides is emerging as an alternative method for synthesizing alloy catalyst nanoparticles. Co-exsolution is a partial decomposition process where multiple B cations diffuse from the bulk of a solid precursor and nucleate on the surface. The unique properties of exsolved alloy catalysts, including improved dispersion, thermal stability, and compositional malleability, make them particularly useful for converting CO2 into chemical commodities and fuels. However, the coexsolution of alloys is still in development, and fundamental insights into the alloying mechanism, formation of nanoparticles, and defect chemistry are needed.This Account examines the solid-state chemistry of perovskite oxide precursors and reaction parameters that can be altered to control the assembly or exsolution of Ni-based alloys. The characteristics of bulk perovskite oxide precursors heavily influence the exsolved alloy catalyst nanoparticle assembly, growth, and composition. Inherent defects, such as oxygen vacancies and grain boundaries, primarily facilitate the transport of catalytic B-cation dopants from the bulk to the surface. An example of how bulk defects can affect the properties of Ni-based alloy catalysts is demonstrated through the formation of NiFe from La(Fe, Ni)O3. The A/B cation ratio plays a significant role in determining the size and composition of NiFe nanoparticles, which directly impacts their catalytic performance. Using in situ X-ray absorption spectroscopy (in situ XAS), the dynamic behavior of exsolved NiFe nanoparticles can be observed in different reaction environments (oxidation, reduction, and dry reforming of methane) by tracking the oxidation state and local environment of the Ni K-edge and Fe K-edge using X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), respectively. Time-resolved experiments with in situ XAS showed that NiFe nanoparticle growth starts at ∼280 °C and transforms from predominantly Ni to NiFe at higher reduction times and temperatures.The challenges of exsolution of higher-order Ni-based alloys, such as 3(NiFeCo), 4(NiCoCuPd), and 5(NiFeCoCuPd) element nanoparticles, to improve the catalyst properties are discussed. The size, concentration, and reducibility of the dopant cation can alter the exsolution kinetics, alloy nanoparticle growth dynamics, and catalyst performance. The size and composition of exsolved Ni-based alloys affect the effectiveness of catalysts in the dry reforming of methane. Large NiFeCo nanoparticles separated from Pd and Cu can lead to catalyst deactivation, but using a complex alloy with smaller NiFeCoPdCu nanoparticles results in a stable performance. The use of in situ XANES reveals how the dry reforming of methane reaction conditions can induce changes in the NiFe with the rapid redissolution of Fe back into the lattice.The dynamicity of the exsolved Ni-based alloy nanoparticles and implications for their regeneration after aging or exposure to waste gas contaminants are discussed. Finally, we summarize the Account and provide promising future directions.

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.

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

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.

A review of wearable biosensors for sweat analysis

Recent advances in the skin-interfaced wearable sweat sensors allow a personalized daily diagnosis and prognosis of the diseases in a form of a non-invasive, portable, and continuous monitoring system. Especially, the soft microfluidic system provides robust quantitative analysis platforms that integrate sweat sampling, storing, and various sensing capabilities. This review systematically introduces the sweat collecting mechanism using soft microfluidic valves, including calculation of sweat storage and loss. In terms of sweat analysis, colorimetric (e.g. enzymatic, chemical, or their mixed reactions), electrochemical (e.g. voltammetric, potentiometric, amperometric, or conductometric), and multiplex measurements of sweat contents facilitate diagnosis of diseases via analysis of combined multiple data, such as vital signals (e.g. ECG, EMG, EEG, etc.) and information from the skin (e.g. temperature, GSR, etc.). The integration of wireless communication with the microfluidic systems enables point-of-care health monitoring for disease and specific physiological status.

Wirelessly controlled, bioresorbable drug delivery device with active valves that exploit electrochemically triggered crevice corrosion

Implantable drug release platforms that offer wirelessly programmable control over pharmacokinetics have potential in advanced treatment protocols for hormone imbalances, malignant cancers, diabetic conditions, and others. We present a system with this type of functionality in which the constituent materials undergo complete bioresorption to eliminate device load from the patient after completing the final stage of the release process. Here, bioresorbable polyanhydride reservoirs store drugs in defined reservoirs without leakage until wirelessly triggered valve structures open to allow release. These valves operate through an electrochemical mechanism of geometrically accelerated corrosion induced by passage of electrical current from a wireless, bioresorbable power-harvesting unit. Evaluations in cell cultures demonstrate the efficacy of this technology for the treatment of cancerous tissues by release of the drug doxorubicin. Complete in vivo studies of platforms with multiple, independently controlled release events in live-animal models illustrate capabilities for control of blood glucose levels by timed delivery of insulin.

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

Soft, skin-interfaced microfluidic systems with integrated enzymatic assays for measuring the concentration of ammonia and ethanol in sweat

Eccrine sweat is a rich and largely unexplored biofluid that contains a range of important biomarkers, from electrolytes, metabolites, micronutrients and hormones to exogenous agents, each of which can change in concentration with diet, stress level, hydration status and physiologic or metabolic state. Traditionally, clinicians and researchers have used absorbent pads and benchtop analyzers to collect and analyze the biochemical constituents of sweat in controlled, laboratory settings. Recently reported wearable microfluidic and electrochemical sensing devices represent significant advances in this context, with capabilities for rapid, in situ evaluations, in many cases with improved repeatability and accuracy. A limitation is that assays performed in these platforms offer limited control of reaction kinetics and mixing of different reagents and samples. Here, we present a multi-layered microfluidic device platform with designs that eliminate these constraints, to enable integrated enzymatic assays with demonstrations of in situ analysis of the concentrations of ammonia and ethanol in microliter volumes of sweat. Careful characterization of the reaction kinetics and their optimization using statistical techniques yield robust analysis protocols. Human subject studies with sweat initiated by warm-water bathing highlight the operational features of these systems.

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.

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.

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.

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.

Injectable,in situ forming poly(propylene fumarate)-based ocular drug delivery systems

This study sought to develop an injectable formulation for long-term ocular delivery of fluocinolone acetonide (FA) by dissolving the anti-inflammatory drug and the biodegradable polymer poly(propylene fumarate) (PPF) in the biocompatible, water-miscible, organic solvent N-methyl-2-pyrrolidone (NMP). Upon injection of the solution into an aqueous environment, a FA-loaded PPF matrix is precipitated in situ through the diffusion/extraction of NMP into surrounding aqueous fluids. Fabrication of the matrices and in vitro release studies were performed in phosphate buffered saline at 37 degrees C. Drug loadings up to 5% were achieved. High performance liquid chromatography was employed to determine the released amount of FA. The effects of drug loading, PPF content of the injectable formulation, and additional photo-crosslinking of the matrix surface were investigated. Overall, FA release was sustained in vitro over up to 400 days. After an initial burst release of 22 to 68% of initial FA loading, controlled drug release driven by diffusion and bulk erosion was observed. Drug release rates in a therapeutic range were demonstrated. Release kinetics were found to be dependent on drug loading, formulation PPF content, and extent of surface crosslinking. The results suggest that injectable, in situ formed PPF matrices are promising candidates for the formulation of long-term, controlled delivery devices for intraocular drug delivery.

Long-term release of fluocinolone acetonide using biodegradable fumarate-based polymers

Intraocular drug delivery systems made from biodegradable polymers hold great potential to effectively treat chronic diseases of the posterior segment of the eye. This study is based on the hypothesis that crosslinked poly(propylene fumarate) (PPF)-based matrices are suitable long-term delivery devices for the sustained release of the anti-inflammatory drug fluocinolone acetonide (FA) due to their hydrophobicity and network density. FA-loaded rods of 10 mm length and 0.6 mm diameter were fabricated by photo-crosslinking PPF with N-vinyl pyrrolidone (NVP). The released amounts of FA and NVP were determined by HPLC analysis. The effects of drug loading and the ratio of PPF to NVP on the release kinetics were investigated using a 2(3-1) factorial design. Overall, FA release was sustained in vitro over almost 400 days by all tested formulations. Low burst release was followed by a dual modality release controlled by diffusion and bulk erosion with release rates up to 1.7 microg/day. The extent of the burst effect and the release kinetics were controlled by the drug loading and the matrix composition. Matrix water content and degradation were determined gravimetrically. Micro-computed tomography was used to image structural and dimensional changes of the devices. The results show that photo-crosslinked PPF-based matrices are promising long-term delivery devices for intraocular drug delivery.

Modification of oligo(poly(ethylene glycol) fumarate) macromer with a GRGD peptide for the preparation of functionalized polymer networks

A novel macromer, oligo(poly(ethylene glycol) fumarate) (OPF), was synthesized by the reaction between poly(ethylene glycol) (PEG) of molecular weight 1000 (PEG 1.0K) and fumaryl chloride. The oligo(PEG fumarate) (OPF 1.0K) was modified with a peptide known to modulate cellular functions, Gly-Arg-Gly-Asp (GRGD), after being activated with 4-nitrophenyl chloroformate (NPC). The determined yield of the GRGD modification in 0.1 M sodium bicarbonate buffer of pH 8.3 was 83% as determined by NMR measurements. The OPF 1.0K and the OPF 1.0K modified with GRGD were cross-linked with an unsaturated biodegradable polyester, poly(propylene fumarate) (PPF), by photopolymerization. The cross-linked PPF was characterized by Fourier transform infrared (FT-IR) spectroscopy and contact angle measurements. The equilibrium contact angle of water on the cross-linked PPF surface decreased with the incorporation of OPF 1.0K and the OPF 1.0K modified with GRGD. The results suggest that the OPF macromer can be used for the preparation of functionalized networks incorporating cell adhesion specific sequences.

Reduced frequencies of peripheral interferon-gamma-producing CD4+ and CD4- cells during acute Kawasaki disease

BACKGROUND

This study was performed to analyze the frequencies of peripheral interferon (IFN)-gamma-producing cells at the single-cell level and to determine concentrations of circulating IFN-gamma in the acute and subacute phases of Kawasaki disease (KD).

METHODS

Ten patients with KD were studied and seven healthy children were selected as control subjects. Using immunofluorescent detection of intracellular IFN-gamma in CD4-positive and CD4-negative cells, the frequencies of IFN-gamma-producing cells in peripheral blood mononuclear cells were studied. Circulating IFN-gamma levels were measured by enzyme-linked immunosorbent assay.

RESULTS

The frequencies of peripheral blood CD4+ and CD4- IFN-gamma-producing cells in acute-phase KD patients were significantly lower than in subacute-phase KD patients and control children (p < 0.05). CD4- cells, thought to be mainly composed of CD8+ cells, appeared to be more responsible for the reduced frequencies of total IFN-gamma-producing cells than CD4+ cells. There were, however, no differences in the frequencies of IFN-gamma-producing cells between KD patients in the subacute phase and control children. In contrast, serum IFN-gamma levels were higher in KD patients in the acute phase than in the subacute phase (p < 0.05).

CONCLUSIONS

The above results show increased levels of circulating IFN-gamma and decreased emergence of peripheral IFN-gamma-producing cells in acute KD patients, suggesting transient infiltration of activated IFN-gamma-producing cells into the inflammatory sites during acute KD. These findings also support the hypothesis that IFN-gamma plays an important role in the pathogenesis of KD-related vasculitis.

RNase P ribozymes selected in vitro to cleave a viral mRNA effectively inhibit its expression in cell culture

An in vitro selection procedure was used to select RNase P ribozyme variants that efficiently cleaved the sequence of the mRNA encoding thymidine kinase of herpes simplex virus 1. Of the 45 selected variants sequenced, 25 ribozymes carried a common mutation at nucleotides 224 and 225 of RNase P catalytic RNA from Escherichia coli (G(224)G(225) --> AA). These selected ribozymes exhibited at least 10 times higher cleavage efficiency (k(cat)/K(m)) than that derived from the wild type ribozyme. Our results suggest that the mutated A(224)A(225) are in close proximity to the substrate and enhance substrate binding of the ribozyme. When these ribozyme variants were expressed in herpes simplex virus 1-infected cells, the levels of thymidine kinase mRNA and protein were reduced by 95-99%. Our study provides the first direct evidence that RNase P ribozyme variants isolated by the selection procedure can be used for the construction of gene-targeting ribozymes that are highly effective in tissue culture. These results demonstrate the potential for using RNase P ribozymes as gene-targeting agents against any mRNA sequences, and using the selection procedure as a general approach for the engineering of RNase P ribozymes.

Surface modification using silanated poly(ethylene glycol)s

Surface-grafted poly(ethylene glycol) (PEG) molecules are known to prevent protein adsorption to the surface. The protein-repulsive property of PEG molecules are maximized by covalent grafting. We have synthesized silanated monomethoxy-PEG (m-PEG) for covalent grafting of PEG to surfaces with oxide layers. Two different trialkoxysilylated PEGs were synthesized and characterized. The first trialkoxysilylated PEG was prepared by direct coupling of m-PEG with 3-isocyanatopropyltriethoxysilane through a urethane bond (silanated PEG I). The other silanated PEG (silanated PEG II) containing a long hydrophobic domain between PEG and a silane domain was prepared by reacting m-PEG with 1,6-diisocyanatohexane and 10-undecen-1-ol in sequence before silylation with 3-mercaptopropyl trimethoxysilane. Silanated PEGs I and II were grafted onto glass, a model surface used in our study. The PEG-grafted glass surfaces were characterized by contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Although contact angle did not change much as the bulk concentration of silanated PEG used for grafting increased from 0.1 to 20 mg/ml for both PEGs I and II, the surface atomic concentrations from XPS measurements showed successful PEG grafting. Surface PEG grafting increased concentration of surface carbon but decreased silicone concentration. The high resolution C1s spectra showed higher ether carbon with lower hydrocarbon compositions for the PEG-grafted surfaces compared to the control surface. AFM images showed that more PEG molecules were grafted onto the surface as the bulk concentration used for grafting was increased. AFM images of the dried surfaces showed that the surfaces were not completely covered by PEG molecules. After hydration, however, the surface appears to be covered completely probably due to the hydration of the grafted PEG chains. Glass surfaces modified with silanated PEGs reduced fibrinogen adsorption by more than 95% as compared with the control surface. Silanated PEGs provides a simple method for PEG grafting to the surface containing oxide layers.

Treatment of superficial esophageal cancer by external radiation therapy alone: results of a multi-institutional experience

PURPOSE

To assess the effectiveness and toxicity of external radiation therapy for superficial esophageal cancer.

METHODS AND MATERIALS

During the period from March 1979 to November 1996, 78 patients with superficial esophageal cancer received radiation therapy without intracavitary irradiation at nine radiotherapy institutions in Japan. All patients had histologically-proven squamous cell carcinoma. Endoscopic ultrasonography was performed in 34 patients to discriminate mucosal from submucosal cancer. Most of the patients had received radiation therapy using conventional fractionation at an average dose of 65.5 Gy.

RESULTS

The survival rates at 1, 2, and 5 years were 88%, 73%, and 45%, respectively. The local control rates at 1, 2, and 5 years were 85%, 79%, and 66%, respectively. Although the difference was not significant, the survival rate of cancer patients with a tumor invading the submucosa was lower than that of the other patients. In 6 mucosal cancer patients, local recurrence was observed in 1 patient with extensive cancer. Regional lymph node recurrence and distant failure were not observed in mucosal cancer patients, while in 28 submucosal cancer patients, the 5-year survival rate and relapse free rate were only 49% and 43%, respectively. Univariate and multivariate analysis identified age as the only significant prognostic factor. Severe late injury, such as esophageal ulcer, perforation, and bleeding, was not observed.

CONCLUSION

External radiation therapy is effective for mucosal cancer. However, further investigation is needed to establish a better standard treatment protocol for submucosal cancer.