Comparative outcomes of catheter-directed thrombolysis plus rivaroxaban vs rivaroxaban alone in patients with acute iliofemoral deep vein thrombosis.

BACKGROUND: Since novel oral anticoagulants (NOACs) have been introduced in the past decade, the first option of deep vein thrombosis (DVT) treatment is toward NOACs. However, aggressive and early thrombus removal strategy is widely used for treating acute iliofemoral DVT. Consequently, optimal treatment duration, efficacy, and safety of rivaroxaban alone or in combination with catheter-directed intrathrombus thrombolysis (CDT) in acute iliofemoral DVT patients should be investigated. METHODS: Patients with recent acute iliofemoral DVT treated with combined CDT-rivaroxaban (CDT) or rivaroxaban alone (control) were followed for mean (standard deviation) of 25.7 (2.5) months. DVT evolution, treatment efficacy and safety, and predisposing factors for patency and postthrombotic syndrome (PTS) development were analyzed through duplex ultrasonography, plethysmography, venography, and computed tomographic venography. RESULTS: 43.2%, 64.9%, 75.7%, and 72.2% of the CDT patients showed complete patency at 3, 6, 12, and 24 months of treatment compared with the control patients having 8.5%, 36.2%, 55.3%, and 57.4% of cumulative patency at 3, 6, 12, and 24 months, respectively (p = 0.001, 0.017, 0.088, and 0.081, respectively). The p value of the log-rank test comparing patency rates of the two groups was 0.009. The median (interquartile range, IQR) Villalta scores at 24 months were 3 (2-5) and 6 (4-8) in CDT and control patients, respectively (p = 0·001). PTS and bleeding events during therapy were, respectively, found in 35.1% and 63.8% (p = 0.017) and in 27% and 17% of CDT and control patients (p = 0.4). The Kaplan-Meier curve analysis of cumulative patency at 24 months for 6 months of rivaroxaban treatment was significant (p = 0.016). CONCLUSION: Treatment therapy and treatment duration with rivaroxaban alone or in combination with CDT are potentially associated with vein patency at 24 months, and a 6-month lysis rate and obstructive vein can influence PTS development. A larger randomized trial is warranted to confirm these findings.

Tandem derivatization combined with salting-out assisted liquid-liquid microextraction for determination of biothiols in urine by gas chromatography-mass spectrometry.

Detection of polar organic compounds (POCs) using gas chromatography (GC) is not straightforward due to high polarity, hydrophilicity, and low volatility of POCs. In this study, we report a tandem microwave-assisted derivatization method combined with salting-out assisted liquid-liquid microextraction (SALLME) to modify successively the polar groups of POCs in protic and aprotic solvents. Biothiols (cysteine and homocysteine) served as a proof of concept for this method because they possess three polar groups (thiol, amine, and carboxyl); the derivatizing reagent was 3,4,5-trifluorobenzyl bromide (Br-TFB) for alkylation. The solubility of the POCs in the protic or aprotic reaction medium affected the number of TFB molecules attached. Using the tandem derivatization with Br-TFB, the thiol and amine groups of biothiols were alkylated in the protic system, and the carboxylic groups of biothiols were alkylated in the aprotic system. The developed method was then successfully applied to measure biothiols in human urine. Because of the complex urine matrix and the lack of urine samples without endogenous biothiols, the standard addition method was utilized to avoid the matrix effect, check the recovery, and calculate the initial biothiol content in the urine. Regarding the linearity of the standard addition curves, the coefficient of determination was >0.996, and the linear regression showed satisfactory reproducibility with a relative standard deviation <3.9% for the slope and <8.8% for the intercept. The levels of cysteine and homocysteine in healthy human urine ranged from 28.8 to 111µmolL-1 and from 1.28 to 3.73µmolL-1, respectively. The proposed method effectively increased the sensitivity of GC-MS assays of water-soluble compounds in human urine.

Fluorescent derivatization combined with aqueous solvent-based dispersive liquid-liquid microextraction for determination of butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma.

A novel aqueous solvent-based dispersive liquid-liquid microextraction (AS-DLLME) method was combined with narrow-bore liquid chromatography and fluorescence detection for the determination of hydrophilic compounds. A remover (non-polar solvent) and extractant (aqueous solution) were introduced into the derivatization system (acetonitrile) to obtain a water-in-oil emulsion state that increased the mass transfer of analytes. As a proof of concept, three quaternary ammonium substances, including butyrobetaine, l-carnitine and acetyl-l-carnitine, were also used as analytes and determined in pharmaceuticals, personal care products, food and human plasma. The analytes were derivatized with 4-bromomethylbiphenyl for fluorescence detection and improved retention in the column. The linear response was 10-2000nM for l-carnitine and acetyl-l-carnitine with a good determination coefficient (r(2)>0.998) in the standard solution. The detection limit for l-carnitine and acetyl-l-carnitine was 4.5 fmol. The method was also successfully applied to a 1µL sample of human plasma. In the linearity calculations for determining butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma, the determination coefficients ranged from 0.996 to 0.999. Linear regression exhibited good reproducibility and a relative standard deviation better than 7.50% for the slope and 9.06% for the intercept. To characterize highly hydrophilic compounds in various samples, the proposed method provides good sensitivity for a small sample volume with a low consumption of toxic solvents.

Dual dispersive liquid-liquid microextraction for determination of phenylpropenes in oils by gas chromatography-mass spectrometry.

A novel, simple and quick sample preparation method was developed and used for pre-concentration and extraction of six phenylpropenes, including anethole, estragole, eugenol, methyl eugenol, safrole and myristicin, from oil samples by dual dispersive liquid-liquid microextraction. Gas chromatography-mass spectrometry was used for determination and separation of compounds. Several experimental parameters affecting extraction efficiency were evaluated and optimized, including forward-extractant type and volume, surfactant type and concentration, water volume, and back-extractant type and volume. For all analytes (10-1000ng/mL), the limits of detection (S/N≧3) ranged from 1.0 to 3.0ng/mL; the limits of quantification (S/N≧10) ranged from 2.5 to 10.0ng/mL; and enrichment factors ranged from 3.2 to 37.1 times. Within-run and between-run relative standard deviations (n=6) were less than 2.61% and less than 4.33%, respectively. Linearity was excellent with determination coefficients (r(2)) above 0.9977. The experiments showed that the proposed method is a simple, effective, and environmentally friendly method of analyzing phenylpropenes in oil samples.

Chemical derivatization combined with capillary LC or MALDI-TOF MS for trace determination of lipoic acid in cosmetics and integrated protein expression profiling in human keratinocytes.

Lipoic acid (LA) is an essential cofactor in mitochondrial enzymes and an ideal antioxidant in prokaryotic and eukaryotic cells. Capillary liquid chromatography coupled with ultraviolet detection (CapLC-UV) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) are two environmentally friendly methods for determining LA. In this study, a pre-column microwave-assisted derivatization with 4-bromomethyl-6,7-dimethoxycoumarin enhanced the UV absorbance of LA and was monitored at 345 nm by CapLC-UV. Gradient separation was performed using a reversed-phase C18 column with a mobile phase consisting of acetonitrile-0.1% formic acid solution. The ionization of LA was increased, and the LA derivative was detected by MALDI-TOF MS at m/z 683 with an α-cyano-4-hydroxycinnamic acid matrix. The linear response ranged from 0.1 to 40 µM with a correlation coefficient of 0.999. The CapLC-UV and MALDI-TOF MS had detection limits of 5 and 4 fmol, respectively. These methods effectively detected LA in dietary supplements and cosmetics. Cellular proteomes of a human keratinocyte cell line (HaCaT) irradiated with UV radiation were also compared with and without LA treatment. The cellular proteomes were identified by nanoultra performance LC with LTQ Orbitrap system after trypsin digestion. Protein identification was performed by simultaneous peptide sequencing and MASCOT search. The analysis revealed changes in several proteins, including CDC42, TPI1, HNRPA2B1, PRDX1, PTGES3 and MYL6.

Dispersive liquid-liquid microextraction combined with microwave-assisted derivatization for determining lipoic acid and its metabolites in human urine.

This study explored dispersive liquid-liquid microextraction for extraction and concentration of lipoic acid in human urine. To improve the detection of lipoic acid by both capillary liquid chromatography (CapLC) with UV detection and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), microwave-assisted derivatization with 4-bromomethyl-6,7-dimethoxycoumarin was performed to render lipoic acid chromophores for UV detection and also high ionization efficiency in MALDI. All parameters that affected lipoic acid extraction and derivatization from urine were investigated and optimized. In the analyses of human urine samples, the two methods had a linear range of 0.1-20 µM with a correlation coefficient of 0.999. The detection limits of CapLC-UV and MALDI-TOF MS were 0.03 and 0.02 µM (S/N ≧ 3), respectively. The major metabolites of lipoic acid, including 6,8-bismethylthio-octanoic acid, 4,6-bismethylthio-hexanoic acid, and 2,4-bismethylthio-butanoic acid were also extracted by dispersive liquid-liquid microextraction and detected by MALDI-TOF MS. The minor metabolites (undetectable by MALDI-TOF MS), bisnorlipoic acid and tetranorlipoic acid were also extracted by dispersive liquid-liquid microextraction and identified with an LTQ Orbitrap mass spectrometer. After dispersive liquid-liquid microextraction and microwave-assisted derivatization, all lipoic acid derivatizations and metabolites were structurally confirmed by LTQ Orbitrap.