Recent molecularly imprinted polymers applications in bioanalysis.

Molecular imprinted polymers (MIPs) as extraordinary compounds with unique features have presented a wide range of applications and benefits to researchers. In particular when used as a sorbent in sample preparation methods for the analysis of biological samples and complex matrices. Its application in the extraction of medicinal species has attracted much attention and a growing interest. This review focus on articles and research that deals with the application of MIPs in the analysis of components such as biomarkers, drugs, hormones, blockers and inhibitors, especially in biological matrices. The studies based on MIP applications in bioanalysis and the deployment of MIPs in high-throughput settings and optimization of extraction methods are presented. A review of more than 200 articles and research works clearly shows that the superiority of MIP techniques lies in high accuracy, reproducibility, sensitivity, speed and cost effectiveness which make them suitable for clinical usage. Furthermore, this review present MIP-based extraction techniques and MIP-biosensors which are categorized on their classes based on common properties of target components. Extraction methods, studied sample matrices, target analytes, analytical techniques and their results for each study are described. Investigations indicate satisfactory results using MIP-based bioanalysis. According to the increasing number of studies on method development over the last decade, the use of MIPs in bioanalysis is growing and will further expand the scope of MIP applications for less studied samples and analytes.

Molecularly imprinted polymers for selective extraction/microextraction of cancer biomarkers: A review.

Over recent years, great efforts have been extensively documented in top scientific journals on the development of methods for early diagnosis, treatment, and monitoring of cancers which are prevalent critical diseases with a high mortality rate among men and women. The determination of cancer biomarkers using different optimum methodologies is one of the finest options for achieving these goals with more precision, speed, and at a lower cost than traditional clinical procedures. In this regard, while focusing on specific biomarkers, molecularly imprinted technology has enabled novel diagnostic techniques for a variety of diseases. Due to the well-known advantages of molecularly imprinted polymers (MIPs), this review focuses on the current trends of MIPs-based extraction/microextraction methods, specifically targeting cancer biomarkers from various matrices. These optimized methods have demonstrated high selectivity, accuracy, sorbent reusability, extraction recovery, and low limits of detection and quantification for a variety of cancer biomarkers, which are a powerful tool to provide early diagnosis, prognosis, and treatment monitoring, with potential clinical application expected soon. This review highlights the key progress, specific modifications, and strategies used for MIP synthesis. The future perspectives for cancer biomarkers purification and determination by fabricating MIP-based techniques are also discussed.

Nanotechnology, Green Synthesis and Biological Activity Application of Zinc Oxide Nanoparticles Incorporated Argemone Mxicana Leaf Extract.

Nanomaterial is a rapidly growing area that is used to create a variety of new materials and nanotechnology applications from medical, pharmaceuticals, chemical, mechanical, electronics and several environmental industries including physical, chemical and biological nanoparticles are very important in our daily life. Nanoparticles with leaf extract from the healthy plant are important in the area of research using biosynthesis methods. Because of it's used as an environmentally ecofriendly, other than traditional physical and chemical strategies. In particular, biologically synthesized nanoparticles have become a key branch of nanotechnology. The present work presents a synthesis of zinc oxide nanoparticles using an extract from the Argemone leaf Mexicana. Biosynthetic nanoparticles are characterized by X-ray diffraction (XRD), Ultraviolet visible (UV-vis) spectroscopy analysis, a Fourier Transform Infrared Spectroscopy analysis (FTIR) and a scanning electron microcopy (SEM), X-ray analysis with dispersive energy (EDAX). XRD is used to examine the crystalline size of zinc oxide nanoparticles. The FTIR test consists in providing evidence of the presence of targeted teams. UV is used for optical properties and calculates the energy of the bandwidth slot. The scanning microscope emission reveals the morphology of the surface and the energy dispersive X-ray analysis confirms the basic composition of zinc oxide nanoparticles. It is found that zinc nanoparticles are capable of achieving high anti-fungal efficacy and therefore have a high potential antimicrobial activity of ZnO NPs, like antibacterial and high antioxidant. Zinc Oxide nanoparticles from the Argemone Mexicana leaf extract have several antimicrobial applications, such as medical specialty, cosmetics, food, biotechnology, nano medicine and drug delivery system. ZnO nanoparticles are important because they provide many practical applications in industry. The most important use of nanoparticles of ZnO would be strong antibacterial and antioxidant activity with a simple and efficient biosynthesis method may be used for future work applications.

Recent applications of microextraction sample preparation techniques in biological samples analysis.

Analysis of biological samples is affected by interfering substances with chemical properties similar to those of the target analytes, such as drugs. Biological samples such as whole blood, plasma, serum, urine and saliva must be properly processed for separation, purification, enrichment and chemical modification to meet the requirements of the analytical instruments. This causes the sample preparation stage to be of undeniable importance in the analysis of such samples through methods such as microextraction techniques. The scope of this review will cover a comprehensive summary of available literature data on microextraction techniques playing a key role for analytical purposes, methods of their implementation in common biological samples, and finally, the most recent examples of application of microextraction techniques in preconcentration of analytes from urine, blood and saliva samples. The objectives and merits of each microextration technique are carefully described in detail with respect to the nature of the biological samples. This review presents the most recent and innovative work published on microextraction application in common biological samples, mostly focused on original studies reported from 2017 to date. The main sections of this review comprise an introduction to the microextraction techniques supported by recent application studies involving quantitative and qualitative results and summaries of the most significant, recently published applications of microextracion methods in biological samples. This article considers recent applications of several microextraction techniques in the field of sample preparation for biological samples including urine, blood and saliva, with consideration for extraction techniques, sample preparation and instrumental detection systems.

Functionalized graphene oxide tablets for sample preparation of drugs in biological fluids: Extraction of ritonavir, a HIV protease inhibitor, from human saliva and plasma using LC-MS/MS.

In this work, graphene oxide-based tablets (GO-Tabs) were prepared by applying a thin layer of functionalized GO on a polyethylene substrate. The GO was functionalized with amine groups (-NH2 ) by poly(ethylene glycol)bis(3-aminopropyl) terminated (GO-NH2 -PEG-NH2 ). The functionalized GO-Tabs were used for the extraction of ritonavir (RTV) in human saliva samples. RTV in plasma and saliva samples was analyzed using LC-MS/MS. Gradient LC system with MS/MS in the positive-ion mode [electrospray ionization (ESI+)] was used. The transitions m/z 721 → 269.0 and m/z 614 → 421 were used for RTV and the internal standard indinavir, respectively. This study determined the human immunodeficiency virus protease inhibitor RTV in human saliva samples using functionalized GO-Tab and LC-MS/MS, and the method was validated. The standard calibration curve for plasma and saliva samples was constructed from 5.0 to 2000 nmol L-1 . The limit of detection was 0.1 nmol L-1 , and the limit of quantification was 5.0 nmol L-1 in both plasma and saliva matrices. The intra- and inter-assay precision values were found to be between 1.5 and 5.8%, and the accuracy values ranged from 88.0 to 108% utilizing saliva and plasma samples. The extraction recovery was more than 80%, and the presented functionalized GO-Tabs could be reused for more than 10 extractions without deterioration in recovery.

Promising Antidiabetic and Antimicrobial Agents Based on Fused Pyrimidine Derivatives: Molecular Modeling and Biological Evaluation with Histopathological Effect.

Diabetes is the most common metabolic disorder in both developing and non-developing countries, and a well-recognized global health problem. The WHO anticipates an increase in cases from 171 million in 2000 to 366 million by 2030. In the present study, we focus on the preparation of pyrimidine derivatives as potential antidiabetic and antimicrobial agents. Thein vivoeffect on total serum glucose concentration, cholesterol and antioxidant activity was assessed in adult male albino Wister rats and compared to the reference drug glimperide. Promising results were observed for compound 5. The histopathological study confirms that compound 5 results in significant activity with liver maintenance. The antimicrobial activities were evaluated against several bacterial strains such as Salmonella typhimurium ATCC 25566, Bacillus cereus, Escherichia coli NRRN 3008, Pseudomonas aeruginosa ATCC 10145, Staphylococcus aureus ATCC 6538and fungi such as Rhizopus oligosporus, Mucor miehei and Asperillus niger. Compounds 4 and 5 showed a good inhibition of the bacterial zone compared to the reference drug cephradine. Finally, we suggest protein targets for these drugs based on computational analysis, and infer their activities from their predicted modes of binding using molecular modeling. The molecular modeling for compounds 4 and 5 resulted in improved docking scores and hydrogen bonding. The docking studies are in good agreement with the in vitro and in vivo studies.

Recent Applications of Molecularly Imprinted Sol-Gel Methodology in Sample Preparation.

Due to their selectivity and chemical stability, molecularly imprinted polymers have attracted great interest in sample preparation. Imprinted polymers have been applied for the extraction and the enrichment of different sorts of trace analytes in biological and environmental samples before their analysis. Additionally, MIPs are utilized in various sample preparation techniques such as SPE, SPME, SBSE and MEPS. Nevertheless, molecularly imprinted polymers suffer from thermal (stable only up to 150 °C) and mechanical stability issues, improper porosity and poor capacity. The sol-gel methodology as a promising alternative to address these limitations allowing the production of sorbents with controlled porosity and higher surface area. Thus the combination of molecularly imprinted technology and sol-gel technology can create influential materials with high selectivity, high capacity and high thermal stability. This work aims to present an overview of molecularly imprinted sol-gel polymerization methods and their applications in analytical and bioanalytical fields.

Graphene Oxide Tablets for Sample Preparation of Drugs in Biological Fluids: Determination of Omeprazole in Human Saliva for Liquid Chromatography Tandem Mass Spectrometry.

In this study, a novel sort of sample preparation sorbent was developed, by preparing thin layer graphene oxide tablets (GO-Tabs) utilizing a mixture of graphene oxide and polyethylene glycol on a polyethylene substrate. The GO-Tabs were used for extraction and concentration of omeprazole (OME) in human saliva samples. The determination of OME was carried out using liquid chromatography-tandem mass spectrometry (LC⁻MS/MS) under gradient LC conditions and in the positive ion mode (ESI+) with mass transitions of m/z 346.3→198.0 for OME and m/z 369.98→252.0 for the internal standard. Standard calibration for the saliva samples was in the range of 2.0⁻2000 nmol L-1. Limits of detection and quantification were 0.05 and 2.0 nmol L-1, respectively. Method validation showed good method accuracy and precision; the inter-day precision values ranged from 5.7 to 8.3 (%RSD), and the accuracy of determinations varied from -11.8% to 13.3% (% deviation from nominal values). The extraction recovery was 60%, and GO-Tabs could be re-used for more than ten extractions without deterioration in recovery. In this study, the determination of OME in real human saliva samples using GO-Tab extraction was validated.

Graphene Oxide/Polyethylene Glycol-Stick for Thin Film Microextraction of ß-Blockers from Human Oral Fluid by Liquid Chromatography-Tandem Mass Spectrometry.

A wooden stick coated with a novel graphene-based nanocomposite (Graphene oxide/polyethylene glycol (GO/PEG)) is introduced and investigated for its efficacy in solid phase microextraction techniques. The GO/PEG-stick was prepared and subsequently applied for the extraction of ß-blockers, acebutolol, and metoprolol in human oral fluid samples, which were subsequently detected by liquid chromatography tandem mass spectrometry (LC-MS/MS). Experimental parameters affecting the extraction protocol including sample pH, extraction time, desorption time, appropriate desorption solvent, and salt addition were optimized. Method validation for the detection from oral fluid samples was performed following FDA (Food and Drug Administration) guidelines on bioanalytical method validation. Calibration curves ranging from 5.0 to 2000 nmol L-1 for acebutolol and 25.0 to 2000 nmol L-1 for metoprolol were used. The values for the coefficient of determination (R2) were found to be 0.998 and 0.996 (n = 3) for acebutolol and metoprolol, respectively. The recovery of analytes during extraction was 80.0% for acebutolol and 62.0% for metoprolol, respectively. The limit of detections (LODs) were 1.25, 8.00 nmol L-1 for acebutolol and metoprolol and the lower limit of quantifications (LLOQ) were 5.00 nmol L-1 for acebutolol and 25.0 nmol L-1 for metoprolol. Validation experiments conducted with quality control (QC) samples demonstrated method accuracy between 80.0% to 97.0% for acebutolol and from 95.0% to 109.0% for metoprolol. The inter-day precision for QC samples ranged from 3.6% to 12.9% for acebutolol and 9.5% to 11.3% for metoprolol. Additionally, the GO/PEG-stick was demonstrated to be reusable, with the same stick observed to be viable for more than 10 extractions from oral fluid samples.

Long-term Outcome and Analysis of Dysfunction of Transjugular Intrahepatic Portosystemic Shunt Placement in Chronic Primary Budd-Chiari Syndrome.

Purpose To evaluate the long-term safety, technical success, and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in a series of patients with Budd-Chiari syndrome (BCS), and to determine the predictors of shunt dysfunction. Materials and Methods From 2004 to 2013, all patients with primary BCS referred for TIPS placement were included in the study. The primary and secondary technical success rates and the number and types of early (ie, before day 7) complications were noted. Factors associated with dysfunction were analyzed with uni- and multivariate analyses. Survival was analyzed with Kaplan-Meier curves. Results Fifty-four patients (34 women [63%]; mean age, 36 years ± 12 [standard deviation]) were included. Twenty-eight patients (52%) had myeloproliferative neoplasms. The mean Model for End-Stage Liver Disease score was 14.5 ± 4. The most frequent indication for TIPS was refractory ascites (50 of 54; 93%). Primary and secondary technical success rates were 93% and 98%, respectively. Early complications occurred in 17 patients (32%). After a mean follow-up of 56 months ± 41 (interquartile range, 22-92), 22 patients (42%) experienced at least one episode of TIPS dysfunction (median delay between administration of TIPS and first episode of dysfunction, 10.8 months). Cumulative 1-, 2-, 3-, 5-, and 10-year primary patency rates were 64%, 59%, 54%, 45%, and 45%, respectively. Dysfunction was associated with a myeloproliferative neoplasm (hazard ratio, 8.18; 95% confidence interval: 1.45, 46.18; P = .017), more than two initial stents (hazard ratio, 3.90; 95% confidence interval:1.16, 13.10; P = .027), and the occurrence of early complications (hazard ratio, 11.34; 95% confidence interval: 1.82, 70.69; P = .009). The 10-year survival rate was 76%. Conclusion TIPS placement in patients with chronic primary BCS was associated with a nonnegligible rate of early complications and required endovascular revision or revisions in 42% of patients. Nevertheless, secondary patency was close to 100%, and long-term survival was good. © RSNA, 2016 Online supplemental material is available for this article.

Role of the transjugular intrahepatic portosystemic shunt in the management of severe complications of portal hypertension in idiopathic noncirrhotic portal hypertension.

UNLABELLED: Idiopathic noncirrhotic portal hypertension is a heterogeneous group of diseases characterized by portal hypertension in the absence of cirrhosis. The efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) in this population are unknown. The charts of patients with idiopathic noncirrhotic portal hypertension undergoing TIPS in seven centers between 2000 and 2014 were retrospectively reviewed. Forty-one patients were included. Indications for TIPS were recurrent variceal bleeding (n = 25) and refractory ascites (n = 16). Patients were categorized according to the presence (n = 27) or absence (n = 14) of significant extrahepatic comorbidities. Associated conditions were hematologic, prothrombotic, neoplastic, immune, and exposure to toxins. During follow-up (mean 27 ± 29 months), variceal rebleeding occurred in 7/25 (28%), including three with early thrombosis of the stent. Post-TIPS overt hepatic encephalopathy was present in 14 patients (34%). Eleven patients died, five due the liver disease or complications of the procedure and six because of the associated comorbidities. The procedure was complicated by hemoperitoneum in four patients (10%), which was fatal in one case. Serum creatinine (P = 0.005), ascites as indication for TIPS (P = 0.04), and the presence of significant comorbidities (P = 0.01) at the time of the procedure were associated with death. Mortality was higher in patients with significant comorbidities and creatinine ≥100 µmol/L (P < 0.001). CONCLUSION: In patients with idiopathic noncirrhotic portal hypertension who have normal kidney function or do not have severe extrahepatic conditions, TIPS is an excellent option to treat severe complications of portal hypertension. (Hepatology 2016;64:224-231).

Cone-Beam CT Angiography for Determination of Tumor-Feeding Vessels During Chemoembolization of Liver Tumors: Comparison of Conventional and Dedicated-Software Analysis.

PURPOSE: To compare the ability of dedicated software and conventional cone-beam computed tomography (CT) analysis to identify tumor-feeding vessels in hypervascular liver tumors treated with chemoembolization. MATERIAL AND METHODS: Between January 2012 and January 2013, 45 patients (32 men, mean age of 61 y; range, 27-85 y) were enrolled, and 66 tumors were treated (mean, 32 mm ± 18; range, 10-81 mm) with conventional chemoembolization with arterial cone-beam CT. Data were independently analyzed by six interventional radiologists with standard postprocessing software, a computer-aided analysis with FlightPlan for liver (FPFL; ie, "raw FPFL"), and a review of this computer-aided FPFL analysis ("reviewed FPFL"). Analyses were compared with a reference reading established by two study supervisors in consensus who had access to all imaging data. Sensitivities, positive predictive values (PPVs), and false-positive (FP) ratios were compared by McNemar, χ(2), and Fisher exact tests. Analysis durations were compared by Mann-Whitney test, and interreader agreement was assessed. RESULTS: Reference reading identified 179 feeder vessels. The sensitivity of raw FPFL was significantly higher than those of reviewed FPFL and conventional analyses (90.9% vs 83.2% and 82.1%; P < .0001), with lower PPV (82.9% vs 91.2% and 90.6%, respectively; P < .0001), higher FP ratio (17.1% vs 9.4% and 8.8%, respectively; P < .0001), and greater interreader agreement (92% vs 80% and 79%, respectively; P < .0001). Reviewed FPFL analysis took significantly longer than both other analyses (P < .0001). CONCLUSIONS: The FPFL analysis software enabled a fast, accurate, and sensitive detection of tumor feeder vessels.

Determination of metoprolol enantiomers in human plasma and saliva samples utilizing microextraction by packed sorbent and liquid chromatography-tandem mass spectrometry.

A sensitive, accurate and reliable bioanalytical method for the enantioselective determination of metoprolol in plasma and saliva samples utilizing liquid chromatography-electrospray ionization tandem mass spectrometry was developed and validated. Human plasma and saliva samples were pretreated by microextraction by packed sorbent (MEPS) prior to analysis. A new MEPS syringe form with two inputs was used. Metoprolol enantiomers and internal standard pentycaine (IS) were eluted from MEPS sorbent using isopropanol after removal of matrix interferences using aliquots of 5% methanol in water. Complete separation of metoprolol enantiomers was achieved on a Cellulose-SB column (150 × 4.6 mm, 5 µm) using isocratic elution with mobile phase 0.1% ammonium hydroxide in hexane-isopropanol (80:20, v/v) with a flow rate of 0.8 mL/min. A post-column solvent-assisted ionization was applied to enhance metoprolol ionization signal in positive mode monitoring (+ES) using 0.5% formic acid in isopropanol at a flow rate of 0.2 mL/min. The total chromatographic run time was 10 min for each injection. The detection of metoprolol in plasma and saliva samples was performed using triple quadrupole tandem mass spectrometer in +ES under the following mass transitions: m/z 268.08 → 72.09 for metoprolol and m/z 303.3 → 154.3 for IS. The linearity range was 2.5-500 ng/mL for both R- and S-metoprolol in plasma and saliva. The limits of detection and quantitation for both enantiomers were 0.5 and 2.5 ng/mL respectively, in both matrices (plasma and saliva). The intra- and inter-day precisions were presented in terms of RSD values for replicate analysis of quality control samples and were <5%; the accuracy of determinations varied from 96 to 99%. The method was able to determine the therapeutic levels of metoprolol enantiomers in both human plasma and saliva samples successfully, which can aid in therapeutic drug monitoring in clinical laboratories. Copyright © 2016 John Wiley & Sons, Ltd.

A new strategy for surface modification of polysulfone membrane by in situ imprinted sol-gel method for the selective separation and screening of L-Tyrosine as a lung cancer biomarker.

In this work, a novel method based on in situ molecularly imprinted sol-gel for the surface modification of a polysulfone membrane (PSM) was developed. A modified molecularly imprinted sol-gel polysulfone membrane (MSM) was placed in a homemade plastic tube and coupled on-line with LC/MS/MS for the selective extraction and screening of l-Tyrosine (Tyr) as a tentative lung cancer biomarker in human plasma samples. The existence of molecularly imprinted sol-gel layers on both sides of a PSM was examined using scanning electron microscopy (SEM). To evaluate the role of precursor in the extraction performance, repeatability, and selectivity of developed method, three precursors, 3-(propylmethacrylate) trimethoxysilane (P1), 3-(triethoxysilyl)-propylamine (P2), tetraethyl orthosilicate (P3), individually and together were used for treatment of PSM. Our investigation showed that a single precursor's route is more repeatable, straightforward, precise, accurate, and selective for the extraction of Tyr in plasma samples. Moreover, to achieve the best conditions and extraction efficiency, the effect of influential parameters, including the conditioning, washing, and elution of solvents, sample flow rate, loading time, desorption time, loading sample volume, salt effect, pH, and adsorption capacity for the most efficiently prepared membranes were truly investigated. The non-molecularly imprinted sol-gel polysulfone membrane (NSM) was prepared as a blank via the same process but in the absence of the Tyr. The LOD (S/N = 3/1) was 0.1 nmol L(-1) and the LOQ (S/N = 10/1) was 0.34 nmol L(-1) for Tyr in the plasma samples. The linearity for the Tyr was in the range of 0.34-2000 nmol L(-1) in the plasma samples. The coefficients of determination values were ≥0.998 for all runs. The extraction recovery was between 80%-85% for Tyr in the plasma samples. In addition, MSM could be used for up to 50 extractions without a significant change in recovery percentage.

On-line determination of sarcosine in biological fluids utilizing dummy molecularly imprinted polymers in microextraction by packed sorbent.

Several years ago, sarcosine received attention as a prostate-cancer marker. Prostate cancer is one of the most widespread types of tumor diseases in men. The prostate-specific antigen is normally used as a marker, and it can only be detected in blood with a sensitivity of approximately 80%. In the present study, dummy molecularly imprinted polymers in microextraction by packed sorbent with on-line liquid chromatography coupled to tandem mass spectrometry was used for the determination of sarcosine in human plasma and urine samples. The polymer network glycine was used for the dummy molecularly imprinted polymers. The selectivity of the method was evaluated using similar prostate-cancer biomarkers. In addition, various parameters affecting the extraction performance were investigated. The method limits of detection and quantification in the plasma and urine were 1.0 and 3.0 ng/mL, respectively. The values of the coefficient of determination were over 0.99 for all runs in the studied concentration range (3.0-10 000 ng/mL). The method recovery was 87 and 89% in plasma and urine, respectively. The intraday and interday precisions of sarcosine in the plasma and urine samples were in the ranges of 4.0-7.1, 3.0-6.3, 2.9-4.7, and 5.0-6.7, respectively.

Hepatic cysts treated with percutaneous ethanol sclerotherapy: time to extend the indications to haemorrhagic cysts and polycystic liver disease.

OBJECTIVES: To describe the long-term clinical and morphological outcome of symptomatic hepatic cysts treated with percutaneous ethanol sclerotherapy (PES). METHODS: From December 2003 to September 2011, all patients with hepatic cysts undergoing PES with a follow-up after 12 months were included. Evolution of the volume of the cysts and clinical and biological data were recorded. Features of the cyst were evaluated in each patient: simple, haemorrhagic or developed on underlying polycystic liver disease (PCLD). RESULTS: Fifty-eight cysts (median volume 666 mL) were treated in 57 patients (52 women, mean age 58 years (18-80)). Twenty-two patients (39 %) had simple hepatic cysts, 19 (33 %) had dominant cysts on PCLD and 20 had haemorrhagic cysts (34.5 %), including 4 with PCLD. After a mean 27.3 months of follow-up, the final median cystic volume was 13.5 mL (p < 0.0001), and the median reduction in cyst volume was 94 % (58-100 %). Treatment was satisfactory in 95 % of the patients (54/57) (symptoms disappeared in 45/57 (79 %), decreased in 9/57 (16 %)). There was no clinical or morphological difference between patients with PCLD, haemorrhagic cysts or simple cysts. CONCLUSION: The clinical and morphological efficacy of a single session of PES is very high, regardless of the presence of intracystic haemorrhage or underlying PCLD. KEY POINTS: • The clinical efficacy of percutaneous ethanol sclerotherapy is very high. • Haemorrhagic content should not be a contraindication for percutaneous sclerotherapy. • Dominant cysts on polycystic liver disease should be treated with PES. • Imaging follow-up should not be performed shortly after the procedure.

Determination of amphetamine and methadone in human urine by microextraction by packed sorbent coupled directly to mass spectrometry: an alternative for rapid clinical and forensic analysis.

Speed and low cost, together with regulatory approval, are the most important requirements of clinical assays. Therefore, a fast and automated on-line sample preparation method is essential for the routine analysis of biological samples. Microextraction by packed sorbent is an option for optimal sample preparation due to its easy automation, minimal requirements for the sample and elution solvent volumes, elimination of evaporation and reconstitution steps, and ability to integrate sample preparation and injection into one step. The use of effective sample preparation steps circumvents the need for chromatographic separation and therefore allows more rapid and less expensive sample analysis in clinical and forensic practice. Two biologically active compounds, amphetamine and methadone, were chosen as representative drugs of abuse for the application of microextraction by packed sorbent coupled directly to mass spectrometry. The developed method was validated, with the results confirming the suitability of the combination of these techniques for the analysis of biological samples. The approach was confirmed to be appropriate for use in clinical and forensic practice with regard to cost and time requirements for analysis.

Dried saliva spot as a sampling technique for saliva samples.

For the first time, dried saliva spot (DSS) was used as a sampling technique for saliva samples. In the DSS technique 50 µL of saliva was collected on filter paper and the saliva was then extracted with an organic solvent. The local anesthetic lidocaine was used as a model compound, which was determined in the DSS using liquid chromatography and mass spectrometry. The results obtained for the determination of lidocaine in saliva using DSS were compared with those from a previous study using a microextraction by packed sorbent syringe as the sampling method for saliva. This study shows that DSS can be used for the analysis of saliva samples. The method is promising and very easy in terms of sampling and extraction procedures. The results from this study are in good agreement with those from our previous work on the determination of lidocaine in saliva. DSS can open a new dimension in the saliva handling process in terms of sampling, storing and transport.

Microextraction by packed sorbent: an emerging, selective and high-throughput extraction technique in bioanalysis.

Sample preparation is an important analytical step regarding the isolation and concentration of desired components from complex matrices and greatly influences their reliable and accurate analysis and data quality. It is the most labor-intensive and error-prone process in analytical methodology and, therefore, may influence the analytical performance of the target analytes quantification. Many conventional sample preparation methods are relatively complicated, involving time-consuming procedures and requiring large volumes of organic solvents. Recent trends in sample preparation include miniaturization, automation, high-throughput performance, on-line coupling with analytical instruments and low-cost operation through extremely low volume or no solvent consumption. Micro-extraction techniques, such as micro-extraction by packed sorbent (MEPS), have these advantages over the traditional techniques. This paper gives an overview of MEPS technique, including the role of sample preparation in bioanalysis, the MEPS description namely MEPS formats (on- and off-line), sorbents, experimental and protocols, factors that affect the MEPS performance, and the major advantages and limitations of MEPS compared with other sample preparation techniques. We also summarize MEPS recent applications in bioanalysis.

Effects of a multimodal management strategy for acute mesenteric ischemia on survival and intestinal failure.

BACKGROUND & AIMS: Acute mesenteric ischemia (AMI) is an emergency with a high mortality rate; survivors have high rates of intestinal failure. We performed a prospective study to assess a multidisciplinary and multimodal management approach, focused on intestinal viability. METHODS: In an Intestinal Stroke Center, we developed a multimodal management strategy involving gastroenterologists, vascular and abdominal surgeons, radiologists, and intensive care specialists; it was tested in a pilot study on 18 consecutive patients with occlusive AMI, admitted to a tertiary center from July 2009 to November 2011. Patients with left ischemic colitis, nonocclusive AMI, chronic mesenteric ischemia, and other emergencies were excluded. Patients received specific medical management: revascularization of viable small bowel and/or resection of nonviable small bowel; 12 patients received arterial revascularization. We evaluated the percentages of patients who survived for 30 days or 2 years, the number with permanent intestinal failure, and morbidity. Lengths and rates of intestinal resection were compared with or without revascularization, and in patients with early or late-stage disease. RESULTS: Patients were followed up for a mean of 497 days (range, 7-2085 d); 95% survived for 30 days, 89% survived for 2 years, and 28% had morbidities within 30 days. Intestinal resection was necessary for 7 cases (39%), with mean lengths of intestinal resection of 30 cm and 207 cm, with or without revascularization, respectively (P = .03). Among patients with early or late-stage AMI, rates of resection were 18% and 71%, respectively (P = .049). Patients with early stage disease had shorter lengths of intestinal resection than those with late-stage disease (7 vs 94 cm; P = .02), and spent less time in intensive care (2.5 vs 49.8; P = .02). CONCLUSIONS: A multidisciplinary and multimodal management approach might increase survival of patients with AMI and prevent intestinal failure.