Schirmer Paper Noninvasive Microsampling for Direct Mass Spectrometry Analysis of Human Tears.

Rapid and sensitive detection of metabolites and chemical residues in human tears is highly beneficial for understanding eye health. In this study, Schirmer paper was used for noninvasive microsampling of human tears, and then paper spray mass spectrometry (PSMS) was performed for direct analysis of human tears. Schirmer PSMS was successfully used for rapid diagnosis of dry-eye syndrome by detecting the volume and metabolites of human tears. Drugs of abuse, therapeutic drugs, and pharmacodynamics in human tears were also investigated by Schirmer PSMS. Furthermore, specific markers of environmental exposures in the air to human eyes, including volatile organic compounds, aerosol, and smoke, were unambiguously sampled and detected in human tears using Schirmer PSMS. Excellent analytical performances were achieved, including single-use, low-sample consumption (1.0 µL), rapid analysis (the whole analytical procedure completed within 3 min), high sensitivity (absolute limit of detection less than or equal to 0.5 pg, signal-to-noise ratio greater than or equal to 3), good reproducibility (relative standard deviation less than 10%, n = 3), and accurate quantitation (average deviation less than 3%, n = 3). Overall, our results showed that Schirmer PSMS is a highly effective method for direct tear analysis and is expected to be a convenient tool for human tear analysis in significant clinical applications.

Investigating distributions and changes of alkaloids in living Catharanthus roseus under low-phosphorus stress using wooden-tip electrospray ionisation mass spectrometry.

INTRODUCTION: Vinca alkaloids are important sources for producing anticancer drugs from Catharanthus roseus. The phosphorus of soil is one of crucial factors for planting C. roseus. OBJECTIVES: We aim to develop an in vivo sampling technique coupled with direct mass spectrometry with wooden tip for investigating distributions and changes of alkaloids in flowers, leaves, stems, veins and roots of living C. roseus under low-phosphorus stress. MATERIALS AND METHODS: Living C. roseus were prepared under low-phosphorus stress (n = 10) and control conditions (n = 10). Wooden-tip electrospray ionisation mass spectrometry and conventional liquid chromatography-mass spectrometry were applied to analyse living C. roseus and extracts of C. roseus, respectively. RESULTS: Distributions and changes of serpentine, vindoline, catharanthine, and anhydrovinblastine in living C. roseus under low-phosphorus stress and control conditions were successfully obtained. CONCLUSION: Compared to control soil conditions, low-phosphorus soil was found to induce C. roseus to generate more serpentine but less catharanthine and vindoline in leaves, veins, stems and roots, and to generate more anhydrovinblastine in flowers, leaves, stems and roots. Overall, our results showed a simple, rapid, and effective method for in vivo sampling and direct analysis of living plants.

Fast-switching high-voltage porous-tip electrospray ionization mass spectrometry for rapid detection of antirheumatic drugs in adulterated herbal dietary supplements.

RATIONALE: Herbal dietary supplements (HDSs) adulterated with undeclared synthetic drugs can lead to serious health problems METHODS: A fast-switching positive/negative high-voltage (+/- HV) was developed to apply on electrospray ionization mass spectrometry (ESI-MS) with porous tips for rapid screening of five antirheumatic drugs in antirheumatic HDSs. The fast-switching (switch-time: 100 ms) negative and positive ions were alternately generated to perform full-MS and tandem-MS analysis, providing an effective method for rapid detection of analytes in whichever mode of detection was most suitable (negative or positive ion mode). The use of different tips and solvents was also optimized in this work. RESULTS: The limits of detection of the five antirheumatic drugs were found to be less than 0.1 ng/g (S/N > 3). The reproducibility of the five drugs was measured to be 10.0-23.3% (n = 5). A single sample analysis could be completed within 1 min. Rapid screening of a total of 28 real HDS samples collected from the market was examined by the fast-switching HV substrate-tip ESI-MS method, and the screening result was further validated by conventional liquid chromatography/mass spectrometry. CONCLUSIONS: Overall, our results demonstrated that fast-switching HV substrate-tip ESI-MS is a rapid, reliable, and effective method for simultaneous screening of various analytes in complex samples.

A review of sources, pathways, and toxic effects of human exposure to benzophenone ultraviolet light filters.

Benzophenone ultraviolet light filters (BPs) are high-production-volume chemicals extensively used in personal care products, leading to widespread human exposure. Given their estrogenic properties, the potential health risks associated with exposure to BPs have become a public health concern. This review aims to summarize sources and pathways of exposure to BPs and associated health risks. Dermal exposure, primarily through the use of sunscreens, constitutes a major pathway for BP exposure. At a recommended application rate, dermal exposure of BP-3 via the application of sunscreens may reach or exceed the suggested reference dose. Other exposure pathways to BPs, such as drinking water, seafood, and packaged foods, contribute minimal to the overall dose. Inhalation is a minor pathway of exposure; however, its contribution cannot be ignored. Human exposure to BPs is an order of magnitude higher in North America than in Asia and Europe. Studies conducted on laboratory animals and cells have consistently demonstrated the toxic effects of BP exposure. BPs are estrogenic and elicit reproductive and developmental toxicities. Furthermore, neurotoxicity, hepatotoxicity, nephrotoxicity, and carcinogenicity have been reported from chronic BP exposure. In addition to animal and cell studies, epidemiological investigations have identified associations between BPs and couples' fecundity and other reproductive disorders, as well as adverse birth outcomes. Further studies are urgently needed to understand the risks posed by BPs on human health.

[Detection of matrix metalloproteinase-11 in menstrual blood by enhanced chemiluminescence method].

OBJECTIVE: To explore the forensic application value of detection of matrix metalloproteinase-11 (MMP-11) in menstrual blood by enhanced chemiluminescence method. METHODS: Menstrual blood, vaginal swab, peripheral blood, saliva stain, urine stain and semen stain were collected to detect whether or not there were MMP-11 using enhanced chemiluminescence method. The specificity and reliability of the MMP-11 assay along with its sensitivity were evaluated. RESULTS: The positive detection rate of MMP-11 in menstrual blood was 89.47%, whereas no MMP-11 was found in vaginal swab, peripheral blood, saliva stain, urine stain and semen stain. When 25 microL sample was added, the mass concentration of protein was 1.329 microg/microL, then MMP-11 could be detected. A positive detection rate of 89.58% was observed in MMP-11 positive menstrual blood samples after stored at 4 degrees C for 20 months. CONCLUSION: Enhanced chemiluminescence method is sensitive and specific for detecting MMP-11, and can be applied to distinguish menstrual blood from common stain such as peripheral blood, vaginal fluid.

Contactless electrospray ionization mass spectrometry for direct detection of analytes in living organisms.

In this study, we developed contactless electrospray ionization mass spectrometry (ESI-MS) for in vivo analysis of living organisms in different applications. The in vivo sampling and direct analysis processess of living organisms were integrated into an operation that only requires the organism close to MS inlet that was applied to a high voltage. Living plants and animals were directly induced to generate spray ionization. Direct detection and in vivo monitoring of metabolites and chemical residues in various living organisms were successfully demonstrated. Analysis of a single sample could be completed within 30 s. Overall, contactless ESI-MS provides an attractive in vivo method to straightforward investigation of living organisms.

Direct Detection of Lysozyme in Viscous Raw Hen Egg White Binding to Sodium Dodecyl Sulfonate by Reactive Wooden-tip Electrospray Ionization Mass Spectrometry.

Direct characterization of native protein binding to ligands in raw biological samples is a challenging task, because the ligand solution might induce proteins to aggregation, flocculation and denaturation. In this work, we developed a reactive wooden-tip electrospray ionization mass spectrometry (ESI-MS) for formation and characterization of protein-ligand complexes upon rapid mixing in electrospray droplets. Raw viscous hen egg white (HEW) was directly loaded onto a wooden tip to induce spray ionization, and sodium dodecyl sulfonate (SDS) solution was directly loaded into the HEW spray by a pipette tip, and thus lysozyme-DS complexes were then formed in the electrospray droplets and were detected subsequently by mass spectrometry. The new approach was successfully applied to investigate interaction of SDS and native lysozyme in electrospray droplets of standard solution and raw egg white. Our results showed that wooden-tip ESI-MS is a promising method to form and characterize protein-ligand complexes.

[Application of ITO method and discriminant functions in full sibling and half sibling identification].

OBJECTIVE: To investigate the application of ITO method and discriminant functions method in full sibling and half sibling identification. METHODS: Five hundred pairs of full siblings (FS), 50 pairs of half siblings (HS) and 500 pairs of unrelated individuals (UR) were genotyped by PowerPlex 16 system. Full sibling index (FSI), half sibling index (HSI) and the FSI:HSI ratio were calculated with ITO method. Allelic matching of each pair of the three groups was compared. The locus numbers of no-allele sharing (x0), half-allele sharing (x1) and two-alleles sharing (x2) were calculated, respectively. The discriminant functions about full-siblings, half-siblings and unrelated individuals (UR) were established by SPSS 13.0 statistical software. RESULTS: (1) Regard FSI > or = 19 or FSI < 1 as the standard of distinguishing full sibling from unrelated individual, the alternate correct percentage was 96.4%. Regard HSI > or = 19 or HSI < 1 as the standard of distinguishing half sibling from unrelated individual, the alternate correct percentage was 85.3%. Regard FSI:HSI > or = 1 or FSI:HSI < 1 as the standard of distinguishing full sibling from half sibling, the alternate correct percentage was 87.5%. (2) Four groups of discriminant functions were established. The alternate correct percentage of these discriminant functions were 84.4%-97.7%, with the highest one in full sibship-unrelated individual group. CONCLUSION: Both ITO method and discriminant functions method are efficient in identification of full sibling or half sibling.

Detection and Seasonal Variations of Huanglongbing Disease in Navel Orange Trees Using Direct Ionization Mass Spectrometry.

Citrus greening disease [Huanglongbing (HLB)] is the most destructive disease of citrus. In this work, we have established a metabolite-based mass spectrometry (MS) method for rapid detection of HLB in navel orange trees. Without sample pretreatment, characteristic mass spectra can be directly obtained from the raw plant samples using the direct MS method. The whole detection process can be accomplished within 1 min. By monitoring and comparisons of the healthy and infected plants throughout a whole year, characteristic MS peaks of metabolites are found to be specific responses from infected plants and, thus, could be used as biomarkers for detection of HLB. Therefore, HLB could be directly detected in the asymptomatic samples, such as stems, using this metabolite-based direct MS method. In addition, principal component analysis and partial least squares discriminant analysis modes of metabolites from healthy and infected trees were established for investigating differentiation and seasonal variations of HLB in leaves, veins, and stems, providing valuable information for understanding the HLB in different seasons.

Analytical properties of electrospray ionization mass spectrometry with solid substrates and nonpolar solvents.

Electrospray ionization mass spectrometry (ESI-MS) is one of the most powerful ionization techniques for characterization of analytes in various areas. Polar solvents such as methanol, water and acetonitrile are commonly used for ESI-MS analysis, while nonpolar solvents such as hexane were usually considered as non-ESI-friendly solvents. Following our recent work on observation of ESI process from solid substrates using nonpolar solvents (Anal Chim Acta, 2018, 1004, 51-57), the analytical properties of ESI-MS with solid substrates and nonpolar solvents were further systematically investigated in this study. Compared to the uses of polar solvents, our results revealed that nonpolar solvents could serve as extractants for enhanced detection of low-polar analytes from complex samples, and could serve as refrigerants for rapid freezing of samples such as peptides, proteins and protein-ligand complexes. Furthermore, nonpolar solvents could be used for formation of ammonia-transition-metal acetylacetonates complexes under ambient conditions.

Comprehensive comparison of ambient mass spectrometry with desorption electrospray ionization and direct analysis in real time for direct sample analysis.

Ambient ionization mass spectrometry is a powerful analytical method for direct analysis of raw samples. Desorption electrospray ionization (DESI) and direct analysis in real time (DART) are two pioneer ambient ionization techniques and have been widely used in various fields. Despite it is a fact that the application and development of DESI and DART are gaining significant attention in analytical science, few comprehensive comparisons of DESI and DART have been made for in-depth understanding their characteristics for direct sample analysis. In this work, substituent effect on DESI and DART were systematically investigated using a serial of model molecules (i.e., tripeptides and fatty acids) that containing same molecular skeleton and different substituents, revealing that DESI response was determined by substituent hydrophilic effect and DART response of analyte was determined by substituent steric effect. Furthermore, matrix effects on DESI and DART were compared by detecting same analyte in different matrices, revealing respective characteristics of DESI and DART for direct sample analysis. Moreover, DESI and DART also were further compared for detecting same samples, including thermostable, thermally unstable, small and larger molecules, demonstrating complementation of DESI and DART to obtain comprehensive information of raw samples for different purposes in real-world applications. Overall, our results provided new insights into the mechanisms and applications of ambient MS with DESI and DART.

Vibrating tip spray ionization mass spectrometry for direct sample analysis.

In this work, a vibrating tip spray ionization source was developed for direct mass spectrometric analysis of raw samples under voltage-free condition. A solid tip was mounted on a vibrator, and the solid tip was placed on the front of MS inlet. Liquid, viscous, and bulk solid samples could be directly loaded on the tip-end surface, and then a drop of solvent at microliter level was subsequently loaded on the tip for dissolution and extraction of analytes, and a vibrator was then started to atomize and ionize the analytes under ambient condition. We demonstrated vibrating tip spray mass spectrometry in various applications, including food safety, pharmaceutical analysis, and forensic science. Furthermore, in situ analysis of biological tissues and in vivo analysis of living plants were conveniently performed, due to voltage-free. Different vibration frequencies and solvent compositions were investigated. The analytical performances, including sensitivity, reproducibility, and linear range, were investigated. The ionization process and mechanism were also discussed in this work.

Clinical safety and efficacy of curcumin use for oral lichen planus: a systematic review.

Objective: Oral lichen planus (OLP) is a relatively common immunological mucocutaneous disease that causes pain and poor quality of life. Curcumin has been reported to be a safe and effective treatment for OLP. The objective of this review is to evaluate the existing evidence for the safety of curcumin in treating OLP as well as its efficacy compared with that of corticosteroids. Methods: We reviewed the published literature by searching PubMed, EMBASE, EBSCO, and Cochrane Library, and then retrieved and analyzed several variables from patient records. Results: Nine studies met the inclusion criteria, including six randomized, double-blind clinical trials; two pilot clinical trials; and one case report. A total of 259 OLP patients were included in the systematic review. Seven studies showed statistically significant differences in pain severity and clinical appearance of oral lesions after treatment with curcumin for a period of time, compared to baseline (p < .05). Three controlled clinical trials compared the efficacy of curcumin to that of corticosteroids; all of these trials showed no statistically significant differences in pain severity and clinical appearance of oral lesions. Conclusions: Curcumin is a safe treatment and can be used as an adjunct in combination with corticosteroids to reduce pain, burning sensations, and the clinical appearance of oral lesions in OLP patients.

[Detection of MMP-11 from menstrual blood using immunohistochemistry].

OBJECTIVE: To prove the feasibility of detecting menstrual blood as well as its cellular localization with rabbit-anti-human matrix metalloproteinase-11 (MMP-11) polyclonal antibody. METHODS: MMP-11 in menstrual blood, peripheral blood, vaginal liquid, aged menstrual bloodstain, and endometrium sections were assayed with SAP immunohistochemistry. RESULTS: MMP-11 was found only in menstrual samples within stroma and epithelium cells. CONCLUSION: MMP-11 polyclonal antibody may be applied in the distinction between menstrual blood and venous blood.

[Species identification of biomaterials by amplifying 12S rRNA gene].

OBJECTIVE: To establish an accurate, simple, quick, specific and sensitive method for species identification by amplifying 12S rRNA gene with the same reaction system. METHODS: Based on the downloaded 12S rRNA gene sequences of eleven species (human, chicken, duck, goose, pig, rabbit, rat, sheep, bull, dog and goat) from GenBank, a pair of universal primers to eleven species and three pairs of specific primers to human, chicken and duck were designed. The amplicons amplified with universal primers were used for internal controls, and the amplicons amplified with specific primers were used as identification of human, chicken and duck. DNA was extracted from various samples including blood stains, fresh or freezing muscles, heat-treated muscles and hairs. Both single DNA of human, chicken or duck and mixed DNA of any two kinds of them were amplified. RESULTS: The lengths of universal amplicons were about 400 bp. The lengths of specific amplicons were 163 bp for human, 286 bp for chicken, and 374 bp for duck, respectively. No cross amplification was observed, indicating a high specificity of the specific primers. The identification rate was 100% for human, 99% for chicken, and 100% for duck, respectively. The detection sensitivity ranged from 2.5 pg to 200 pg of DNA concentration depending on species, even in mixtures of different species DNA without interference. CONCLUSION: The method established could identify different species under the same reaction system.

Analyte-substrate interactions at functionalized tip electrospray ionization mass spectrometry: Molecular mechanisms and applications.

Conventional electrospray ionization mass spectrometry (ESI-MS) commonly uses capillary tip for sample introduction and ionization. In recent years, ESI-MS using noncapillary substrate tips has attracted growing interest as it allows separation and enrichment of analytes from complex samples due to analytes-substrate interactions. In this work, model mixtures and functionalized tips were employed to investigate the molecular mechanism of the analyte-substrate interactions. The mixtures were directly loaded on substrate tips, and then temporal responses of analytes were investigated by monitoring selected ion chromatogram (SIC) responses of each analyte. It is found that all analytes are sprayed out together when bulk solution loaded substrate surface and then sequential ionization of analytes were observed. Sequential ionization of analytes was affected by the analytes-substrate interactions which caused analytes of weaker-interaction to be faster moved and the analytes of stronger-interactions to be retained on the substrate. The main molecular mechanisms of analyte-substrate interactions were revealed to be hydrophobic interactions and electrostatic interactions. Furthermore, based on the mechanistic insights, functionalized tips were further applied for rapid extractive sampling of target analytes from complex samples with good analytical performances. Overall, this study on the mechanism and applications of analyte-substrate interactions is useful for understanding the fundamental principles and further developments of functionalized tip electrospray ionization (TESI).

[A primary analysis of oral mucosa and periodontal status of chronic graft-versus-host disease caused by hematopoietic stem cell transplantation].

PURPOSE: The aim of this study was to investigate the severity and status of oral mucosa and periodontal status in early and late stage after receiving hematopoietic stem cell transplantation(HSCT). METHODS: This study enrolled patients submitted to hematopoietic stem cell transplantation. Through a survey questionnaire, clinical examination, we collected clinical data from 108 HSCT recipients and divided them into 2 groups: transplantation time less than 1 year and more than 1 year. The oral mucosal and periodontal status were recorded and statistically analyzed with SPSS 21.0 software package. RESULTS: The incidence of oral features after HSCT was 78.95%. The incidence of mild symptoms with HSCT less than 1year (n=32) and HSCT more than 1 year (n=43) was 59.38% and 18.60%, respectively. There was significant difference between the two groups (P=0.001).The percent of lichenoid/hyperkeratotic plaques was 31.25% and 60.47%, respectively. The lichenoid/hyperkeratotic plaques were significantly different between the two groups (P=0.012). The detection rate of shallow and moderate pockets was 49.38% and 40.74%, respectively. Visual plaque, calculus and bleeding on probing were 62.96%, 64.20% and 50.62%, respectively. CONCLUSIONS: The incidence of periodontal and mucosal lesions after HSCT is high. The mild symptoms of oral graft versus host disease in early stage are identified obviously, mainly like lichenoid/hyperkeratotic plaques in late stage.

[Comparation on Haversian system between human and animal bones by imaging analysis].

OBJECTIVE: To explore the differences in Haversian system between human and animal bones through imaging analysis and morphology description. METHODS: Thirty-five slices grinding from human being as well as dog, pig, cow and sheep bones were observed to compare their structure, then were analysed with the researchful microscope. RESULTS: Plexiform bone or oeston band was not found in human bones; There were significant differences in the shape, size, location, density of Haversian system, between human and animal bones. The amount of Haversian lamella and diameter of central canal in human were the biggest; Significant differences in the central canal diameter and total area percentage between human and animal bones were shown by imaging analysis. CONCLUSION: (1) Plexiform bone and osteon band could be the exclusive index in human bone; (2) There were significant differences in the structure of Haversian system between human and animal bones; (3) The percentage of central canals total area was valuable in species identification through imaging analysis.