Goldenseal-Mediated Inhibition of Intestinal Uptake Transporters Decreases Metformin Systemic Exposure in Mice.

Goldenseal is a perennial plant native to eastern North America. A recent clinical study reported goldenseal decreased metformin Cmax and area under the blood concentration versus time curve (AUC) by 27% and 23%, respectively, but half-life and renal clearance were unchanged. These observations suggested goldenseal altered processes involved in metformin absorption. The underlying mechanism(s) remain(s) unknown. One mechanism for the decreased metformin systemic exposure is inhibition by goldenseal of intestinal uptake transporters involved in metformin absorption. Goldenseal extract and three goldenseal alkaloids (berberine, (-)-ß-hydrastine, hydrastinine) were tested as inhibitors of organic cation transporter (OCT) 3, plasma membrane monoamine transporter (PMAT), and thiamine transporter (THTR) 2 using human embryonic kidney 293 cells overexpressing each transporter. The goldenseal extract, normalized to berberine content, was the strongest inhibitor of each transporter (IC50: 4.9, 13.1, and 5.8 µM for OCT3, PMAT, and THTR2, respectively). A pharmacokinetic study in mice compared the effects of berberine, (-)-ß-hydrastine, goldenseal extract, and imatinib (OCT inhibitor) on orally administered metformin. Goldenseal extract and imatinib significantly decreased metformin Cmax by 31% and 25%, respectively, and had no effect on half-life. Berberine and (-)-ß-hydrastine had no effect on metformin pharmacokinetics, indicating neither alkaloid alone precipitated the interaction in vivo. A follow-up murine study involving intravenous metformin and oral inhibitors examined the contributions of basolateral enteric/hepatic uptake transporters to the goldenseal-metformin interaction. Goldenseal extract and imatinib had no effect on metformin AUC and half-life, suggesting lack of inhibition of basolateral enteric/hepatic uptake transporters. Results may have implications for patients taking goldenseal with drugs that are substrates for OCT3 and THTR2. SIGNIFICANCE STATEMENT: Goldenseal is used to self-treat respiratory infections and digestive disorders. We investigated potential mechanisms for the clinical pharmacokinetic interaction observed between goldenseal and metformin, specifically inhibition by goldenseal of intestinal uptake transporters (OCT3, PMAT, THTR2) involved in metformin absorption. Goldenseal extract inhibited all three transporters in vitro and decreased metformin systemic exposure in mice. These data may have broader implications for patients co-consuming goldenseal with other drugs that are substrates for these transporters.

Modulation of in Vitro SARS-CoV-2 Infection by Stephania tetrandra and Its Alkaloid Constituents.

Botanical natural products have been widely consumed for their purported usefulness against COVID-19. Here, six botanical species from multiple sources and 173 isolated natural product compounds were screened for blockade of wild-type (WT) SARS-CoV-2 infection in human 293T epithelial cells overexpressing ACE-2 and TMPRSS2 protease (293TAT). Antiviral activity was demonstrated by an extract from Stephania tetrandra. Extract fractionation, liquid chromatography-mass spectrometry (LC-MS), antiviral assays, and computational analyses revealed that the alkaloid fraction and purified alkaloids tetrandrine, fangchinoline, and cepharanthine inhibited WT SARS-CoV-2 infection. The alkaloids and alkaloid fraction also inhibited the delta variant of concern but not WT SARS-CoV-2 in VeroAT cells. Membrane permeability assays demonstrate that the alkaloids are biologically available, although fangchinoline showed lower permeability than tetrandrine. At high concentrations, the extract, alkaloid fractions, and pure alkaloids induced phospholipidosis in 293TAT cells and less so in VeroAT cells. Gene expression profiling during virus infection suggested that alkaloid fraction and tetrandrine displayed similar effects on cellular gene expression and pathways, while fangchinoline showed distinct effects on cells. Our study demonstrates a multifaceted approach to systematically investigate the diverse activities conferred by complex botanical mixtures, their cell-context specificity, and their pleiotropic effects on biological systems.

How Low Can You Go? Selecting Intensity Thresholds for Untargeted Metabolomics Data Preprocessing.

Untargeted mass spectrometry (MS) metabolomics is an increasingly popular approach for characterizing complex mixtures. Recent studies have highlighted the impact of data preprocessing for determining the quality of metabolomics data analysis. The first step in data processing with untargeted metabolomics requires that signal thresholds be selected for which features (detected ions) are included in the dataset. Analysts face the challenge of knowing where to set these thresholds; setting them too high could mean missing relevant features, but setting them too low could result in a complex and unwieldy dataset. This study compared data interpretation for an example metabolomics dataset when intensity thresholds were set at a range of feature heights. The main observations were that low signal thresholds (1) improved the limit of detection, (2) increased the number of features detected with an associated isotope pattern and/or an MS-MS fragmentation spectrum, and (3) increased the number of in-source clusters and fragments detected for known analytes of interest. When the settings of parameters differing in intensities were applied on a set of 39 samples to discriminate the samples through principal component analyses (PCA), similar results were obtained with both low- and high-intensity thresholds. We conclude that the most information-rich datasets can be obtained by setting low-intensity thresholds. However, in the cases where only a qualitative comparison of samples with PCA is to be performed, it may be sufficient to set high thresholds and thereby reduce the complexity of the data processing and amount of computational time required.

Kratom (Mitragyna speciosa) Validation: Quantitative Analysis of Indole and Oxindole Alkaloids Reveals Chemotypes of Plants and Products.

Many consumers are turning to kratom (Mitragyna speciosa) to self-manage pain and opioid addiction. In the United States, an array of capsules, powders, and loose-leaf kratom products are readily available. Additionally, several online sites supply live kratom plants. A prerequisite to establishing quality control and quality assurance standards for the kratom industry, or understanding how alkaloid levels effect clinical outcomes, is the identification and quantitation of major and minor alkaloid constituents within available products and preparations. To this end, an ultra-high performance liquid chromatography-high resolution mass spectrometry method was developed for the analysis of 8 indole alkaloids (7-hydroxymitragynine, ajmalicine, paynantheine, mitragynine, speciogynine, isopaynantheine, speciociliatine, and mitraciliatine) and 6 oxindole alkaloids (isomitraphylline, isospeciofoleine, speciofoline, corynoxine A, corynoxeine, and rhynchophylline) in US-grown kratom plants and commercial products. These commercial products shared a qualitatively similar alkaloid profile, with 12 - 13 detected alkaloids and high levels of the indole alkaloid mitragynine (13.9 ± 1.1 - 270 ± 24 mg/g). The levels of the other major alkaloids (paynantheine, speciociliatine, speciogynine, mitraciliatine, and isopaynantheine) and the minor alkaloids varied in concentration from product to product. The alkaloid profile of US-grown M. speciosa "Rifat" showed high levels of the indole alkaloid speciogynine (7.94 ± 0.83 - 11.55 ± 0.18 mg/g) and quantifiable levels of isomitraphylline (0.943 ± 0.033 - 1.47 ± 0.18 mg/g). Notably, the alkaloid profile of a US-grown M. speciosa seedling was comparable to the commercial products with a high level of mitragynine (15.01 ± 0.20 mg/g). This work suggests that there are several M. speciosa chemotypes.

Clinical Pharmacokinetic Assessment of Kratom (Mitragyna speciosa), a Botanical Product with Opioid-like Effects, in Healthy Adult Participants.

Increasing use of the botanical kratom to self-manage opioid withdrawal and pain has led to increased kratom-linked overdose deaths. Despite these serious safety concerns, rigorous fundamental pharmacokinetic knowledge of kratom in humans remains lacking. We assessed the pharmacokinetics of a single low dose (2 g) of a well-characterized kratom product administered orally to six healthy participants. Median concentration-time profiles for the kratom alkaloids examined were best described by a two-compartment model with central elimination. Pronounced pharmacokinetic differences between alkaloids with the 3S configuration (mitragynine, speciogynine, paynantheine) and alkaloids with the 3R configuration (mitraciliatine, speciociliatine, isopaynantheine) were attributed to differences in apparent intercompartmental distribution clearance, volumes of distribution, and clearance. Based on noncompartmental analysis of individual concentration-time profiles, the 3S alkaloids exhibited a shorter median time to maximum concentration (1-2 vs. 2.5-4.5 h), lower area under the plasma concentration-time curve (430-490 vs. 794-5120 nM × h), longer terminal half-life (24-45 vs. ~12-18 h), and higher apparent volume of distribution during the terminal phase (960-12,700 vs. ~46-130 L) compared to the 3R alkaloids. Follow-up mechanistic in vitro studies suggested differential hepatic/intestinal metabolism, plasma protein binding, blood-to-plasma partitioning, and/or distribution coefficients may explain the pharmacokinetic differences between the two alkaloid types. This first comprehensive pharmacokinetic characterization of kratom alkaloids in humans provides the foundation for further research to establish safety and effectiveness of this emerging botanical product.

Stop the crop: Insights into the insecticidal mode of action of cinnamodial against mosquitoes.

Cinnamodial (CDIAL) is a drimane sesquiterpene dialdehyde found in the bark of Malagasy medicinal plants (Cinnamosma species; family Canellaceae). We previously demonstrated that CDIAL was insecticidal, antifeedant, and repellent against Aedes aegypti mosquitoes. The goal of the present study was to generate insights into the insecticidal mode of action for CDIAL, which is presently unknown. We evaluated the effects of CDIAL on the contractility of the ventral diverticulum (crop) isolated from adult female Ae. aegypti. The crop is a food storage organ surrounded by visceral muscle that spontaneously contracts in vitro. We found that CDIAL completely inhibited spontaneous contractions of the crop as well as those stimulated by the agonist 5-hydroxytryptamine. Several derivatives of CDIAL with known insecticidal activity also inhibited crop contractions. Morphometric analyses of crops suggested that CDIAL induced a tetanic paralysis that was dependent on extracellular Ca2+ and inhibited by Gd3+, a non-specific blocker of plasma membrane Ca2+ channels. Screening of numerous pharmacological agents revealed that a Ca2+ ionophore (A23187) was the only compound other than CDIAL to completely inhibit crop contractions via a tetanic paralysis. Taken together, our results suggest that CDIAL induces a tetanic paralysis of the crop by elevating intracellular Ca2+ through the activation of plasma membrane Ca2+ channels, which may explain the insecticidal effects of CDIAL against mosquitoes. Our pharmacological screening experiments also revealed the presence of two regulatory pathways in mosquito crop contractility not previously described: an inhibitory glutamatergic pathway and a stimulatory octopaminergic pathway. The latter pathway was also completely inhibited by CDIAL.

Digitizing clinical trials.

Clinical trials are a fundamental tool used to evaluate the efficacy and safety of new drugs and medical devices and other health system interventions. The traditional clinical trials system acts as a quality funnel for the development and implementation of new drugs, devices and health system interventions. The concept of a "digital clinical trial" involves leveraging digital technology to improve participant access, engagement, trial-related measurements, and/or interventions, enable concealed randomized intervention allocation, and has the potential to transform clinical trials and to lower their cost. In April 2019, the US National Institutes of Health (NIH) and the National Science Foundation (NSF) held a workshop bringing together experts in clinical trials, digital technology, and digital analytics to discuss strategies to implement the use of digital technologies in clinical trials while considering potential challenges. This position paper builds on this workshop to describe the current state of the art for digital clinical trials including (1) defining and outlining the composition and elements of digital trials; (2) describing recruitment and retention using digital technology; (3) outlining data collection elements including mobile health, wearable technologies, application programming interfaces (APIs), digital transmission of data, and consideration of regulatory oversight and guidance for data security, privacy, and remotely provided informed consent; (4) elucidating digital analytics and data science approaches leveraging artificial intelligence and machine learning algorithms; and (5) setting future priorities and strategies that should be addressed to successfully harness digital methods and the myriad benefits of such technologies for clinical research.

Semi-synthetic cinnamodial analogues: Structural insights into the insecticidal and antifeedant activities of drimane sesquiterpenes against the mosquito Aedes aegypti.

The Aedes aegypti mosquito serves as a major vector for viral diseases, such as dengue, chikungunya, and Zika, which are spreading across the globe and threatening public health. In addition to increased vector transmission, the prevalence of insecticide-resistant mosquitoes is also on the rise, thus solidifying the need for new, safe and effective insecticides to control mosquito populations. We recently discovered that cinnamodial, a unique drimane sesquiterpene dialdehyde of the Malagasy medicinal plant Cinnamosma fragrans, exhibited significant larval and adult toxicity to Ae. aegypti and was more efficacious than DEET-the gold standard for insect repellents-at repelling adult female Ae. aegypti from blood feeding. In this study several semi-synthetic analogues of cinnamodial were prepared to probe the structure-activity relationship (SAR) for larvicidal, adulticidal and antifeedant activity against Ae. aegypti. Initial efforts were focused on modification of the dialdehyde functionality to produce more stable active analogues and to understand the importance of the 1,4-dialdehyde and the α,ß-unsaturated carbonyl in the observed bioactivity of cinnamodial against mosquitoes. This study represents the first investigation into the SAR of cinnamodial as an insecticide and antifeedant against the medically important Ae. aegypti mosquito.

Two-point nasomaxillary fixation of the Le Fort I osteotomy: assessment of stability at one year postoperative.

The purpose was to assess maxillary position among patients undergoing Le Fort I maxillary advancement with internal fixation placed only at the nasomaxillary buttresses. This was a retrospective study of patients undergoing a Le Fort I osteotomy for maxillary advancement, with internal fixation placed only at the nasomaxillary buttresses. Demographic and cephalometric measures were recorded. The outcome of interest was the change in maxillary position between immediately postoperative (T1), 6 weeks postoperative (T2), and 1 year postoperative (T3). Fifty-eight patients were included as study subjects (32 male, 26 female; mean age 18.4±1.8 years). Twenty-five subjects (43.1%) had a diagnosis of cleft lip and palate. Forty-three subjects (74.1%) had bimaxillary surgery, 16 (27.6%) had bone grafts, and 18 (31.0%) had segmental maxillary osteotomies. At T3, there were no subjects with non-union, malunion, malocclusion, or relapse requiring repeat surgery. Mean linear changes between T1 and T3 were ≤1mm. Mean angular changes between T1 and T3 were <1°. There was no significant difference in stability in multi-segment maxillary osteotomies (P= 0.22) or with bone grafting (P= 0.31). In conclusion, anterior fixation alone in the Le Fort I osteotomy results in a stable maxillary position at 1 year postoperative.

Is alteration of the occlusal plane stable with isolated nasomaxillary fixation of the Le Fort I osteotomy?

The purpose of this work was to evaluate the stability of maxillary position in the setting of occlusal plane rotations in bimaxillary surgery with rigid fixation of the mandible and bilateral nasomaxillary fixation at the Le Fort I level. This was a retrospective assessment of patients undergoing bimaxillary surgery for the correction of dentofacial deformities with occlusal plane alterations. Demographic measures assessed included age, sex, history of craniofacial anomaly, segmental maxillary osteotomy, and maxillary bone grafting. Cephalometric measures assessed included occlusal plane rotation (clockwise (CWR) or counterclockwise (CCWR)), angular measurements of maxillary and mandibular position (SNA, SNB, and ANB), and occlusal plane angle (occlusal plane to corrected Frankfort horizontal); these were assessed preoperatively (T0) and immediately (T1), 6 weeks (T2), and 1year postoperative (T3). Descriptive and bivariate statistics were computed; P≤0.05 was considered significant. Thirty-six patients were included as study subjects (mean age 18.6±1.8 years; 17 (47.2%) female); 27 (75%) had a primary diagnosis of craniofacial anomaly. Eleven patients (30.6%) had segmental maxillary osteotomies; 10 patients (27.8%) had simultaneous maxillary bone grafting. Twelve patients underwent CCWR; 24 patients underwent CWR. No patient required repeat surgery for malocclusion or relapse; there were no malunions or non-unions during follow-up. For CCWR patients, the mean occlusal plane change from preoperative to postoperative was 5.8±2.8°, remaining stable at 1 year postoperative (ΔT3-T1 1.6±1.0°, P>0.05). For CWR patients, the mean occlusal plane rotation was 4.5 ± 2.2°, remaining stable at 1 year postoperative (ΔT3-T1 1.1±0.9°, P>0.05). In patients undergoing bimaxillary surgery for occlusal plane rotation, two-point fixation of the Le Fort I osteotomy resulted in a stable maxillary position at 1 year postoperative.

Insecticidal and Antifeedant Activities of Malagasy Medicinal Plant (Cinnamosma sp.) Extracts and Drimane-Type Sesquiterpenes against Aedes aegypti Mosquitoes.

The overuse of insecticides with limited modes of action has led to resistance in mosquito vectors. Thus, insecticides with novel modes of action are needed. Secondary metabolites in Madagascan plants of the genus Cinnamosma (Canellaceae) are commonly used in traditional remedies and known to elicit antifeedant and toxic effects in insect pests. Here we test the hypothesis that extracts of Cinnamosma sp. enriched in drimane sesquiterpenes are toxic and/or antifeedant to the yellow fever mosquito Aedes aegypti. We show that the bark and root extracts, which contain a higher abundance of drimane sesquiterpenes compared to leaves, were the most efficacious. Screening isolated compounds revealed cinnamodial to be the primary driver of adulticidal activity, whereas cinnamodial, polygodial, cinnafragrin A, and capsicodendrin contributed to the larvicidal activity. Moreover, an abundant lactone (cinnamosmolide) in the root extract synergized the larvicidal effects of cinnamodial. The antifeedant activity of the extracts was primarily contributed to cinnamodial, polygodial, and cinnamolide. Parallel experiments with warburganal isolated from Warburgia ugandensis (Canellaceae) revealed that aldehydes are critical for-and a hydroxyl modulates-insecticidal activity. Our results indicate that plant drimane sesquiterpenes provide valuable chemical platforms for developing insecticides and repellents to control mosquito vectors.

Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R and Lactobacillus rhamnosus CLR2 improve quality-of-life and IBS symptoms: a double-blind, randomised, placebo-controlled study.

A combination of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R and Lactobacillus rhamnosus CLR2 was compared to placebo for relief of symptoms of irritable bowel syndrome (IBS). A total of 113 subjects at 3 clinical sites were randomised in a 2:1 ratio and followed for 12 weeks. Subjects ingested either 2 capsules of active study product, containing 50×109 cfu of live organisms, or 2 placebo capsules daily. Endpoints included improvement in abdominal pain, days of pain, distention, stool consistency and frequency, quality of life (QOL), and adequate relief (AR) of IBS symptoms. IBS subtypes constipation (IBS-C), diarrhoea (IBS-D), and mixed (IBS-M) were evaluated separately; the effect of gender was also examined. For all efficacy endpoints improvement of 30% or more vs placebo was considered clinically significant. With the exception of pain intensity and AR, the endpoints demonstrated a therapeutic advantage of active over placebo for IBS symptoms in at least some subject subgroups. The IBS-D and female subgroups showed the largest and most consistent effects. Stool frequency and consistency were evaluated in the IBS-C and IBS-D subgroups, and improvement of active vs placebo was noted in both. QOL improvement was seen overall and in specific domains. Adverse events (AEs) were limited to 7 subjects; all were of mild or moderate intensity except one, severe cramping. Four AEs in the same subject in the placebo group were judged to be related to study product; these resolved by the end of study. There were no serious AEs.

Validation of a Laparoscopic Ferromagnetic Technology-based Vessel Sealing Device and Comparative Study to Ultrasonic and Bipolar Laparoscopic Devices.

INTRODUCTION: Ferromagnetic heating is a new electrosurgery energy modality that has proven effective in hemostatic tissue dissection as well as sealing and dividing blood vessels and vascularized tissue. The purpose of this study was to evaluate a ferromagnetic-based laparoscopic vessel sealing device with respect to sealing and dividing vessels and vascularized tissue and to compare performance against current vessel sealing technologies. MATERIALS AND METHODS: A laparoscopic vessel sealing device, Laparoscopic FMsealer (LFM), was studied for efficacy in sealing and dividing blood vessels and comparative studies against predicate ultrasonic, Harmonic Ace+(US), and/or bipolar, LigaSure 5 mm Blunt Tip and/or Maryland (BP), devices in vivo using a swine model and in vitro for comparison of seal burst pressure and reliability. Mann-Whitney and Student t test were used for statistical comparisons. RESULTS: In division of 10 cm swine small bowel mesentery in vivo, the laparoscopic FMsealer [12.4±1.8 sec (mean±SD)], was faster compared with US (26.8±2.5 s) and BP (30.0±2.7 s), P<0.05 LFM versus US and BP. Blinded histologic evaluation of 5 mm vessel seals in vivo showed seal lateral thermal spread to be superior in LFM (1678±433 µm) and BP (1796±337 µm) versus US (2032±387 µm), P<0.001. In vitro, seal burst strength and success of sealing 2 to 4 mm arteries were as follows (mean±SD mm Hg, % success burst strength >240 mm Hg): LFM (1079±494 mm Hg, 98.1% success) versus BP (1012±463, 99.0%), P=NS. For 5 to 7 mm arteries: LFM (1098±502 mm Hg, 95.3% success) versus BP (715±440, 91.8%), P<0.001 in burst strength and P=NS in % success. Five 60 kg female swine underwent 21-day survival studies following ligation of vessels ranging from 1 to 7 mm in diameter (n=186 total vessels). Primary seal was successful in 97%, 99% including salvage seals. There was no evidence of postoperative bleeding at sealed vessels at 21-day necropsy. CONCLUSION: The Laparoscopic FMsealer is an effective tool for sealing and dividing blood vessels and vascularized tissue and compares favorably to current technologies in clinically relevant end points.

Ferromagnetic Heating for Vessel Sealing and Division: Utility and Comparative Study to Ultrasonic and Bipolar Technologies.

INTRODUCTION: Vessel sealing technologies have improved surgical efficiency and outcomes. Ferromagnetic technology has potential utility in this area. The aim of this study was to evaluate ferromagnetic heating in sealing and dividing vessels. METHODS: A novel ferromagnetic (FM) sealer, FMsealer, was developed for sealing and dividing vessels. Using a swine in vivo model, the following endpoints were evaluated: (1) proof of concept, (2) 21-day survival surgery, and (3) comparison with ultrasonic (US) and/or bipolar (BP) devices for subjective outcomes. Seal burst strengths were measured in vitro. Mann-Whitney and Student's t test were used. RESULTS: After showing proof of concept, 5 swine underwent survival splenectomy, nephrectomy, hysterectomy, and mesenteric vessel division (arteries ranging from 1 to 7 mm in diameter) with necropsy after day 21 showing no evidence of surgical site bleeding. FM was equivalent to BP in tissue retention and superior to BP in spread/tissue desiccation, sticking, and charring (P ≤ .01). The FM was superior to US and BP in speed of 10 cm mesentery division (mean ± SD seconds): FM (12.9 ± 1.0 seconds), US (23.3 ± 4.4 seconds), BP (46.1 ± 5.2 seconds) (P ≤ .01 FM vs US or BP). Seal burst strength and success of sealing a 5-mm carotid artery were as follows (mean ± SD mmHg, % success burst strength >240 mm Hg): FM (710 ± 206 mm Hg, 94% success), US (848 ± 565 mm Hg, 79%), and BP (619 ± 373 mm Hg, 83%). CONCLUSION: Ferromagnetic heating is an effective and efficient technology for sealing and dividing of vessels. An initial prototype of the FMsealer compared favorably with commercially available products based on ultrasonic and bipolar technologies.

Biodegradable mulch performed comparably to polyethylene in high tunnel tomato (Solanum lycopersicum L.) production.

BACKGROUND: High tunnels in the cool climate of north western Washington state improve the growing environment for crops otherwise suited to warmer climates. Biodegradable mulch may improve the sustainability of high tunnel vegetable production if it performs comparably to polyethylene. Four biodegradable mulch treatments (BioAgri, BioTelo, WeedGuardPlus and SB-PLA-10/11/12) were compared to black polyethylene and bare ground in high tunnels and open field settings to assess the impact of production system and mulch treatment on weed control, tomato yield, and fruit quality. RESULTS: Fewer weeds grew in high tunnels than in the open field. High tunnels increased total and marketable fruit yields and increased individual fruit weight. High tunnel production increased juice content and pH of tomato fruit, but decreased total soluble solids, titratable acidity, and total phenolics compared to the open field. All mulch treatments except SB-PLA-10 controlled weeds. BioAgri, BioTelo and polyethylene increased total yields by 20%, though marketability was reduced 14% compared to bare ground and WeedGuardPlus treatments. CONCLUSION: High tunnels can improve tomato yield and affect fruit quality in north western Washington. Biodegradable plastic mulches performed comparably to polyethylene in weed control, tomato yield, and fruit quality and may, therefore, improve the sustainability of high tunnel vegetable production.

Intracranial electrical impedance tomography: a method of continuous monitoring in an animal model of head trauma.

BACKGROUND: Electrical impedance tomography (EIT) is a method that can render continuous graphical cross-sectional images of the brain's electrical properties. Because these properties can be altered by variations in water content, shifts in sodium concentration, bleeding, and mass deformation, EIT has promise as a sensitive instrument for head injury monitoring to improve early recognition of deterioration and to observe the benefits of therapeutic intervention. This study presents a swine model of head injury used to determine the detection capabilities of an inexpensive bedside EIT monitoring system with a novel intracranial pressure (ICP)/EIT electrode combination sensor on induced intraparenchymal mass effect, intraparenchymal hemorrhage, and cessation of brain blood flow. Conductivity difference images are shown in conjunction with ICP data, confirming the effects. METHODS: Eight domestic piglets (3-4 weeks of age, mean 10 kg), under general anesthesia, were subjected to 4 injuries: induced intraparenchymal mass effect using an inflated, and later, deflated 0.15-mL Fogarty catheter; hemorrhage by intraparenchymal injection of 1-mL arterial blood; and ischemia/infarction by euthanasia. EIT and ICP data were recorded 10 minutes before inducing the injury until 10 minutes after injury. Continuous EIT and ICP monitoring were facilitated by a ring of circumferentially disposed cranial Ag/AgCl electrodes and 1 intraparenchymal ICP/EIT sensor electrode combination. Data were recorded at 100 Hz. Two-dimensional tomographic conductivity difference (Δσ) images, rendered using data before and after an injury, were displayed in real time on an axial circular mesh. Regions of interest (ROI) within the images were automatically selected as the upper or lower 5% of conductivity data depending on the nature of the injury. Mean Δσ within the ROIs and background were statistically analyzed. ROI Δσ was compared with the background Δσ after an injury event using an unpaired, unequal variance t test. Conductivity change within an ROI after injury was likewise compared with the same ROI before the injury making use of unpaired t tests with unequal variance. RESULTS: Eight animal subjects were studied, each undergoing 4 injury events including euthanasia. Changes in conductivity due to injury showed expected pathophysiologic effects in an ROI identified within the middle of the left hemisphere; this localization is reasonable given the actual site of injury (left hemisphere) and spatial warping associated with estimating a 3-dimensional conductivity distribution in 2-dimensional space. Results are shown as mean ± 1 SD. When averaged across all 8 animals, balloon inflation caused the mean Δσ within the ROI to shift by -11.4 ± 10.9 mS/m; balloon deflation by +9.4 ± 8.8 mS/m; blood injection by +19.5 ± 11.5 mS/m; death by -12.6 ± 13.2 mS/m. All induced injuries were detectable to statistical significance (P < 0.0001). CONCLUSION: This study confirms that the bedside EIT system with ICP/EIT combination sensor can detect induced trauma. Such a technique may hold promise for further research in the monitoring and management of traumatically brain-injured individuals.

Intravenous buprenorphine and norbuprenorphine pharmacokinetics in humans.

BACKGROUND: Prescribed sublingual (SL) buprenorphine is sometimes diverted for intravenous (IV) abuse, but no human pharmacokinetic data are available following high-dose IV buprenorphine. METHODS: Plasma was collected for 72 h after administration of placebo or 2, 4, 8, 12, or 16 mg IV buprenorphine in escalating order (single-blind, double-dummy) in 5 healthy male non-dependent opioid users. Buprenorphine and its primary active metabolite, norbuprenorphine, were quantified by liquid chromatography-tandem mass spectrometry with limits of quantitation of 0.1 µg/L. RESULTS: Maximum buprenorphine concentrations (mean ± SE) were detected 10 min after 2, 4, 8, 12, 16 mg IV: 19.3 ± 1.0, 44.5 ± 4.8, 85.2 ± 7.7, 124.6 ± 16.6, and 137.7 ± 18.8 µg/L, respectively. Maximum norbuprenorphine concentrations occurred 10-15 min (3.7 ± 0.7 µg/L) after 16 mg IV administration. CONCLUSIONS: Buprenorphine concentrations increased in a significantly linear dose-dependent manner up to 12 mg IV buprenorphine. Thus, previously demonstrated pharmacodynamic ceiling effects (over 2-16 mg) are not due to pharmacokinetic adaptations within this range, although they may play a role at doses higher than 12 mg.

Utility of metabolomics toward assessing the metabolic basis of quality traits in apple fruit with an emphasis on antioxidants.

A gas chromatography-mass spectrometry approach was employed to evaluate the use of metabolite patterns to differentiate fruit from six commercially grown apple cultivars harvested in 2008. Principal component analysis (PCA) of apple fruit peel and flesh data indicated that individual cultivar replicates clustered together and were separated from all other cultivar samples. An independent metabolomics investigation with fruit harvested in 2003 confirmed the separate clustering of fruit from different cultivars. Further evidence for cultivar separation was obtained using a hierarchical clustering analysis. An evaluation of PCA component loadings revealed specific metabolite classes that contributed the most to each principal component, whereas a correlation analysis demonstrated that specific metabolites correlate directly with quality traits such as antioxidant activity, total phenolics, and total anthocyanins, which are important parameters in the selection of breeding germplasm. These data sets lay the foundation for elucidating the metabolic basis of commercially important fruit quality traits.

Storage effects on anthocyanins, phenolics and antioxidant activity of thermally processed conventional and organic blueberries.

BACKGROUND: Consumer demand for products rich in phytochemicals is increasing as a result of greater awareness of their potential health benefits. However, processed products are stored for long-term and the phytochemicals are susceptible to degradation during storage. The objective of this study was to assess the storage effects on phytochemicals in thermally processed blueberries. Thermally processed canned berries and juice/puree were analysed for phytochemicals during their long-term storage. RESULTS: The phytochemical retention of thermally processed blueberries during storage was not influenced by production system (conventional versus organic). During 13 months of storage, total anthocyanins, total phenolics and total antioxidant activity in canned blueberry solids decreased by up to 86, 69 and 52% respectively. In canned blueberry syrup, total anthocyanins and total antioxidant activity decreased by up to 68 and 15% respectively, while total phenolic content increased by up to 117%. Similar trends in phytochemical content were observed in juice/puree stored for 4 months. The extent of changes in phytochemicals of thermally processed blueberries during storage was significantly influenced by blanching. CONCLUSION: Long-term storage of thermally processed blueberries had varying degrees of influence on degradation of total anthocyanins, total phenolics and total antioxidant activity. Blanching before thermal processing helped to preserve the phytochemicals during storage of blueberries.