BACKGROUND: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows rapid and accurate identification of clinical yeast isolates. In-tube formic acid/acetonitrile (FA/ACN) extraction is recommended prior to the analysis with MALDI Biotyper, but the direct on-plate FA extraction is simpler. We compared the Biotyper with the VITEK MS for the identification of various clinically relevant yeast species, focusing on the use of the FA extraction method. METHODS: We analyzed 309 clinical isolates of 42 yeast species (four common Candida species, Cryptococcus neoformans, and 37 uncommon yeast species) using the Biotyper and VITEK MS systems. FA extraction was used initially for all isolates. If ‘no identification' result was obtained following the initial FA extraction, these samples were then retested by using FA (both systems, additive FA) or FA/ACN (Biotyper only, additive FA/ACN) extraction. These results were compared with those obtained by sequence-based identification. RESULTS: Both systems correctly identified all 158 isolates of the four common Candida species after the initial FA extraction. The Biotyper correctly identified 8.7%, 30.4%, and 100% of 23 C. neoformans isolates after performing initial FA, additive FA, and FA/ACN extractions, respectively, while VITEK MS identified all C. neoformans isolates after the initial FA extraction. Both systems had comparable identification rates of 37 uncommon yeast species (128 isolates), following the initial FA (Biotyper, 74.2%; VITEK MS, 73.4%) or additive FA (Biotyper, 82.0%; VITEK MS, 73.4%). CONCLUSIONS: The identification rate of most common and uncommon yeast isolates is comparable between simple FA extraction/Biotyper method and VITEK MS methods, but FA/ACN extraction is necessary for C. neoformans identification by Biotyper.
Candida ; Cryptococcus neoformans ; Mass Spectrometry* ; Methods* ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Yeasts*

Imaging mass spectrometry (IMS) is currently receiving large attention from the mass spectrometric community, although its use is not yet well known in the clinic. As matrix-assisted laser desorption/ionization time-of-flight (MALDI)-IMS can show the biomolecular changes in cells as well as tissues, it can be an ideal tool for biomedical diagnostics as well as the molecular diagnosis of clinical specimens, especially aimed at the prompt detection of premalignant lesions much earlier before overt mass formation, or for obtaining histologic clues from endoscopic biopsy. Besides its use for pathologic diagnosis, MALDI-IMS is also a powerful tool for the detection and localization of drugs, proteins, and lipids in tissue. Measurement of parameters that define and control the implications, challenges, and opportunities associated with the application of IMS to biomedical tissue studies might be feasible through a deep understanding of mass spectrometry. In this focused review series, new insights into the molecular processes relevant to IMS as well as other field applications are introduced.
Biopsy ; Chemoprevention ; Diagnosis ; Mass Spectrometry* ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Biomarkers

Biomarkers ; analysis ; Child ; Humans ; Mass Spectrometry ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Wilms Tumor ; metabolism

Phospholipids are key components of cellular membrane and signaling. Among cellular phospholipids, phosphoinositides, phosphorylated derivatives of phosphatidylinositol are important as a participant in essential metabolic processes in animals. However, due to its low abundance in cells and tissues, it is difficult to identify the composition of phosphoinositides. Recent advances in mass spectrometric techniques, combined with established separation methods, have allowed the rapid and sensitive detection and quantification of a variety of lipid species including phosphoinositides. In this mini review, we briefly introduce progress in profiling of cellular phosphoinositides using mass spectrometry. We also summarize current progress of matrices development for the analysis of cellular phospholipids using matrix-assisted laser desorption/ionization mass spectrometry. The phosphoinositides profiling and phospholipids imaging will help us to understand how they function in a biological system and will provide a powerful tool for elucidating the mechanism of diseases such as diabetes, cancer and neurodegenerative diseases. The investigation of cellular phospholipids including phosphoinositides using electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry will suggest new insights on human diseases, and on clinical application through drug development of lipid related diseases.
Animals ; Humans ; Mass Spectrometry/*methods ; Phosphatidylinositols/*metabolism ; Phospholipids/*metabolism ; Spectrometry, Mass, Electrospray Ionization ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

The alkaloids in Zanthoxylum nitidum were identified by HPLC-DAD/ESI-Q-TOF-MS. Separation was performed on a Hanbon C18 column with acetonitrile (with 0.1% formic acid) and water(with 0.1% formic acid) as mobile phase. Based on the high-resolution mass information, MS/MS fragmentation behaviors and chemical components from literatures, 48 components were identified or tentatively characterized including 6 new compounds. This work could be useful for the quality control and further studies of the plant.
Alkaloids ; chemistry ; Chromatography, High Pressure Liquid ; Spectrometry, Mass, Electrospray Ionization ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Zanthoxylum ; chemistry

In this study, a method was established for in-situ visualization of metabolite distribution in the rhizome of Paris polyphylla var. yunnanensis. To be specific, through matrix-assisted laser desorption/ionization-mass spectrometry imaging(MALDI-MSI), the spatial locations of steroidal saponins, amino acids, organic acids, phytosterols, phytoecdysones, nucleosides, and esters in rhizome of the medicinal plant were directly analyzed, and six unknown compounds with differential distribution in rhizome tissues were identified. The specific procedure is as follows: preparation of rhizome tissue section, matrix screening and optimization, and MALDI-MSI analysis. The results showed that the steroidal saponins were mainly distributed in the central, amino acids in epidermis and cortex, low-molecular-weight organic acids in central epidermis, phytosterols in the epidermis and lateral cortex, the phytoecdysones in epidermis and cortex, nucleosides(uneven distribution) in epidermis and cortex, growth hormones around the epidermis and cortex, particularly outside the cortex, and esters in cortex with unobvious difference among different tissues. In this study, the spatial distribution of meta-bolites in the rhizome of P. polyphylla var. yunnanensis was characterized for the first time. The result can serve as a reference for identifying and extracting endogenous metabolites of P. polyphylla var. yunnanensis, exploring the synthesis and metabolism mechanisms of the metabolites, and evaluating the quality of medicinal materials.
Liliaceae/chemistry* ; Melanthiaceae ; Rhizome/chemistry* ; Saponins/analysis* ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

There are many deficiencies in forensic traumatic molecular markers detected by the techniques of traditional immunohistology and molecular biology, because these markers are isolated and obscure of the mechanism of interaction. The imaging mass spectrometry (IMS) is more suitable for the forensic molecular markers using function of screening, analysis and graphical representation. In this paper, the techniques and the latest research in screening and identification of typical molecular markers by IMS based on matrix-assisted laser adsorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) are reviewed. And its application values in forensic injury are discussed.
Biomarkers/analysis* ; Diagnostic Imaging ; Molecular Biology ; Molecular Weight ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods*

Matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF-IMS) has been a classical technique for studying proteomics in present and a tool for analyzing the distribution of proteins and small molecules within biological tissue sections. MALDI-TOF-IMS can analyze multiple unknown compounds in biological tissue sections simultaneously through a single measurement which can obtain molecule imaging of the tissue while maintaining the integrity of cellular and molecules in tissue. In recent years, imaging mass spectrometry technique develops relatively quickly in all biomedical domain. This paper based on the relevant data and reviews the present developing level of MALDI-TOF-IMS, the principle of imaging mass spectrometry, methology and the prospect in forensic pathology.
Diagnostic Imaging ; Forensic Sciences/methods* ; Humans ; Male ; Proteins ; Proteomics ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Aims: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is increasingly used to identify Candida spp. in diagnostic laboratories due to its strength in providing accurate information results, speed and cost-effectiveness. However, its accuracy varies on instrument platform, reference database, sample preparation techniques and interlaboratory comparisons. Therefore, the use of MALDI-TOF MS for species identification was evaluated against traditional biochemical identification, namely BrillianceTM Candida and Remel RapIDTM Yeast Plus System. Methodology and results: To evaluate and compare identification efficiency, turnaround time and consumable cost, 194 clinical isolates of Candida were collected. The results showed overall 85.6% concordant identification between two methods with 94.9-99.5% and 100% accuracy in traditional and MALDI-TOF MS, respectively, in the identification of four common Candida species; C. albicans, C. tropicalis, C. parapsilosis sensu stricto and C. glabrata sensu stricto. Other Candida species were also identified with 85.6% and 97.5% accuracy rates by traditional and MALDI-TOF MS, respectively. Additionally, identification using MALDI-TOF MS reduced overall turnaround time and cost by approximately 99.8% and 86.5%, respectively. Conclusion, significance and impact of study This study highlights the performance of MALDI-TOF MS, which is more accurate in identifying Candida spp. with a less hands-on approach, cheaper cost and shorter turnaround time.
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Candida ; Tertiary Care Centers

Formaldehyde ; Humans ; Microdissection ; Paraffin Embedding ; Proteomics ; methods ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Tissue Fixation