Triple artemisinin-based combination therapies versus artemisinin-based combination therapies for uncomplicated Plasmodium falciparum malaria: a multicentre, open-label, randomised clinical trial.

BACKGROUND: Artemisinin and partner-drug resistance in Plasmodium falciparum are major threats to malaria control and elimination. Triple artemisinin-based combination therapies (TACTs), which combine existing co-formulated ACTs with a second partner drug that is slowly eliminated, might provide effective treatment and delay emergence of antimalarial drug resistance. METHODS: In this multicentre, open-label, randomised trial, we recruited patients with uncomplicated P falciparum malaria at 18 hospitals and health clinics in eight countries. Eligible patients were aged 2-65 years, with acute, uncomplicated P falciparum malaria alone or mixed with non-falciparum species, and a temperature of 37·5°C or higher, or a history of fever in the past 24 h. Patients were randomly assigned (1:1) to one of two treatments using block randomisation, depending on their location: in Thailand, Cambodia, Vietnam, and Myanmar patients were assigned to either dihydroartemisinin-piperaquine or dihydroartemisinin-piperaquine plus mefloquine; at three sites in Cambodia they were assigned to either artesunate-mefloquine or dihydroartemisinin-piperaquine plus mefloquine; and in Laos, Myanmar, Bangladesh, India, and the Democratic Republic of the Congo they were assigned to either artemether-lumefantrine or artemether-lumefantrine plus amodiaquine. All drugs were administered orally and doses varied by drug combination and site. Patients were followed-up weekly for 42 days. The primary endpoint was efficacy, defined by 42-day PCR-corrected adequate clinical and parasitological response. Primary analysis was by intention to treat. A detailed assessment of safety and tolerability of the study drugs was done in all patients randomly assigned to treatment. This study is registered at ClinicalTrials.gov, NCT02453308, and is complete. FINDINGS: Between Aug 7, 2015, and Feb 8, 2018, 1100 patients were given either dihydroartemisinin-piperaquine (183 [17%]), dihydroartemisinin-piperaquine plus mefloquine (269 [24%]), artesunate-mefloquine (73 [7%]), artemether-lumefantrine (289 [26%]), or artemether-lumefantrine plus amodiaquine (286 [26%]). The median age was 23 years (IQR 13 to 34) and 854 (78%) of 1100 patients were male. In Cambodia, Thailand, and Vietnam the 42-day PCR-corrected efficacy after dihydroartemisinin-piperaquine plus mefloquine was 98% (149 of 152; 95% CI 94 to 100) and after dihydroartemisinin-piperaquine was 48% (67 of 141; 95% CI 39 to 56; risk difference 51%, 95% CI 42 to 59; p<0·0001). Efficacy of dihydroartemisinin-piperaquine plus mefloquine in the three sites in Myanmar was 91% (42 of 46; 95% CI 79 to 98) versus 100% (42 of 42; 95% CI 92 to 100) after dihydroartemisinin-piperaquine (risk difference 9%, 95% CI 1 to 17; p=0·12). The 42-day PCR corrected efficacy of dihydroartemisinin-piperaquine plus mefloquine (96% [68 of 71; 95% CI 88 to 99]) was non-inferior to that of artesunate-mefloquine (95% [69 of 73; 95% CI 87 to 99]) in three sites in Cambodia (risk difference 1%; 95% CI -6 to 8; p=1·00). The overall 42-day PCR-corrected efficacy of artemether-lumefantrine plus amodiaquine (98% [281 of 286; 95% CI 97 to 99]) was similar to that of artemether-lumefantrine (97% [279 of 289; 95% CI 94 to 98]; risk difference 2%, 95% CI -1 to 4; p=0·30). Both TACTs were well tolerated, although early vomiting (within 1 h) was more frequent after dihydroartemisinin-piperaquine plus mefloquine (30 [3·8%] of 794) than after dihydroartemisinin-piperaquine (eight [1·5%] of 543; p=0·012). Vomiting after artemether-lumefantrine plus amodiaquine (22 [1·3%] of 1703) and artemether-lumefantrine (11 [0·6%] of 1721) was infrequent. Adding amodiaquine to artemether-lumefantrine extended the electrocardiogram corrected QT interval (mean increase at 52 h compared with baseline of 8·8 ms [SD 18·6] vs 0·9 ms [16·1]; p<0·01) but adding mefloquine to dihydroartemisinin-piperaquine did not (mean increase of 22·1 ms [SD 19·2] for dihydroartemisinin-piperaquine vs 20·8 ms [SD 17·8] for dihydroartemisinin-piperaquine plus mefloquine; p=0·50). INTERPRETATION: Dihydroartemisinin-piperaquine plus mefloquine and artemether-lumefantrine plus amodiaquine TACTs are efficacious, well tolerated, and safe treatments of uncomplicated P falciparum malaria, including in areas with artemisinin and ACT partner-drug resistance. FUNDING: UK Department for International Development, Wellcome Trust, Bill & Melinda Gates Foundation, UK Medical Research Council, and US National Institutes of Health.

Investigating the Impact of Crohn's Disease on the Bioaccessibility of a Lipid-Based Formulation with an In Vitro Dynamic Gastrointestinal Model.

The aim of the study was to investigate the impact of Crohn's disease (CD) on the performance of a lipid-based formulation of ciprofloxacin in a complex gastrointestinal simulator (TIM-1, TNO) and to compare the luminal environment in terms of bile salt and lipid composition in CD and healthy conditions. CD conditions were simulated in the TIM-1 system with a reduced concentration of porcine pancreatin and porcine bile. The bioaccessibility of ciprofloxacin was similar in simulated CD and healthy conditions considering its extent as well as its time course in the jejunum and ileum filtrate. Differences were observed in terms of the luminal concentration of triglycerides, monoglycerides, and fatty acids in the different TIM-1 compartments, indicating a reduction and delay in the lipolysis of formulation excipients in CD. The quantitative analysis of bile salts revealed higher concentrations for healthy conditions (standard TIM-1 fasted-state protocol) in the duodenum and jejunum TIM-1 compartments compared to published data in human intestinal fluids of healthy subjects. The reduced concentrations of bile salts in simulated CD conditions correspond to the levels observed in human intestinal fluids of healthy subjects in the fasted state.A lipidomics approach with ultra performance liquid chromatography (UPLC)/mass spectrometry (MS) has proven to be a time-efficient method to semiquantitatively analyze differences in fatty acid and bile salt levels between healthy and CD conditions. The dynamic luminal environment in CD and healthy conditions after administration of a lipid-based formulation can be simulated using the TIM-1 system. For ciprofloxacin, an altered luminal lipid composition had no impact on its performance indicating a low risk of altered performance in CD patients.

Structure Driven Prediction of Chromatographic Retention Times: Applications to Pharmaceutical Analysis.

Pharmaceutical drug development relies heavily on the use of Reversed-Phase Liquid Chromatography methods. These methods are used to characterize active pharmaceutical ingredients and drug products by separating the main component from related substances such as process related impurities or main component degradation products. The results presented here indicate that retention models based on Quantitative Structure Retention Relationships can be used for de-risking methods used in pharmaceutical analysis and for the identification of optimal conditions for separation of known sample constituents from postulated/hypothetical components. The prediction of retention times for hypothetical components in established methods is highly valuable as these compounds are not usually readily available for analysis. Here we discuss the development and optimization of retention models, selection of the most relevant structural molecular descriptors, regression model building and validation. We also present a practical example applied to chromatographic method development and discuss the accuracy of these models on selection of optimal separation parameters.

Retrospective Review of Need for Delayed Naloxone or Oxygen in Emergency Department Patients Receiving Naloxone for Heroin Reversal.

BACKGROUND: Emergency departments (EDs) are experiencing an increasing number of heroin overdose visits. Currently, there is no generally agreed upon ED observation period for heroin overdose patients who receive naloxone. OBJECTIVES: We aimed to determine the safety of a 2-h observation period for heroin overdose patients who receive naloxone. METHODS: We performed a chart review of all patients who presented with any opioid-related complaint between 2009 and 2014 to our urban academic trauma center. Subset analysis of patients with isolated heroin overdose who received naloxone was performed, with the intent of excluding patients intoxicated with long-acting/enteral opioids. The primary outcome was the number of patients who required delayed intervention-specifically, additional naloxone or supplemental oxygen. RESULTS: Between 2009 and 2014, we recorded 806 visits to our ED for heroin use after receiving naloxone. Twenty-nine patients (3.6%) received a repeat dose of naloxone, and 17 patients (2%) received oxygen ≥2 h after initial naloxone administration. Our 2-h intervention rate was 4.6% (N = 37). This decreased to 1.9% (N = 15) after 3 h and 0.9% (N = 7) after 4 h. Patients with polysubstance use were more likely to receive repeat naloxone (p < 0.01), but not oxygen (p = 0.10). Preexisting cardiopulmonary conditions did not correlate with a need for supplemental oxygen (p = 0.24) or repeat naloxone (p = 0.30). CONCLUSIONS: A 2-h ED observation period for heroin overdose patients reversed with naloxone resulted in a delayed intervention rate of 5%. Clinicians may consider a 3-h observation period, with extra scrutiny in polysubstance abuse.

Integrated Analytical and Statistical Two-Dimensional Spectroscopy Strategy for Metabolite Identification: Application to Dietary Biomarkers.

A major purpose of exploratory metabolic profiling is for the identification of molecular species that are statistically associated with specific biological or medical outcomes; unfortunately, the structure elucidation process of unknowns is often a major bottleneck in this process. We present here new holistic strategies that combine different statistical spectroscopic and analytical techniques to improve and simplify the process of metabolite identification. We exemplify these strategies using study data collected as part of a dietary intervention to improve health and which elicits a relatively subtle suite of changes from complex molecular profiles. We identify three new dietary biomarkers related to the consumption of peas (N-methyl nicotinic acid), apples (rhamnitol), and onions (N-acetyl-S-(1Z)-propenyl-cysteine-sulfoxide) that can be used to enhance dietary assessment and assess adherence to diet. As part of the strategy, we introduce a new probabilistic statistical spectroscopy tool, RED-STORM (Resolution EnhanceD SubseT Optimization by Reference Matching), that uses 2D J-resolved 1H NMR spectra for enhanced information recovery using the Bayesian paradigm to extract a subset of spectra with similar spectral signatures to a reference. RED-STORM provided new information for subsequent experiments (e.g., 2D-NMR spectroscopy, solid-phase extraction, liquid chromatography prefaced mass spectrometry) used to ultimately identify an unknown compound. In summary, we illustrate the benefit of acquiring J-resolved experiments alongside conventional 1D 1H NMR as part of routine metabolic profiling in large data sets and show that application of complementary statistical and analytical techniques for the identification of unknown metabolites can be used to save valuable time and resources.

The Dilator Naris Muscle as a Reporter of Facial Nerve Regeneration in a Rat Model.

OBJECTIVE: Many investigators study facial nerve regeneration using the rat whisker pad model, although widely standardized outcomes measures of facial nerve regeneration in the rodent have not yet been developed. The intrinsic whisker pad "sling" muscles producing whisker protraction, situated at the base of each individual whisker, are extremely small and difficult to study en bloc. Here, we compare the functional innervation of 2 potential reporter muscles for whisker pad innervation: the dilator naris (DN) and the levator labii superioris (LLS), to characterize facial nerve regeneration. METHODS: Motor supply of the DN and LLS was elucidated by measuring contraction force and compound muscle action potentials during stimulation of individual facial nerve branches, and by measuring whisking amplitude before and after DN distal tendon release. RESULTS: The pattern of DN innervation matched that of the intrinsic whisker pad musculature (ie, via the buccal and marginal mandibular branches of the facial nerve), whereas the LLS seemed to be innervated almost entirely by the zygomatic branch, whose primary target is the orbicularis oculi muscle. CONCLUSIONS: Although the LLS has been commonly used as a reporter muscle of whisker pad innervation, the present data show that its innervation pattern does not overlap substantially with the muscles producing whisker protraction. The DN muscle may serve as a more appropriate reporter for whisker pad innervation because it is innervated by the same facial nerve branches as the intrinsic whisker pad musculature, making structure/function correlations more accurate, and more relevant to investigators studying facial nerve regeneration.

Generating Tonal Distinctions in Mandarin Chinese Using an Electrolarynx with Preprogrammed Tone Patterns.

An electrolarynx (EL) is a valuable rehabilitative option for individuals who have undergone laryngectomy, but current monotone ELs do not support controlled variations in fundamental frequency for producing tonal languages. The present study examined the production and perception of Mandarin Chinese using a customized hand-held EL driven by computer software to generate tonal distinctions (tonal EL). Four native Mandarin speakers were trained to articulate their speech coincidentally with preprogrammed tonal patterns in order to produce mono- and di-syllabic words with a monotone EL and tonal EL. Three native Mandarin speakers later transcribed and rated the speech samples for intelligibility and acceptability. Results indicated that words produced using the tonal EL were significantly more intelligible and acceptable than those produced using the monotone EL.

Hind limb ischemia-reperfusion injury in diet-induced obese mice.

BACKGROUND: Obesity is a major risk factor for the development of diabetes. Limb ischemia-reperfusion injury (IR) is a common clinical problem in diabetics who have compromised lower extremity perfusion. This study compared the histologic, metabolic, and functional outcomes after hind limb IR in diet-induced obese (DIO) and non-diabetic (ND) mice during the acute and the regenerative phases of IR. METHODS: DIO and ND mice were subjected to 1.5 h unilateral hind limb ischemia followed by 1- or 28-d IR. Muscle morphology, metabolic, and genomic stress were evaluated at days 1 and 28 IR; Acute inflammation and thrombosis were only measured at day-1 IR. At day 28, IR, skeletal muscle contractility, and maturation were also assessed. RESULTS: At day-1 IR, similar levels of acute muscle fiber necrosis were seen in both groups. DIO mice demonstrated substantially greater inflammatory, prothrombotic, and genomic stress responses, which were also associated with a greater reduction in energy substrates and Akt phosphorylation. At 28d, there was no difference in the peak forces generated in the hind limbs for the two groups. DIO mice had reduced fatigue resistance compared with ND and larger areas of fat accumulation although there was no significant difference in muscle fiber maturation. CONCLUSIONS: DIO mice had an exacerbated acute response to IR with enhanced metabolic deficit, fat accumulation, and defective functional recovery during the regenerative phase of IR. These changes in fatigue resistance reflect compromised functional recovery after IR injury and have relevance for the functional recovery of patients with metabolic syndrome and insulin resistance.

Genome-wide association study reveals a complex genetic architecture underpinning-induced CYP3A4 enzyme activity.

Atypical cytochrome P450 3A4 (CYP3A4) enzyme activity-induced and inhibited-is thought to be the driver of numerous poor or adverse therapeutic responses to up to 50 % of all commonly prescribed drugs. We carried out a genome-wide association study to identify common genetic variants associated with variation in induced CYP3A4 activity. A total of 310 twins were included in this study. Each participant had already completed a 14 days course of St John's Wort to induce CYP3A4, which was quantified through the metabolic ratio of exogenous 3-hydroxyquinine to quinine. We failed to detect any genome-wide significant associations (P < 1 × 10(-8)) with variation in induced CYP3A4 activity although several genomic regions were highlighted which may play minor roles. We report the first GWAS of variation in induced CYP3A4 activity and our preliminary results indicate a complex genetic architecture underpinning induced CYP3A4 enzyme activity.

Minimizing Thermal Damage During Thulium Laser-Assisted Partial Arytenoidectomy: Pulsed Versus Continuous Cutting in an Ex-Vivo Calf Model.

OBJECTIVES: The 2 µm-wavelength thulium laser is an effective cutter during partial arytenoidectomy, but thermal trauma can damage adjacent laryngeal tissue. Pulsing laser energy may reduce trauma when compared to continuous-wave cutting. This study measured temperature changes, thermal trauma, and time to complete partial arytenoidectomy, with and without pulsing, in an ex-vivo calf model. METHODS: Tissue temperature and time to complete a trans-cartilaginous cut were measured during partial arytenoidectomy on ex-vivo calf vocal folds (N = 24) using a thulium laser in continuous-wave (CW, N = 12) and pulsed-wave (PW, N = 12) modes. Energy was 5 W for CW and PW cuts; pulse-widths were 250, 500, and 750 ms. Thermal damage was analyzed histologically by measuring the depth of lactate dehydrogenase (LDH) inactivation perpendicular to the laser-cut edge at the vocal process. Paired t-tests compared CW and PW modes. RESULTS: Change in temperature was lower using CW (6.5°C) compared to PW modes (250 ms = 18°; 500 ms = 16°; 750 = 19°; P < .05). Trans-cartilaginous cuts were completed faster using CW (37 seconds) compared to PW (250 ms = 136 seconds; 500 ms = 61 seconds; 750 = 44 seconds; P < .05), and both modes delivered the same total Joules. The average depth of LDH depletion (thermal damage) was similar for all cuts. CONCLUSIONS: 1. Thulium laser cuts in continuous-mode unexpectedly produced less tissue heating yet created similar thermal damage than pulsed-mode cuts during simulated partial arytenoidectomy. 2. Trans-cartilaginous cuts were completed significantly faster in continuous-mode as compared to pulsed-mode cutting. 3. Pulsing the thulium laser does not minimize thermal damage compared to continuous wave cutting during thulium laser-assisted partial arytenoidectomy.

Electrical Stimulation of Vocal Fold Adduction Triggered by Laryngeal Electromyography Using a Custom Implant.

PURPOSE: Medialization procedures for unilateral vocal fold (VF) paralysis generally improve voice but do not fully replace dynamic VF adduction. Paralyzed VFs typically experience synkinetic reinnervation, which makes it feasible to elicit movement through electrical stimulation. We tested a novel laryngeal pacing implant capable of providing closed-loop (automatic) stimulation of a VF triggered by electromyography (EMG) potentials from the contralateral VF. METHOD: A custom, battery-powered, microprocessor-based stimulator was tested in eight dogs with bipolar electrodes implanted for recording EMG from the left VF and stimulating adduction of the right VF. A cuff electrode on the left recurrent laryngeal nerve (RLN) stimulated unilateral VF adduction, modeling voluntary control in anesthetized animals. Closed-loop stimulation was tested in both acute and chronic experiments. Synkinetic reinnervation was created in two animals by right RLN transection and suture repair to model unilateral VF paralysis. RESULTS: In all animals, left VF activation through RLN stimulation generated a robust EMG response that rapidly triggered stimulation of contralateral thyroarytenoid and lateral cricoarytenoid muscles, causing nearly simultaneous bilateral adduction. Optimal triggering of VF stimulation from elicited EMG was achieved using independent onset and offset thresholds. Real-time artifact blanking allowed closed-loop stimulation without self-perpetuating feedback, despite the proximity of recording and stimulation electrodes. CONCLUSIONS: Using a custom implant system, we demonstrated real-time closed-loop stimulation of one VF triggered by the activation of the contralateral VF. This approach could potentially restore dynamic glottic closure for reflexive behaviors or phonation in cases of unilateral VF paralysis with synkinetic reinnervation. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24492133.

The convergence of facial nerve branches providing whisker pad motor supply in rats: implications for facial reanimation study.

INTRODUCTION: Rodent whisking behavior is supported by the buccal and mandibular branches of the facial nerve, but a description of how these branches converge and contribute to whisker movement is lacking. METHODS: Eight rats underwent isolated transection of either the buccal or mandibular branch and subsequent opposite branch transection. Whisking function was analyzed after both transections. Anatomical measurements, and video recording of stimulation to individual branches, were taken from both facial nerves in 10 rats. RESULTS: Normal to near-normal whisking was demonstrated after isolated branch transection. Whisking was eliminated after transection of both branches. The buccal and mandibular branches form a convergence just proximal to the whisker pad, herein called "distal pes." Distal to this convergence, we identified consistent anatomy that demonstrated cross-innervation. CONCLUSION: The overlap of efferent supply to the whisker pad must be considered when studying facial nerve regeneration in the rat facial nerve model.

Novel device for tissue cooling during endoscopic laryngeal laser surgery: thermal damage study in an ex vivo calf model.

OBJECTIVES: Minimizing collateral thermal damage during endoscopic laryngeal laser surgery remains a priority, and tissue cooling is one way to achieve this goal. Cooling systems utilizing compressed air have been shown to reduce the extent of thermal trauma on the vocal folds, but these units are not ideal for endoscopic applications because cooling is inefficient at the low airflows needed. We examined whether a novel vortex cooling device that generates cooled air at low flow rates would provide a cooling benefit beyond that which could be obtained by using room-temperature air for cooling tissue or by using no cooling during simulated laryngeal laser surgery. METHODS: A continuous-wave thulium laser was used to incise glottic tissue in 12 calf vocal folds. Cooling was achieved with a prototype vortex cooler (9 degrees C air output; flow rate, 3 L/min), and tissue temperature measurements were compared to those with room-air cooling and no cooling. Thermal damage was analyzed histologically by measuring the depth of lactate dehydrogenase inactivation surrounding the mucosal incision. The cooling conditions were tested during time-constant cuts (8 seconds) and depth-constant cuts (into the thyroarytenoid muscle). RESULTS: During time-constant cuts, comparison between vortex cooling and room-air cooling revealed that vortex cooling resulted in a thermal damage zone that was 14% smaller (519 versus 603 microm; p < 0.05). During depth-constant cuts, vortex cooling created a thermal damage zone that was 32% smaller than that created with no cooling (p <0.01) and 9% smaller than that created with room-air cooling (p < 0.01). CONCLUSIONS: Vortex cooling reduces thermal damage more effectively than room-air cooling or no cooling during both time-constant and depth-constant thulium laser cuts.

Prediction of variability in CYP3A4 induction using a combined 1H NMR metabonomics and targeted UPLC-MS approach.

The activity of Cytochrome P450 3A4 (CYP3A4) enzyme is associated with many adverse or poor therapeutic responses to drugs. We used (1)H NMR-based metabonomics to identify a metabolic signature associated with variation in induced CYP3A4 activity. A total of 301 female twins, aged 45--84, participated in this study. Each volunteer was administered a potent inducer of CYP3A4 (St. John's Wort) for 14 days and the activity of CYP3A4 was quantified through the metabolism of the exogenously administered probe drug quinine sulfate (300 mg). Pre- and postintervention fasting urine samples were used to obtain metabolite profiles, using (1)H NMR spectroscopy, and were analyzed using UPLC--MS to obtain a marker for CYP3A4 induction, via the ratio of 3-hydroxyquinine to quinine (3OH-Q:Q). Multiple linear regression was used to build a predictive model for 3OH-Q:Q values based on the preintervention metabolite profiles. A combination of seven metabolites and seven covariates showed a strong (r = 0.62) relationship with log(3OH-Q:Q). This regression model demonstrated significant (p < 0.00001) predictive ability when applied to an independent validation set. Our results highlight the promise of metabonomics for predicting CYP3A4-mediated drug response.

Genetic epidemiology of induced CYP3A4 activity.

AIM: The cytochrome P450 3A4 (CYP3A4) enzyme is implicated in the metabolism of more than 50% of all prescribed medications and its activity - including induced or inhibited activity - is deemed to be a crucial determinant of interindividual variability in drug disposition, poor therapeutic efficacy, and adverse response to medication. METHODS: We used the classical twin model in conjunction with an induction experiment to uncover the relative contribution of genetic and environmental factors to interindividual variation in induced CYP3A4 activity. A total of 367 healthy twins participated in the study. Each volunteer was administered a potent inducer of CYP3A4 (St John's Wort) for 14 days and the activity of CYP3A4 was quantified through the metabolism of the exogenously administered probe drug quinine sulfate. RESULTS: Baseline and induced CYP3A4 activity were highly variable with a seven-fold and 11-fold difference among our population, respectively. Alcohol consumption, BMI, and smoking were significantly associated with induced CYP3A4 activity, collectively explaining 20% of the variation (P<1×10(-4)). The narrow-sense heritability of induced CYP3A4 activity was estimated at 66%, whereas the remainder of the variation was attributed to unique environmental factors. CONCLUSION: To our knowledge, this is the first genetic epidemiological study of induced CYP3A4 activity. Our results motivate further research to identify common and rarer genetic variants that underpin the heritable component of variation in induced CYP3A4 activity.

Systematic evaluation of acetone and acetonitrile for use in hydrophilic interaction liquid chromatography coupled with electrospray ionization mass spectrometry of basic small molecules.

Sub-2-µm particle size hydrophilic interaction liquid chromatography [HILIC] combined with mass spectrometry has been increasing in popularity as a complementary technique to reversed-phase LC for the analysis of polar analytes. The organic-rich mobile phase associated with HILIC techniques provides increases in compound ionization, due to increased desolvation efficiency during electrospray ionisation mass spectrometric (ESI-MS) analysis. Although recent publications illustrated selectivity and response comparisons between reversed-phase LC/MS and HILIC LC/MS, there are limited discussions evaluating the optimisation of the mass spectrometry parameters regarding analytes and alternative mobile phases. The use of acetone as an alternative organic modifier in HILIC has been investigated with respect to signal-to-noise in ESI-MS for a variety of polar analytes. Analyte reponses were measured based on a variety of cone and capillary voltages at low and high pH in both acetone and acetonitrile. In order to visualise compound behaviour in the ESI source, surface plots were constructed to assist in interpreting the observed results. The use of acetone in ESI is complicated at low m/z due to the formation of condensation products. Favourable responses were observed for certain analytes and we envisage offering an insight into the use of acetone as an alternative to acetonitrile under certain analytical conditions for particular compound classifications for small molecule analysis. We also highlight the importance of optimising source voltages in order to obtain the maximum signal stability and sensitivity, which are invariably, highly solvent composition dependent parameters.

Evaluation of Chinese medicinal herbs fingerprinting by HPLC-DAD for the detection of toxic aristolochic acids.

Aristolochic acids are known to contribute to various renal disorders; therefore, expanding the availability of analytical methodology to detect these compounds is important in order to assess the quality of Chinese herbal medicines in which they can be found. Twelve medicinal herbal samples were procured from various sources and extracted in duplicate prior to a "fingerprint" analysis using conventional HPLC-DAD. Multivariate analysis was performed on the entire chromatographed fingerprints. The resulting output was a partial least-square discriminant analysis model, which was able to evaluate the potential presence of aristolochic acids I and II as well as providing an individual herbal "fingerprint". The results of this study provide evidence that the presence of aristolochic acids contained within certain herbal extractions could be detected using a simple method, although some limitations apply to this method for quality control, since newly detected samples for aristolochic acid (positives) will need further confirmation with purity checks or MS hyphenation.

Assessment of canine vocal fold function after injection of a new biomaterial designed to treat phonatory mucosal scarring.

OBJECTIVES: Most cases of irresolvable hoarseness are due to deficiencies in the pliability and volume of the superficial lamina propria of the phonatory mucosa. By using a US Food and Drug Administration-approved polymer, polyethylene glycol (PEG), we created a novel hydrogel (PEG30) and investigated its effects on multiple vocal fold structural and functional parameters. METHODS: We injected PEG30 unilaterally into 16 normal canine vocal folds with survival times of 1 to 4 months. High-speed videos of vocal fold vibration, induced by intratracheal airflow, and phonation threshold pressures were recorded at 4 time points per subject. Three-dimensional reconstruction analysis of 11.7 T magnetic resonance images and histologic analysis identified 3 cases wherein PEG30 injections were the most superficial, so as to maximally impact vibratory function. These cases were subjected to in-depth analyses. RESULTS: High-speed video analysis of the 3 selected cases showed minimal to no reduction in the maximum vibratory amplitudes of vocal folds injected with PEG30 compared to the non-injected, contralateral vocal fold. All PEG30-injected vocal folds displayed mucosal wave activity with low average phonation threshold pressures. No significant inflammation was observed on microlaryngoscopic examination. Magnetic resonance imaging and histologic analyses revealed time-dependent resorption of the PEG30 hydrogel by phagocytosis with minimal tissue reaction or fibrosis. CONCLUSIONS: The PEG30 hydrogel is a promising biocompatible candidate biomaterial to restore form and function to deficient phonatory mucosa, while not mechanically impeding residual endogenous superficial lamina propria.

Surgeon Positioning During Awake Laryngeal Surgery: An Ergonomic Analysis.

OBJECTIVES: While it is acknowledged that otolaryngologists performing microlaryngeal surgery can develop musculoskeletal symptoms due to suboptimal body positioning relative to the patient, flexible laryngoscopy and awake laryngeal surgeries (ALSs) can also pose ergonomic risk. This prospective study measured the effects of posture during ergonomically good and bad positions during laryngoscopy using ergonomic analysis, skin-surface electromyography (EMG), and self-reported pain ratings. STUDY DESIGN: Prospective cohort study. METHODS: Eight participants trained in laryngoscopy assumed four ergonomically distinct standing positions (side/near, side/far, front/near, front/far) at three different heights (neutral-top of patient's head in line with examiner's shoulder, high-6 inches above neutral, and low-6 inches below neutral) in relation to a simulated patient. Participants' postures were analyzed using the validated Rapid Upper Limb Assessment (RULA, 1 [best] to 7 [worst]) tool for the 12 positions. Participants then simulated ALS for 10 minutes in a bad position (low-side-far) and a good position (neutral-front-near) with 12 EMG sensors positioned on the limbs and torso. RESULTS: The position with the worst RULA score was the side/near/high (7.0), and the best was the front/near/neutral (4.5). EMG measurements revealed significant differences between simulated surgery in the bad and good positions, with bad position eliciting an average of 206% greater EMG root-mean-squared magnitude across all sampled muscles compared to the good posture (paired t-test, df = 7, P < .01), consistent with self-reported fatigue/pain when positioned poorly. CONCLUSION: Quantitative and qualitative measurements demonstrate the impact of surgeon posture during simulated laryngoscopy and suggest ergonomically beneficial posture that should facilitate ALSs. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2752-2758, 2021.

Subcutaneous Ports for Chronic Nerve Cuff and Intramuscular Electrode Stimulation in Animal Models.

OBJECTIVE: Tracking recovery after nerve injury may require many intermittent assessments over long periods, preferably with non- or minimally invasive methods. We developed subcutaneous electrical connection ports (ECPs) for repeated connection to nerve cuff or intramuscular electrodes via transdermal needles and evaluated them during studies of laryngeal reinnervation. STUDY DESIGN: Animal experiment. SETTING: Laboratory. METHODS: ECPs were designed and 3-dimensionally printed for connection to bipolar electrodes with biocompatible polymers. Dual compartments filled with conductive silicone capped with nonconductive silicone were used to make the connections between electrode leads and transdermally inserted needles. Ten dogs (19-29 kg) were implanted with 22 ECPs. In 7 dogs, 11 electrodes were placed on recurrent laryngeal nerves proximal to transection and suture repair to track laryngeal reinnervation. In 6 dogs, 8 spinal accessory nerve cuff electrodes were used to stimulate neck muscle contraction. In 2 dogs, 3 electrodes were implanted in the thyroarytenoid muscle. Stimulation thresholds, electromyography, and videolaryngoscopic imaging were obtained in 156 tests over survival periods up to 32 months. Stimulation data provided information about ECP performance. RESULTS: ECPs added negligible resistance to electrodes (mean ± SD, 2.14 ± 0.9 Ω). Despite some electrode leads breaking distally, ECPs were reliable and well tolerated at implant sites and enabled periodic assessment of nerve and muscle function over the time course of laryngeal reinnervation. Histology showed ECP encapsulation as thin layers of connective tissue and minimal acute inflammation. CONCLUSION: Custom ECPs are easily fabricated and cause little tissue reaction over months to years of subcutaneous implantation, facilitating long-term physiologic studies.