ABSTRACT
Purpose: To evaluate two-year outcomes of intravitreal aflibercept injection for neovascular age-related macular degeneration (nAMD) treated with 'observe before treat-and-extend' (O-TAE) strategy in the real-world setting. Methods: This retrospective study included treatment-naïve nAMD patients treated with aflibercept using O-TAE regimen and followed up for more than 2 years. Patients were observed bimonthly to check recurrence after 3 monthly loading injections. In case of recurrence, treatment was resumed using the treat-and-extend (TAE) regimen starting from the 4th injection. In case of non-recurrence, observation was continued. Best-corrected visual acuity (BCVA), central macular thickness (CMT), number of injections, TAE intervals, and proportion of recurrence after dry-up following 3 loadings were analyzed. Results: 38 eyes of 34 patients were included. Follow-up period was 37.0 ± 11.0 months. BCVA by logMAR improved from 0.33 ± 0.29 at baseline to 0.24 ± 0.23 in the 1st year (p = 0.01), and 0.25 ± 0.22 in the 2nd year (p = 0.054). CMT decreased significantly from 357.4 ± 74.5 at baseline to 269.6 ± 48.1 in the 1st year (p < 0.001), and 279.1 ± 54.6 in the 2nd year (p < 0.001). Numbers of injections were 5.1 ± 1.7 in the first year and 3.8 ± 2.4 in the second year. The percentage of eyes with a TAE interval of ≥12 weeks was 37.0% in the first year and 34.4% in the second year. Of the 36 eyes that dried up after 3 loadings, 28 eyes (78%) recurred, and the average period of recurrence was 6.5 months. The remaining 8 eyes (22%) had no recurrence during the mean follow-up period of 29.7 months. Conclusion: This study showed that the newly suggested O-TAE strategy can reduce the treatment burden significantly reducing the number of injections while improving BCVA and CMT in the first and second year.
ABSTRACT
BACKGROUND: Increased blood/sputum neutrophil counts are related to poor clinical outcomes of severe asthma (SA), where we hypothesized that classical monocytes (CMs)/CM-derived macrophages (Mφ) are involved. We aimed to elucidate the mechanisms of how CMs/Mφ induce the activation of neutrophils/innate lymphoid cells (ILCs) in SA. METHODS: Serum levels of monocyte chemoattractant protein-1 (MCP-1) and soluble suppression of tumorigenicity 2 (sST2) were measured from 39 patients with SA and 98 those with nonsevere asthma (NSA). CMs/Mφ were isolated from patients with SA (n = 19) and those with NSA (n = 18) and treated with LPS/interferon-gamma. Monocyte/M1Mφ extracellular traps (MoETs/M1ETs) were evaluated by western blotting, immunofluorescence, and PicoGreen assay. The effects of MoETs/M1ETs on neutrophils, airway epithelial cells (AECs), ILC1, and ILC3 were assessed in vitro and in vivo. RESULTS: The SA group had significantly higher CM counts with increased migration as well as higher levels of serum MCP-1/sST2 than the NSA group. Moreover, the SA group had significantly greater production of MoETs/M1ETs (from CMs/M1Mφ) than the NSA group. The levels of MoETs/M1ETs were positively correlated with blood neutrophils and serum levels of MCP-1/sST2, but negatively correlated with FEV1%. In vitro/in vivo studies demonstrated that MoETs/M1ETs could activate AECs, neutrophils, ILC1, and ILC3 by increased migration as well as proinflammatory cytokine production. CONCLUSIONS: CM/Mφ-derived MoETs/M1ETs could contribute to asthma severity by enhancing neutrophilic airway inflammation in SA, where modulating CMs/Mφ may be a potential therapeutic option.
Subject(s)
Asthma , Extracellular Traps , Humans , Monocytes , Immunity, Innate , Lymphocytes , Neutrophils , Inflammation , MacrophagesABSTRACT
Progesterone has been shown to have neuroprotective capabilities against a wide range of nervous system injuries, however there are negative clinical studies that have failed to demonstrate positive effects of progesterone therapy. Specifically, we looked into whether progesterone receptors or its metabolizing enzymes, cytochrome P450c17 and 5α-reductase, are involved in the effects of progesterone on neuropathic pain after chronic constriction injury (CCI) of the sciatic nerve in mice. Intrathecal progesterone administration during the induction phase of chronic pain enhanced mechanical allodynia development and spinal glial fibrillary acidic protein (GFAP) expression, and this enhancement was inhibited by administration of ketoconazole, a P450c17 inhibitor, but not finasteride, a 5α-reductase inhibitor. Furthermore, phospho-serine levels of P450c17 in the spinal cord were elevated on day 1 after CCI operation, but not on day 17. In contrast, intrathecal progesterone administration during the maintenance phase of chronic pain decreased the acquired pain and elevated GFAP expression; this inhibition was restored by finasteride administration, but not by ketoconazole. The modification of mechanical allodynia brought on by progesterone in CCI mice was unaffected by the administration of mifepristone, a progesterone receptor antagonist. Collectively, these findings imply that progesterone suppresses spinal astrocyte activation via 5α-reductase activity during the maintenance phase of chronic pain and has an analgesic impact on the mechanical allodynia associated with the growing neuropathy. Progesterone, however, stimulates spinal astrocytes during the induction stage of peripheral neuropathy and boosts the allodynic impact caused by CCI through early spinal P450c17 activation.
ABSTRACT
It has been suggested that stress responses induced by fasting have analgesic effects on nociception by elevating the levels of stress-related hormones, while there is limited understanding of pain control mechanisms. Here, we investigated whether acute or intermittent fasting alleviates formalin-induced pain in mice and whether spinal orexin A (OXA) plays a role in this process. 6, 12, or 24 h acute fasting (AF) and 12 or 24 h intermittent fasting (IF) decreased the second phase of pain after intraplantar formalin administration. There was no difference in walking time in the rota-rod test and distance traveld in the open field test in all groups. Plasma corticosterone level and immobility time in the forced swim test were increased after 12 h AF, but not after 12 h IF. 12 h AF and IF increased not only the activation of OXA neurons in the lateral hypothalamus but also the expression of OXA in the lateral hypothalamus and spinal cord. Blockade of spinal orexin 1 receptor with SB334867 restored formalin-induced pain and spinal c-Fos immunoreactivity that were decreased after 12 h IF. These results suggest that 12 h IF produces antinociceptive effects on formalin-induced pain not by corticosterone elevation but by OXA-mediated pathway.
Subject(s)
Acute Pain , Mice , Animals , Orexins/pharmacology , Formaldehyde/toxicity , Intermittent Fasting , Corticosterone/pharmacology , Analgesics/pharmacology , Spinal Cord/metabolism , Orexin Receptors/metabolismABSTRACT
Non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1), also known as growth differentiation factor-15 (GDF-15), is associated with cancer, diabetes, and inflammation, while there is limited understanding of the role of NAG-1 in nociception. Here, we examined the nociceptive behaviors of NAG-1 transgenic (TG) mice and wild-type (WT) littermates. Mechanical sensitivity was evaluated by using the von Frey filament test, and thermal sensitivity was assessed by the hot-plate, Hargreaves, and acetone tests. c-Fos, glial fibrillary acidic protein (GFAP), and ionized calcium binding adaptor molecule-1 (Iba-1) immunoreactivity was examined in the spinal cord following observation of the formalin-induced nociceptive behaviors. There was no difference in mechanical or thermal sensitivity for NAG-1 TG and WT mice. Intraplantar formalin injection induced nociceptive behaviors in both male and female NAG-1 TG and WT mice. The peak period in the second phase was delayed in NAG-1 TG female mice compared with that of WT female mice, while there was no difference in the cumulative time of nociceptive behaviors between the two groups of mice. Formalin increased spinal c-Fos immunoreactivity in both TG and WT female mice. Neither GFAP nor Iba-1 immunoreactivity was increased in the spinal cord of TG and WT female mice. These findings indicate that NAG-1 TG mice have comparable baseline sensitivity to mechanical and thermal stimulation as WT mice and that NAG-1 in female mice may have an inhibitory effect on the second phase of inflammatory pain. Therefore, it could be a novel target to inhibit central nervous system response in pain.
ABSTRACT
PURPOSE: To investigate the toxicity of repeated simultaneous intrastromal and intracameral injections of voriconazole in corneal endothelial cells in a rabbit model. METHODS: Thirty-six eyes of 18 New Zealand white rabbits (six eyes per group) were divided into 6 groups according to the concentration of voriconazole (Group A, 0%; Group B, 0.05%; Group C, 0.1%; Group D, 0.25%; Group E, 0.5%; Group F, 1%). A combination of intrastromal and intracameral voriconazole injections were administrated to the eyes of each group three times on days 0, 3, and 7. Corneal clouding grades and central corneal thickness (CCT) were examined on days 0, 3, 7, 10, and 14. The endothelial cell counts (ECC) were measured on days 0 and 14. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed on day 14. RESULTS: Group F (1%) showed more severe corneal clouding than the other groups (Groups A-E) from day 7 (p < 0.05, respectively). There were no significant differences in CCT and ECC among the six groups at any time point (p > 0.05, respectively). SEM revealed blurring of the cell border and loss of microvilli at concentrations ≥0.25% (Groups D-F). TEM revealed microstructural changes in endothelial cells at concentrations ≥0.1% (Groups C-F), and multiple vacuoles were observed at a concentration of 1% voriconazole (Group F). CONCLUSIONS: Repeated simultaneous intrastromal and intracameral voriconazole injections at a concentration of 0.1% or higher induced microstructural endothelial damage in rabbit corneal endothelial cells.
Subject(s)
Corneal Diseases , Endothelium, Corneal , Rabbits , Animals , Voriconazole/toxicity , Endothelial Cells , InjectionsABSTRACT
PURPOSE: Severe asthma (SA) is characterized by persistent airway inflammation and remodeling, followed by lung function decline. The present study aimed to evaluate the role of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the pathogenesis of SA. METHODS: We enrolled 250 adult asthmatics (54 with SA and 196 with non-SA) and 140 healthy controls (HCs). Serum TIMP-1 levels were determined by enzyme-linked immunosorbent assay. The release of TIMP-1 from airway epithelial cells (AECs) in response to stimuli as well as the effects of TIMP-1 on the activations of eosinophils and macrophages were evaluated in vitro and in vivo. RESULTS: Significantly higher levels of serum TIMP-1 were noted in asthmatics than in HCs, in the SA group than in non-SA group, and in the type 2 SA group than in non-type 2 SA group (P < 0.01 for all). A negative correlation between serum TIMP-1 and FEV1% values (r = -0.400, P = 0.003) was noted in the SA group. In vitro study demonstrated that TIMP-1 was released from AECs in response to poly I:C, IL-13, eosinophil extracellular traps (EETs) and in coculture with eosinophils. TIMP-1-stimulated mice showed eosinophilic airway inflammation, which was not completely suppressed by steroid treatment. In vitro and in vivo functional studies showed that TIMP-1 directly activated eosinophils and macrophages, and induced the release of EETs and macrophages to polarize toward M2 subset, which was suppressed by anti-TIMP-1 antibody. CONCLUSIONS: These findings suggest that TIMP-1 enhances eosinophilic airway inflammation and that serum TIMP-1 may be a potential biomarker and/or therapeutic target for type 2 SA.
ABSTRACT
The hiPSC line was generated from peripheral blood mononuclear cells (PBMCs) collected from a female patient with young onset Parkinson's disease (PD), carrying on heterozygous c.1448 T > C (L483P), c1483 G > C (A495P) and c.1497 G > C (V499V) mutations in the GBA gene. The PBMCs was reprogrammed into an induced pluripotent stem cell (iPSC) line (GBA PD8 or PNUSCRi004-A hiPSCs) using non-integrative Sendai virus. The cell line, PNUSCRi004-A displayed a normal karyotype and expression of pluripotency markers capable of producing derivatives of three germ layers (Ectoderm, Endoderm and Mesoderm).
Subject(s)
Induced Pluripotent Stem Cells , Parkinson Disease , Humans , Female , Induced Pluripotent Stem Cells/metabolism , Cellular Reprogramming , Parkinson Disease/genetics , Parkinson Disease/metabolism , Leukocytes, Mononuclear/metabolism , Cell Differentiation , Mutation/geneticsABSTRACT
PURPOSE: To evaluate changes in ocular surface indices and tear cytokines after cataract surgery in type 2 diabetic patients. METHODS: Ocular surface indices and concentrations of tear cytokines (MCP-1, IL-6, IL-8, and VEGF) were evaluated at baseline and one week and one month postoperatively. RESULTS: Patients (30 diabetic and 30 control) were enrolled. In the diabetic group, changes in ocular symptom and tear breakup time remained until one month postoperatively (P < .05, respectively); in the control group, ocular symptom increased at one week postoperatively (P = .015). MCP-1 level in the diabetic group significantly increased postoperatively (all P < .05); however, in the control group, the IL-8 level was significantly decreased postoperatively (all P < .05). MCP-1 concentration was negatively correlated with TBUT in the diabetic group. CONCLUSION: Diabetic patients can experience more prominent changes after surgery and these changes were accompanied by an increase of several tear cytokines.
Subject(s)
Cataract , Diabetes Mellitus, Type 2 , Humans , Cytokines , Diabetes Mellitus, Type 2/complications , Interleukin-8 , CorneaABSTRACT
The hiPSC line was generated from peripheral blood mononuclear cells (PBMCs) collected by a male patient with young onset Parkinson's disease, carrying on heterozygous c.680 A > G (N227S) mutation in the GBA gene. The PBMCs was reprogrammed into an induced pluripotent stem cell (iPSC) line (PNUSCRi001-A hiPSCs) using non-integrative sendai virus. The hiPSC line, PNUSCRi001-A displayed a normal karyotype and the Expression of pluripotency markers that is capable of producing derivatives of three germ layers (Ectoderm, Endoderm and Mesoderm).
Subject(s)
Induced Pluripotent Stem Cells , Parkinson Disease , Humans , Male , Parkinson Disease/genetics , Leukocytes, Mononuclear , Mutation/geneticsSubject(s)
Central Serous Chorioretinopathy , Retinal Detachment , Humans , Retinal Detachment/diagnosis , Retinal Detachment/etiology , Retinal Detachment/surgery , Subretinal Fluid , Central Serous Chorioretinopathy/complications , Central Serous Chorioretinopathy/diagnosis , Vitrectomy/adverse effects , Drainage/adverse effectsABSTRACT
Mutation in the glucocerebrosidase encoding gene 1 (GBA) is one of the most frequent causes of Parkinson's disease (PD). Herein, we obtained peripheral blood mononuclear cells (PBMCs) from a patient with PD with a heterozygous c.475C > T (p.R159W) mutation in the GBA gene, and generated an induced pluripotent stem cell (iPSC) line (GBA PD9 or PNUSCRi002-A hiPSCs) using a non-integrative Sendai virus. The iPSC line expressed pluripotency markers (OCT4, NANOG, SSEA-4, TRA-1-60) and displayed differentiation properties in the three germ layers (ectoderm, endoderm, and mesoderm). Additionally, the patient had a normal karyotype.
Subject(s)
Glucosylceramidase , Induced Pluripotent Stem Cells , Parkinson Disease , Humans , Leukocytes, Mononuclear , Mutation/genetics , Parkinson Disease/genetics , Cell Line , Glucosylceramidase/geneticsABSTRACT
PURPOSE: To evaluate the level of agreement between ANTERION (Heidelberg Engineering, Heidelberg, Germany), OA-2000 (Tomey, Nagoya, Japan), and IOLMaster 500 (Carl Zeiss AG, Jena, Germany). METHODS: Fifty-one eyes of 51 patients were included in the study. Flat keratometry (K) and steep K, vector component of astigmatism (Jackson cross-cylinder at 0° and 90° [J0] and Jackson cross-cylinder at 45° and 135° [J45]), anterior chamber depth, and axial length were compared using the three devices. Repeated measures analysis of variance was conducted to compare the mean values of the biometrics. Pearson correlation test was conducted to analyze the correlations of the measured values, and a Bland-Altman plot was used to assess the agreement between the three devices. The predicted intraocular lens power of each device was compared to the others using the SRK/T, Haigis, Barrett Universal II, and Kane formulas. RESULTS: All K values measured using ANTERION were flatter than those of other instruments. However, good agreement was observed for flat K (ANTERION - OA-2000; 95% limits of agreement [LoA], 0.86 diopters [D]) and steep K (ANTERION - OA2000; 95% LoA, 0.93 D) and OA-2000 - IOLMaster 500 (95% LoA, 0.93 D). J0 and J45 vector components of astigmatism were not statistically different; however, the agreements were poor between the devices (95% LoA ≥1.97 D). Anterior chamber depth values of ANTERION and OA-2000 were interchangeable (95% LoA, 0.15 mm). The axial length showed a high agreement (95% LoA ≤0.17 mm) among the three devices. The predicted intraocular lens powers of the three devices were not interchangeable regardless of formulas (95% LoA ≥1.04 D). CONCLUSIONS: Significant differences in ocular biometrics were observed between ANTERION and the other two devices. This study demonstrated that only axial length showed good agreement among devices.
Subject(s)
Astigmatism , Lenses, Intraocular , Anterior Chamber/anatomy & histology , Anterior Chamber/diagnostic imaging , Astigmatism/diagnosis , Axial Length, Eye/anatomy & histology , Biometry/methods , Cornea/diagnostic imaging , Humans , Prospective Studies , Reproducibility of Results , Tomography, Optical Coherence/methodsABSTRACT
Phthalates are one of the most commonly used endocrine disruptors and have been considered a risk factor for respiratory disease including asthma. However, it is not yet known how they are related to urticaria. We investigated the association between phthalate exposure and urticaria in 10 healthy controls and 20 adult patients with active urticaria. The urinary levels of mono-n-butyl phthalate (MnBP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), mono-(2-ethyl-5-oxohexyl) phthalate, and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were measured by using high performance liquid chromatography tandem mass spectrometry, and mast cell releasability was determined after phthalate treatment. The levels of phthalate metabolites, especially di-ethylhexyl phthalate (DEHP), are significantly increased in the urine of patients with urticaria compared to the healthy controls. The release of ß-hexosaminidase in human mast cells is more significantly increased by MnBP, mono-benzyl phthalate, MEHHP, and MECPP compared to the negative controls; interestingly, the highest secretion of ß-hexosaminidase is observed after the lowest stimulation of MECPP. Phthalates, including DEHP, may act as aggravating factors for chronic spontaneous urticaria and can be used as potential therapeutic targets in future studies.
ABSTRACT
BACKGROUND: Obesity is a common comorbid condition in adult asthmatics and known as a feature of asthma severity. However, the molecular mechanism under obesity-induced inflammation has not yet been fully understood. OBJECTIVE: Considering the essential role of hydrophobic surfactant protein B (SP-B) in lung function, SP-B was targeted to examine its involvement in the development of obesity-induced airway inflammation in asthmatics. METHODS: The aim was to examine an alteration in circulating SP-B according to obesity in adult asthmatics, 129 asthmatics were enrolled and classified into 3 groups (obese, overweight and normal-weight groups) according to body mass index (BMI). Circulating SP-B levels were determined by enzyme-linked immunosorbent assay. Four single nucleotide polymorphisms of SFTPB gene were genotyped. Serum ceramide levels were measured by liquid chromatography-tandem mass spectrometry. RESULTS: Significantly lower serum SP-B levels were noted in the obese group than in the overweight or normal-weight group (p = .002). The serum SP-B level was significantly correlated with serum levels of C18:0 ceramide and transforming growth factor beta 1 as well as BMI (r = -0.200; r = -0.215; r = -0.332, p < .050 for all). An inverse correlation was noted between serum SP-B and fractional exhaled nitric oxide levels in female asthmatics (r = -0.287, p = .009). Genetic predisposition of the SFTPB gene at 9306 A>G to the obese and overweight groups was noted. CONCLUSION: Obesity altered ceramide metabolism leading to pulmonary surfactant dysfunction and impaired resolution of airway inflammation, finally contributing to the phenotypes of obese asthmatics.
Subject(s)
Asthma , Overweight , Female , Humans , Asthma/diagnosis , Asthma/genetics , Obesity/complications , Inflammation , Ceramides , Transforming Growth Factor beta , Surface-Active AgentsABSTRACT
BACKGROUND: Asthma is a chronic inflammatory airway disease characterized by the predominant infiltration of inflammatory cells in the airways. Thymus and activation-regulated chemokine/C-C motif chemokine 17 (TARC/CCL17) is a chemokine responsible for trafficking T helper 2 cells into sites of allergic inflammation. OBJECTIVE: To validate the role of TARC in association with clinical and inflammatory parameters in adult asthmatics. METHODS: We enrolled 128 asthmatic patients and 70 healthy controls (HCs). Asthma-related clinical and laboratory parameters, including lung function and eosinophil counts, were measured. Serum levels of TARC, free immunoglobulin E (IgE), and eosinophil-derived neurotoxin (EDN) were determined by using enzyme-linked immunosorbent assay; serum total IgE level was measured using ImmunoCAP. The levels of inflammatory lipid mediators, such as leukotriene E4 (LTE4), 15-hydroxyeicosatetraenoic acid (15-HETE), thromboxane B2 (TXB2), and prostaglandin F2α (PGF2α), were measured by liquid chromatography-tandem mass spectrometry. RESULTS: Serum TARC levels are significantly higher in asthmatics than in HCs and in allergic asthmatics than in HCs (P < 0.010 for all), with significantly negative correlations between serum TARC levels and FEV1%/MMEF% values (r = -0.314, r = -0.268, P < 0.050 for both). The patients with higher serum TARC levels had higher levels of serum total and free IgE levels (P < 0.050 for both) with positive correlations to serum levels of EDN, TXB2, and 15-HETE (r = 0.233, r = 0.264, and r = 0.223, respectively, P < 0.050 for all). CONCLUSION: We suggest the role of TARC in allergic asthma via contributing to mast cell and eosinophilic inflammation.
Subject(s)
Antibodies, Antinuclear , Asthma , Asthma/diagnosis , Biomarkers , Eosinophils , Humans , SputumABSTRACT
OBJECTIVES: Insomnia is one of the most common sleep disorders and is difficult to completely treat because of the undesirable side effects of hypnotics. The present study was designed to investigate the hypnotic effect of acupuncture stimulation at HT7 on caffeine-induced sleep disorders and locomotor activity in rats. We also evaluated neuronal activity changes in the arousal region of the basal forebrain. METHODS: Rats received intraperitoneal injections of caffeine, and then electroencephalogram power spectrum analysis and locomotor activity measurements were performed. Stimulation at HT7 was performed using a mechanical acupuncture instrument (MAI) before caffeine injection, and its effects on caffeine-induced changes in sleep architecture, locomotor activity and c-Fos expression were examined. RESULTS: Caffeine injection (7.5 mg/kg) produced a significant decrease in slow-wave sleep and an increase in wake time compared with saline injection. Caffeine injection also increased locomotor activity and c-Fos expression in the medial septum-vertical limb of the diagonal band of Broca (MS-VDB), one of the arousal regions of the basal forebrain. Stimulation at HT7 with the MAI alleviated the caffeine-induced sleep disturbance and the increase in locomotor activity. In addition, MAI treatment at HT7, compared with treatment at a location not corresponding to any traditional acupuncture point, reduced the caffeine-induced increase in c-Fos expression. CONCLUSION: These results indicate that the hypnotic effect of HT7 acupuncture stimulation on caffeine-induced insomnia was associated with suppression of neuronal activity in the basal forebrain.
Subject(s)
Acupuncture Points , Acupuncture Therapy , Sleep Initiation and Maintenance Disorders/therapy , Animals , Caffeine/adverse effects , Humans , Male , Proto-Oncogene Proteins c-fos/genetics , Proto-Oncogene Proteins c-fos/metabolism , Rats , Rats, Sprague-Dawley , Sleep , Sleep Initiation and Maintenance Disorders/etiology , Sleep Initiation and Maintenance Disorders/metabolism , Sleep Initiation and Maintenance Disorders/physiopathologyABSTRACT
A cyclodextrin-decorated gold nanosatellite (AuNSL) substrate was developed as a surface-enhanced Raman scattering sensor for the selective sensing of bipyridylium pesticides such as paraquat (PQ), diquat (DQ), and difenzoquat (DIF). The AuNSL structure was fabricated via vacuum deposition of gold nanoparticles (AuNPs) on a gold nanopillar substrate, and a large density of hot-spots was formed for Raman signal enhancement. Thiolated ß-cyclodextrin (SH-CD) was surface-modified on the AuNSL as a chemical receptor. The detection limit of PQ, DQ, and DIF on the SH-CD-coated AuNSL (CD-AuNSL) was 0.05 ppm for each, and showed linear correlation in a concentration range of 10 ppm-0.05 ppm. Then, selective bipyridylium pesticide detection was performed by comparing the Raman intensity of each pesticide with and without the washing step. After the washing step, 90% of the PQ, DQ, and DIF Raman signals were maintained on the CD-AuNSL substrate with a uniform selectivity in a mapping area of 200 µm × 200 µm. Furthermore, selective pesticide detection was performed using a ground-apple solution without pretreatment. Raman signals were clearly observed after the washing step and they showed a limit of detection down to a concentration of 0.05 ppm for each pesticide. Principal component analysis (PCA) of the binary and ternary mixtures of PQ, DQ, and DIF showed that each component could be easily identified via the typical Raman fingerprint analysis. The developed CD-AuNSL is expected to be applied for various chemical sensors, especially for pyridine-containing toxic substances in the environment and metabolite biomarkers in biofluids.
Subject(s)
Cyclodextrins , Metal Nanoparticles , Pesticides , Gold , Pesticides/analysis , Spectrum Analysis, RamanABSTRACT
The identification of microorganisms in closely related groups is challenging. The present work focused on the different molecular methodology for the accurate microbial identification in the five commercially available organic agriculture materials enriched with effective microorganisms. From the tested five organic agricultural materials, a total of seven distinct bacterial colonies (A-1, B-1, C-1, D-1, E-1, E-2, and E-3) were isolated and processed for sequential identification utilizing HiCrome™ Bacillus agar, biochemical tests with API CHB50, 16S rRNA gene analysis, random amplified polymorphic DNA (RAPD), and species-specific PCR analysis. All the isolated microorganisms were Gram-positive rods and spore former belonging to Bacillus group and appeared as a differential characteristic feature on HiCrome™ Bacillus agar. All isolates showed high-percentage similarities with the different members of Bacillus species in biochemical testing and 16S rRNA gene analysis. The collective identification results revealed isolates, A-1, B-1, and C-1, close to B. velezensis. Further RAPD-PCR and species-specific PCR discriminated and provided confirmatory evidence for D-1 as B. thuringiensis and E-1, E-2, and E-3 as B. licheniformis, respectively. In addition, presence of B. thuringiensis was also confirmed by toxin crystal protein staining. In conclusion, the species-specific primers could be used as a rapid and accurate identification tool to discriminate closely related Bacillus species such as B. subtilis, B. licheniformis, and B. thuringiensis.