Method For Simultaneous Monitoring Research Articles

A factorial-design/assisted HPLC method for simultaneous monitoring of phenytoin, trimethoprim, and sulphamethoxazole in plasma samples to optimize therapy and mitigate toxicity risks

Phenytoin, an anticonvulsant drug, has a narrow therapeutic index and exhibits significant affinity to plasma proteins, mainly albumin. It is mainly metabolized by cytochrome P450 enzymes 2C9, 2C8, and 2C19. The potential for increased phenytoin toxicity may arise when a drug with enzyme-blocking properties are concurrently administered. The co-administration of trimethoprim is reported to decrease phenytoin clearance by 30 %, therefore, monitoring its plasma concentrations is recommended to minimize the risk of its toxicity and optimize its therapeutic efficacy. This study involves development of a novel and simple HPLC method for concurrent measurement of trimethoprim, sulphamethoxazole and phenytoin in plasma samples. The proposed method was optimized using full factorial design to optimize the variable factors affecting chromatographic responses. The separation was performed via isocratic elution on HyperClone C8 column, using a mobile phase consisting of 30: 38.5: 31.5 (v/v/v) of acetonitrile: 3.3 mM heptane-1-sulphonic acid sodium salt: 0.05 M phosphate buffer containing 0.1 % triethylamine at pH 3.7. The mobile phase was delivered at a flow rate of 1 mL/min with UV detection at 210 nm. The method was validated to verify agreement to the criteria set by the International Council for Harmonization (ICH) and Bioanalytical Methods validation. The results showed excellent linearity over the concentration ranges of 0.5–20.0, 1.0–25.0 and 1.0–20.0 µg/mL with detection limits of 0.41, 0.82 and 0.92 µg/mL for trimethoprim, sulphamethoxazole and phenytoin, respectively.The proposed method was extended for the assessment and of the studied drugs in spiked human plasma samples with % recoveries ranging from 92.60 to 105.30 %, indicating bioanalytical applicability. The proposed method can be utilized to study drug-drug interactions for in-patients therapeutic drug monitoring.

Demethylation-activated light-up dual-color RNA aptamersensor for label-free detection of multiple demethylases in lung tissues

Methylation is one of the most prevalent epigenetic modifications in natural organisms, and the processes of methylation and demethylation are closely associated with cell growth, differentiation, gene transcription and expression. Abnormal methylation may lead to various human diseases including cancers. Simultaneous analysis of multiple DNA demethylases remains a huge challenge due to the requirement of diverse substrate probes and scarcity of proper signal transduction strategies. Herein, we propose a sensitive and label-free method for simultaneous monitoring of multiple DNA demethylases on the basis of demethylation-activated light-up dual-color RNA aptamers. The presence of targets AlkB homologue-3 (ALKBH3) and fat mass and obesity-associated enzyme (FTO) erases the methyl group in DNA substrate probes, activating the ligation-mediate bidirectional transcription amplification reaction to produce enormous Spinach and Mango aptamers. The resulting RNA aptamers (i.e., Spinach and Mango aptamers) can bind with their cognate nonfluorescent fluorogens (DFHBI and TO1-biotin) to significantly improve the fluorescence signals. This aptamersensor shows high specificity and sensitivity with a limit of detection (LOD) of 8.50 × 10−14 M for ALKBH3 and 6.80 × 10−14 M for FTO, and it can apply to screen DNA demethylase inhibitors, evaluate DNA demethylase kinetic parameters, and simultaneously measure multiple endogenous DNA demethylases in a single cell. Importantly, this aptamersensor can accurately discriminate the expressions of ALKBH3 and FTO between healthy tissues and non-small cell lung cancer (NSCLC) patient tissues, offering a powerful platform for clinical diagnosis and drug discovery.

Method for Simultaneous Monitoring of Uterine Contractions and Abdominal Pushing in a Childbirth

Method for Simultaneous Monitoring of Uterine Contractions and Abdominal Pushing in a Childbirth

Fabrication of monolith-based electrodes for simultaneous solid-phase microextraction of phenylurea and sulfonylurea herbicides assisted by electric field

Efficient co-extraction of phenylurea and sulfonylurea herbicides is challenging due to their distinct difference in chemical properties. In this connection, two novel monolith-based electrodes were prepared and employed as adsorbents of electric field assisted solid-phase microextraction (EFA-SPME) for simultaneously capturing phenylurea and sulfonylurea herbicides. Poly (vinylimidazole-co-ethylene dimethacrylate) monolith and poly (methylacrylic acid co-ethylene dimethacrylate/divinylbenzene) monolith were fabricated on the surface of stainless steel wires and utilized as anode and cathode of EFA-SPME, respectively. Various fabrication conditions and extraction parameters affecting the co-capture performance were studied systematically. Results revealed that the implement of electric field in adsorption duration, phenylurea and sulfonylurea herbicides were captured in cathode and anode, respectively. At the same time, the co-extraction performance was improved, adsorption and eluting durations were shortened. Combining with HPLC analysis technique, sensitive and reliable method for simultaneous monitoring of trace phenylurea and sulfonylurea herbicides in various environmental water and soil samples were developed. The limits of detection of phenylureas in water and soil samples were 0.0047–0.014 μg/L and 0.059–0.18 μg/kg, respectively. The corresponding values of sulfonylureas in water and soil sample were 0.011–0.015 μg/L and 0.099–0.19 μg/kg, respectively. In addition, the detailed extraction mechanism under electric field was studied. Finally, the practicality of established method was evaluated by successfully quantifying studied analytes at trace contents in environment water and soil samples, and confirmatory experiments were utilized to confirm the method accuracy.

Video based non-contact monitoring of respiratory rate and chest indrawing in children with pneumonia

Objective. Pneumonia is the single largest cause of death in children worldwide due to infectious diseases. According to WHO guidelines, fast breathing and chest indrawing are the key indicators of pneumonia in children requiring antibiotic treatments. The aim of this study was to develop a video based novel method for simultaneous monitoring of respiratory rate and chest indrawing without upsetting babies. Approach. Respiratory signals, corresponding to periodic movements of chest-abdominal walls during breathing, were extracted by analyzing RGB (red, green, blue) components in video frames captured by a smartphone camera. Respiratory rate was then obtained by applying fast Fourier transform on the de-noised respiratory signal. Chest indrawing was detected by analysing relative phases of regional chest-abdominal wall mobility. The performance of the developed algorithm was evaluated on both healthy and pneumonia children. Main results. The proposed method can measure respiratory rate with an overall mean absolute error of 1.8 bpm in the range 18–105 bpm. Phase difference between regional chest wall movements in the chest indrawing (pneumonia) cases was found to be 143 ± 23.9 degrees, which was significantly higher than that in the healthy cases 52.3 ± 32.6 degrees (p < 0.001). Significance. Being non-intrusive and non-subjective, this computer-aided method can be useful in the monitoring for respiratory rate and chest indrawing for the diagnosis of pneumonia and its severity in children.

Rapid simultaneous clinical monitoring of five oral anti-coagulant drugs in human urine using green microextraction technique coupled with LC–MS/MS

ObjectivesThere is no analytical method for simultaneous monitoring of warfarin and novel direct oral anticoagulants (NOACs) in human urine samples in a single run in the clinics. Although several studies have reported their measurements in human blood samples, but its sample collection is more invasive and time-consuming, thereby challenging to monitor frequently. MethodsIn this work, we developed a fast microextraction technique (ultrasound-assisted salt-induced liquid-liquid microextraction, USA-SI-LLME) coupled with high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS) to rapidly quantify four commonly used NOACs drugs (apixaban, dabigatran, edoxaban, and rivaroxaban) and warfarin in human urine samples. USA-SI-LLME conditions were optimized using a water-miscible organic solvent as an extraction solvent, high salt concentrations, sample pH, and extraction time (∼5.5 min). Results and conclusionsThe analytical method showed excellent linearities from 0.5 to 500 μg/L for apixaban, edoxaban, rivaroxaban, warfarin, and 1 ∼ 500 μg/L for dabigatran. Intra- and inter-day precision values were <9.31% and R2 > 0.99 for all analytes. Limits of detection ranged between 0.07 ∼ 0.18 μg/L, and relative recoveries ranged between 92.18 and 110.15%. This method was successfully applied to analyze 15 one-spot urine samples from 15 clinical patients who regularly took warfarin or NOACs, and high accuracy was found. We concluded that this method could be used as a non-invasive high-throughput and rapid monitoring of NOACs and warfarin in human urine in clinical settings and could provide timely analysis during emergency care.

Comprehensive Monitoring of Bad Head and Shoulder Postures by Wearable Magnetic Sensors and Deep Learning

In this work, a simultaneous monitoring method for bad posture, including the forward head posture (FHP), rounded shoulder (RS), and elevated shoulder (ES), is proposed. These postures and the resulting symptoms are becoming increasingly prevalent, and a comprehensive, simultaneous, and extensive analysis of such posture disorders is needed. The proposed method involves collecting posture data from a new combination of accelerometers and magnetometers paired with miniature magnets. The sensor locations are optimally chosen to reliably calculate neck and shoulder angles representing the craniovertebral angle (CVA) for FHP, forward shoulder angle (FSA) for RS, and symmetry angle (SA) for ES. Processing of the collected sensor data is achieved by deep neural network (DNN) and convolutional neural network (CNN) algorithms. Experimental results demonstrate successful bad posture classification with high accuracy (DNN: 88.1%, CNN: 88.7%) even with the simultaneous analysis of FHP, RS, and ES.

Two-dimensional liquid chromatography - high resolution mass spectrometry method for simultaneous monitoring of 70 regulated and emerging mycotoxins in Pu-erh tea

• Need for specific methods for the analysis of mycotoxins in complex matrix. • Online heart-cutting 2D-LC-ToF-HRMS method was developed for determination of 70 mycotoxins in Pu-erh tea. • Validation of the method was performed in accordance with the legislation and performance criteria set in EU guidelines. • The approach was successfully applied to 20 samples of Pu-erh tea available in Latvian market.

Simultaneous monitoring for regression coefficients and baseline hazard profile in Cox modeling of time-to-event data.

The Cox model is the most popular tool for analyzing time-to-event data. The nonparametric baseline hazard function can be as important as the regression coefficients in practice, especially when prediction is needed. In the context of stochastic process control, we propose a simultaneous monitoring method that combines a multivariate control chart for the regression coefficients and a profile control chart for the cumulative baseline hazard function that allows for data blocks of possibly different censoring rates and sample sizes. The method can detect changes in either the parametric or the nonparametric part of the Cox model. In simulation studies, the proposed method maintains its size and has substantial power in detecting changes in either part of the Cox model. An application in lymphoma survival analysis in which patients were enrolled by 2-month intervals in the Surveillance, Epidemiology, and End Results program identifies data blocks with structural model changes.

Application of UPLC-MS/MS for Simultaneous Determination of Malachite Green and Metabolites Residues in Tilapia

In this work, a convenient, sensitive method for simultaneous monitoring of malachite green, leucomalachite green in tilapia samples was developed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The tilapia samples were extracted by acetonitrile, separated withacetonitrile-5mmol/L ammonium acetate as mobile phase, and then detected under ESI+ mode. The method showed a good linearity for all the analysts over the range of 0.1-100 μg kg-1 with r2≥0.998. And the detection limits both were 0.10 μg kg-1 for Malachite green and leucomalachite green. Tests for recovery were made by addition of standards at four different concentration levels (0.5, 2.0, 10.0, 20.0 μg kg-1) to the blank sample. The recoveries of the four spiked concentrations were ranged from 81.5% to 104%, with the relative standard deviations lower than 5%. The sensitivity, accuracy and precision of this method were able to meet the requirements for malachite green and leucomalachite green residue analysis.

Lanthanide-Loaded Nanoparticles as Potential Fluorescent and Mass Probes for High-Content Protein Analysis.

Multiparametric and high-content protein analysis of single cells or tissues cannot be accomplished with the currently available flow cytometry or imaging techniques utilizing fluorophore-labelled antibodies, because the number of spectrally resolvable fluorochromes is limited. In contrast, mass cytometry can resolve more signals by exploiting lanthanide-tagged antibodies; however, only about 100 metal reporters can be attached to an antibody molecule. This makes the sensitivity of lanthanide-tagged antibodies substantially lower than fluorescent reporters. A new probe that can carry more lanthanide molecules per antibody is a desirable way to enhance the sensitivity needed for the detection of protein with low cellular abundance. Herein, we report on the development of new probes utilizing mesoporous silica nanoparticles (MSNPs) with hydroxyl, amine, or phosphonate functional groups. The phosphonated MSNPs proved to be best at loading lanthanides for up to 1.4 × 106 molecules per particle, and could be loaded with various lanthanide elements (Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu) at relatively similar molar extents. The modified MSNPs can also load a fluorescent dye, allowing bimodal mass and fluorescence-based detection. We achieved specificity of antibody-conjugated nanoparticles (at 1.4 × 103 antibodies per nanoparticle) for targeting proteins on the cell surface. The new materials can potentially be used as mass cytometry probes and provide a method for simultaneous monitoring of a large host of factors comprising the tumor microenvironment (e.g., extracellular matrix, cancer cells, and immune cells). These novel probes may also benefit personalized medicine by allowing for high-throughput analysis of multiple proteins in the same specimen.

Using the Formozov–Malyshev–Pereleshin formula to convert mammal spoor counts into density estimates for long‐term community‐level monitoring

AbstractFinding an appropriate method to monitor a wide range of mammal species simultaneously is notoriously difficult, as each method has its limitations. Here, we examine a formula, known as the Formozov–Malyshev–Pereleshin (FMP), which uses mean daily travel distances (day ranges) to convert spoor counts into density estimates. Availability of accurate estimates of day ranges is a limitation of the FMP formula. Here, we used allometry to estimate day ranges for those species that lacked empirical movement data and general additive models (GAM) to assess trends in density estimates. With this approach, we derived density estimates for 10 mammal species, regardless of whether they were abundant, or rare and elusive (e.g. carnivores). General additive models suggest that six species are stable or increasing, and four declining, although all nonsignificantly. Use of allometric estimates in lieu of empirical estimates led to falsely increased precision in density estimates, highlighting the need to fill the knowledge gap in movement ecology for certain species. Simulations were used to examine error introduced into trend estimates by this bias. We conclude that the FMP formula, when properly employed, can be an efficient method for simultaneous monitoring of multispecies in different functional groups.

Impact of Brain Fatty Acid Signaling on Peripheral Insulin Action in Mice.

Glucose homeostasis and energy balance are under control by peripheral and brain processes. Especially insulin signaling in the brain seems to impact whole body glucose homeostasis and interacts with fatty acid signaling. In humans circulating saturated fatty acids are negatively associated with brain insulin action while animal studies suggest both positive and negative interactions of fatty acids and insulin brain action. This apparent discrepancy might reflect a difference between acute and chronic fatty acid signaling. To address this question we investigated the acute effect of an intracerebroventricular palmitic acid administration on peripheral glucose homeostasis. We developed and implemented a method for simultaneous monitoring of brain activity and peripheral insulin action in freely moving mice by combining radiotelemetry electrocorticography (ECoG) and euglycemic-hyperinsulinemic clamps. This method allowed gaining insight in the early kinetics of brain fatty acid signaling and its contemporaneous effect on liver function in vivo, which, to our knowledge, has not been assessed so far in mice. Insulin-induced brain activity in the theta and beta band was decreased by acute intracerebroventricular application of palmitic acid. Peripherally it amplified insulin action as demonstrated by a significant inhibition of endogenous glucose production and increased glucose infusion rate. Moreover, our results further revealed that the brain effect of peripheral insulin is modulated by palmitic acid load in the brain. These findings suggest that insulin action is amplified in the periphery and attenuated in the brain by acute palmitic acid application. Thus, our results indicate that acute palmitic acid signaling in the brain may be different from chronic effects.

Emission Characteristic Analysis on Highway Rainwater Runoff Pollution of Asphalt Pavement

In order to investigate the emission characteristics of rainwater runoff pollution from highway with asphalt pavement, simultaneous monitoring method of rainfall-runoff-pollutants was adopted. During 2006 to 2009, rainfall runoff samples from six asphalt pavement highways in 3 typical areas were collected and monitored, including Pearl River Delta Region in South China, Chongqing Province in South-west and Qingdao in East China. Results showed that average concentrations of SS, COD, TN and TP in runoff samples exceeded the Class V standard of surface water defined in Environmental Quality Standard for Surface Water (GB3838-2002). SS was the main pollutant of the highway asphalt pavement runoff, and was an important carrier of other major pollutants (such as heavy metals and chemical oxygen demand, COD) as well. The dust particle size of expressway road surface was generally small (more than 90 % less than 2mm). There was a big difference in concentrations of the same pollutant in particles with various sizes. Pollutant concentrations were increased with the reduction of particle size. Pavement runoff was less biodegradable and the ratio of BOD5/COD was 0.0188. Therefore, the ecological ditch combining percolation and drainage was proposed to purify the highway asphalt pavement runoff.

Fabric phase sorptive extraction-high performance liquid chromatography-photo diode array detection method for simultaneous monitoring of three inflammatory bowel disease treatment drugs in whole blood, plasma and urine

This paper reports a novel fabric phase sorptive extraction-high performance liquid chromatography-photodiode array detection (FPSE-HPLC-PDA) method for the simultaneous extraction and analysis of three drug residues (ciprofloxacin, sulfasalazine, and cortisone) in human whole blood, plasma, and urine samples, generally administered in human patients to treat inflammatory bowel disease (IBD).The drugs of interest were well resolved using a Luna C18 column (250 mm × 4.6 mm; 5 μm particle size) in gradient elution mode within 20 min. The analytical method was optimized and validated in the range 0.05–10 μg/mL for whole blood, 0.25–10 μg/mL for human plasma, and 0.10–10 μg/mL for human urine. Blank human whole blood, plasma, and urine were used as the sample matrix for the method development and validation; while methyl-p-hydroxybenzoate was used as the internal standard (IS). Weighted-matrix matched standard calibration curves showed a good linearity up to a concentration of 10 μg/mL. The intra- and inter-day accuracy values (precision and trueness) were found in the range from −10.9% to 12.3%, and the performances of the validated FPSE-HPLC-PDA were further tested on real IBD patient samples.This is the first FPSE procedure applied simultaneously to whole blood, plasma, and urine samples for the determination of residual IBD drugs, which possess a wide range of polarity (logP values ranging from 2.30 for Ciprofloxacin, to 1.66 for Cortisone, and 2.92 for Sulfasalazine). The new approach exhibits high potential for immediate adoptation as a rapid, robust and green analytical tool for future clinical and pharmaceutical applications.

Using Seawater to Document Coral-Zoothanthella Diversity: A New Approach to Coral Reef Monitoring Using Environmental DNA

Frequent, high-density coral monitoring is essential to understand coral reef ecosystems. For this purpose, we developed a novel method for simultaneous monitoring of Acropora corals and their symbiont, Symbiodinium, from environmental DNA (eDNA) in seawater using next generation sequencing technology (NGS). We performed a tank experiment with running seawater using 19 Acropora species. Complete mitochondrial genomes of all the Acropora species were assembled to create a database and major types of their Symbiodinium symbionts were identified. Then eDNA was isolated by filtering inlet and outlet seawater from the tanks. Acropora and Symbiodinium DNA were amplified by PCR and sequenced. We detected all of the tested Acropora types from eDNA samples. Proportions of the DNA sequences and the weights of corals, and the number of DNA sequences and the masses of corals were positively correlated in the tanks, respectively. In this trial, we detected DNA sequences from as little as 0.04 kg of Acropora colony, suggesting that existence of at least one adult Acropora colony (approx. 30 cm diameter = 1kg) per m2 at depths <10m could be detected using eDNA in the field. In addition, we detected major types of Symbiodinium within host corals from seawater, suggesting that it should be possible to detect major coral symbiont types if Acropora corals exist nearby, and possible free-living state Symbiodinium cells from eDNA in sea water. eDNA abundance of Symbiodinium types did not correlate well with frequencies of major Symbiodinium types in the corals, suggesting that quantification of Symbiodinium is difficult at this stage. Although this is the initial attempt to detect coral and Symbiodinium simultaneously from eDNA in seawater, this method may allow us to perform high-frequency, high-density coral reef monitoring of both corals and their symbionts in the near future.

A simple method for simultaneous monitoring of respiratory and cardiac function in mice

A simple method for simultaneous monitoring of respiratory and cardiac function in mice

Simultaneous monitoring of intra- and extracellular nitric oxide in living cells by means of dual-color fluorescence imaging

A dual-color fluorescence imaging method for simultaneous monitoring of intra- and extracellular nitric oxide (NO) was developed. Assisted by confocal laser scanning microscope, the intra- and extracellular NO can be successfully visualized by using two selected probes, 4,4-difluoro-8-(3,4-diaminophenyl)-3,5-bis(4-methoxyphenyl)-4-bora-3a,4a-diaza-s-indacene (p-MOPB) and disodium 2,6-disulfonate-1,3-dimethyl-5-hexadecyl-8-(3,4-diaminophenyl)-4,4’-difluoro-4-bora-3a,4a-diaza-s-indacene (DSDMHDAB), which display distinct membrane permeability and show different colors of fluorescence after reaction with NO. Results indicated that intra- and extracellular NO could be fluorometrically detected without mutual interference. The applicability of the proposed method was validated by dual-color imaging of NO on both sides of the plasma membrane in RAW 264.7 murine macrophages and human vascular endothelial (ECV-304) cells. This multi-labeling approach using multi-laser excitation and multi-color fluorescence detection holds great promise for simultaneous analysis of NO as well as other gasotransmitters in living cells with subcellular resolution.

Simultaneous analysis of neutral monosaccharides, fatty acids and cholesterol as biomarkers from a drop of blood.

We have developed a method for simultaneous monitoring of more biomarkers from three different classes of compounds by simultaneous analysis of neutral monosaccharides, fatty acids (FAs) and cholesterol as their per-O-methylated derivatives from a drop of blood by GC-MS. This work is a development of our previous results about analysis of neutral monosaccharides from a drop of blood. The simultaneous per-O-methylation was obtained by methylation in one step with methyl iodide and NaOH in DMSO. The per-O-methylated derivatives were separated in one chromatogram. The quantitative analysis was reproducible for five monosaccharides, 22 FAs and cholesterol. The results of this method were compared with those of the enzymatic methods using commercial kits. This method can avoid the saponification of the FA methyl esters and can analyze for the first time simultaneously neutral monosaccharides, FAs and cholesterol from a drop of blood.

Validation of a liquid chromatography ultraviolet method for determination of herbicide diuron and its metabolites in soil samples

Diuron is one of the most widely herbicide used worldwide, which can undergo degradation producing three primary metabolites: 3,4-dichlorophenylurea, 3-(3,4-dichlorophenyl)-1-methylurea, and 3,4-dichloroaniline. Since the persistence of diuron and its by-products in ecosystems involves risk of toxicity to environment and human health, a reliable quantitative method for simultaneous monitoring of these compounds is required. Hence, a simple method without preconcentration step was validated for quantitation of diuron and its main metabolites by high performance liquid chromatography with ultraviolet detection. Separation was achieved in less than 11 minutes using a C18 column, mobile phase composed of acetonitrile and water (45:55 v/v) at 0.86 mL min-1 and detection at 254 nm. The validated method using solid-liquid extraction followed by an isocratic chromatographic elution proved to be specific, precise and linear (R2 ˃ 0.99), presenting more than 90% of recovery. The method was successfully applied to quantify diuron and their by-products in soil samples collected in a sugarcane cultivation area, focusing on the environmental control.