Implementation of a Dual-Column Liquid Chromatography-Tandem Mass-Spectrometry Method for the Quantification of Isavuconazole in Clinical Practice

Objectives Therapeutic drug monitoring (TDM) of isavuconazole, which is a novel broad-spectrum antimycoticum against invasive fungal infections, ensures an effective exposure of the drug and minimizes the risk of toxicity. This study is aimed at evaluating the analytical performance of a dual-column liquid chromatography-tandem mass-spectrometry (LC-MS/MS) method for isavuconazole quantification. Materials and Methods The method was performed on a Voyager TSQ Quantum triple quadrupole instrument equipped with an Ultimate 3000 chromatography system (Thermo Fisher Scientific, San Jose, California, United States). Analytical and preanalytical requirements of the isavuconazole LC-MS/MS method were evaluated. Sample stability measurements were performed at room temperature (RT) and in serum tubes with separator gel. Results The isavuconazole LC-MS/MS method was linear over the concentration range of 0.2 to 12.8 mg/L. The coefficient of determination (r 2) always exceeded 0.999. Within- and between-run precision ranged between 1.4 to 2.9% and 1.5 to 3.0%, the recovery between 93.9 and 102.7%. At RT, serum samples were stable for 3 days. Isavuconazole serum concentrations were significantly lower after incubation (18 hours) in serum tubes with separator gel at RT. Conclusion The dual-column isavuconazole LC-MS/MS is a reliable tool for the TDM of isavuconazole. Serum samples are stable for at least 3 days and should be collected in tubes without separator gel.

Validation of Qualitative Broth Volatilization Checkerboard Method for Testing of Essential Oils: Dual-Column GC–FID/MS Analysis and In Vitro Combinatory Antimicrobial Effect of Origanum vulgare and Thymus vulgaris against Staphylococcus aureus in Liquid and Vapor Phases

Combinatory action of antimicrobial agents such as essential oils (EOs) show to be an effective strategy to overcome the problem with increasing antibiotic resistance of microorganisms, including Staphylococcus aureus. The objective of this study was to evaluate in vitro antimicrobial interactions between Origanum vulgare and Thymus vulgaris EOs against various S.aureus strains in both liquid and vapor phases using the broth volatilization checkerboard method. Fractional inhibitory concentrations (FICs) were determined for both liquid and vapor phases, and the composition of EOs was analyzed by gas chromatography-mass spectrometry using dual-column/dual-detector gas chromatograph. Results of oregano and thyme EOs combination showed additive effects against all S. aureus strains in both phases. In several cases, sums of FICs were lower than 0.6, which can be considered a strong additive interaction. The lowest FICs obtained were 0.53 in the liquid phase and 0.59 in the gaseous phase. Chemical analysis showed that both EOs were composed of many compounds, including carvacrol, thymol, γ-terpinene, and p-cymene. This is the first report on oregano and thyme EOs interactions against S. aureus in the vapor phase. It also confirms the accuracy of the broth volatilization checkerboard method for the evaluation of combinatory antimicrobial effects of EOs in the vapor phase.

Consumer Comprehension of the Nutrition Facts Label: A Comparison of the Original and Updated Labels

Purpose: Compare consumers’ overall label comprehension of the original Nutrition Facts (NF) label with the updated label. Design: Online survey conducted in 2019. Participants randomly assigned to original label, updated-single column, or updated-dual column labeling condition and asked to complete a series of label comprehension questions. Setting: Online survey; participants recruited through Prolific. Sample: N = 992 U.S. adults. Sample similar to U.S. population in terms of sex (49.2% female), race (73.3% White/Caucasian), and household size (mean = 2.7 members). However, sample was younger (median age: 29.0), more educated (98.8% high school graduate or higher), and exhibited a lower rate of obesity (22.6% obese) than the U.S. population. Measures: Dependent variables: objective (% correct) NF label comprehension. Independent variables: label condition, nutrition knowledge, and socio-demographic variables. Analysis: Regression analysis assessed relationships between label condition and label comprehension. Significance level of 5% used for analyses. Results: Average score for objective comprehension was 81.4%. The updates did not significantly improve label comprehension. Participants in the updated NF label conditions had trouble answering questions related to total and added sugars. Conclusions: Results suggest consumers may struggle to correctly utilize information on the updated NF label, specifically total and added sugars. Consumers may benefit from educational opportunities on using the new label.

Metabolomic Profiling After a Meal Shows Greater Changes and Lower Metabolic Flexibility in Cardiometabolic Diseases

Context Metabolic flexibility is the physiologic acclimatization to differing energy availability and requirement states. Effectively maintaining metabolic flexibility remains challenging, particularly since metabolic dysregulations in meal consumption during cardiometabolic disease (CMD) pathophysiology are incompletely understood. Objective We compared metabolic flexibility following consumption of a standardized meal challenge among adults with or without CMDs. Design, Setting, and Participants Study participants (n = 349; age 37-54 years, 55% female) received a standardized meal challenge (520 kcal, 67.4 g carbohydrates, 24.3 g fat, 8.0 g protein; 259 mL). Blood samples were collected at baseline and 2 hours postchallenge. Plasma samples were assayed by high-resolution, nontargeted metabolomics with dual-column liquid chromatography and ultrahigh-resolution mass spectrometry. Metabolome-wide associations between features and meal challenge timepoint were assessed in multivariable linear regression models. Results Sixty-five percent of participants had ≥1 of 4 CMDs: 33% were obese, 6% had diabetes, 39% had hypertension, and 50% had metabolic syndrome. Log2-normalized ratios of feature peak areas (postprandial:fasting) clustered separately among participants with versus without any CMDs. Among participants with CMDs, the meal challenge altered 1756 feature peak areas (1063 reversed-phase [C18], 693 hydrophilic interaction liquid chromatography [HILIC]; all q < 0.05). In individuals without CMDs, the meal challenge changed 1383 feature peak areas (875 C18; 508 HILIC; all q < 0.05). There were 108 features (60 C18; 48 HILIC) that differed by the meal challenge and CMD status, including dipeptides, carnitines, glycerophospholipids, and a bile acid metabolite (all P < 0.05). Conclusions Among adults with CMDs, more metabolomic features differed after a meal challenge, which reflected lower metabolic flexibility relative to individuals without CMDs.

The Unintended Effect of Attention to the New Nutrition Facts Label Formats on Consumer Purchase Intentions

Objectives To assess the effect of new Nutrition Facts Label (NFL) formats on consumer purchase intentions. Methods The study conducted a within-subject design experiment. Subjects were randomly assigned to one of the three treatment groups (newly designed NFL formats proposed by U.S. Food and Drug Administration (FDA) or the control group as follows: 1) a new standard NFL format, which is displayed in a newly designed single-column format, in which the number of calories and nutrients of a multiple-serving product are presented based upon one serving, 2) a dual-column NFL format, which is displayed in a two-column format, in which the number of calories and nutrients are presented based on “per serving” and “per container/package” basis, 3) a single-serving container NFL format, which is displayed in a single-column format in which only the number of calories and nutrients per package/container are presented, and 4) an original NFL format, which had been previously used before. Total 673 college students in the U.S. completed an online experiment survey. An ordered probit regression model was used in the analysis. Results The single-serving container NFL had the largest effect. Subjects who were presented with this format were 26.2% more likely to decrease their purchase intentions. The dual-column NFL (22.1%) and the new standard NFL (15.1%) had the smaller effect. The 27% of the effect of the single-serving container NFL on decreasing purchase intentions was associated with the increase in the anticipated guilt of consumption, followed by the dual-column NFL (24.74%) and the new standard NFL (9.29%), respectively. Conclusions The newly designed NFL formats attract more consumer attention. The formats significantly decreased consumer purchase intentions in which the effect was mediated by the significant increase in the anticipated guilt of consumption.They are more effective than the original NFL format in improving mindful consumption. Funding Sources Junior/Senior Intramural Research Award 2016/2017, California State University Fullerton.

iDirac: a field-portable instrument for long-term autonomous measurements of isoprene and selected VOCs

The iDirac is a new instrument to measure selected hydrocarbons in the remote atmosphere. A robust design is central to its specifications, with portability, power efficiency, low gas consumption and autonomy as the other driving factors in the instrument development. The iDirac is a dual-column isothermal oven gas chromatograph with photoionisation detection (GC-PID). The instrument is designed and built in-house. It features a modular design, with the novel use of open-source technology for accurate instrument control. Currently configured to measure biogenic isoprene, the system is suitable for a range of compounds. For isoprene measurements in the field, the instrument precision (relative standard deviation) is ±10 %, with a limit of detection down to 38 pmol mol−1 (or ppt). The instrument was first tested in the field in 2015 during a ground-based campaign, and has since shown itself suitable for deployment in a variety of environments and platforms. This paper describes the instrument design, operation and performance based on laboratory tests in a controlled environment as well as during deployments in forests in Malaysian Borneo and central England.