ChemFOnt: the chemical functional ontology resource.

The Chemical Functional Ontology (ChemFOnt), located at https://www.chemfont.ca, is a hierarchical, OWL-compatible ontology describing the functions and actions of >341 000 biologically important chemicals. These include primary metabolites, secondary metabolites, natural products, food chemicals, synthetic food additives, drugs, herbicides, pesticides and environmental chemicals. ChemFOnt is a FAIR-compliant resource intended to bring the same rigor, standardization and formal structure to the terms and terminology used in biochemistry, food chemistry and environmental chemistry as the gene ontology (GO) has brought to molecular biology. ChemFOnt is available as both a freely accessible, web-enabled database and a downloadable Web Ontology Language (OWL) file. Users may download and deploy ChemFOnt within their own chemical databases or integrate ChemFOnt into their own analytical software to generate machine readable relationships that can be used to make new inferences, enrich their omics data sets or make new, non-obvious connections between chemicals and their direct or indirect effects. The web version of the ChemFOnt database has been designed to be easy to search, browse and navigate. Currently ChemFOnt contains data on 341 627 chemicals, including 515 332 terms or definitions. The functional hierarchy for ChemFOnt consists of four functional 'aspects', 12 functional super-categories and a total of 173 705 functional terms. In addition, each of the chemicals are classified into 4825 structure-based chemical classes. ChemFOnt currently contains 3.9 million protein-chemical relationships and ∼10.3 million chemical-functional relationships. The long-term goal for ChemFOnt is for it to be adopted by databases and software tools used by the general chemistry community as well as the metabolomics, exposomics, metagenomics, genomics and proteomics communities.

HMDB 5.0: the Human Metabolome Database for 2022.

The Human Metabolome Database or HMDB (https://hmdb.ca) has been providing comprehensive reference information about human metabolites and their associated biological, physiological and chemical properties since 2007. Over the past 15 years, the HMDB has grown and evolved significantly to meet the needs of the metabolomics community and respond to continuing changes in internet and computing technology. This year's update, HMDB 5.0, brings a number of important improvements and upgrades to the database. These should make the HMDB more useful and more appealing to a larger cross-section of users. In particular, these improvements include: (i) a significant increase in the number of metabolite entries (from 114 100 to 217 920 compounds); (ii) enhancements to the quality and depth of metabolite descriptions; (iii) the addition of new structure, spectral and pathway visualization tools; (iv) the inclusion of many new and much more accurately predicted spectral data sets, including predicted NMR spectra, more accurately predicted MS spectra, predicted retention indices and predicted collision cross section data and (v) enhancements to the HMDB's search functions to facilitate better compound identification. Many other minor improvements and updates to the content, the interface, and general performance of the HMDB website have also been made. Overall, we believe these upgrades and updates should greatly enhance the HMDB's ease of use and its potential applications not only in human metabolomics but also in exposomics, lipidomics, nutritional science, biochemistry and clinical chemistry.

Influence of the Pringle maneuver during partial hepatectomy on the neuromuscular block induced by intermittent and continuous dosing of rocuronium.

PURPOSE: The Pringle maneuver (PM) is a common procedure in hepatectomy that is known to interrupt drug elimination. The purpose of this study was to examine the influence of PM on the duration of action of rocuronium administered by intermittent bolus dosing, the continuous rocuronium infusion dose required for maintenance of a moderate neuromuscular block, and changes in plasma concentrations of rocuronium. METHODS: Twenty-seven adult patients undergoing partial hepatectomy with PM were enrolled in this study. The duration of action of 0.2 mg/kg rocuronium boluses (DUR), and the continuous rocuronium infusion dose required for maintenance of the height of the first twitch of the train-of-four (T1) at 10-20% of the control value (%T1), respectively, were electromyographically monitored on the adductor digiti minimi muscle. The effects of PM on DUR, %T1, and the plasma concentration of rocuronium were measured. RESULTS: The DUR was significantly prolonged during PM [mean: 42.2 (SD: 8.0) min, P < 0.001] compared to baseline [29.7 (6.3) min]. It was prolonged even after completion of the PM [46.2 (10.5) min, P < 0.001]. The plasma concentration of rocuronium measured at every reappearance of T1 was comparable between before and during PM. %T1 [15.5 (5.6)%] was significantly depressed after the start of PM [6.5 (3.9)%, P < 0.001], with persistence of the depression even after completion of PM. However, there were no significant changes in the plasma concentration of rocuronium. CONCLUSIONS: Rocuronium-induced neuromuscular block is significantly augmented during PM. However, the augmentation is not associated with an increase in plasma rocuronium concentration.

A Comparison Between the Adductor Pollicis Muscle Using TOF-Watch SX and the Abductor Digiti Minimi Muscle Using TetraGraph in Rocuronium-Induced Neuromuscular Block: A Prospective Observational Study.

BACKGROUND: The commonly used acceleromyography (AMG)-based neuromuscular monitor TOF-Watch SX is no longer manufactured. Recently, a new portable electromyography (EMG)-based neuromuscular monitor TetraGraph was introduced in clinical anesthesia. The aim of the study was to compare the responses obtained simultaneously from the abductor digiti minimi (ADM) muscle with TetraGraph and the adductor pollicis (AP) muscle with TOF-Watch SX during rocuronium-induced neuromuscular block. METHODS: Patients undergoing orthopedic surgery with general anesthesia were enrolled in this prospective, observational study. During total intravenous general anesthesia, train-of-four (TOF) responses following 0.9-mg·kg -1 rocuronium administration were monitored at the AP muscle with TOF-Watch SX and the ADM muscle with TetraGraph on the opposite arms. Sugammadex 2 mg·kg -1 was administered when both devices showed TOF counts (TOFCs) = 2. The primary outcome was time from rocuronium administration to first appearance of posttetanic count (PTC) response (first PTC). The secondary outcomes were baseline TOF ratios (TOFRs), onset time, time to first reappearance of TOFC = 1 (time to TOFC1), time to first reappearance of TOFC = 2 (time to TOFC2), and time from sugammadex administration to TOFR ≥0.9 with TetraGraph or to normalized TOFR ≥0.9 with TOF-Watch SX (recovery time). We used paired t test and Wilcoxon signed-rank test to analyze parametric and nonparametric data, respectively. P <.05 defined statistical significance. RESULTS: A total of 20 patients were analyzed. The baseline TOFRs were significantly higher with TOF-Watch SX than with TetraGraph (105 [96-110] vs 100 [98-101]; P = .0002). The time to first PTC (minutes) (31.7 ± 9.6 vs 41.1 ± 12.3; P < .001), time to TOFC1 (minutes) (48.0 ± 12.7 vs 58.8 ± 19.2; P < .001), time to TOFC2 (minutes) (56.2 ± 15.7 vs 74.2 ± 23.7; P < .001), and recovery time (seconds) (61.5 [32-148] vs 75.5 [94-102]); P = .043) were significantly faster with TOF-Watch SX than with TetraGraph. There were no significant differences in onset time. CONCLUSIONS: TOF-Watch SX overestimated recovery from rocuronium-induced neuromuscular block compared with TetraGraph.

Preparation and characterization of glycopolymers with biphenyl spacers via Suzuki coupling reaction.

Poly(vinylbiphenyl)s bearing glycoside ligands at the side chains were prepared using the Suzuku coupling reaction. Effects of glycoside reactant concentration, halide species, glycoside species, and catalyst species on the incorporation of glycoside ligand into the polymer were investigated. The obtained glycopolymers exhibited specific binding to proteins corresponding to the glycoside ligands. In addition, the biphenyl spacers formed by the Suzuki coupling reaction in the glycopolymer were fluorescent, whereas the polymer precursor was not.

The Utility of Point-of-Care Transesophageal Echocardiography in the Intensive Care Unit for Detecting the Cause of Hemolytic Anemia After Ascending Aorta Replacement.

Hemolysis is well-known as a complication after mitral valve surgery, and hemolytic anemia after valvular surgery in the intensive care unit (ICU) usually leads ICU physicians to a careful imaging examination. However, hemolytic anemia following aortic replacement rarely has been described and little is known. The authors present a patient with hemolytic anemia after ascending aortic replacement for type A aortic dissection repair. In the patient, transthoracic echocardiography (TTE), contrast-enhanced computed tomography (CT), and laboratory tests failed to identify the cause of hemolytic anemia. Transesophageal echocardiography (TEE) finally revealed a stenosis of the proximal anastomosis of the graft, with turbulent flow due to protrusion into the lumen. This finding was thought to represent the cause of hemolysis and was sufficient to convince the surgeons to repair the lesion. In the repair surgery, inversion of the inner felt strip that had been applied to the proximal anastomosis of the replacement ascending aorta was confirmed as shown with TEE, and the constricted anastomosis was repaired. Although TTE and CT generally have been used to identify the lesion of mechanical hemolysis after cardiac surgery, point-of-care TEE could have promptly identified the causative lesion in the present patient. Point-of-care TEE in the ICU could become a first-line imaging examination for postoperative hemolysis in cardiac patients.

Potency estimation of sugammadex for the reversal of moderate rocuronium-induced neuromuscular block: a non-randomized dose-response study.

PURPOSE: There is no report investigating the precise potency of sugammadex for antagonizing various intensities of rocuronium-induced neuromuscular block. The aim of this study was to evaluate the ED95 of reversibility of sugammadex and reveal the safety factor of 2 mg/kg of sugammadex for moderate rocuronium-induced neuromuscular block. METHODS: Fifteen patients were enrolled in this study. After induction of anesthesia, we recorded the adductor pollicis muscle response to ulnar nerve stimulation using acceleromyography. All patients received 0.6 mg/kg rocuronium. When the first twitch (T1) of the train-of-four (TOF) response reappeared, rocuronium infusion was commenced to maintain T1 at 10% of the control. After the surgery was completed and infusion of rocuronium was stopped, patients were given sugammadex by a cumulative dose technique. The effective doses of sugammadex that led to recovery of the amplitude of T1 and the TOF ratio by 95% (ED95) were calculated from the regression lines of least-squares regression analysis. RESULTS: The mean ED95 of sugammadex for recovery of T1 and the TOF ratio from rocuronium-induced moderate neuromuscular block was 1.34 (0.24) and 1.14 (0.24) mg/kg, respectively. CONCLUSIONS: The ED95 of sugammadex for the recovery of T1 was significantly greater than that for the TOF ratio. However, a sugammadex dose of 2 mg/kg is equivalent to about 1.5 times the ED95 of sugammadex for reversal of moderate rocuronium-induced block, indicating its safety margin.

Metabolomics reveals elevated urinary excretion of collagen degradation and epithelial cell turnover products in irritable bowel syndrome patients.

INTRODUCTION: Irritable bowel syndrome (IBS), the most commonly diagnosed functional gastrointestinal (GI) disorder in developed countries, is characterized by chronic abdominal pain, and altered bowel habits. OBJECTIVES: Accurate and timely diagnosis is challenging as it relies on symptoms and an evolving set of exclusion criteria to distinguish it from other related GI disorders reflecting a complex etiology that remains poorly understood. Herein, nontargeted metabolite profiling of repeat urine specimens collected from a cohort of IBS patients (n = 42) was compared to healthy controls (n = 20) to gain insights into the underlying pathophysiology. METHODS: An integrated data workflow for characterization of the urine metabolome with stringent quality control was developed to authenticate reliably measured (CV < 30%) and frequently detected (> 75%) metabolites using multisegment injection-capillary electrophoresis-mass spectrometry. Complementary statistical methods were then used to rank differentially excreted urinary metabolites after normalization to osmolality that were subsequently identified by high resolution tandem mass spectrometry and their electrophoretic migration behavior. RESULTS: Our work revealed ten consistently elevated urinary metabolites in repeat samples collected from IBS patients at two different time points (q < 0.05 after age and Benjamini-Hochberg/FDR adjustment), which were associated with greater collagen degradation and intestinal mucosal turn-over processes likely due to low-grade inflammation. IBS-specific metabolites identified in urine included a series of hydroxylysine metabolites (O-glycosylgalactosyl-hydroxylysine, O-galactosyl-hydroxylysine, lysine), mannopyranosy-L-tryptophan, imidazole propionate, glutamine, serine, ornithine, dimethylglycine and dimethylguanosine. A major limitation in this retrospective case-control study was significant co-morbidity of IBS patients with other illnesses, including depression and prescribed medications as compared to healthy controls. CONCLUSION: This work provides new mechanistic insights into the pathophysiology of IBS while also offering a convenient way to monitor patient disease progression and treatment responses to therapy based on a panel of urinary metabolites that avoids invasive blood sampling, colonoscopy and/or tissue biopsies.

Quantitative distinction of the morphological characteristic of erythrocyte precursor cells with texture analysis using gray level co-occurrence matrix.

BACKGROUND: Morphological characteristics of blood cells are still qualitatively defined. So a texture analysis (Tx) method using gray level co-occurrence matrices (GLCMs; CM-Tx method) was applied to images of erythrocyte precursor cells (EPCs) for quantitatively distinguishing four types of EPC stages: proerythroblast, basophilic erythroblast, polychromatic erythroblast, and orthochromatic erythroblast. METHODS: Fifty-five images of four types of EPCs were downloaded from an atlas uploaded by the Blood Cell Morphology Standardization Subcommittee (BCMSS) of the Japanese Society of Laboratory Hematology (JSLH). Using in-house programs, two types of GLCMs-(R: d=1, θ=0°) and (U: d=1, θ=270°)-and nine types of texture distinction index (TDI) were calculated with images removed outer part of cell. RESULTS: Three binary decision trees were sequentially divided among four types of EPC with the sum average of GLCM (U), the contrast of GLCM (R), and the sum average of GLCM (U). The average concordance rate (sensitivity) of CM-Tx method with the judgments of eleven experts in the BCMSS of the JSLH was 95.8% (87.5-100.0), and the average specificity was 97.6% (92.5-100.0). CONCLUSIONS: The CM-Tx method is an effective tool for quantitative distinction of EPC with their morphological features.

Effects of cardiac output on the onset of rocuronium-induced neuromuscular block in elderly patients.

PURPOSE: The aim of this study was to elucidate the relationship between the onset of rocuronium-induced neuromuscular block and arterial pressure-based cardiac output (CO) in elderly patients. METHODS: Forty elderly patients aged 65-83 years were enrolled in this study. After induction of anesthesia, contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation were acceleromyographically evaluated and 1 mg/kg rocuronium was administered following CO measurement. The correlation between onset of rocuronium action and CO was analyzed. RESULTS: The mean [SD] CO reduced after induction of anesthesia from 5.1 [1.8] L/min to 3.8 [1.1] L/min. The onset time of rocuronium-induced neuromuscular block was 110.3 [23.9] s (range 60-165). There was a statistically significant inverse correlation between the onset time of rocuronium and CO [onset time (s) = - 13.2·CO + 159.7, R2 = 0.376]. CONCLUSIONS: In the elderly, CO influences the onset of action of rocuronium.

Quantitative Distinction of Morphological Characteristics of White Blood Cells in Peripheral Blood Through Texture Analysis Using Gray Level Co-Occurrence Matrix.

BACKGROUND: Texture features are valuable clues for skilled technicians to differentiate peripheral blood (PB) white blood cells (WBCs). Some studies have tried to distinguish WBCs automatically by using texture analysis. However, no study so far has applied a gray level co-occurrence matrix (GLCM) to images of PB WBCs. Here, we developed a new GLCM method, called the CM-Tx method, for automatically distinguishing PB WBCs. METHODS: We used a total of 199 images of six different types of PB WBCs, taken from PB smears of 12 healthy volunteers, as objective standard images for the analysis. The six types were band form neutrophil, segmented form neutrophil, eosinophil, basophil, lymphocyte, and monocyte. Using in-house FORTRAN programs, three types of GLCM (R: distance (d) = 1, direction (θ) = 0°), (U: d = 1, θ = 270°) and (AE: d = 1, θ = 15° x q: q = 0, ..., 23), the mean intensity (MI) of each image and nine different texture distinction indexes (TDIs) for each GLCM were calculated. Then, a threshold value (TV) for distinguishing the type of PB WBC was selected from the dot plots of all TDIs and the MI. RESULTS: In total, we made 1,194 GLCMs. Using the selected TVs of the TDI, four sequential binary divisions could distinguish five types of PB WBCs. First, monocytes were distinguished (sensitivity 100%, specificity 100%, p < 0.0001) with the TV of the inverse difference moment of the GLCM (U). Then, segmented and band form neutrophils were distinguished from the remaining (100%, 99%, p < 0.0001) with the TV of the contrast of the GLCM (AE). Next, lymphocytes were distinguished (100%, 98%, p < 0.0001) with the TV of the entropy of the GLCM (AE). Finally, basophils were distinguished (82.4%, 100%, p < 0.0001) from eosinophils with the TV of the summed entropy of the GLCM (R). Band form neutrophils could not be distinguished from segmented form neutrophils. The average sensitivity of the CM-Tx method for the five types was 95.6%, and its average specificity was 99.3%. CONCLUSIONS: The CM-Tx method can distinguish five types of PB WBCs by using numerical differences only in texture futures quantified with GLCM. However, some other method was needed to distinguish the band and segmented form neutrophils from each other.

Semi-Automatic Rating Method for Neutrophil Alkaline Phosphatase Activity.

BACKGROUND: The neutrophil alkaline phosphatase (NAP) score is a valuable test for the diagnosis of myeloproliferative neoplasms, but it has still manually rated. Therefore, we developed a semi-automatic rating method using Photoshop® and Image-J, called NAP-PS-IJ. METHODS: Neutrophil alkaline phosphatase staining was conducted with Tomonaga's method to films of peripheral blood taken from three healthy volunteers. At least 30 neutrophils with NAP scores from 0 to 5+ were observed and taken their images. From which the outer part of neutrophil was removed away with Image-J. These were binarized with two different procedures (P1 and P2) using Photoshop® . NAP-positive area (NAP-PA) and granule (NAP-PGC) were measured and counted with Image-J. RESULTS: The NAP-PA in images binarized with P1 significantly (P < 0.05) differed between images with NAP scores from 0 to 3+ (group 1) and those from 4+ to 5+ (group 2). The original images in group 1 were binarized with P2. NAP-PGC of them significantly (P < 0.05) differed among all four NAP score groups. The mean NAP-PGC with NAP-PS-IJ indicated a good correlation (r = 0.92, P < 0.001) to results by human examiners. CONCLUSIONS: The sensitivity and specificity of NAP-PS-IJ were 60% and 92%, which might be considered as a prototypic method for the full-automatic rating NAP score.

Alteration in plasma free amino acid levels and its association with gout.

BACKGROUND: Studies on the association of plasma-free amino acids with gout are very limited and produced conflicting results. Therefore, we sought to explore and characterize the plasma-free amino acid (PFAA) profile in patients with gout and evaluate its association with the latter. METHODS: Data from a total of 819 subjects (including 34 patients with gout) undergoing an annual health examination program in Shimane, Japan were considered for this study. Venous blood samples were collected from the subjects and concentrations of 19 plasma amino acids were determined by high-performance liquid chromatography-electrospray ionization-mass spectrometry. Student's t-test was applied for comparison of variables between patient and control groups. The relationships between the presence or absence of gout and individual amino acids were investigated by logistic regression analysis controlling for the effects of potential demographic confounders. RESULTS: Among 19 amino acids, the levels of 10 amino acids (alanine, glycine, isoleucine, leucine, methionine, phenylalanine, proline, serine, tryptophan, valine) differed significantly (P < .001 to .05) between the patient and control groups. Univariate logistic regression analysis revealed that plasma levels of alanine, isoleucine, leucine, phenylalanine, tryptophan and valine had significant positive associations (P < .005 to .05) whereas glycine and serine had significant inverse association (P < .05) with gout. CONCLUSIONS: The observed significant changes in PFAA profiles may have important implications for improving our understanding of pathophysiology, diagnosis and prevention of gout. The findings of this study need further confirmation in future large-scale studies involving a larger number of patients with gout.

Plasma free amino acid profiles evaluate risk of metabolic syndrome, diabetes, dyslipidemia, and hypertension in a large Asian population.

BACKGROUND: Recently, the association of plasma free amino acid (PFAA) profile and lifestyle-related diseases has been reported. However, few studies have been reported in large Asian populations, about the usefulness of PFAAs for evaluating disease risks. We examined the ability of PFAA profiles to evaluate lifestyle-related diseases in so far the largest Asian population. METHODS: We examined plasma concentrations of 19 amino acids in 8589 Japanese subjects, and determined the association with variables associated with obesity, blood glucose, lipid, and blood pressure. We also evaluated the PFAA indexes that reflect visceral fat obesity and insulin resistance. The contribution of single PFAA level and relevant PFAA indexes was also examined in the risk assessment of lifestyle-related diseases. RESULTS: Of the 19 amino acids, branched-chain amino acids and aromatic amino acids showed association with obesity and lipid variables. The PFAA index related to visceral fat obesity showed relatively higher correlation with variables than that of any PFAA. In the evaluation of lifestyle-related disease risks, the odds ratios of the PFAA index related to visceral fat obesity or insulin resistance with the diseases were higher than most of those of individual amino acid levels even after adjusting for potential confounding factors. The association pattern of the indexes and PFAA with each lifestyle-related disease was distinct. CONCLUSIONS: We confirmed the usefulness of PFAA profiles and indexes as markers for evaluating the risks of lifestyle-related diseases, including diabetes mellitus, metabolic syndrome, dyslipidemia, and hypertension in a large Asian population.

[Outcomes of an Independent Clinical Study to Compare Branded and Generic Formulations of Sustained-Release Oxycodone].

To evaluate the potential for the adoption of a generic formulation of sustained-release oxycodone(Oxycodone SR Capsules), an independent clinical study was planned to accurately evaluate the efficacy and safety during a 9-day period. After a 3-day pretreatment period, the generic formulation was administered to patients with progressive cancer, who had been treated with a branded formulation(OxyContin®Tablets)of the drug for 5 days at the same dose. This was followed by a 1- day observation period. Drug administration to 3 patients with pulmonary cancer achieved the primary(dose, pain level, and adverse drug reactions)and secondary(rescue dose frequency and quality of life)endpoints, as well as safety goals. The merits of adopting a different dosage form were also noted. Independent data collection using an appropriate evaluation method consequently promoted the understanding of generic opioids in the clinical setting.

The SAC51 Family Plays a Central Role in Thermospermine Responses in Arabidopsis.

The acaulis5 (acl5) mutant of Arabidopsis thaliana is defective in the biosynthesis of thermospermine and shows a dwarf phenotype associated with excess xylem differentiation. SAC51 was identified from a dominant suppressor of acl5, sac51-d, and encodes a basic helix-loop-helix protein. The sac51-d mutant has a premature termination codon in an upstream open reading frame (uORF) that is conserved among all four members of the SAC51 family, SAC51 and SACL1-SACL3 This suggests that thermospermine cancels the inhibitory effect of the uORF in main ORF translation. Another suppressor, sac57-d, has a mutation in the conserved uORF of SACL3 To define further the function of the SAC51 family in the thermospermine response, we analyzed T-DNA insertion mutants of each gene. Although sacl1-1 may not be a null allele, the quadruple mutant showed a semi-dwarf phenotype but with an increased level of thermospermine and decreased sensitivity to exogenous thermospermine that normally represses xylem differentiation. The sac51-1 sacl3-1 double mutant was also insensitive to thermospermine. These results suggest that SAC51 and SACL3 play a key role in thermospermine-dependent negative control of thermospermine biosynthesis and xylem differentiation. Using 5' leader-GUS (ß-glucuronidase) fusion constructs, however, we detected a significant enhancement of the GUS activity by thermospermine only in SAC51 and SACL1 constructs. Furthermore, while acl5-1 sac51-1 showed the acl5 dwarf phenotype, acl5-1 sacl3-1 exhibited an extremely tiny-plant phenotype. These results suggest a complex regulatory network for the thermospermine response in which SAC51 and SACL3 function in parallel pathways.

Robust and High-Throughput Method for Anionic Metabolite Profiling: Preventing Polyimide Aminolysis and Capillary Breakages under Alkaline Conditions in Capillary Electrophoresis-Mass Spectrometry.

Capillary electrophoresis-mass spectrometry (CE-MS) represents a high efficiency microscale separation platform for untargeted profiling of polar/ionic metabolites that is ideal for volume-restricted biological specimens with minimal sample workup. Despite these advantages, the long-term stability of CE-MS remains a major obstacle hampering its widespread application in metabolomics notably for routine analysis of anionic metabolites under negative ion mode conditions. Herein, we report for the first time that commonly used ammonia containing buffers compatible with electrospray ionization (ESI)-MS can compromise the integrity of fused-silica capillaries via aminolysis of their outer polyimide coating. Unlike organic solvent swelling effects, this chemical process occurs under aqueous conditions that is dependent on ammonia concentration, buffer pH, and exposure time resulting in a higher incidence of capillary fractures and current errors during extended operation. Prevention of polyimide aminolysis is achieved by using weakly alkaline ammonia containing buffers (pH < 9) in order to preserve the tensile strength of the polyimide coated fused-silica capillary. Alternatively, less nucleophilic primary/secondary amines can be used as electrolytes without polyimide degradation, whereas chemically resistant polytetrafluoroethylene coating materials offer higher pH tolerance in ammonia. In this work, multisegment injection (MSI)-CE-MS was used as multiplexed separation platform for high throughput profiling of anionic metabolites when using optimized buffer conditions to prevent polyimide degradation. A diverse range of acidic metabolites in human urine were reliably measured by MSI-CE-MS via serial injection of seven urine samples within a single run, including organic acids, food-specific markers, microbial-derived compounds and over-the-counter drugs as their sulfate and glucuronide conjugates. This approach offers excellent throughput (<5 min/sample) and acceptable intermediate precision (average CV ≈ 16%) with high separation efficiency as reflected analysis of 30 anionic metabolites following 238 repeated sample injections of human urine over 3 days while using a single nonisotope internal standard for data normalization. Careful optimization and rigorous validation of CE-MS protocols are crucial for developing a rapid, low cost, and robust screening platform for metabolomics that is amenable to large-scale clinical and epidemiological studies.

Synthesis, Characterization, and Evaluation of Thiazolidine Derivatives of Cysteine for Suppressing Eumelanin Production.

In the pathway of melanin biosynthesis, cysteine (Cys) is utilized for the synthesis of pheomelanin. Accordingly, Cys is considered to suppress the formation of brown-black eumelanin. Although attempts have been made to utilize Cys and its derivatives as skin-whitening agents, their instability and odor hinders their application as a cosmetic agent. Herein, N-acetyl-2-methylthiazolidine-2,4-dicarboxylic acid ethyl ester (AcCP2Et) was proposed as a candidate for a stable and prolonged-release derivative of Cys to inhibit dopachrome formation after its degradation in melanocytes. It was synthesized by acetylation of 2-methylthiazolidine-2,4-dicarboxylic acid 2-ethyl ester (CP2Et), the condensation derivative of Cys and ethyl pyruvate. AcCP2Et suppressed melanogenesis in melanocytes in vitro, was stable in phosphate buffer at 70°C for five days, and exhibited far less odor than CP2Et. Therefore, AcCP2Et was validated to be a useful deriative of Cys for application as a skin-whitening agent. AcCP2Et comprises four stereoisomers; thus characterization of each stereoisomer was required. The stereochemistry of AcCP2Et was confirmed via a single-crystal X-ray structure analysis of N-acetyl-2-methylthiazolidine-2,4-dicarboxylic acid (AcCP) derived from AcCP2Et. In the synthesis of AcCP2Et, the acetylation of CP2Et proceeded with epimerization at C4 to give trans-isomers when excess acetyl chloride and an organic amine was used, whereas it proceeded while retaining the original (R) configuration at C4 to give the cis- and trans-isomer when an equivalent of acetyl chloride with an inorganic base was used. These results indicate that the formation of an intermolecular mixed acid anhydride is responsible for the isomerization at the C4 asymmetric center.

Mib-Jag1-Notch signalling regulates patterning and structural roles of the notochord by controlling cell-fate decisions.

In the developing embryo, cell-cell signalling is necessary for tissue patterning and structural organization. During midline development, the notochord plays roles in the patterning of its surrounding tissues while forming the axial structure; however, how these patterning and structural roles are coordinated remains elusive. Here, we identify a mechanism by which Notch signalling regulates the patterning activities and structural integrity of the notochord. We found that Mind bomb (Mib) ubiquitylates Jagged 1 (Jag1) and is essential in the signal-emitting cells for Jag1 to activate Notch signalling. In zebrafish, loss- and gain-of-function analyses showed that Mib-Jag1-Notch signalling favours the development of non-vacuolated cells at the expense of vacuolated cells in the notochord. This leads to changes in the peri-notochordal basement membrane formation and patterning surrounding the muscle pioneer cells. These data reveal a previously unrecognized mechanism regulating the patterning and structural roles of the notochord by Mib-Jag1-Notch signalling-mediated cell-fate determination.