Synthesis of lysinonorleucine and mass spectrometric analysis of lysinonorleucine and merodesmosine in bovine ligament and eggshell membrane.

Elastin is an important extracellular matrix protein that contributes to the elasticity of cells, tissues, and organs. Although crosslinking amino acids such as desmosine and isodesmosine have been identified in elastin, details regarding the structure remain unclear. In this study, an elastin crosslinker, lysinonorleucine, was chemically synthesized and detected in hydrolyzed bovine ligament and eggshell membrane samples utilizing tandem mass spectrometry. Merodesmosine, another crosslinker of elastin, was also measured in the same samples using the same analytical method. The resulting data should aid in the elucidating the crosslinking structure of elastin and eggshell membranes.

[Development and Verification of an irAEs Self-Reported Interview System(ISRIS)].

A variety of immune-related adverse events(irAEs)occur during the use of immune checkpoint inhibitors, and delayed detection may make it difficult to continue treatment. To detect irAEs as early as possible, we have been administering an irAEs self-reported interview system(ISRIS)to all outpatients using a tablet device. We conducted a retrospective study of outpatients who received pembrolizumab, nivolumab, atezolizumab, ipilimumab, and durvalumab and utilized the ISRIS from June 2019 to May 2020. The survey items were the primary disease, initial symptoms of irAEs, and detected irAEs. The total number of patients was 140, and the total number of interviews was 1,095. Overall, 42 irAEs occurred. The ISRIS is useful for detecting subjective skin disorders. However, its detection rate of myocarditis and thyroid, hepatic, and renal dysfunction was low, and there is room for improvement. We are currently developing an ISRIS application that maintains sensitivity and increases specificity to allow for early detection of irAEs at home.

LC-MS/MS analysis of elastin crosslinker desmosines and microscopic evaluation in clinical samples of patients with hypertrophy of ligamentum flavum.

Ligamentum flavum (LF) pathologies often lead to severe myelopathy or radiculopathy characterized by reduced elasticity, obvious thickening, or worsened ossification. Elastin endows critical mechanical properties to tissues and organs such as vertebrae and ligaments. Desmosine (DES) and isodesmosine (IDES) are crosslinkers of elastin monomers called tropoelastin. These crosslinkers are potential biomarkers of chronic obstructive pulmonary disease. As a biological diagnostic tool that supplements existing symptomatic, magnetic resonance imaging scanning or radiological imaging diagnostic measures for LF hypertrophy and associated pathologies, an isotope-dilution liquid chromatography-tandem mass spectrometry method with selected reaction monitoring mode for the quantitation of DESs in human plasma, urine, cerebrospinal fluid (CSF), and yellow ligamentum was investigated. Isotopically labeled IDES-13C3,15N1 was used as an internal standard (ISTD) for DES quantitation for the first time. The samples plus ISTD were hydrolyzed with 6 N hydrochloric acid. Analytes and ISTD were extracted using a solid phase extraction cellulose cartridge column. The assays were repeatable, reproducible, and accurate with % CV ≤ 7.7, ISTD area % RSD of 7.6, and % AC ≤ (101.2 ± 3.90) of the calibrations. The ligamentum samples gave the highest average DES/IDES content (2.38 µg/mg) on a dry-weight basis. A high percentage of the CSF samples showed almost no DESs. Urine and plasma samples of patients showed no significant difference from the control (p-value = 0.0519 and 0.5707, respectively). Microscopy of the yellow ligamentum samples revealed dark or blue-colored zones of elastin fibers that retained the hematoxylin dye and highly red-colored zones of collagen after counterstaining with van Gieson solution. Thus, we successfully developed a method for DES/IDES quantitation in clinical samples.

Synthesis and Antioxidant Activity of Silver Nanoparticles Using the Odontonema strictum Leaf Extract.

The aqueous extract of the leaves of Odontonema strictum (OSM) is used in folk medicine for its antihypertensive properties, and it contains a wide range of secondary metabolites, mostly polyphenols such as verbascoside and isoverbascoside, which could play a major role in the preparation of silver nanoparticles. In this study, we aimed to prepare AgNPs for the first time using the OSM leaf extract (OSM-AgNPs) to investigate their free radical-scavenging potency against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2). Dynamic light scattering (DLS), UV/Vis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS) were used to characterize the OSM-AgNPs. With a size around 100 nm and a ζ-potential of -41.1 mV, OSM-AgNPs showed a good stability and a better colloidal property due to electrostatic repulsion and the dispersity. The strong absorption peak at 3 keV in the EDX spectra indicated that silver was the major constituent. Additionally, the existence of silver atoms was confirmed by the Ag 3d5/2 peak around 367 eV in the XPS spectra. IC50 values of 116 µg/mL and 4.4 µg/mL were obtained for the scavenging activities of DPPH and H2O2, respectively. The synthetic OSM-AgNPs can be further exploited as potential antioxidant agents.

Extraction of essential oils from tea tree (Melaleuca alternifolia) and lemon grass (Cymbopogon citratus) using betaine-based deep eutectic solvent (DES).

INTRODUCTION: The essential oils of tea tree (Melaleuca alternifolia) leaves mainly contain eucalyptol, α-terpinene, γ -terpinene, and terpinen-4-ol and have anti-bacterial, anti-fungal, anti-infective, and anti-inflammatory actions. The essential oils of lemon grass (Cymbopogon citratus) leaves mainly contain neral, geranial, and geraniol and have anti-microbial and anti-fungal activities and hypocholesterolemic effect. OBJECTIVES: The present study describes the use of low-toxicity solvents called betaine-based deep eutectic solvents (DESs) for efficient extraction of essential oils from tea tree and lemon grass. H2 O and EtOH were used for extraction as control methods. METHODOLOGY: Quantitative analysis was performed using gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring mode. Scanning electron micrography (SEM) and antioxidant assays for extracted samples were also conducted. RESULTS: The results indicated that extraction for tea tree using betaine/sucrose (molar ratio 2:1) improved the yields of terpinolene and eucalyptol 2.5- and 1.9-fold, respectively, compared with the control method. In lemon grass, extraction using betaine/sucrose (molar ratio 2:1) improved the yields of neral and geranial 1.9- and 1.7-fold, respectively, compared with the control method. CONCLUSION: These results demonstrated the effective extraction of essential oils from plant leaves under milder conditions than those needed for the conventional methods. The environmentally benign DESs for the extraction would be applicable to the food and cosmetic industries.

Liquid Formulation of Gemcitabine Increases Venous Pain in Patients With Cancer: A Retrospective Study.

PURPOSE: Venous pain induced by peripheral intravenous infusion of gemcitabine has remained an unresolved issue in clinical practice. This study aimed to identify differences between gemcitabine formulations as well as risk factors associated with gemcitabine-induced venous pain in patients with cancer. METHODS: We retrospectively analyzed data from consecutive patients with cancer who had received chemotherapy including a lyophilized or liquid formulation of gemcitabine diluted with 5% glucose solution via a peripheral vein. The study was conducted at Ehime University Hospital using electronic medical records dated between January 2015 and July 2017. The primary end point was the prevalence of venous pain at the administration site during gemcitabine infusion, classified as injection site reaction of grade ≥2 according to the Common Terminology Criteria for Adverse Events, version 4.0. A multivariate logistic regression analysis with generalized estimating equations for longitudinal data was used to identify risk factors for venous pain during all courses of gemcitabine treatment. FINDINGS: A total of 1150 treatment courses in 141 Japanese patients were evaluated in this study. Venous pain occurred in 115 courses (10.0%) and in 49 patients (34.8%). The multivariate logistic regression analysis with generalized estimating equations revealed that a dose increase of gemcitabine and use of the liquid formulation of gemcitabine were significantly associated with an increased risk for venous pain (dose increase, adjusted odds ratio [OR] = 1.25; 95% CI, 1.11-1.40 [P < 0.001]; and liquid formulation, adjusted OR = 12.43, 95% CI, 5.61-27.51 [P < 0.001]), whereas age, course number of gemcitabine, and use of the soft-back product of 5% glucose solution were significantly associated with a reduced risk for venous pain (age, adjusted OR = 0.75; 95% CI, 0.57-0.98 [P = 0.037]; course number, adjusted OR = 0.96; 95% CI, 0.92-0.99 [P = 0.023]; and soft back, adjusted OR = 0.39; 95% CI, 0.21-0.74 [P = 0.004]). IMPLICATIONS: The use of the liquid formulation of gemcitabine was associated with a significant increase in the frequency of gemcitabine-induced venous pain despite dilution with 5% glucose solution compared to that with the lyophilized formulation. The lyophilized formulation of gemcitabine should hence be used in peripheral intravenous infusion for the treatment of patients with cancer.

Tolyprolinol, a new dipeptide from Tolypocladium sp. FKI-7981.

A new dipeptide, named tolyprolinol, was isolated from the static culture of a fungus, Tolypocladium sp. FKI-7981. The structure of tolyprolinol was elucidated as N-acetyl-L-phenylalanyl-L-prolinol. It showed moderate antimalarial activity but did not show cytotoxicity or any other antimicrobial property.

Radiosensitizing Effect of P2X7 Receptor Antagonist on Melanoma in Vitro and in Vivo.

Melanoma is highly malignant, and generally exhibits radioresistance, responding poorly to radiation therapy. We previously reported that activation of P2X7, P2Y6, and P2Y12 receptors is involved in the DNA damage response after γ-irradiation of human lung adenocarcinoma A549 cells. However, it is not clear whether these receptors are also involved in the case of melanoma cells, although P2X7 receptor is highly expressed in various cancers, including melanoma. Here, we show that P2X7 receptor antagonist enhances radiation-induced cytotoxicity in B16 melanoma cells in vitro and in vivo. We confirmed that these cells express P2X7 receptor mRNA and exhibit P2X7 receptor-mediated activities, such as ATP-induced pore formation and cytotoxicity. We further examined the radiosensitizing effect of P2X7 receptor antagonist Brilliant Blue G (BBG) in vitro by colony formation assay of B16 cells. γ-Irradiation dose-dependently reduced cell survival, and pretreatment with BBG enhanced the radiation-induced cytotoxicity. BBG pretreatment also decreased the number of DNA repair foci in nuclei, supporting involvement of P2X7 receptor in the DNA damage response. Finally, we investigated the radiosensitizing effect of BBG on B16 melanoma cells inoculated into the hind footpad of C57BL/6 mice. Neither 1 Gy γ-irradiation alone nor BBG alone suppressed the increase of tumor volume, but the combination of irradiation and BBG significantly suppressed tumor growth. Our results suggest that P2X7 receptor antagonist BBG has a radiosensitizing effect in melanoma in vitro and in vivo. BBG, which is used as a food coloring agent, appears to be a promising candidate as a radiosensitizer.