Rapid Screening of Vaping Liquids by DART-MS.

BACKGROUND: E-cigarette, or vaping, product use-associated lung injury was reported in over 2800 cases from August 2019 to February 2020. Samples of vaping products were submitted for laboratory analysis in conjunction with investigation of the outbreak. A rapid screening method that was selective and sensitive for multiple analytes was required to aid in the investigation. OBJECTIVE: To develop a multi-analyte method capable of screening vaping liquid samples that consumed small amounts of sample, required minimal sample preparation and analysis time, employed automated data processing, and provided the necessary sensitivity and selectivity. METHODS: Vaping liquids were dissolved in acetonitrile and sampled with DIP-it® tips. The tips were analyzed by direct analysis in real-time mass spectrometry (DART-MS) and the resulting data processed with TraceFinder™ software. Laboratory-fortified samples consisting of various analytes and matrixes were evaluated prior to the analysis of submitted samples. RESULTS: The method was successful at detecting all target analytes in all matrixes evaluated, although the method detection limits varied by analyte/matrix combination: from 0.1% nicotine in poly(propylene glycol) average Mn 1000 (the lowest level evaluated) to 5.0% poly(ethylene glycol) average Mn 400 in cannabis concentrate. Results for the analysis of submitted samples by this method compared favorably to GC-MS and FTIR results. CONCLUSION: The DART-MS method met the objective of speed, sensitivity, and selectivity (although certain cannabinoid isomers could not be distinguished). The method may be easily adapted or expanded for additional analytes. HIGHLIGHTS: This is a simple DART-MS method for screening vaping liquids for substances of concern in less than 2 min per sample.

Simultaneous Temperature Measurements and Aerosol Collection During Vaping for the Analysis of Δ9-Tetrahydrocannabinol and Vitamin E Acetate Mixtures in Ceramic Coil Style Cartridges.

Incidence of e-cigarette, or vaping, product use-associated lung injury (EVALI) has been linked to the vaping of tetrahydrocannabinol (THC) products to which vitamin E acetate (VEA) has been added. In this work we vaped THC/VEA mixtures at elevated power levels using a variety of ceramic coil vaping cartridges and a commercially available vaping device, while simultaneously measuring temperature and collecting the vaporized condensate. The collected vapor condensate was analyzed for evidence of VEA decomposition by GC/MS, GC/FT-IR/MS, and LC-APCI-HRMS/MS. Mean temperature maxima for all examined cartridges at the selected power exceeded 430°C, with a range of 375-569°C, well beyond that required for thermal decomposition of VEA. The percent recovery of VEA and Δ9-THC from the vaporized mixture in six cartridges ranged from 71.5 to 101% and from 56.4 to 88.0%, respectively. Analysis of the condensed vaporized material identified VEA decomposition products duroquinone (DQ), 1-pristene, and durohydroquinone monoacetate (DHQMA); a compound consistent with 4-acetoxy-2,3,5-trimethyl-6-methylene-2,4-cyclohexadienone (ATMMC) was also detected. The concentration of DQ produced from vaporization of the THC/VEA mixture in one cartridge was found to be 4.16 ± 0.07 µg per mg of vapor condensate.

The bicipital groove as a landmark for humeral version reference during shoulder arthroplasty: a computed tomography study of normal humeral rotation.

BACKGROUND: Accurate reproduction of humeral version is important in shoulder arthroplasty. Traditional referencing relative to the transepicondylar axis (TEA) is prone to error as it is absent on preoperative imaging and inaccurately reproduced intraoperatively. The bicipital groove is present on preoperative imaging and in the operative field and thus may be a useful landmark for accurate reproduction of humeral version. MATERIALS AND METHODS: Two trained observers analyzed 101 full-humerus computed tomography scans of patients undergoing a myeloma screening protocol. Measurements of humeral retroversion relative to the TEA (angle A), humeral articular axis retroversion relative to the bicipital groove (angle B), and the bicipital groove axis relative to the TEA (angle C) were made with comparison of the measurement properties of each. RESULTS: Humeral retroversion relative to the TEA was 23.7° ± 8° (range, 0.2°-48.7°; 95% confidence interval, 22°-26°). The humeral articular axis was retroverted to the bicipital groove axis (angle B) by 33.5° ± 9.4° (range, 15.5°-61.7°; 95% confidence interval, 32°-35°). Overall inter-rater reliability was 0.88. DISCUSSION: Measurement of humeral head retroversion relative to the bicipital groove is not inferior to the gold-standard measurement. The bicipital groove is present both on preoperative imaging and in the operative field, making it a potential reference landmark for accurate reproduction of humeral version in shoulder arthroplasty.

Hydrogen Bonding between Tetrahydrocannabinol and Vitamin E Acetate in Unvaped, Aerosolized, and Condensed Aerosol e-Liquids.

Vitamin E acetate (VEA) has recently been identified as a potential chemical of concern in the investigation of e-cigarette, or vaping, product use associated lung injury (EVALI). According to the Centers for Disease Control and Prevention (CDC), most patients report a history of using tetrahydrocannabinol (THC)-containing e-cigarette or vaping products; approximately 50% of the THC-containing vaping products examined by the Food and Drug Administration (FDA) in this investigation have been found to contain VEA. This letter demonstrates that THC and VEA exist in the unvaped e-liquids, vaped e-liquids, and the aerosol produced from vaporizing the mixture, as a hydrogen bonded THC/VEA complex linked by the THC hydroxyl and VEA carbonyl groups. Additional work should therefore be considered to investigate what happens to this complex in the lungs.

Forensic Drug Identification, Confirmation, and Quantification Using Fully Integrated Gas Chromatography with Fourier Transform Infrared and Mass Spectrometric Detection (GC-FT-IR-MS).

This manuscript is a continuation of a recent study that described the use of fully integrated gas chromatography with direct deposition Fourier transform infrared detection and mass spectrometric detection (GC-FT-IR-MS) to identify and confirm the presence of sibutramine and AB-FUBINACA. The purpose of the current study was to employ the GC-FT-IR portion of the same instrument to quantify these compounds, thereby demonstrating the ability to identify, confirm, and quantify drug substances using a single GC-FT-IR-MS unit. The performance of the instrument was evaluated by comparing quantitative analytical figures of merit to those measured using an established, widely employed method for quantifying drug substances, high performance liquid chromatography with ultraviolet detection (HPLC-UV). The results demonstrated that GC-FT-IR was outperformed by HPLC-UV with regard to sensitivity, precision, and linear dynamic range (LDR). However, sibutramine and AB-FUBINACA concentrations measured using GC-FT-IR were not significantly different at the 95% confidence interval compared to those measured using HPLC-UV, which demonstrates promise for using GC-FT-IR as a semi-quantitative tool at the very least. The most significant advantage of GC-FT-IR compared to HPLC-UV is selectivity; a higher level of confidence regarding the identity of the analyte being quantified is achieved using GC-FT-IR. Additional advantages of using a single GC-FT-IR-MS instrument for identification, confirmation, and quantification are efficiency, increased sample throughput, decreased consumption of laboratory resources (solvents, chemicals, consumables, etc.), and thus cost.

Contamination of the Surgical Field with Propionibacterium acnes in Primary Shoulder Arthroplasty.

BACKGROUND: Propionibacterium acnes is a common pathogen identified in postoperative shoulder infection. It has been shown to be present in culture specimens during primary shoulder arthroplasty; however, recent work has suggested that it is most likely to be a contaminant. Our aim was to identify the potential sources of contamination in shoulder arthroplasty. METHODS: Tissue swabs were obtained for microbiological analysis from consecutive patients undergoing primary shoulder arthroplasty. Routine surgical technique was maintained, and 5 specimens were taken from different sites: (1) the subdermal layer, (2) the tip of the surgeon's glove, (3) the inside scalpel blade (used for deeper incision), (4) the forceps, and (5) the outside scalpel blade (used for the skin incision). RESULTS: Forty patients (25 female patients and 15 male patients) were included. Thirteen (33%) of the 40 patients had at least 1 culture specimen positive for P. acnes. Two (8%) of the 25 female patients and 11 (73%) of the 15 male patients had ≥1 culture specimen positive for P. acnes. The most common site of growth of P. acnes was the subdermal layer (12 positive samples), followed by the forceps (7 positive samples), the tip of the surgeon's glove (7 positive samples), the outside scalpel blade (4 positive samples), and the inside scalpel blade (1 positive sample). There were 27 of 75 swabs that were positive on culture for P. acnes in male patients compared with 4 of 125 swabs in female patients. Male patients had 66 times (95% confidence interval, 6 to 680 times) higher odds of having a positive culture indicating subdermal colonization compared with female patients (p < 0.001). CONCLUSIONS: P. acnes is a common contaminant of the surgical field in primary shoulder arthroplasty. The subdermal layer may be the source of this contamination, and the prevalence of P. acnes in the surgical wound may be due to the surgeon's manipulation with gloves and instruments. Our findings are consistent with those regarding the increased rates of P. acnes bacterial load and intraoperative growth in male patients compared with female patients. CLINICAL RELEVANCE: P. acnes is likely to be spread throughout the surgical field from the subdermal layer via soft-tissue handling by the surgeon and instruments. Strategies need to be utilized to minimize this contact and to reduce the chance of colonization.

Serial MRI and clinical assessment of cyclops lesions.

PURPOSE: 'Clinical cyclops syndrome' is associated with pain and a palpable 'clunk' at terminal extension with the loss of full extension. The aims of this prospective controlled study were: (1) to assess whether the minimal debridement of the ACL stump and notch is associated with an increased incidence of clinical cyclops lesions, (2) to look at the incidence and natural history of 'MRI cyclops' lesions using serial MRI's and (3) to assess whether 'MRI cyclops' lesions are associated with the loss of extension. METHODS: Forty-eight patients were randomized for ACL reconstruction into standard (23) and minimal debridement (24) techniques. One patient was excluded from the study. All patients underwent MR scanning postoperatively at 2, 6 and 12 months, together with the clinical assessment using a KT-1000 arthrometer and International Knee Documentation Committee evaluation. All observations were made by investigators blinded to the surgical technique. RESULTS: There was no statistical difference in the incidence of cyclops lesions between the two groups (n.s.). The overall incidence of cyclops lesions was 46.8% (22 of 47). The natural history is variable with some getting larger, smaller or remaining static in size. Of patients with cyclops lesions, 17 patients (77%) had cyclops lesions in the setting of full extension. Five patients (23%) had loss of extension at 12 months with no MRI cyclops detected at 2 months. CONCLUSIONS: The natural history is variable; although once present, the majority of cyclops remain static or regress in size. The onset of cyclops lesions is usually between 6- and 12-month post-ACL reconstruction. Minimal debridement does not lead to an increased incidence of clinical cyclops lesions. The authors conclude that loss of extension is multi-factorial, and there is a discrepancy between what we term 'MRI cyclops' and true 'clinical cyclops'. LEVEL OF EVIDENCE: Case-control study, Level II.

Management of peripheral arterial disease in the elderly: focus on cilostazol.

Symptomatic and asymptomatic peripheral arterial disease (PAD) is a common problem in the elderly. The management of PAD includes the prevention of cardiovascular events and relief of symptoms--most commonly intermittent claudication (IC). Both require treatment of the causes and consequences of atherothrombosis, but some strategies are more effective for prevention of cardiovascular events and others are more effective for the relief of symptoms. Priorities for the prevention of cardiovascular events include smoking cessation, exercise, antiplatelet therapy, and the treatment of dyslipidemia, hypertension, and diabetes. Walking time and ability are improved by exercise. The benefit of numerous drugs in the treatment of IC has been assessed. The results have generally been disappointing, but there is some evidence that statins and cilostazol (an inhibitor of phosphodiesterase 3) are of benefit. Meta-analyses suggest that cilostazol increases maximum walking distance by 40%-50% and improves other objective measures of walking. The safety profile of cilostazol in patients with PAD appears to be acceptable although the mechanism for its effect on IC is unclear. In addition to risk factor management, treatment with cilostazol should be considered in patients with disabling IC.