Simultaneous determination of colistin sulfate and tigecycline in human plasma by liquid chromatography-tandem mass spectrometry method.

OBJECTIVE: To establish a high-performance liquid chromatography-tandem mass spectrometry method (HPLC-MS/MS) to simultaneously determine colistin sulfate and tigecycline in human plasma. METHODS: Polymyxin B1 internal standard (20 µL) was added into 200 µL of plasma sample. The samples were treated with methanol-5% trichloroacetic acid (50:50, V/V) solution, and the protein precipitation method was adopted for post-injection analysis. The chromatographic column was a Dikma C18 (4.6 mm × 150 mm, 5 µm). For the mobile phase, 0.1% formic acid in aqueous solution was used for phase A, 0.1% formic acid in acetonitrile solution for phase B, and gradient elution was also applied. The flow rate was 0.8 mL/min, the column temperature was 40 °C, and the injection volume was 10 µL; Electrospray ionization and multiple reaction ion monitoring were adopted and scanned by the HPLC-MS/MS positive ion mode. RESULTS: The endogenous impurities in the plasma had no interference in the determination of the analytes. There existed a good linear relationship of colistin sulfate within the range of 0.1-10 µg/mL (R2 = 0.9986), with the lower limit of quantification (LLOQ) of 0.1 µg/mL. There existed a good linear relationship of tigecycline within the range of 0.05-5 µg/ mL (R2 = 0.9987), with the LLOQ of 0.05 µg/mL. The intra- and inter-day relative standard deviations of colistin sulfate and tigecycline were both less than 15%, and the accuracy was between 88.21% and 108.24%. The extraction had good stability, the extraction recovery rate was 87.75-91.22%, and the matrix effect was 99.40-105.26%. CONCLUSION: This study successfully established a method for simultaneously detecting colistin sulfate and tigecycline plasma concentrations. The method was simple, rapid, and highly sensitive and could be applied for therapeutic medication monitoring.

The Plasma Concentration of Ticagrelor and Aspirin as a Predictor of Bleeding Complications in Chinese Acute Coronary Syndrome Patients With Dual Antiplatelet Therapy: A Prospective Observational Study.

PURPOSE: This study evaluated the association among the plasma concentration of ticagrelor, ARC124910XX, aspirin, and salicylic acid with the risk of recent bleeding in patients with the acute coronary syndrome. To this end, we developed an accurate model to predict bleeding. METHODS: A total of 84 patients included in this study cohort between May 2021 and November 2021. The risk factors were identified by univariate and multivariate analyses, and statistically significant risk factors identified in the multivariate analysis were included in the nomogram. We used the calibration curve and the receiver operating characteristic curve to verify the accuracy of the prediction model. RESULTS: Multivariable logistic analysis showed that ticagrelor concentration (odds ratio [OR]: 2.47, 95% confidence interval [CI], 1.51-4.75, P = 0.002), ST-segment elevation acute myocardial infarction (OR: 32.2, 95% CI, 2.37-780, P = 0.016), and lipid-lowering drugs (OR: 11.52, 95% CI, 1.91-110, P = 0.015) were positively correlated with bleeding. However, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker (OR: 0.04, 95% CI, 0.004-0.213, P < 0.001) was negatively correlated with bleeding. The receiver operating characteristic curve analysis showed that ticagrelor concentration and these factors together predict the occurrence of bleeding (area under receiver operating characteristic curve = 0.945, 95% CI, 0.896-0.994) and that ticagrelor concentration >694.90 ng/mL is the threshold of bleeding concentration (area under receiver operating characteristic curve = 0.696, 95% CI, 0.558-0.834). CONCLUSION: In patients with acute coronary syndrome treated with dual antiplatelet therapy, ticagrelor concentration >694.90 ng/mL was an independent risk factor for bleeding (OR: 2.47, 95% CI, 1.51-4.75, P = 0.002), but ARC124910XX and salicylic acid concentration did not affect bleeding risk ( P > 0.05).

Assessment of the effectiveness of parent-targeted interventions for the use of child restraint systems: a systematic review and meta-analysis.

Background: It is essential to implement parent-targeted interventions to increase the use of child restraint systems (CRS) and thus reduce the injuries and deaths of children due to motor vehicle collisions. To optimize future intervention designs, this meta-analysis sought to quantify the effects of parent-targeted interventions and explore potential intervention moderators. Methods: Studies met inclusion criteria if they included a parents-targeted intervention that focused on increasing CRS use for children, published from the inception of the databases to January 2022, were systematically retrieved from the PubMed, Embase, Cochrane library, Web of Science, Sinomed, Wanfang, and CNKI databases. Next, 2 researchers independently screened the retrieved articles, evaluated their quality according to the Cochrane Tool, and extracted the data. Finally, Stata12.0 was used for the meta-analysis. Heterogeneity was examined with I2, stratified analyses, and meta-regression. Results: Of the 1,690 articles retrieved, 9 studies, comprising 22,329 parents of children aged 0-12 years, were ultimately included in the analysis. The results of the meta-analysis showed that the CRS use rate of the intervention group was 1.62 times higher than that of the control group [95% confidence interval (CI): 1.25-2.11, Z=3.616, P<0.001], indicating the positive effect of parent-targeted interventions on promoting the use of CRS. The subgroup analysis found that interventions guided by behavioral theories increased the use of CRS (odds ratio: 1.44, 95% CI: 1.27-1.63, n=5). The difference in the use of CRS between the groups in the studies that were not guided by theories was not statistically significant, indicating that interventions guided by behavioral theories may be the source of the heterogeneity. Risk of bias was low in most studies. Conclusions: It is necessary to conduct interventions with parents to increase the use of CRS. The effects on CRS use appear to differ depending on whether the interventions are guided by behavioral theories. In-depth research needs to be conducted to explore the characteristics of the interventions, especially those guided by different behavioral theories, to reduce child vehicle injuries.

A Direct Injection Technique to Improve Biosafety to Analyze Levetiracetam Concentrations in Human Serum and Its Application in Therapeutic Drug Monitoring.

BACKGROUND: With the outbreak of COVID-19, it has become very important to improve biosafety measures taken by medical staff. Fewer pretreatment steps correspond to lower chances of infection. The authors established a direct injection technique to analyze levetiracetam (LEV) concentrations in human serum and studied its application in therapeutic drug monitoring. METHODS: Serum samples were prepared by hollow fiber centrifugal ultrafiltration and the filtrate was directly injected into a ultra-high performance liquid chromatography apparatus (Waters UPLC BEH C18 column: 50 × 2.1 mm, 1.7 µm) for analysis. The mobile phase consisted of acetonitrile and water (8:92) at a flow rate of 1.0 mL/min. The column temperature was maintained at 30°C. The detected wavelength was 210 nm. RESULTS: A linear relationship was obtained for LEV from 0.625 to 80 mcg/mL (r2 = 0.999). The limit of detection for the analysis of LEV was 0.125 mcg/mL. The analysis time was shortened to 4 minutes. The recovery rate of LEV based on the current method was 96.6%-100.1%, whereas the absolute recovery rate was 93.2%-96.8%. The relative SD of intraday and interday precision was <7.3%. Stability was achieved at room temperature for 24 hours after 3 freeze-thaw cycles and at -80°C for 21 days. The method was successfully applied to determine LEV concentrations in the serum of 19 patients. CONCLUSIONS: The present method is simple, accurate, and sensitive, and can improve biosafety with the direct injection technique. It is suitable for the analysis of LEV concentrations in therapeutic drug monitoring.

CFTR activation suppresses glioblastoma cell proliferation, migration and invasion.

The aim of this study was to investigate the function of Cystic fibrosis transmembrane conductance regulator (CFTR) in human glioblastoma (GBM) cells. Data dining results of the Human Protein Atlas showed that low CFTR expression was associated with poor prognosis for GBM patients. We found that CFTR protein expression was lower in U87 and U251 GBM cells than that in normal humane astrocyte cells. CFTR activation significantly reduced GBM cell proliferation. In addition, CFTR activation significantly abrogated migration and invasion of GBM cells. Besides, CFTR activator Forskolin treatment markedly reduced MMP-2 protein expression. These effects of CFTR activation were significantly inhibited by CFTR inhibitor CFTRinh-172 pretreatment. Our findings suggested that JAK2/STAT3 signaling was involved in the anti-glioblastoma effects of CFTR activation. Moreover, CFTR overexpression in combination with Forskolin induced a synergistic anti-proliferative response in U87 cells. Overall, our findings demonstrated that CFTR activation suppressed GBM cell proliferation, migration and invasion likely through the inhibition of JAK2/STAT3 signaling.

Effect of biodegradable polymer drug-eluting stents versus biocompatible polymer everolimus-eluting stents: a meta-analysis.

OBJECTIVE: Biocompatible polymer everolimus-eluting stents (EES) are associated with risk of stent thrombosis (ST); biodegradable polymer drug-eluting stents (BP-DES) were designed to reduce these risks. However, the long-term benefits are not completely clear. METHOD: We undertook a meta-analysis of randomized studies identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database. Primary outcome was the risk of ST. RESULTS: Twelve studies (11,692 patients) were included. Overall, compared with EES, BP-DES were associated with a broadly equivalent risk of definite and probable ST (OR, 0.91; 95% CI, 0.55 to 1.50; P = 0.71; I2 = 0.0%), early ST (OR, 2.25; 95% CI, 0.78 to 6.47; P = 0.13; I2 = 0.0%), late ST (OR, 3.57; 95% CI, 0.42 to 30.58; P = 0.25; I2 = 0.0%) and very late ST (OR, 0.50; 95% CI, 0.05 to 5.52; P = 0.57). Meanwhile, there was no significant difference in all-cause mortality (OR, 1.07; 95% CI, 0.86 to 1.32; P = 0.54; I2 = 0.0%), myocardial infarction (OR, 1.07; 95% CI, 0.88 to 1.30; P = 0.47; I2 = 0.0%), target vessel revascularization (OR, 1.02; 95% CI, 0.86 to 1.21; P = 0.80; I2 = 12.0%), and major adverse cardiac events (OR, 1.04; 95% CI, 0.93 to 1.16; P = 0.53; I2 = 0.0%). Furthermore, angiographic data showed that in-stent and in-segment late luminal loss were similar between the two groups. CONCLUSIONS: Compared with biocompatible polymer EES, biodegradable polymer stents appear to have equivalent clinical benefits.

[Effect of the Flow Patterns of Main-stream Reactors on the Efficiency of Nitrification Enhancement with Bioaugmentation].

A nitrifying sequencing batch reactor (SBR) and continuous stirred-tank reactor (CSTR) were operated at 15℃ under the same conditions to investigate the effect of two typical flow patterns (plug flow and complete mixing) on the efficiency of nitrification enhancement. The results show that, during bioaugmentation, the ammonia utilized rate(AUR)and nitrite utilized rate(NUR)in the SBR were 2.34 and 2.39 times of that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR slightly decreased to 2.01 and 1.78 times of that before bioaugmentation. Meanwhile, the AUR and NUR in the CSTR were 2.63 and 2.44 times that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR decreased to 1.48 and 1.31 times that before bioaugmentation. Fluorescence In-Situ Hybridization (FISH) results showed that during bioaugmentation, the ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) in the SBR were 2.67 and 2.71 times of that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR slightly decreased to 2.14 and 1.95 times that before bioaugmentation. Meanwhile, the AUR and NUR in the CSTR were 2.91 and 1.77 times of that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR decreased to 1.25 and 1.50 times of that before bioaugmentation. Therefore, the efficiency of nitrification enhancement was similar between the two types of flow patterns during bioaugmentation, but the seeded nitrifiers were much more vulnerable to wash out in the CSTR than that in the SBR due to r/K selectivity of the flow patterns.

Online restricted-access material combined with high-performance liquid chromatography and tandem mass spectrometry for the simultaneous determination of vanillin and its vanillic acid metabolite in human plasma.

An automated online solid-phase extraction with restricted-access material combined with high-performance liquid chromatography and tandem mass spectrometry was developed and validated for the simultaneous quantification of vanillin and its vanillic acid metabolite in human plasma. After protein precipitation by methanol, which contained the internal standards, the supernatant of plasma samples was injected to the system, the endogenous large molecules were flushed out, and target analytes were trapped and enriched on the adsorbent, resulting in a minimization of sample complexity and ion suppression effects. Calibration curves were linear over the concentrations of 5-1000 ng/mL for vanillin and 10-5000 ng/mL for vanillic acid with a coefficient of determination >0.999 for the determined compounds. The lower limits of quantification of vanillin and vanillic acid were 5.0 and 10.0 ng/mL, respectively. The intra- and inter-run precisions expressed as the relative standard deviation were 2.6-8.6 and 3.2-10.2%, respectively, and the accuracies expressed as the relative error were in the range of -6.1 to 7.3%. Extraction recoveries of analytes were between 89.5 and 97.4%. There was no notable matrix effect for any analyte concentration. The developed method was proved to be sensitive, repeatable, and accurate for the quantification of vanillin and its vanillic acid metabolite in human plasma.

The Influence of Plasma Albumin Concentration on the Analysis Methodology of Free Valproic Acid by Ultrafiltration and Its Application to Therapeutic Drug Monitoring.

BACKGROUND: Free drug analysis is increasingly becoming popular in therapeutic drug monitoring (TDM). Centrifugal ultrafiltration (CF-UF) is the primary method to separate free drug from that of bound drug. However, the volume ratio of ultrafiltrate to sample solution (Vu/Vs) affects the accuracy of CF-UF, which highly depends on the different plasma conditions. Plasma protein concentrations in patients are different from those observed in healthy subjects, and there are also significant differences among patients with different diseases. Only very few studies have reported on the effect of protein concentration on the analysis methodology of free drug by CF-UF. METHODS: In this study, valproic acid was used as the representative drug, and plasma samples with different albumin concentrations were analyzed by CF-UF and hollow fiber centrifugal ultrafiltration (HFCF-UF). RESULTS: There was no significant difference of free drug concentrations by HFCF-UF and CF-UF when plasma albumin concentrations ranged 40-60 g/L. However, at low albumin concentrations (<40 g/L), a considerable difference was detected, and the difference was increased with the decrease of plasma albumin concentration. When the albumin concentration was as low as 10 g/L, the free drug concentration was 17.3 mcg/mL by CF-UF, whereas it was 10.2 mcg/mL by HFCF-UF. CONCLUSIONS: The accuracy of free drug measurement by CF-UF was albumin concentration dependent. However, such an effect was not observed when samples were prepared by HFCF-UF, which was more suitable for TDM of plasma samples from different patients. Therefore, this method could be readily applied to the measurement of free valproic acid plasma concentrations for TDM in patients.

Practical method for the rapid screening of xanthine oxidase inhibitors in herbal extracts by high-performance liquid chromatography based on on-line precolumn enzymatic reaction.

A high-performance liquid chromatography method with on-line precolumn enzymatic reaction for the screening of xanthine oxidase inhibitors in natural extracts was developed. In this method, the enzymatic reaction occurred at the capillary inlet during a predetermined waiting period, after which the reaction product, uric acid, was separated and detected by liquid chromatography using ultraviolet absorption at 295 nm. Enzyme inhibition can be read out directly from the reduced peak area of uric acid in comparison to a reference chromatogram obtained in the absence of any inhibitor. In the present study, the availability of on-line precolumn enzymatic reaction with ultraviolet detection was firstly evaluated by determining the inhibitory mechanism and IC50 values of allopurinol, a commercially available positive drug. Then, the newly developed method was applied to screening of ten natural extracts from traditional Chinese medicine and as a result, the extract of Epimedium sagittatum (Sieb. et Zucc.) Maxim was found to be most positive for xanthine oxidase inhibition. The results obtained were compared with those obtained by offline enzyme assay and the effectiveness of the present method was confirmed. A rapid, low-cost, and fully automated method for xanthine oxidase inhibitor screening was proposed.

Molecular variability and evolution of a natural population of tomato yellow leaf curl virus in Shanghai, China.

Tomato yellow leaf curl virus (TYLCV), belonging to the genus Begomovirus of the family Geminiviridae, is emerging as the most destructive pathogen of tomato plants. Since the first report of TYLCV in Shanghai, China in 2006, TYLCV has spread rapidly to 13 provinces or autonomous regions of China. In this study, the molecular variability and evolution of TYLCV were monitored in Shanghai from its first upsurge in 2006 until 2010. Full-length genomic sequences of 26 isolates were obtained by rolling circle amplification. Sequence analysis showed that the intergenic region was the most variable, with a mean mutation rate of 4.81×10(-3) nucleotide substitutions per site per year. Genetic differentiation was found within isolates obtained from 2006, 2009, and 2010, though a linear increase in genetic diversity over time was not evident. Whilst significant parts of TYLCV genes were under negative selection, the C4 gene embedded entirely within the C1 gene had a tendency to undergo positive selection. Our results indicate that a mechanism of independent evolution of overlapping regions could apply to the natural population of TYLCV in Shanghai, China.

Enhanced vitellogenesis in a whitefly via feeding on a begomovirus-infected plant.

BACKGROUND: The MEAM1 (B biotype) Bemisia tabaci (Gennadius) is one of the most widespread and damaging whitefly cryptic species. Our previous studies discovered that the MEAM1 whitefly indirectly benefits from interactions with the tomato yellow leaf curl China virus (TYLCCNV) via accelerated ovarian development and increased fecundity. However, the physiological mechanism of begomoviruse-infected plants acting on the reproduction of the insect vector was unknown. METHODOLOGY/PRINCIPAL FINDINGS: Biochemical and molecular properties of vitellogenin (Vg) and vitellin (Vt) were characterized in the MEAM1 whitefly. In addition, kinetics of Vt levels in ovary and Vg levels in hemolymph in different stages were detected using a sandwich ELISA. The level of hemolymph Vg increased rapidly after eclosion. A significantly higher level of hemolymph Vg and ovary Vt were observed in whiteflies feeding on virus-infected tobacco plants than those feeding on uninfected plants. In order to detect the levels of Vg mRNA transcription, complete vitellogenin (Vg) mRNA transcripts of 6474 bp were sequenced. Vg mRNA level in whiteflies feeding on virus-infected plants was higher than those feeding on uninfected plants. However, virus-infection of the whiteflies per se, as demonstrated using an artificial diet system, did not produce significant changes in Vg mRNA level. CONCLUSIONS/SIGNIFICANCE: In MEAM1 whitefly, increased levels of both vitellin and vitellogenin as well as increased transcription of Vg mRNA are associated with feeding on begomovirus-infected plants, thus providing a mechanism for accelerated vitellogenesis. We conclude that MEAM1 whitefly profits from feeding on begomovirus-infected plants for yolk protein synthesis and uptake, and thereby increases its fecundity. These results not only provide insights into the molecular and physiological mechanisms underlying the elevated reproduction of a whitefly species through its association with a begomovirus-infected plant, but also provide a better understanding of the molecular mechanisms related to whitefly reproduction.

[Clinical application of spiral CT in locating impacted teeth of children,s anterior maxilla].

PURPOSE: To discuss the accuracy of localization and clinical usefulness of spiral CT for anterior maxillary impacted teeth. METHODS: In 89 children with impacted teeth in our department during June 2004 and December 2009, Spiral CT was performed in 30 cases whose impacted teeth can't be localized clearly by conventional occlusal film and panoramic radiogragh. Multip-lanarreformation(MPR) and the surface shaded display(SSD) of the spiral CT were used to observe the number,size, shape,location,its relationship with adjacent tissue,angle between crown and root of the impacted teeth. The region of operation was exposed to evaluate the accuracy of localization and the value of clinical application of the Spiral CT. RESULTS: It was found that the number,size, shape,location,angle between crown and root of all the 33 impacted teeth could be displayed accurately. CONCLUSIONS: Spiral CT enables us to make a quick and accurate diagnosis of teeth impaction in the maxilla and can provide the best path for operation,which is helpful for pretreatment evaluation of the impacted teeth in clinic.

[An analysis of psychological problems of patients in cardiology clinic].

OBJECTIVE: To explore the current condition of psychological problems of patients in cardiology clinic. METHODS: A total of 347 patients in the cardiology clinic of Prof. HU Da-yi were screened by self-rating depression scale (SDS), Self-rating anxiety scale (SAS), Hamilton rating scale for depression (HRSD) and Hamilton anxiety scale (HAMA). RESULTS: The rates of patients with somatic disease only or with psychological disorder only were 52.4% and 12.7%, the rate of somatic disease accompanied with psychological disorder was 27.7%. For the patients with psychological problems, there were 31 cases with depression (8.9%), 62 cases with anxiety (17.9%), and 28 cases (8.1%) suffering from mixed depression and anxiety the diagnosis of cardiovascular disease, functional disease or digestive disease was always used by doctors for the patients with psychological problems only, as they always did not accept the diagnosis of psychological disorder. CONCLUSIONS: It is very common that patients in cardiology clinic department suffered from psychological problems. The patients with psychological disorder only were easily misdiagnosed as somatic disease especially cardiovascular disease.