Survey of diversity awareness and environment among members of the Pediatric Rheumatology Association of Japan.

BACKGROUND: Diversity management has gained traction in Japan. The Pediatric Rheumatology Association of Japan (PRAJ) has an Advisory Committee for Diversity Promotion with a broader focus on promoting diversity. The objectives of this study were to better understand the problems faced by PRAJ members regarding the work environment, childcare and nursing care, and work-life balance. METHODS: A web-based questionnaire was administered to members of the PRAJ and 79 responses were evaluated. RESULTS: Of the respondents, 73% were male and 27% were female. A total of 14% worked for more than 12 h on weekdays, and 22% worked for more than 60 h per week and 38% had fewer than 4 days off per month. Regarding childcare, 54% of the respondents were raising preschool children and 83% had taken parental leave for less than 1 year. A total of 17% of participants had family members in need of care. For both childcare and caregiving, the burden was greater for women. Only 18% of the respondents reported a well-balanced work-life balance, and the most common reasons for a lack of balance were not having enough time, heavy workload, and heavy housework load. CONCLUSIONS: The working hours of the respondents were long, and female members had a greater burden of childcare and caregiving, which was considered a barrier to the career development of women. In the future, there will be a need to promote a sense of equality in diverse human resources, develop support for family life, and shorten working hours.

Kinetics of Enzymatic Reactions at the Solid/Liquid Interface in Nanofluidic Channels.

Nanostructures can realize highly efficient reactions due to their structural advantages. However, the mechanism of accelerating enzyme reactions in a nanospace is still unknown from a kinetic perspective because it is difficult to control a well-defined nanospace, enzyme density, and reaction time. Here, we investigated kinetic parameters of an immobilized enzyme in micro- and nanochannels using nanofabrication, partial enzyme patterning, fluidic control, and a high sensitivity detection system. Devices with channel depths of 300 nm, 4.4 µm, and 13.6 µm were fabricated. Kinetic parameters were determined by the Michaelis-Menten model. Compared to the bulk reaction, all kcats for immobilized enzyme reactors were decreased, although the kcats were approximately the same for the immobilized enzyme reactors of different depths. An ultrafast enzyme reaction could overcome the drawback due to immobilization by an increase of the apparent [E]0 due to the decreased channel depth.

A case of cryopyrin-associated periodic fever syndrome during canakinumab administration complicated by inflammatory bowel disease.

Cryopyrin-associated periodic fever syndrome (CAPS) is a highly debilitating disorder, which is characterized by unregulated interleukin-1ß production driven by autosomal dominantly inherited mutations in the NLRP3 gene. Patients with CAPS often present with early-onset episodes of fever and rash. These patients also present with variable systemic signs and symptoms, such as arthritis, sensorineural hearing loss, chronic aseptic meningitis, and skeletal abnormalities, but minimal gastrointestinal symptoms. Recently, effective therapies for CAPS targeted against interleukin-1 have become available. We report a case of a young Japanese woman with CAPS who developed inflammatory bowel disease during canakinumab therapy. The patient had colostomy after intestinal perforation and changed canakinumab to infliximab. To the best of our knowledge, this is the first report of a case of inflammatory bowel disease secondary to CAPS complicated by gastrointestinal symptoms and arthritis which canakinumab could not control. Patients with CAPS who have symptoms that cannot be controlled by canakinumab should be considered for possible co-morbidities.

Picoliter enzyme reactor on a nanofluidic device exceeding the bulk reaction rate.

Single-cell analyses have recently become important to understand cell heterogeneity, the mechanism of cell function, and diseases. In contrast to single-cell analyses that target nucleic acids, single-cell protein analyses still pose challenges. We have proposed a general concept of integration and extended this concept to the 10-1000 nm scale with femtoliter-picoliter volumes which are smaller than the volume of a single cell exploring ultimate analytical performances (e.g. single-cell target proteomics). However, single-cell shotgun proteomics, which is used to analyze even unknown proteins, is still challenging because there is no digestion column with picoliter volume. The issues were long reaction time (overnight) and much larger reaction volume (microliter) in the conventional bulk method. In this study, an ultra-fast picoliter enzyme reactor using a nanochannel was developed. A device with a channel depth of 300 nm and a volume of 32.4 pL was fabricated. To prevent the self-digestion of trypsin (enzyme), the picoliter enzyme reactor was prepared by immobilizing trypsinogen which was activated to trypsin by enterokinase. The enzyme density obtained by the trypsinogen immobilization process was 2.5 times higher than that obtained by the conventional trypsin immobilization process. Furthermore, the apparent enzyme concentration was 36 times higher due to an extremely high surface-to-volume ratio of the nanochannel, compared to the limit concentration in the bulk. Finally, the enzyme reaction in the picoliter enzyme reactor was accelerated 25 times compared to that in the bulk. Using the picoliter enzyme reactor, protein solution with picoliter volume will be digested without self-digestion and artificial modification, which will greatly contribute to single-cell shotgun proteomics.

The Use of a Combination of a Sugar and Surfactant to Stabilize Au Nanoparticle Dispersion against Aggregation during Freeze-Drying.

Drying a suspension of nanoparticles typically results in the irreversible aggregation of nanoparticles; however, solutions that contain unstable ingredients are often converted into dried powders to prolong their shelf lives. In this study, the use of a combination of a surface-active agent and sugar was investigated with regard to avoiding the aggregation of nanoparticles during drying. Suspensions of Au nanoparticles (∼60 nm diameter, AuNPs) were freeze-dried in the presence of different combinations of various sugars with a surfactant. Sucrose monopalmitate (SEC16) was mainly used as the surfactant, based on a comparison of antiaggregation effects conferred by various surfactants. The freeze-dried AuNP suspension was then reconstituted, and the avoidance of AuNP aggregation was then examined. The results demonstrated that the use of a combination of a small amount of SEC16 and sugar resulted in a greater redispersibility of AuNPs after freeze-drying than when the individual components were used. Repetition tests of freeze-drying and reconstitution were conducted. The sucrose/SEC16 mixture was freeze-dried on an electroless-plated Au film and then analyzed by infrared spectroscopy. Strong interactions between SEC16 and the Au surface were detected, and these interactions appear to play a crucial role in the antiaggregation of AuNPs during freeze-drying.

Immobilization of surface non-affinitive protein onto a metal surface by an external electric field.

We investigated an alternate technique to coat the surface with a protein having no surface affinity, without the use of any exotic chemical agents. An external electric field was utilized to prepare the protein coating on a metal substrate. Stainless steel (St) substrate and lysozyme (LSZ) were used as the surface to be coated and the model non-adsorptive protein, respectively. Dynamics of the adsorption of LSZ on the St surface in the presence and absence of an external electric potential (EEP) were monitored by in-situ ellipsometry. Applying negative surface potential (-0.4 V vs Ag/AgCl) forced the adsorption of LSZ onto the St surface where LSZ did not adsorb without applying any EEP. The repetition of the EEP-application and -cut-off indicated the controllability of the LSZ coating amount depending on the total duration of the EEP-application. The coated LSZ largely remained bound to the surface even by the cut-off of the external electric field, the ratio of which to the detached amount was roughly constant (approximately 7:3). Furthermore, the LSZ coated surface on the St substrate was found to be reversibly switched between being affinitive and non-affinitive to a typical model protein adsorbate (bovine serum albumin) by the EEP-application and cut-off.

Physical Stability of an Amorphous Sugar Matrix Dried From Methanol as an Amorphous Solid Dispersion Carrier and the Influence of Heat Treatment.

An amorphous sugar matrix, after drying from an organic solvent, was investigated for use as a method for dispersing hydrophobic drugs (solid dispersion). However, the amorphous sugar, originally contained in the organic solvent, had a significantly low glass transition temperature (Tg), thus rendering it physically unstable. In this study, we examined the physicochemical properties of a sugar in a dried matrix and in an organic solvent, using α-maltose and methanol as a representative sugar and organic solvent. The apparent molar volume of α-maltose was ∼30% smaller in methanol than in water. The methanol-originated amorphous α-maltose exhibited a much greater degree of hydrogen bonding than the water-originated one. Considering these findings, we conclude that the α-maltose maintained its compact conformation in the dried state and consequently caused the markedly low Tg. Second, it was found that heating under appropriate conditions resulted in an increase in the Tg of the methanol-originated amorphous α-maltose as well as a decrease in the level of hydrogen bonding. The aqueous dissolution of 2 model hydrophobic drugs (indomethacin and ibuprofen) from the solid dispersion was also improved as the result of the heat treatment, whereas, to the contrary, the dissolution of another model drug (curcumin) was lowered.

S100A12 and vascular endothelial growth factor can differentiate Blau syndrome and familial Mediterranean fever from systemic juvenile idiopathic arthritis.

OBJECTIVES: Systemic juvenile idiopathic arthritis (sJIA) has recently become regarded as one of the autoinflammatory syndromes (AIS). However, other AIS, such as familial Mediterranean fever (FMF) and Blau syndrome, have been initially misdiagnosed as sJIA because of the clinical similarities. Making the correct diagnosis in the early stage of these AIS is desirable. Therefore, we evaluated serum S100A12 and vascular endothelial growth factor (VEGF) levels to determine if they could be biomarkers for differentiating these AIS. METHOD: Serum S100A12 and VEGF levels were examined in patients with Blau syndrome (n = 4), FMF (n = 4), and sJIA (n = 11) in the active and inactive phases. RESULTS: In the active phase, S100A12 levels were significantly higher in patients with sJIA and FMF compared with those with Blau syndrome (p < 0.001). VEGF levels of patients with sJIA were significantly higher than those of patients with others (p = 0.001). In the inactive phase, there was no significant difference in VEGF levels. However, colchicine-resistant patients or patients without treatment with FMF showed high levels of S100A12 compared with others. CONCLUSIONS: Measuring both serum S100A12 and VEGF levels may be useful for differentiating patients with Blau syndrome and FMF from those with sJIA at the early stage.

Adsorption characteristics of various proteins on a metal surface in the presence of an external electric potential.

The effect of the properties of a protein on its adsorption to a metal surface in the presence of external electric potential was investigated. Protein adsorption processes at different surface potentials were measured for fifteen types of proteins using an in-situ ellipsometry. The tested proteins were classified into three groups, based on the amount of protein that was adsorbed as a function of the surface potential: In First group of proteins, an increasing trend for the amount adsorbed with a more positive surface potential was found; The amount adsorbed of α-chymotrypsinogen A and ribonuclease A (Second group) were roughly constant and independent of the applied surface electric potentials; In Third group, the amount adsorbed decreased with increasing surface potential. This protein classification was correlated with the isoelectric points of the proteins (First group: ≤9.3; Second group: 9.3-10; Third group: >10). Increasing the pH positively and negatively shifted the surface potentials, allowing ß-lactoglobulin (First group) and lysozyme (Third) to become adsorbed, respectively. The surface potential range for protein adsorption was also markedly shifted depending on the metal substrate type. These findings were interpreted based on the electrostatic interactions among the protein, surface hydroxyl groups, and the applied external electric field.

Influence of an external electric field on removal of protein fouling on a stainless steel surface by proteolytic enzymes.

Enzymatic cleaning is a potentially useful method for removing proteinaceous fouling from solid surfaces under mild conditions. Herein, the influence of an external electric field on the enzymatic cleaning of a metal surface fouled with a protein was investigated. The model fouling protein (BSA; lysozyme) was prepared on a stainless steel (St) surface, and the resulting surface subjected to enzymatic cleaning with an electric potential being applied to the St plate. Trypsin, α-chymotrypsin, and thermolysin were used as model proteases. The amounts of protein remaining on the plate before and during the cleaning process were measured by means of a reflection absorption technique using Fourier transform infrared spectroscopy. In the case for BSA fouling, the cleaning efficiency of the protease tended to increase at more negative applied potentials. Whereas, there was an optimum applied potential for removing the lysozyme fouling. Atomic force microscopy analyses indicated that applying an adequate range of electric potential enhanced the enzymatic removal of protein fouling inside scratches on the St plate surface. These findings suggest the existence of two modes of electrostatic interactions for the external electric field, one with protease molecules and the other with digested fragments of the fouling protein.

Surfactant-Free Solid Dispersions of Hydrophobic Drugs in an Amorphous Sugar Matrix Dried from an Organic Solvent.

The technique for homogeneously dispersing hydrophobic drugs in a water-soluble solid matrix (solid dispersion) is a subject that has been extensively investigated in the pharmaceutical industry. Herein, a novel technique for dispersing a solid, without the need to use a surfactant, is reported. A freeze-dried amorphous sugar sample was dissolved in an organic solvent, which contained a soluble model hydrophobic component. The suspension of the sugar and the model hydrophobic component was vacuum foam dried to give a solid powder. Four types of sugars and methanol were used as representative sugars and the organic medium. Four model drugs (indomethacin, ibuprofen, gliclazide, and nifedipine) were employed. Differential scanning calorimetry analyses indicated that the sugar and model drug (100:1) did not undergo segregation during the drying process. The dissolution of the hydrophobic drugs in water from the solid dispersion was then evaluated, and the results indicated that the Cmax and AUC0-60 min of the hydrophobic drug in water were increased when the surfactant-free solid dispersion was used. Palatinose and/or α-maltose were superior to the other tested carbohydrates in increasing Cmax and AUC0-60 min for all tested model drugs, and the model drug with a lower water solubility tended to exhibit a greater extent of over-dissolution.

Characteristics of proteinaceous additives in stabilizing enzymes during freeze-thawing and -drying.

Protein-stabilizing characteristics of sixteen proteins during freeze-thawing and freeze-drying were investigated. Five enzymes, each with different instabilities against freezing and dehydration, were employed as the protein to be stabilized. Proteinaceous additives generally resulted in greater enzyme stabilization during freeze-thawing than sugars while the degree of stabilization for basic lysozyme and protamine were inferior to that of neutral and acidic proteins. Freeze-drying-induced inactivation of enzyme was also reduced by the presence of a proteinaceous additive, the extent of which was lower than that for a sugar. In both freeze thawing and freeze drying, the enzymes stabilization by the proteinaceous additive increased with increasing additive concentration. The enhancement of enzyme inactivation caused by pH change was also reduced in the presence of proteinaceous additives. The combined use of a sugar such as sucrose and dextran tended to increase the stabilizing effect of the proteinaceous additive.

Adsorption of lysozyme on base metal surfaces in the presence of an external electric potential.

The impact of external electric potential on the adsorption of a protein to base metal surfaces was examined. Hen egg white lysozyme (LSZ) and six types of base metal plates (stainless steel SUS316L (St), Ti, Ta, Zr, Cr, or Ni) were used as the protein and adsorption surface, respectively. LSZ was allowed to adsorb on the surface under different conditions (surface potential, pH, electrolyte type and concentration, surface material), which was monitored using an ellipsometer. LSZ adsorption was minimized in the potential range above a certain threshold and, in the surface potential range below the threshold, decreasing the surface potential increased the amount of protein adsorbed. The threshold potential for LSZ adsorption was shifted toward a positive value with increasing pH and was lower for Ta and Zr than for the others. A divalent anion salt (K2SO4) as an electrolyte exhibited the adsorption of LSZ in the positive potential range while a monovalent salt (KCl) did not. A comprehensive consideration of the obtained results suggests that two modes of interactions, namely the electric force by an external electric field and electrostatic interactions with ionized surface hydroxyl groups, act on the LSZ molecules and determine the extent of suppression of LSZ adsorption. All these findings appear to support the view that a base metal surface can be controlled for the affinity to a protein by manipulating the surface electric potential as has been reported on some electrode materials.

The use of a proteinaceous "cushion" with a polystyrene-binding peptide tag to control the orientation and function of a target peptide adsorbed to a hydrophilic polystyrene surface.

In immobilizing target biomolecules on a solid surface, it is essential (i) to orient the target moiety in a preferred direction and (ii) to avoid unwanted interactions of the target moiety including with the solid surface. The preferred orientation of the target moiety can be achieved by genetic conjugation of an affinity peptide tag specific to the immobilization surface. Herein, we report on a strategy for reducing the extent of direct interaction between the target moiety and surface in the immobilization of hexahistidine peptide (6His) and green fluorescent protein (GFP) on a hydrophilic polystyrene (PS) surface: Ribonuclease HII from Thermococcus kodakaraensis (cHII) was genetically inserted as a "cushion" between the PS-affinity peptide tag and target moiety. The insertion of a cushion protein resulted in a considerably stronger immobilization of target biomolecules compared to conjugation with only a PS affinity peptide tag, resulting in a substantially enhanced accessibility of the detection antibody to the target 6His peptide. The fluorescent intensity of the GFP moiety was decreased by approximately 30% as the result of fusion with cHII and the PS-affinity peptide tag but was fully retained in the immobilization on the PS surface irrespective of the increased binding force. Furthermore, the fusion of cHII did not impair the stability of the target GFP moiety. Accordingly, the use of a proteinaceous cushion appears to be promising for the immobilization of functional biomolecules on a solid surface. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:527-534, 2016.

The safety and effectiveness of HBV vaccination in patients with juvenile idiopathic arthritis controlled by treatment.

OBJECTIVES: To evaluate the safety and effectiveness of hepatitis B virus (HBV) vaccination in patients with juvenile idiopathic arthritis (JIA) controlled by treatment. METHODS: Among 49 patients with juvenile idiopathic arthritis (JIA) at the outpatient clinic of Kagoshima University Hospital, we enrolled 25 who were controlled by treatment. All children were unimmunized and were vaccinated against HBV according to the schedule. Their responses to the vaccine and vaccine adverse events were examined during their visits. RESULTS: Nineteen of the 25 patients with JIA controlled by treatment developed effective antibody responses (76%). All eight patients with JIA below 10 years of age achieved seroconversion. The seroconversion was not influenced by biologics. Five adverse events were observed (6.7%). The rate of all adverse events did not surpass that of a previous report, and all adverse events were immediately resolved. None of the patients with JIA experienced a flare-up or clinical deterioration related to the vaccination. CONCLUSIONS: HBV vaccination is safe and effective. Pediatric rheumatologists should consider HBV vaccination for unimmunized patients with JIA, because the response to HBV vaccine might be influenced by age, and children have a higher risk for potential HBV infection than adults.

Disease activity score in 28 joints at 3 months after the initiation of biologic agent can be a predictive target for switching to the second biologic agent in patients with polyarticular juvenile idiopathic arthritis.

OBJECTIVE: To clarify polyarticular juvenile idiopathic arthritis (pJIA) patients who failed to maintain prolonged remission with the first biologic agent. METHODS: Fourteen pJIA patients were observed for 47.5 months (median) after initiating the first biologic agent. RESULTS: Eight maintained sustained clinical remission (median 47 months) with the first biologic agents, while the six switched to the second one due to lack of efficacy, thereafter. Receiver operating characteristic (ROC) analysis revealed that disease activity score in 28 joints (DAS28) of 2.37 at 3 months could distinguish between the two patient groups (p = 0.001). CONCLUSION: pJIA patients with DAS28 >2.37 at 3 months of the initial biologic therapy may be considered to switch to the second biologics.

Prediction of long-term remission of oligo/polyarticular juvenile idiopathic arthritis with S100A12 and vascular endothelial growth factor.

OBJECTIVES: This study aimed to evaluate the usefulness of S100A12 and vascular endothelial growth factor (VEGF) for predicting the stability of remission for discontinuing methotrexate (MTX) and/or biological agents in Japanese patients with oligo/polyarticular juvenile idiopathic arthritis (JIA). METHODS: Forty-four patients with oligo/polyarticular JIA who received MTX with or without biological agents were enrolled. Serum concentration of both S100A12 and VEGF were simultaneously evaluated by ELISA in active and in remission phase determined by activity markers including DAS-28. RESULTS: S100A12 and VEGF were correlated with DAS-28. Of the 22 patients with oligo/polyarticular JIA in clinical remission, 13 patients with low S100A12 and VEGF concentrations could discontinue treatment without relapse over 2 years. However, nine patients without low S100A12 and VEGF concentrations relapsed afterwards, even though they had been in clinical remission. The cut-off levels of S100A12 and VEGF for division into two groups of the maintenance remission and relapse groups were 177 ng/ml and 158 pg/ml, respectively. CONCLUSIONS: S100A12 and VEGF are useful markers for assessing disease activity of oligo/polyarticular JIA in remission phase. These markers should be kept low when clinicians consider tapering or discontinuing treatments in oligo/polyarticular JIA patients.

Surfactant-free solid dispersion of fat-soluble flavour in an amorphous sugar matrix.

A solid dispersion technique to homogeneously disperse hydrophobic ingredients in a water-soluble solid without using surfactant was examined as follows: first, freeze-dried amorphous sugar was dissolved in an organic medium that contained a soluble model hydrophobic component. Second, the mixed solution of sugar and the model hydrophobic component was vacuum dried into a solid (solid dispersion). Methanol and six fat-soluble flavours, including cinnamaldehyde, were used as organic media and model hydrophobic components. The retention of flavours in the solid dispersion during drying and storage under vacuum was evaluated. The amorphised disaccharides dissolved in methanol up to 100mg/mL, even temporarily (20s to 10 days) and could be solidified without any evidence of crystallisation and segregation from flavour. The solid dispersion, prepared using α-maltose usually showed 65-95% flavour retention during drying (and storage for cinnamaldehyde), whereas ⩾ 50% of the flavour was lost when the flavour was O/W emulsified with a surfactant and then freeze-dried with sugar.