Startup performance and microbial composition of a pilot-scale rapid sand filter for the treatment of manganese-containing mine water

The inexpensive removal of soluble manganese [Mn(II)] from mine water that contains large quantities of Mn(II) should be prioritized given that large quantities of alkaline reagents are typically used in the chemical treatment of Mn-rich water from abandoned mines. Rapid sand filter (RSF) systems are widely used as a cost-effective technology in drinking water treatment processes to remove iron and Mn from groundwater. Here, we applied a pilot-scale RSF to treat mine water with a neutral pH and containing approximately 22 mg/L of Mn(II). Following a lag phase from its startup (day 1-day 26), Mn removal rates increased to approximately 40% for around 1 month (day 27-day 55) without the use of alkaline reagents but did not increase during further operation. Quantitative elemental analysis revealed Mn oxides on the sand filters during the Mn removal period. The bacterial communities on the RSFs, recorded on day 42 and day 85, were characterized and compared using 16S rRNA gene amplicon sequencing. Although the well-known Mn-oxidizing bacteria (MOB) were not listed among the ten most dominant operational taxonomic units (OTUs) on the sand filters (relative abundances: >0.68%), a significant increase in the OTUs related to well-known alphaproteobacterial MOB, such as Pedomicrobium spp., were observed during the period.

Nitrate-Driven Trophic Association of Sulfur-Cycling Microorganisms in Tsunami-Deposited Marine Sediment Revealed by High-Sensitivity 13C-Bicarbonate Probing

Although denitrification-dependent chemolithotrophic sulfur oxidizers proliferated in tsunami-deposited marine sediment with nitrate amendment, their ecophysiological roles in biogeochemical carbon transfer are not addressed. We employed time-resolved high-sensitivity ¹³C-bicarbonate probing of rRNA to unveil the carbon fixation and resulting trophic relationship of the nitrate-amended sediment microorganisms. Nitrate reduction and sulfur oxidation co-occurred along with significant decreases in the ¹³CO₂ and dissolved bicarbonate concentrations for the first 4 days of the incubation, during which the denitrification-dependent sulfur-oxidizing chemolithotrophs, i.e., the Sulfurimonas sp. HDS01 and Thioalkalispira sp. HDS22 relatives, and the sulfate-reducing heterotrophs, i.e., the Desulfobulbus spp. and Desulfofustis glycolicus relatives, actively incorporated ¹³C. These indicated that the sulfur oxidizers and sulfate reducers were tightly associated with each other through the direct carbon transfer. Relatives of the fermentative Thalassomonas sediminis and the hydrolytic Pararheinheimera aquatica, in addition to various sulfur-cycling microorganisms, significantly assimilated ¹³C at day 14. Although the incorporation of ¹³C was not detected, a syntrophic volatile-fatty-acid oxidizer and hydrogenotrophic methanogens significantly expressed their 16S rRNA molecules at day 21, indicating the metabolic activation of these final decomposers under the latter nutrient-limited conditions. The results demonstrated the nitrate-driven trophic association of sulfur-cycling microorganisms and the subsequent microbial activation and diversification, triggering the restoration of the marine ecosystem function.

Effective Se reduction by lactate-stimulated indigenous microbial communities in excavated waste rocks

Waste rocks generated from tunnel excavation contain the metalloid selenium (Se) and its concentration sometimes exceeds the environmental standards. The possibility and effectiveness of dissolved Se removal by the indigenous microorganisms are unknown. Chemical analyses and high-throughput 16S rRNA gene sequencing were implemented to investigate the functional and structural responses of the rock microbial communities to the Se and lactate amendment. During anaerobic incubation of the amended rock slurries from two distinct sites, dissolved Se concentrations decreased significantly, which coincided with lactate degradation to acetate and/or propionate. Sequencing indicated that relative abundances of Desulfosporosinus burensis increased drastically from 0.025 % and 0.022% to 67.584% and 63.716 %, respectively, in the sites. In addition, various Desulfosporosinus spp., Symbiobacterium-related species and Brevibacillus ginsengisoli, as well as the Se(VI)-reducing Desulfitobacterium hafniense, proliferated remarkably. They are capable of incomplete lactate oxidation to acetate as only organic metabolite, strongly suggesting their involvement in dissimilatory Se reduction. Furthermore, predominance of Pelosinus fermentans that ferments lactate to propionate and acetate implied that Se served as the electron sink for its fermentative lactate degradation. These results demonstrated that the indigenous microorganisms played vital roles in the lactate-stimulated Se reduction, leading to the biological Se immobilization treatment of waste rocks.

Microbial community in an anaerobic membrane bioreactor and its performance in treating organic solid waste under controlled and deteriorated conditions

The adoption of anaerobic membrane bioreactors (AnMBRs) for organic solid waste management is important for the recovery of energy and high-quality treated water. However, few studies have focused on AnMBR treatment of high-strength organic solid waste and the microorganisms involved under deteriorated operating conditions. In the present study, a 15-L bench-scale AnMBR was operated using a model slurry of high-strength organic solid waste with the organic loading rate (OLR) increasing from 2.3 g chemical oxygen demand (COD) L^-1 day^-1 (represented as a controlled condition) to 11.6 g COD L^-1 day^-1 (represented as a deteriorated condition), and microbial community dynamics over 120 days of operation were analyzed. The abundances of methanogens and bacteria that were dominant under the controlled condition decreased as a result of both high organic loading and sludge withdrawal under the deteriorated condition and did not recover thereafter. Instead, numbers of putative volatile fatty acid (VFA)-producing bacterial operational taxonomic units (OTUs) related to the genus Prevotella increased rapidly, reaching a relative abundance of 43.2%, leading to the deterioration of methanogenic AnMBR operation. Considering that the sequences of these OTUs exhibited relatively low sequence identity (91-95%) to those of identified Prevotella species, the results strongly suggest that the accumulation of VFAs by novel VFA-producing bacteria in the digestion sludge promotes the disruption of the methanogen community under deteriorated conditions.

Clarifying prokaryotic and eukaryotic biofilm microbiomes in anaerobic membrane bioreactor by non-destructive microscopy and high-throughput sequencing

Anaerobic membrane bioreactor (AnMBR) is used for the treatment of organic solid waste. Clogging of filtration membrane pores, called membrane fouling, is one of the most serious issues for the sustainable operation of AnMBR. Although the physical and chemical mechanisms of the membrane fouling have been widely studied, the biological mechanisms are still unclear. The biofilm formation and development on the membrane might cause the membrane fouling. In this study, the prokaryotic and eukaryotic microbiomes of the membrane-attached biofilms in an AnMBR treating a model slurry of organic solid waste were investigated by non-destructive microscopy and high-throughput sequencing of 16S and 18S rRNA genes. The non-destructive visualization indicated that the biofilm was layered with different structures. The lowermost residual fouling layer was mesh-like and composed of filamentous microorganisms, while the upper cake layer was mainly the non-dense and non-cell region. The principal coordinate and phylogenetic analyses of the sequence data showed that the biofilm microbiomes were different from the sludge. The lowermost layer consisted of operational taxonomic units that were related to Leptolinea tardivitalis and Methanosaeta concilii (9.53-10.07% and 1.14-1.64% of the total prokaryotes, respectively) and Geotrichum candidum (30.22-82.31% of the total eukaryotes), all of which exhibited the filamentous morphology. Moreover, the upper layer was inhabited by the presumably cake-degrading bacteria and predatory eukaryotes. The biofilm microbiome features were consistent with the microscope-visualized structure. These results demonstrated that the biofilm structure and microbiome were the layer specific, which provides better understanding of biological mechanisms of membrane fouling in the AnMBR.

Unexpected diversity of acetate degraders in anaerobic membrane bioreactor treating organic solid waste revealed by high-sensitivity stable isotope probing

In anaerobic membrane bioreactor (AnMBR) treating organic solid waste, acetate is one of the most important precursors to CH₄. However, the identity and diversity of anaerobic acetate degraders are largely unknown, possibly due to their slow growth rates and low abundances. Here, we identified acetate-degrading microorganisms in the AnMBR sludges by high-sensitivity stable isotope probing. Degradation of the amended ¹³C-acetate coincided with production of ¹³CH₄ and ¹³CO₂ during the sludge incubation. High-throughput sequencing of RNA density fractions indicated that the aceticlastic and hydrogenotrophic methanogens, i.e., Methanosaeta sp. (acetate dissimilator) and Methanolinea sp. (acetate assimilator), incorporated ¹³C-acetate significantly. Remarkably, 22 bacterial species incorporating ¹³C-acetate were identified, whereas their majority was distantly related to the cultured representatives. Only two of them were the class Deltaproteobacteria-affiliated lineages with syntrophic volatile fatty acid oxidation activities. Phylogenetic tree analysis and population dynamics tracing revealed that novel species of the hydrolyzing and/or fermenting taxa, such as the phyla Bacteroidetes, Chloroflexi and Lentisphaerae, exhibited low relative abundances comparable to that of Methanolinea sp. (0.00011%) during the AnMBR operation, suggesting that these bacteria were involved in anaerobic acetate assimilation. Meanwhile, novel species of the phyla Firmicutes, Synergistetes and Caldiserica, the candidate phyla Aminicenantes and Atribacteria and the candidate division GOUTA4-related clade, as well as the known Deltaproteobacteria members, existed at relatively high abundances (0.00031%-0.31121%) in the reactor, suggesting that these bacterial species participated in anaerobic dissimilation of acetate, e.g., syntrophic acetate oxidation. The results of this study demonstrated the unexpected diversity and ecophysiological features of the anaerobic acetate degraders in the AnMBR treating organic solid waste.

Effects of the Wastewater Flow Rate on Interactions between the Genus Nitrosomonas and Diverse Populations in an Activated Sludge Microbiome

The present study characterized the interactions of microbial populations in activated sludge systems during the operational period after an increase in the wastewater flow rate and consequential ammonia accumulation using a 16S rRNA gene sequencing-based network analysis. Two hundred microbial populations accounting for 81.8% of the total microbiome were identified. Based on a co-occurrence analysis, Nitrosomonas-type ammonia oxidizers had one of the largest number of interactions with diverse bacteria, including a bulking-associated Thiothrix organism. These results suggest that an increased flow rate has an impact on constituents by changing ammonia concentrations and also that Nitrosomonas- and Thiothrix-centric responses are critical for ammonia removal and microbial community recovery.

Role of membrane fouling substances on the rejection of N-nitrosamines by reverse osmosis

The impact of fouling substances on the rejection of four N-nitrosamines by a reverse osmosis (RO) membrane was evaluated by characterizing individual organic fractions in a secondary wastewater effluent and deploying a novel high-performance liquid chromatography-photochemical reaction-chemiluminescence (HPLC-PR-CL) analytical technique. The HPLC-PR-CL analytical technique allowed for a systematic examination of the correlation between the fouling level and the permeation of N-nitrosamines in the secondary wastewater effluent and synthetic wastewaters through an RO membrane. Membrane fouling caused by the secondary wastewater effluent led to a notable decrease in the permeation of N-nitrosodimethylamine (NDMA) while a smaller but nevertheless discernible decrease in the permeation of N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPYR) and N-nitrosomorpholine (NMOR) was also observed. Fluorescence spectrometry analysis revealed that major foulants in the secondary wastewater effluent were humic and fulvic acid-like substances. Analysis using the size exclusion chromatography technique also identified polysaccharides and proteins as additional fouling substances. Thus, further examination was conducted using solutions containing model foulants (i.e., sodium alginate, bovine serum albumin, humic acid and two fulvic acids). Similar to the secondary wastewater effluent, membrane fouling with fulvic acid solutions resulted in a decrease in N-nitrosamine permeation. In contrast, membrane fouling with the other model foulants resulted in a negligible impact on N-nitrosamine permeation. Overall, these results suggest that the impact of fouling on the permeation of N-nitrosamines by RO is governed by specific small organic fractions (e.g. fulvic acid-like organics) in the secondary wastewater effluent.

Expression of human Gaucher disease gene GBA generates neurodevelopmental defects and ER stress in Drosophila eye

Gaucher disease (GD) is the most common of the lysosomal storage disorders and is caused by defects in the GBA gene encoding glucocerebrosidase (GlcCerase). The accumulation of its substrate, glucocylceramide (GlcCer) is considered the main cause of GD. We found here that the expression of human mutated GlcCerase gene (hGBA) that is associated with neuronopathy in GD patients causes neurodevelopmental defects in Drosophila eyes. The data indicate that endoplasmic reticulum (ER) stress was elevated in Drosophila eye carrying mutated hGBAs by using of the ER stress markers dXBP1 and dBiP. We also found that Ambroxol, a potential pharmacological chaperone for mutated hGBAs, can alleviate the neuronopathic phenotype through reducing ER stress. We demonstrate a novel mechanism of neurodevelopmental defects mediated by ER stress through expression of mutants of human GBA gene in the eye of Drosophila.

Physical properties of self-assembled monolayers of Mercapto Oligo (ethylene oxide) methyl ether on gold

Physical properties (chemical adsorption rate, viscoelasticity, thickness, and conformation) for self-assembled monolayers (SAMs) of mercapto oligo (ethylene oxide) methyl ethers on gold were determined by quartz crystal microbalance (QCM). The values of thickness, shear viscosity and elastic shear modulus of SAMs increase with unit number of oligo (ethylene oxide) segment. However, the chemical adsorption rate determined by a Langmuir isotherm does not show such a unit number regularity. Those results suggest that difference in unit number of oligo (ethylene oxide) segment can significantly affects physical properties of SAMs.

Prevalence and impact of rhinitis in asthma. SACRA, a cross-sectional nation-wide study in Japan

BACKGROUND

Asthma and rhinitis are common co-morbidities everywhere in the world but nation-wide studies assessing rhinitis in asthmatics using questionnaires based on guidelines are not available.

OBJECTIVE

To assess the prevalence, classification, and severity of rhinitis using the Allergic Rhinitis and its Impact on Asthma (ARIA) criteria in Japanese patients with diagnosed and treated asthma.

METHODS

The study was performed from March to August 2009. Patients in physicians' waiting rooms, or physicians themselves, filled out questionnaires on rhinitis and asthma based on ARIA and Global Initiative for Asthma (GINA) diagnostic guides. The patients answered questions on the severity of the diseases and a Visual Analog Scale. Their physicians made the diagnosis of rhinitis.

RESULTS

In this study, 1910 physicians enrolled 29,518 asthmatics; 15,051 (51.0%) questionnaires were administered by physician, and 26,680 (90.4%) patients were evaluable. Self- and physician-administered questionnaires gave similar results. Rhinitis was diagnosed in 68.5% of patients with self-administered questionnaires and 66.2% with physician-administered questionnaires. In this study, 994 (7.6%) patients with self-administered and 561 (5.2%) patients with physician-administered questionnaires indicated rhinitis symptoms on the questionnaires without a physician's diagnosis of rhinitis. Most patients with the physician's diagnosis of rhinitis had moderate/severe rhinitis. Asthma control was significantly impaired in patients with a physician's diagnosis of rhinitis for all GINA clinical criteria except exacerbations. There were significantly more patients with uncontrolled asthma as defined by GINA in those with a physician's diagnosis of rhinitis (25.4% and 29.7%) by comparison with those without rhinitis (18.0% and 22.8%).

CONCLUSION

Rhinitis is common in asthma and impairs asthma control.

Periostin, a matrix protein, is a novel biomarker for idiopathic interstitial pneumonias

Idiopathic interstitial pneumonias (IIPs) are histopathologically classified into several types, including usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP) and cryptogenic organising pneumonia (COP). We investigated whether periostin, a matrix protein, could be used as a biomarker to assess histopathological types of IIPs. We performed immunohistochemical analyses in each histopathological type of IIP, examined serum levels of periostin in IIP patients and analysed the relationship between serum levels of periostin and the pulmonary functions in patients with idiopathic pulmonary fibrosis (IPF). Periostin was strongly expressed in lungs of UIP and fibrotic NSIP patients, whereas expression of periostin was weak in the lungs of cellular NSIP and COP patients, as well as in normal lungs. Serum levels of periostin in IPF were significantly higher than those of healthy subjects and COP patients. Furthermore, periostin levels in IPF patients were inversely correlated with their pulmonary functions. Thus, we have found that periostin is a novel component of fibrosis in IIP. Periostin may be a potential biomarker to distinguish IIP with fibrosis.

The mechanism of mucus production in bronchial asthma

Mucus production is a cardinal feature of bronchial asthma, contributing to morbidity and mortality in the disease. Goblet cells are major mucus-producing cells, and goblet cell hyperplasia (GCH) is one feature of airway remodeling, defined as structural changes occurring in the airway. A number of studies have demonstrated that Th2-type cells play critical roles in this process and that particularly interleukin-13 (IL-13), among Th2-type cytokines, is a central mediator for GCH. However, the mechanism underlying how Th2 cytokines induce mucus production or GCH is poorly understood. Mouse calcium-activated chloride channel-3 (mCLCA-3; gob-5)/human CLCA-1 acts as a downstream molecule of Th2 cytokines, IL-4/IL-9/IL-13 signals, playing an important role in mucus production. Moreover, we have recently found that pendrin, an anion transporter, is induced by IL-13 and causes mucus production in airway epithelial cells. It is hoped that if we can clarify how mucus is produced, this will lead to development of novel therapeutic reagents to suppress mucus production in bronchial asthma.

HLA-DRB1 alleles influence clinical phenotypes in Japanese patients with ulcerative colitis

The human leukocyte antigen (HLA) region has been implicated in the disease susceptibility of inflammatory bowel disease by several linkage and association studies. In Caucasians, HLA-DRB1 has been reported to determine the clinical phenotypes of ulcerative colitis (UC). Others and we previously reported that HLA-DRB1*1502 was strongly associated with UC in the Japanese population. However, the contribution of HLA-DRB1 to the clinical phenotypes in Japanese UC has not been elucidated yet. The aim of this study was to determine whether HLA-DRB1 alleles were associated with the clinical phenotypes in Japanese patients with UC. A total of 353 patients with UC were recruited. Patients were classified into subgroups by sex, age at diagnosis, disease extent, need for steroid therapy or need for surgical treatment. The allele frequency of HLA-DRB1*08 was significantly higher in patients whose disease extended beyond the rectum (left-sided and extensive UC) than in those with proctitis [odds ratio (OR)=2.20, Pc=0.043). The allele frequency of HLA-DRB1*09 was significantly higher in patients with UC diagnosed at the age of 40 years or older than in those with UC diagnosed before the age of 40 years (OR=2.31, Pc=0.022). Besides these positive associations, no significant differences were found in the allele frequencies between the other subgroups. We conclude that HLA-DRB1*09 is associated with the age at diagnosis and HLA-DRB1*08 is associated with the disease extent of UC in Japanese. These results indicate that HLA-DRB1 is not only associated with the overall UC susceptibility but also associated with the clinical phenotypes in Japanese.

Interleukin-18 production and pulmonary function in COPD

Interleukin (IL)-18 production and pulmonary function were evaluated in patients with chronic obstructive pulmonary disease (COPD) in order to determine the role of IL-18 in COPD. Immunohistochemical techniques were used to examine IL-18 production in the lungs of patients with very severe COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage IV, n = 16), smokers (n = 27) and nonsmokers (n = 23). Serum cytokine levels and pulmonary function were analysed in patients with GOLD stage I-IV COPD (n = 62), smokers (n = 34) and nonsmokers (n = 47). Persistent and severe small airway inflammation was observed in the lungs of ex-smokers with very severe COPD. IL-18 proteins were strongly expressed in alveolar macrophages, CD8+ T-cells, and both the bronchiolar and alveolar epithelia in the lungs of COPD patients. Serum levels of IL-18 in COPD patients and smokers were significantly higher than those in nonsmokers. Moreover, serum levels of IL-18 in patients with GOLD stage III and IV COPD were significantly higher than in smokers and nonsmokers. There was a significant negative correlation between serum IL-18 level and the predicted forced expiratory volume in one second in patients with COPD. In contrast, serum levels of IL-4, IL-13 and interferon-gamma were not significantly increased in any of the three groups. In conclusion, overproduction of interleukin-18 in the lungs may be involved in the pathogenesis of chronic obstructive pulmonary disease.

Effects of MCI-186 upon neutrophil-derived active oxygens

Reactions of 3-methyl-1-phenyl-2-pyrazoline-5-one (MCI-186) with hypochlorous acid and superoxide were analysed by spectrophotometry and mass spectrometry. The results were applied to the neutrophil system to evaluate the scavenging activity of neutrophil-derived active oxygen species by MCI-186. MCI-186 reacted rapidly with hypochlorous acid (1 x 10(6) M(-1)s(-1)) to form a chlorinated intermediate, followed by a slow conversion to a new spectrum. MCI-186 consumed 3 moles of hypochlorous acid and did not react with superoxide. The newly synthesized fluorescence probes, 2-[6-(4'-amino)-phenoxy-3H-xanthen-3-on-9-yl]benzoic acid (APF) and 2-[6-(4'-hydroxy)phenoxy-3H-anthen-3-on-9-yl]benzoic acid (HPF) successfully detected neutrophil-derived active oxygens (Setsukinai K, Urano Y, Kakinuma K, Majima HJ, Nagano T. Development of novel fluorescence probes that can reliably detect reactive oxygen species and distinguish specific species. J Biol Chem 2003; 278: 3170-3175). The rate constants for the reaction of hypochlorous acid with MCI-186 and fluorescence probes was in the order of MCI-186 > APF > HPF. Fluorescence due to the oxidation of APF and HPF was observed with the stimulated neutrophils. The result that the intensity from APF oxidation was higher than that from HPF oxidation is compatible with reports that APF selectively reacts with hypochlorous acid. Fluorescence due to oxidation of both APF and HPF decreased when the reactions were carried out in the presence of a fluorescence probe and MCI-186 in a dose-dependent manner. These results indicate that MCI-186 effectively scavenges neutrophil-derived hypochlorous acid and other active oxygens.

Phase I study of cisplatin/carboplatin/irinotecan (CPI) regimen in patients with ED small-cell lung cancer

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Cisplatin/irinotecan(IP) is standard regimen for ED-SCLC in Japan. Cisplatin (CDDP)-based treatment requires copious hydration, which can lead to a deterioration of outpatients’ quality of life. CDDP and carboplatin (CBDCA) have a common active form, but are associated with different adverse reactions. We considered that the combined use of these two agents could increase the dose intensity of active form platinum complexes without enhancing their toxicities. The IP was modified to nearly half the dose of CDDP/CBDCA to facilitate outpatient administration. We conducted a phase I study to determine the maximum tolerated dose (MTD) and dose limiting toxicity (DLT) of this modified regimen for patients with ED-SCLC and stage IV NSCLC. Eligibility criteria included: PS 0–1, age <75 yrs, no prior therapy, measurable disease, adequate organ functions. DLT was defined as follows: 1) grade 4 neutropenia lasting 4 days or febrile neutropenia, 2) grade 4 thrombocytopenia, 3) prolongation of treatment due to toxicity, 4) grade 3 or worse non-hematological toxicity. Three patients were enrolled at level 1(CDDP/CBDCA: 25 mg/m2/AUC2), 3 patients at level 2 (25 mg/m2/AUC 2.5) and 3 patients at level 3 (30 mg/m2/ AUC 2.5), respectively. DLT was not observed at level 1, 2, 3. At dose level 4 (30 mg/m2/AUC3), two of three patients experienced DLT, suggesting this level to be the MTD. The recommended dose for phase II study is CDDP 30 mg/m2 on day 1, CBDCA AUC 2.5 on day 1 and irinotecan 60 mg/m2 on days 1, 8, 15. A phase II study of this regimen in ED-SCLC is ongoing.

No significant financial relationships to disclose.

Surface plasmon resonance-based trace detection of small molecules by competitive and signal enhancement immunoreaction

A surface plasmon resonance (SPR)-immunosensor for detection of the low molecular weight compound 2,4-dinitorophenol (DNP) at ultra-low concentration has been developed. The sensor strategy is based on a competitive immunoreaction between DNP and a DNP-protein conjugate, namely DNP-bovine serum albumin conjugate (DNP-BSA). Anti-DNP monoclonal antibody was immobilized on a gold thin-film coated SPR-sensor chip by means of a chemical coupling process. DNP-BSA, on contact with the anti-DNP antibody immobilized SPR-immunosensor chip causes an increase in the resonance angle of the sensor chip. The optimum concentration of immobilized antibody on the SPR-sensor chip is 100 microg mL(-1). The SPR-immunosensor response for free DNP determination using the competitive immunoreaction had a response time of ca. 15 min. Using this method, DNP could be determined in the concentration range 1 ppt to 1 ppb. The SPR signal for ppt levels of DNP was enhanced by a factor of three by subsequently treating immuno-bound DNP-BSA with a secondary anti-DNP antibody.

Quartz crystal microbalance immunosensors for environmental monitoring

This paper presents discussion of quartz crystal microbalance (QCM) immunosensors for environmental monitoring. Factors limiting the practical application of antibodies to analytical problems are also presented. Among several candidates for the QCM immunosensor device, selected QCM devices and oscillating circuits were tested thoroughly and developed to obtain highly stable and sensitive frequency signals. The biointerface of QCM immunosensor was designed and controlled to immobilize antibody on the QCM surface, to reduce non-specific binding and to suppress denaturation of immobilizing antibody by self-assembled monolayer technique and artificial phospholipid (2-methacryloyloxyethyl phosphorylcholine (MPC)) polymer. MPC polymer as a antibody-stabilizing reagent was added to reduce non-specific binding of the antigen solution and stabilize the immunologic activity of the antibody-immobilized QCM. In addition, it provides examples for detection and quantitation of environmental samples using QCM immunosensors. The analytical results for fly ash extracted samples of dioxins using the QCM immunosensor indicated a good relationship with GC/MS methods. The integrating protocols of the competitive immunoassay and signal-enhancing step are for detecting low molecular analytes with extremely low detection limits using an QCM immunosensor. Furthermore, its detect limitation was extended from 0.1 to 0.01 ng/ml by the signal-enhancing step when the anti-bisphenol-A antibody conjugated MPC polymeric nanoparticles was used. The QCM immunosensor method has demonstrated its effectiveness as an alternative screening method for environmental monitoring because these results were compared with results obtained through environmental monitoring methods such as ELISA and GC/MS.

Once-daily administration of fluticasone propionate does not worsen controlled airway hyperresponsiveness in patients with asthma

BACKGROUND

Inhaled steroids are currently the most important drugs for asthma patients, but compliance tends to be low. Compliance could be improved by reducing the number of daily administrations.

OBJECTIVES

In the present study, we compared once- and twice-daily administration of fluticasone propionate (FP) to determine the differences in efficacy.

METHODS

Subjects were 40 patients diagnosed with bronchial asthma with stable symptoms and pulmonary functions who were on twice-daily FP administration of 100 microg. There were 14 men and 26 women ranging from 29 to 72 years of age. After a 4-week observation period, subjects were randomized into two administration groups by the envelope method and followed for 8 weeks: group A, once-daily administration (200 microg of FP at night), and group B, twice-daily administration (100 microg of FP in the morning and at night). Clinical symptoms, pulmonary functions and airway responsiveness were compared between these two groups.

RESULTS

No significant deterioration in clinical symptoms, pulmonary functions and airway responsiveness were observed in group A compared with group B.

CONCLUSIONS

These results demonstrate that once-daily FP administration is as effective as twice-daily administration, and that it may improve the compliance for inhaled steroids.

Dioxin immunosensor using anti-2,3,7,8-TCDD antibody which was produced with mono 6-(2,3,6,7-tetrachloroxanthene-9-ylidene) hexyl succinate as a hapten

To detect dioxin using a quartz crystal microbalance (QCM) immunosensor, anti-2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD) monoclonal antibodies (MAbs) were produced as types of IgG1 and IgM, with mono 6-(2,3,6,7-tetrachloroxanthene-9-ylidene) hexyl succinate (as a hapten) conjugated with bovine serum albumin (dioxin-BSA). Furthermore, ScFv was generated from hybridoma-producing IgG1 MAb. Among these antibodies, ScFv showed excellent capability for dioxin detection using QCM immunosensors.

Piezoelectric immunosensor for bisphenol A based on signal enhancing step with 2-methacrolyloxyethyl phosphorylcholine polymeric nanoparticle

An immunoassay in which BPA competed with a BPA-horseradish peroxidase conjugate for binding to anti-BPA antibodies, coupled to a piezoelectric (PZ) immunosensor, was able to detect 0.1 ng mL(-1) BPA. To enhance the sensitivity of the assay, we tested nanoparticles approximately 200 nm in diameter, coupled to anti-BPA antibodies, to increase the mass change on the surface of the immunosensor and thereby increase the frequency shift detected. This second step, using nanoparticles coated with anti-BPA antibodies, improved the sensitivity of the assay by approximately eight times at BPA concentrations below 10 ng mL(-1). Field emission-scanning electron microscopy (FE-SEM) showed that polymeric 2-methacrolyloxyethyl phosphorylcholine (MPC) nanoparticles coupled to antibodies remained monodisperse on the surface of the immunosensor and therefore produced stable signals in the immunosensors. Since the frequency shift detected in the assay mainly originated from the mass change on the surface of the PZ crystal, the colloidal stability of the antibody-conjugated particles used in the enhancement step played an extremely important role in achieving a stable and highly sensitive signal.