Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry traces the geographical source of Biomphalaria pfeifferi and Bulinus forskali,involved in schistosomiasis transmission

Background Freshwater snails of the genera Bulinus spp.,Biomphalaria spp.,and Oncomelania spp.are the main intermediate hosts of human and animal schistosomiasis.Identification of these snails has long been based on mor-phological and/or genomic criteria,which have their limitations.These limitations include a lack of precision for the morphological tool and cost and time for the DNA-based approach.Recently,Matrix-Assisted Laser Desorp-tion/lonization Time-Of-Flight(MALDI-TOF)mass spectrometry,a new tool used which is routinely in clinical microbi-ology,has emerged in the field of malacology for the identification of freshwater snails.This study aimed to evaluate the ability of MALDI-TOF MS to identify Biomphalaria pfeifferi and Bulinus forskali snail populations according to their geographicalorigin.Methods This study was conducted on 101 Bi.pfeifferi and 81 Bu.forskali snails collected in three distinct geo-graphical areas of Senegal(the North-East,South-East and central part of the country),and supplemented with wild and laboratory strains.Specimens which had previously been morphologically described were identified by MALDl-TOF MS[identification log score values(LSV)≥1.7],after an initial blind test using the pre-existing database.After DNA-based identification,new reference spectra of Bi.pfeiferi(n=10)and Bu.forskali(n=5)from the geographical areas were added to the MALDI-TOF spectral database.The final blind test against this updated database was per-formed to assess identification at the geographic source level.Results MALDI-TOF MS correctly identified 92.1%of 101 Bi.pfeifferi snails and 98.8%of 81 Bu.forskali snails.At the final blind test,88%of 166 specimens were correctly identified according to both their species and sampling site,with LSVs ranging from 1.74 to 2.70.The geographical source was adequately identified in 90.1%of 91 Bi.pfeifferi and 85.3%of 75 Bu.forskalii samples.Conclusions Our findings demonstrate that MALDI-TOF MS can identify and differentiate snail populations according to geographical origin.It outperforms the current DNA-based approaches in discriminating laboratory from wild strains.This inexpensive high-throughput approach is likely to further revolutionise epidemiological studies in areas which are endemic for schistosomiasis.

Detection of Sialylated N-Linked Glycans by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Native and methyl-esterified sialylated glycans were analyzed with 2,4,6-trihydroxyacetophenone（THAP）and 2,5-dihydroxybenzoic acid（DHB）as matrix by a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer（MALDI-TOF MS）.High quality negative-ion spectra of commercial sialylated glycan were obtained with THAP as matrix.Detection limit of the glycan was less than 0.1 pmol.After methyl esterification of sialic acid（SA）residue,sialylated glycans were detected sensitively in the positive-ion mode using DHB as matrix.Neutral and sialylated glycans from the mixture of asialofetuin and fetuin were methylesterified and simultaneously recognized in one manipulation.Methyl esterification of SA residue offers a convenient and sensitive way to identify the structure of N-linked glycans for glycan profiling.

Studies on extracting solutions of endohedral rare-earth metallofullerenes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Thirteen extracting solutions of rare-earth metallofullerenes containing La,Ce,Pr,Nd Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm and Yb respectively have been investigated by means of matrix-assisted laser desorpuon/ ionization time-of-flight mass spectrometry.The influences of the positive-ion/negative-ion mode,laser intensity,ma trix and mass discrimination to the analytical results are studied,based on which the optimal analytical conditions have been determined.The results show that the extracting solutions contain large quantities of rare-earth metallofullerenes besides empty fullerenes.On the basis of comparing their relative intensities,the different structure stabilities and solubilities of metallofullerenes with different rare-earth metals encapsulated into the fullerene cages,as well as some possible reasons to those differences,are discussed.

MicrobMatcher: a microbial comparison software based on matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry

Matrix-assisted Laser Desorption/Ionization with Time-of-flight Mass Spectrometry (MALDI-TOFMS) was investigated as a method for the rapid identifica-tion of species. Current demand in microbial identi-fication is how to compare unknown strains to the known one quickly, semi-automatically and accurately. In this paper, we present a software tool that allows flexibly microbial matching in a user-friendly way, by letting the users to customize comparison parameters including: in vitro transcription enzyme, mass tolerance,minimum fragment length, intensity threshold and corresponding weights. We provide three spectral scoring functions to compute the affin-ity between the species. Therefore, the precision of microbial comparison increases. To test and verify this tool, we employed experimental spectral data based on MALDI-TOFMS and the gene sequences of E.coli and Salmonella. This software is written in Java for cross-platform intention.

Rapid Profiling of Alkaloids in Several Medicinal Herbs by Matrix-assisted Laser Desorption/Ionization Mass Spectrometry

A simple method was developed for rapid and direct profiling of alkaloids in medical herbs via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry（MALDI-TOF MS）. The dry herbs were first ground to powder and passed through a stainless steel sieve, mixed with the matrix solution to form a homogeneous suspension, which was then directly applied to MALDI analysis. Several matrices were investigated and 2,5- dihydroxybenzoic acid（DHB） was chosen as the optimized one, and the particle with small size was found to favor the analysis. Using this method, the profiles of alkaloids in several medical herbs were readily obtained, and the toxicities of crude and processed Radix Aconiti Lateralis Preparata were compared via the relative intensities of the peaks of the corresponding toxic components shown in their MALDI spectra. This method therefore provides a rapid and reliable protocol for obtaining profiles of alkaloids in medical herbs by using MALDI-TOF MS.

Serum proteomic profiling for autism using magnetic bead-assisted matrix-assisted laser desorption ionization time-of-flight mass spectrometry: a pilot study

Background The pathogenesis of autism spectrum disorders remains elusive and currently there are no diagnostic or pre-dictive biomarkers in autism available. Proteomic profiling has been used in a wide range of neurodevelopmental disorder studies, which could produce deeper perceptions of the molecular bases behind certain disease and potentially becomes useful in discovering biomarkers in autism spectrum disorders. Methods Serum samples were collected from autistic children about 3 years old in age (n = 32) and healthy controls (n = 20) in similar age and gender. The samples were identified specific proteins that are diff erentially expressed by magnetic bead-based pre-fractionation and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF-MS). Results Eight protein peaks were significantly different in autistic children from the healthy controls (P < 0.0001). The two peaks with the most significant diff erences were 6428 and 7758 Da in size. Conclusion According to diff erences in serum protein profiles between the autistic children and healthy controls, this study identified a set of diff erentially expressed proteins those are significant for further evaluation and might function as biomark-ers in autism.

MALDI coupled with laser-postionization and trapped ion mobility spectrometry contribute to the enhanced detection of lipids in cancer cell spheroids

Cancer cell spheroids(CCS) are a valuable three-dimensional cell model in cancer studies because they could replicate numerous characteristics of solid tumors. Increasing researches have used matrix-assisted laser desorption/ionization mass spectrometry imaging(MALDI-MSI) to investigate the spatial distribution of endogenous compounds(e.g., lipids) in CCS. However, only limited lipid species can be detected owing to a low ion yield by using MALDI. Besides, it is still challenging to fully characterize the structural diversity of lipids due to the existence of isomeric/isobaric species. Here, we carried out the initial application of MALDI coupled with laser-postionization(MALDI-2) and trapped ion mobility spectrometry(TIMS) imaging in HCT116 colon CCS to address these challenges. We demonstrated that MALDI-2 is capable of detecting more number and classes of lipids in HCT116 colon CCS with higher signal intensities than MALDI. TIMS could successfully separate numerous isobaric/isomeric species of lipids in CCS. Interestingly, we found that some isomeric/isobaric species have totally different spatial distributions in colon CCS. Further MS/MS imaging analysis was employed to determine the compositions of fatty acid chains for isomeric species by examining disparities in signal intensities and spatial distributions of product ions. This work stresses the robust ability of TIMS and MALDI-2 imaging in analyzing endogenous lipids in CCS, which could potentially become powerful tools for future cancer studies.

Multiple skin abscesses associated with bacteremia caused by Burkholderia gladioli:A case report

BACKGROUND Burkholderia gladioli(B.gladioli)is regarded as a rare opportunistic pathogen.Only a few patients with abscesses caused by B.gladioli infections have been reported,and these are usually abscesses at the incision caused by traumatic surgery.CASE SUMMARY A 74-year-old male patient with abscesses and pain throughout his body for 1 mo was admitted to our hospital.Some of the abscesses had ruptured with purulent secretions on admission.Color Doppler ultrasound examination of the body surface masses showed mixed masses 75 mm×19 mm,58 mm×17 mm,17 mm×7 mm,and 33 mm×17 mm in size in the muscle tissues of both the right and left forearms,the posterior area of the right knee and the left leg,respectively.Abscess secretions and blood cultures grew B.gladioli.The following 3 methods were used to jointly identify the bacterium:an automatic microbial identification system,matrix-assisted laser desorption/ionization time-of-flight mass spectrometry,and full-length 16 S rDNA sequencing.After 27 d of treatment with meropenem,etimicin,trimethoprim-sulfamethoxazole and other antibiotics,most of his skin abscesses were flat and he was discharged without any symptoms.CONCLUSION This is the first reported case of multiple skin abscesses associated with bacteremia caused by B.gladioli.Our study provides important reference values for the clinical diagnosis and treatment of B.gladioli infections.

Elizabethkingia miricola :A rare non-fermenter causing urinary tract infection

Elizabethkingia miricola(E.miricola) is a gram-negative non-fermentative bacterium which is rarely encountered.It is usually misidentified or considered as a contaminant in routine microbiology laboratories due to the limitations in conventional biochemical techniques.However,with the advent of the matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOFMS),the identification of non-fermenters has become easy and this has led to enhanced understanding of the clinical significance of these uncommonly isolated microorganisms.The genus Elizabethkingia has only two species E.meningoseptica and E.miricola.Both of these organisms are known to be multi-drug resistant and therefore,their accurate identification and antimicrobial susceptibility testing are necessary prior to the initiation of appropriate therapy.In the world literature till date,only 3 cases of sepsis caused by E.miricola have been reported.We present the first case of E.miricola association with urinary tract infection.

利用基质辅助激光解吸电离飞行时间质谱快速鉴定产气荚膜梭菌

分别采用基质辅助激光解吸电离飞行时间质谱方法(matrix-assisted laser desorption/ionization time-offlight mass spectrometry,MALDI-TOF MS)、16S rRNA基因测序、VITEK 2 COMPACT和传统生化方法(牛乳汹涌发酵实验)鉴定实验室保存的51株产气荚膜梭菌,以评估MALDI-TOF MS方法是否适用于产气荚膜梭菌的快速鉴定。MALDI-TOF MS方法将51株菌均鉴定为产气荚膜梭菌且鉴定分值在2. 300以上,达到鉴定到种的要求。16S rRNA基因序列比对结果与MALDI-TOF MS方法结果一致。VITEK 2 COMPACT将49株菌鉴定为产气荚膜梭菌,2株菌未能成功鉴定。47株菌的牛乳汹涌发酵实验呈阳性,4株菌为牛乳汹涌发酵实验阴性,且这4株菌经其他3种方法均鉴定为产气荚膜梭菌。结果表明,无论是牛乳汹涌发酵实验还是VITEK 2 COMPACT,在检测产气荚膜梭菌时都有可能发生漏检。相比牛乳汹涌发酵实验、VITEK 2 COMPACT和16S rRNA测序方法,MALDI-TOF MS方法更加快速、准确和低成本,适用于产气荚膜梭菌的快速鉴定。

Upregulation of macrophage migration inhibitory factor and calgizzarin by androgen in TM4 mouse Sertoli cells

Aim： To identify proteins induced by androgen in Sertoli cells during spermatogenesis. Methods： We analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone （DHT） using surface enhanced laser desorption ionization time-of-flight mass spectrometry （SELDI-TOF-MS）. Results： We found increases in the expression of a 5.0-kDa protein at 15 min, an 11.3-kDa protein at 24 h and 4.3 kDa, 5.7 kDa, 5.8 kDa, 9.95 kDa and 9.98 kDa proteins at 48 h after the treatment. In contrast, the expression of 6.3 kDa and 8.6 kDa proteins decreased at 30 min, and 4.9 kDa, 5.0 kDa, 12.4 kDa and 19.8 kDa proteins at 48 h after the treatment. The ll.3-kDa protein was identified as macrophage migration inhibitory factor （MIF） known to having various functions. The 9.98-kDa protein was identified as calgizzarin related to calcium channels. The timing of their expression suggests that MIF and calgizzarin are involved in late regulation of spermatogenesis in Sertoli cells by androgen. Conclusion： MIF and calgizzarin are two important androgen-responsive proteins produced by Sertoli cells and they might play a role in regulating spermatogenesis.

Arsenic trioxide inhibits metastatic potential of mouse hepatoma H22 cells in vitro and in vivo

BACKGROUND:It has been pointed out that only low-dose arsenic trioxide(ATO)presents therapeutic benefits outweighing the toxic side effects.Low-dose ATO can effectively alleviate acute promyelocytic leukemia(APL). However,it is quite challenging in treating solid tumors. The purpose of this study was to investigate the effect of ATO at low concentrations on the metastatic potential of mouse hepatoma H22 cells and the anti-metastatic mechanism of ATO. METHODS:The metastatic potential of H22 cells was evaluated by adhesion,migration and invasion assays after exposure to a low dose of ATO in vitro.The mouse lung metastatic model induced by injection of H22 cells via the tail vein was adopted for the evaluation of metastatic potential. Different proteins in the lysate of H22 cells exposed to ATO at different concentrations were investigated by surface- enhanced laser desorption and ionization time-of-flight mass spectrometry(SELDI-TOF-MS).Finally,Western blotting analyses were made to detect the expression pattern of MMP-2 and nm23-M1 proteins. RESULTS:Significant cell death started at ATO concentrations above 2μmol/L.The growth and adhesion potential of H22 cells was inhibited in a time-and dose- dependent manner,and the migration and invasion potential of H22 cells was inhibited in a dose-dependent manner while ATO concentration was below 2μmol/L. Mice injected with ATO at a dose of 0.5 mg/kg had fewer lung metastases.However,mice injected with ATO at a dose of 2 mg/kg or 4 mg/kg had a high mortality rate and more liver injuries.A total of 15 different protein peaks were identified between the lysate of H22 cells treated with ATO and controls.Two proteins that peaked atm/z 5302 and 17207 coincided with MMP-2(fragment) and nm23-M1,respectively.Western blotting analyses demonstrated that MMP-2 and MMP-2 fragments were down-regulated and nm23-M1 was up-regulated in H22 cells treated with 2μmol/L ATO for 48 hours. CONCLUSIONS:ATO at a low dose inhibits the metastatic potential of mouse hepatoma H22 cells in vitro and in vivo, and involves down-regulation of MMP-2 and up-regulation of nm23-M1.

Identification of serum biomarkers for diagnosing stage Ⅰ lung adenocarcinoma by MALDI-TOF mass spectrometry

Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 patients with stage Ⅰ lung adenocarcinoma and 17 age-and sex-matched healthy controls,and the serum proteomic profiles were obtained by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. Results Compared with healthy control group,two highly expressed potential biomarkers were identified with the relative molecular weights of 6 631.64 Da and 4 964.21 Da. The two best novel protein peaks were automatically chosen for the system training and the development of the constructed model. The constructed model was then used to test an independent set of masked serum samples from 15 lung adenocarcinoma patients and 22 healthy individuals. The analysis yielded a sensitivity of 93.3%,and a specificity of 95.5%. Conclusion These results suggest that MALDI-TOF-MS ProteinChip technology is a quick,convenient,and high-output analyzing method that is capable of selecting several relatively potential biomarkers from the serum of lung adenocarcinoma patients and may have a clinical value in the future,and will provide clues to identifying new serologic biomarkers of lung adenocarcinoma.

Lipopeptide Antibiotics Produced by the Engineered Strain Bacillus subtilis GEB3 and Detection of Its Bioactivity

MALDI-TOF-MS technology was used for identification of lipopeptide antibiotics producedby GEB3 strain, a derivative of Bacillus subtilis 168 which was transformed by lpaB3gene. The result showed GEB3 only produced lipopeptide antibiotic surfactin. The analysisby LC-MS demonstrated that GEB3 produced standard surfactin isoforms with side chainlengths of 13,14 and 15 carbon atoms. The bioactivity detection of surfactin indicatedthat the surfactin produced by GEB3 had inhibition effect on plant pathogens Rhizoctoniasolani and Pyricularia oryzae.

C_(60)衍生物的MALDI-TOFMS分析

C60衍生物在超导、非线性光学、催化、材料和生物活性等方面有巨大的潜在应用价值.C60衍生物大多为固体,蒸汽压较低,采用需要加热才能够使样品气化电离的质谱或"硬"电离质谱方法进行测定,易造成C60衍生物分解并释放出配体.……

Characterization of Tannin-Based Resins from the Barks of <i>Ficus platyphylla</i>and of <i>Vitellaria paradoxa</i>: Composites’ Performances and Applications

This work investigates the physico-chemical and mechanical properties of tannins extracted from wood for composite materials manufacturing. Sustainable knowledge (in terms of physico-chemical properties and behaviours) of the material is needed to further enhance its applications. The condensed tannins extracted from the Bark of Ficus platyphylla (BFP) and the Bark of Vitellaria paradoxa (BVP) were analyzed using Matrix Assisted Laser Desorption/Ionization Time-Of-Flight (MALDI-TOF), Mass Spectroscopy and Attenuated Total Reflectance Fourier Transform Mid-InfraRed (ATR-FT MIR) spectra in the ranges 1800 cm-1 and 600 cm-1, as well as using CP MAS 13C-NMR. It was found that, these two tannins are procyanidin/prodelphinidin and made up of catechin/epicatechin, gallocatechin/epigallocatechin units, fisetinidin, galloyl and carbohydrates residues. Furthermore, BFP and BVP tannin bonded particleboard densities lie in the range recommended by NF EN 326-1994 standard. The resins also yielded good internal bond strength results of the panels, above relevant international standard specifications minimum requirements for interior-grade panels. The Transmission Electron Microscopy with Energy Dispersive X-ray Spectroscopy Analysis (TEM/ EDXA) are showing the ultrastructure and reveal that most of the resin material appears to be in an amorphous phase mainly composed of carbon/oxygen with small amounts of K, Ca and Mg. These particles have a very irregular morphology.

Radial Basis Function Networks Applied in Bacterial Classification Based on MALDI-TOF-MS

The radial basis function networks were applied to bacterial classification based on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOF-MS) data. The classification of bacteria cultured at different time was discussed and the effect of the network parameters on the classification was investigated. The cross-validation method was used to test the trained networks. The correctness of the classification of different bacteria investigated changes in a wide range from 61.5% to 92.8%. Owing to the complexity of biological effects in bacterial growth, the more rigid control of bacterial culture conditions seems to be a critical factor for improving the rate of correctness for bacterial classification.

Obligate aerobic, gram-positive, weak acid-fast, nonmotile bacilli, Tsukamurella tyrosinosolvens: Minireview of a rare opportunistic pathogen

Tsukamurella species are obligate aerobic,gram-positive,weak acid-fast,nonmotile bacilli.They are found in various environments,such as soil,water,sludge,and petroleum reservoir wastewater,and belong to the order Actinomycetales.In 2016,there was a reclassification of species within the genus Tsukamurella,merging the species Tsukamurella tyrosinosolvens(T.tyrosinosolvens)and Tsukamurella carboxydivorans.Tsukamurella species are clinically considered to be a rare opportunistic pathogen,because most reported cases have been related to bacteremia and intravascular prosthetic devices and immunosuppression.To date,it has been isolated only from human specimens,and has always been associated with clinical disease;human infections are very rare.Reported infections have included pneumonia,brain abscesses,catheter-related bloodstream infections,ocular infections,bacteremia,and sepsis presenting with septic pulmonary emboli in patients who are immunocompromised.To date,there is no commercially available test for identification.On the other hand,sequence-based identification,including matrix-assisted laser desorption ionization time-of-flight mass spectrometry,is an alternative method for identifying clinical isolates that are either slow growers or difficult to identify through biochemical profiling.The golden standards for diagnosis and optimal management still remain to be determined.However,newer molecular biological techniques can provide accurate identification,and contribute to the appropriate selection of definitive therapy for infections caused by this organism.Combinations of several antimicrobial agents have been proposed for treatment,though the length of treatment for infections has yet to be determined,and should be individualized according to clinical response.Immunocompromised patients often experience severe cases due to infection,and life-threatening T.tyrosinosolvens events associated with dissemination and/or failure of source control have occurred.Favorable prognoses can be achieved through earlier identification of the cause of infection,as well as successful management,including appropriate antibiotic therapy together with source control.Further analyses of similar cases are required to establish the most adequate diagnostic methods and treatment regimens for infections.

Comparision of FAB and MALDI Mass Spectrometry of Ginsenosides

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