Background: Dense LDL phenotypes are associated with increased atherogenicity, and are commonly evaluated for the purposes of atherosclerosis research and cardiovascular risk discrimination. Objective: To examine the ability of LDL subclasses, expressed as a ratio of dense-to-buoyant subclass, to predict LDL density phenotype. Methods: LDL subclasses and density phenotypes were measured with vertical auto profile ultracentrifugation in 1,339,898 consecutive lipid profiles between 2009 and 2011 from a clinical sample of US adults. Logarithmic LDL density ratio (LLDR) was calculated as ratio of dense-to-buoyant LDL subclasses, ln[(LDL 3-C + LDL 4-C) / (LDL 1-C +LDL 2-C)]; normally distributed after log-transformation. LLDR was compared to density phenotype using ROC C-statistic with optimum sensitivity and specificity cutpoints determined. Results: There was a strong, highly significant, monotonic increase in LLDR across progressively higher density phenotypes (p<0.001). Mean LLDR for Phenotype A was 0.122 (95% CI 0.121-0.123), Phenotype A/B was 0.751 (95% CI 0.750-0.752), and Phenotype B was 1.336 (95% CI 1.335-1.338). ROC analysis showed a strong association of LLDR with phenotype A, C=0.915 (0.914-0.915), p<10-4 , optimum cutpoint <0.398, sensitivity 72%, specificity 95%; and phenotype B, C= 0.923 (0.923-0.924), p<10-4 optimum cutpoint >0.905, sensitivity 81%, specificity 86%. There was also a positive correlation between LLDR and LDL Max Time (R 2 =0.802). Conclusion: LLDR is a convenient, easily calculated, and continuous variable that is strongly associated with LDL density phenotype and LDL Max Time. Further research is needed to investigate the relationship between lipoprotein density and size, and whether LLDR provides more cardiovascular risk discrimination than LDL density phenotype.
Potentiometric method based on the sharp change of electrode potential for the ferricyanide/ferrocyanide mediator system after addition of the seminal or follicular fluid sample into the measuring electrochemical cell has been developed to enable the easy assessment of the oxidant/antioxidant status of these kind of biological fluids. Platinum screen printed electrode has been used as an indicator. Essential advantage of the proposed method is simultaneous use of the both forms of the ferricyanide/ferrocyanide mediator system (oxidized and reduced ones) that allows estimating oxidant and antioxidant components of the seminal or follicular fluids samples which were obtained, respectively, from 99 male and 27 female subjects. Oxidant activity of seminal fluids has been observed in pathology conditions of reproductive system of male studied subjects and related with possible male infertility symptoms.
The aim of this pilot study was to investigate the possible role of adenovirus infection in etiology of obesity.Antibodies (IgG, IgA, IgM) to adenovirus were determined in a total of 71 Caucasian, apparently healthy, middle aged (mean 45.9 ± 13.6 years), living in urban area, cohort of women -including overweight/obese (OW/OB, n = 50) and normal weight (NW, n = 21) group -by using serotype non-specific enzyme linked immunosorbent assay (ELISA).Triglycerides (TG), total-(TChol) and HDL-cholesterol (HDLChol) concentrations in collected serum samples were performed by standard enzymatic methods.The level of LDL cholesterol (LDLChol) was calculated using the Friedewald formula.Anthropometric measurements were taken and body mass index (BMI), percentage of fat mass (%FM) and waist-to-hip ratio (WHR) were calculated.There were no associations (p > 0.05) observed between IgG + or IgA + seropositivity for adenovirus and measured obesity indicators as BMI, %FM, WHR in studied female groups.However, in the group of OW/OB subjects with combined seropositivity (IgG + /IgA + ) -both for IgG and IgA antibodies to adenoviruswhich suggest chronic adenoviral infection the significantly (p < 0.05) lower serum TG, TChol and LDLChol concentrations have been observed in comparison with the seronegative (IgG -/IgA -) females from the OW/OB and NW group of females.Findings of our pilot study suggest that infection of some adenoviruses may predispose to altered serum lipids in some adult OW/OB females.Further studies should be made to critically evaluate this association and its possible consequences to currently accepted protocols for obesity prevention and treatment.Especially, in this group of OW/OB females, the involvement of measurements of the serotype-specific neutralizing antibodies to adenovirus or isolation/identification of specific adenovirus like particles in serum and adipose tissue using convective interaction media (CIM) monolithic column technology should be advisable.
Carotenoids are biologically active phytochemicals present as micro-components in fruits and vegetables, being responsible for their yellow, orange and red colors. The chromatographic behavior and the UV absorption spectrum provided by HPLC-DAD analysis constitute the clues for their identification. Mushrooms are of increasing importance in modern nutrition and medicine, due to the presence of metabolites with pharmacological potential. In this work, samples of wild and commercial mushroom species (Agaricus bisporus, Amanita caesarea, Amanita rubescens, Boletus edulis, Cantharellus cibarius, Fistulina hepatica, Hydnum rufescens, Hygrophorus agathosmus, Pholiota nameko, Pleurotus ostreatus, Russula cyanoxantha, Suillus bellini, Suillus bovinus, Suillus granulatus, Suillus luteus, Tricholoma equestre and Tricholoma portentosum) were screened by HPLC-DAD for the presence of carotenoids. By applying this methodology to 22 samples, comprising either lyophilized or fresh materials, only � -carotene was found and just in C. cibarius species. The occurrence of this pigment in other three of the analyzed species previously described raises some questions about the methodology used.
A molecularly imprinted polymer (MIP) was synthesized and evaluated to selectively extract ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), from human urine.The synthesis of the MIP was performed in dimethylformamide with acrylamide as functional monomer, ethylene glycol dimethacrylate as the cross linker and ibuprofen template as the target drug.The performance of the synthesized MIP as solid phase extraction (SPE) packing to recognize and bind ibuprofen was evaluated against other structurally related NSAIDs such as naproxen and ketoprofen.Using a mixture of acetonitrile-water (1/9 v/v) as a solvent for ibuprofen the binding recovery at approximately 90% was obtained for developed MIP in optimized conditions.Batch rebinding capacity of ibuprofen was determined from the derived Freundlich isotherm and was found to be 1.45 mol g -1 .Furthermore, a higher selectivity of developed MIP for ibuprofen over structurally related analogues was observed.The synthesized MIP has enabled the direct percolation of humane urine and the easy elimination of endogenous compounds from it with simple aqueous washing of the MIP-SPE packing.HPLC analysis has confirmed the high extraction recovery (ca.85 %) of ibuprofen from such urine samples with use of proposed MIP-SPE system.
The development, fabrication and testing of a compact electrospray device are presented with the dual goal of increasing yields and total particle amounts by orders of magnitude and retaining the monodispersity of the generated polymeric particles.A new and optimized electrospraying device producing 285 mg/24h monodisperse micro-sized particles with a yield of 79.2% was developed and tested.The new design allowed continuous particle production and collection.By optimization of the chamber design, high velocities in combination with reduced turbulences led to increasing yields.In comparison to a simple electrospraying configuration, the new device enabled collection 14.25 times more particles in 24h.Besides this significant increase in particle amounts and numbers, collection effectiveness increased as well.While a basic electrospraying device allowed collection of only 34.7% of the generated particles, the yields determined for the new device were 79.2%.We report a 2.28 times increase in effectiveness combined with the potential to generate continuously particles with enhanced productivity while maintaining monodispersity of the particles.This modified electrospraying device may facilitate the production of micro-and nano-sized particles for biomedical and pharmaceutical applications in relevant amounts and reduced losses inside the device.
Compared to other voltammetric techniques a square wave voltammetry (SWV), which is presented in this minireview, has a several advantages such as high speed, increased analytical sensitivity and relative insensitivity to the presence of dissolved oxygen. Also it is an electrochemical technique used in analytical applications and fundamental studies of electrode mechanism. This paper delivers both the underlying theory and the practical guidance needed to apply square wave techniques and also provides a wide collection of data for the description of diverse tendencies that characterize several electrochemical reactions analyzed by SWV. This review summarizes some of the recent developments and application of direct and stripping SWV for drug compounds in their dosage forms and biological samples as reported in the period from 1997 till 2010 year.
A biomimetic sensor is proposed as a promising new analytical method for determination of norfloxacin (NF) in pharmaceuticals.The sensor was prepared by modifying a glassy carbon electrode surface with a Nafion ® membrane doped with poly(copper phthalocyanine) complex [poly-CuPc].Amperometric measurements carried out with the sensor under an applied potential of -0.05 V vs Ag|AgCl in 0.1 mol L -1 acetic acid containing 1.5 10 -3 mol L -1 hydrogen peroxide showed a linear response range from 2.0 10 -4 to 1.2 10 -3 mol L -1 .Selectivity and interference studies were also performed.A sensor response mechanism is proposed, based on the experimental evidence.Recovery studies were carried out using environmental samples, in order to evaluate the sensor's potential for use with these sample classes.Finally, sensor performance was evaluated using analyses of commercial formulations.
This Hot Topic issue of “The Open Chemical and Biomedical Methods Journal” is devoted to applications of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in environmental monitoring and fingerprinting. ICP-MS has become a common method for monitoring environmental quality and processes, and for fingerprinting of natural and anthropogenic pollution sources because of its multi-elemental capability, high sensitivity, low detection limits and capability to measure isotopes. The papers herein span a wide range of interesting applications, from monitoring trace elements in atmospheric particulate matter and biota to fingerprinting sources of naturally occurring radioactive material (NORM) and historical air pollution to determining the provenance of food supply to improving sample preparation and analysis schemes. As is always the case, knowledge of the fundamentals of the instrument and technique (i.e., ICP-MS) is invaluable to obtain accurate data and avoid many of the pitfalls (e.g., matrix effects, isobaric interferences, instrumental drift) that can lead to poor data quality and misleading information. Thus, another objective of this issue is to show how different researchers effectively use ICP-MS, both solutionand laser-based, for diverse environmental samples and applications.
Dr. James Cizdziel is an Assistant Professor in the Department of Chemistry and Biochemistry at the University of Mississippi. He received degrees from the State University of New York at Buffalo (B.S. in Analytical Chemistry, 1991) and the University of Nevada, Reno (Ph.D. in Environmental Science and Health, Environmental Chemistry Track, 1998). Prior to attending graduate school he was laboratory manager at Buffalo Tungsten Incorporated (1991-1993). His dissertation research, under Dr. Vernon Hodge, and associated journal publications examining attic dust as a historical record of air pollution are recognized as ground-breaking and innovative. He served as a National Research Council Postdoctoral Associate at the U.S. Environmental Protection Agency (EPA), National Exposure Research Laboratory from 1998-2000. His research there resulted in some of the first papers on the determination of Hg in environmental and biological samples using automated combustionatomic absorption spectrometry. In 2000, he was hired as Senior Scientist at the Harry Reid Center for Environmental Studies at the University of Nevada, Las Vegas. There he led a team of researchers who, among other things, utilized ICP-MS to measure trace elements in groundwater from near Yucca Mountain and the Nevada Test Site for various modeling studies. While in Las Vegas, he was active in the American Chemical Society, holding positions of Chair and Councilor in the Southern Nevada Section. He also served on the ACS National Committee for Technician Affairs. In 2008, he moved to Oxford, Mississippi to join the faculty at Ole Miss. He has been principal investigator on grants from the U.S. National Science Foundation (NSF), EPA, and the Department of Energy. Recently, he was awarded an NSF grant to develop an ICP-MS facility for the U.S. Mid-South region. His research interests are in the area of analytical, environmental, and forensic chemistry. He is particularly interested in environmental monitoring and fingerprinting using isotope based methods. He is also interested in the biogeochemical cycling of Hg and supervises a state-of-the-art Hg laboratory. Often what counts in science is novelty. To that end, he enjoys developing new measurement techniques or applying analytical methods in novel ways. For example, he published the first work on determining Pb in blood by laser ablation ICP-MS of filter paper spotted with blood.
She has been involved in several analytical chemistry projects related to electroanalytical chemistry and separation techniques on drug active compounds and DNA-Drug interactions.She has organized and participated in organizing committees of a number of international meetings related to Pharmaceutical Sciences (Series of ISOPS-Ankara-Turkey). Her research interest focuses on the electrochemical investigations of pharmaceutically active compounds and their analysis using electroanalytical, chromatographic and spectrophotometric methods, and their validations.Her research area currently moves to the development of DNA biosensors and their interactions with drugs.
This mini review describes the results regarding the voltammetric determination of micromolar, submicromolar and nanomolar concentrations of various fluoroquinolones antibacterial agents using both traditional hanging mercury drop electrode, carbon paste electrode, glassy carbon paste electrode and chemically modified electrodes. We concentrate on the interaction of quinolones with DNA in solution and at electrode surface in the context of the general development in the field.
A rapid method is presented for measuring V(IV) and V(V) in groundwater, without preconcentration or complexing agents, using direct injection of the water samples (which were collected under an argon atmosphere) into an ion chromatograph-inductively coupled plasma mass spectrometer (ICPMS). The mobile phase is 1.5% v/v nitric acid, which minimizes the buildup of solids in the ultrasonic nebulizer, the torch, and on the entrance cones of the ICPMS - a problem with methods using organic complexing agents and inorganic salts. The result is much less instrument downtime for cleaning the affected parts. Limits of detection are 0.02 � g L -1 for V(IV) and 0.06 � g L -1 for V(V). The pentavalent form of vanadium represents 98% to 99% of the vanadium in these Southern Nevada groundwater samples and ranges from 3.7±0.1 � g L -1 to 82.1±0.5 � g L -1 . The remaining few percent is V(IV). Total vanadium was determined by ICPMS
By combining recent advances in inductively coupled plasma mass spectrometry (ICP-MS) technology including improved collision cell efficiency, aerosol dilution and discrete sampling, a rare synergy has been achieved resulting in a system that is not only much faster than previous instruments, but also shows improved ease of use and superior matrix tolerance.This work demonstrates the benefits of such a system by demonstrating United States Environmental Protection Agency (USEPA) compliant analysis of a range of high matrix certified reference materials for 26 elements in less than 2 minutes per sample.
Electrochemistry of cyclodextrins (CDs) and cyclodextrin inclusion complexes with different pharmaceutical compounds is reviewed.The article highlights some electrochemical investigations of the CD-drugs interactions in solution.Cyclodextrin modified electrodes and their applications as electrochemical sensors in pharmaceutical analysis based on the self-assembly of CD derivatives on metal electrodes and nanoparticles, and cyclodextrin-modified multiwalled carbon nanotubes are also discussed.
A gas chromatographic method was developed and validated for the determination of bilobalide and ginkgolides A, B, C and J in Ginkgo biloba L. The Ginkgo terpene trilactones have been dissolved in 57% of pure ethanol in purified water and separated by extraction with a mixture of toluene/ethyl acetate.After evaporation of the solvent with nitrogen and derivatization, these chemical markers have been quantified using GC-FID.The intra-day RSD was ranged from 1.13% for bilobalide to 2.34% in case of ginkgolides.The inter-day RSD was ranged from 2.54% and 3.68% for, bilobalide and ginkgolides respectively.Mean recoveries were 99.78% ± 0.82% and 99.48% ± 0.86% for ginkgolides and bilobalide, respectively.Based on chromatograms, the response of the terpene trilactones was linearly dependent on the terpene concentration, i.e. linear calibration curve was found in the range of the method and was applied to analyze standard extract (containing 5-7% total terpenoids and 22-25% total flavonoids) as working standard and for the analysis of six Ginkgo pharmaceutical products offered on the market.
The determination of enantiomeric composition of chiral xenobiotics and pollutants is a very difficult job due to their low amounts and poor detection by commonly used UV detector.But this sort of analysis is an important issue from the health point of view.The chiral analyses of these notorious pollutants by capillary electrophoresis have been discussed in this article.This review discusses the new trends and advancements, which have been achieved in the analyses of chiral pollutants using capillary electrophoresis and the state-of-art of their enaniomeric resolution.This article focuses on sample treatment, applications, optimization, detection, mechanisms of chiral resolution and future perspectives of CE in chiral resolution of xenobiotics.Besides, efforts have also been made to suggest the improvement in CE machine to make it ideal for the analyses of chiral xenobiotics at trace levels.
Enantioselective, potentiometric membrane electrodes (EPMEs) based on � -, � - and � -cyclodextrins (CDs) as chiral selectors were proposed for the assay of S-deprenyl. The response characteristics proved that the proposed EPMEs could be reliably used in the assay of S-deprenyl. The best slope is exhibited by the EPME based on � -cyclodextrin. The limits of detection are very low: 10 -9 mol L -1 magnitude order for � -cyclodextrin based EPME, and 10 -11 mol L -1 magnitude order for � -, and � -cyclodextrins based EPMEs. The surfaces of the electrodes are stable and easily renewable by polishing on alumina paper.
The provenance identification of selected types of food and drink was undertaken from data obtained using both solution and laser ablation based inductively coupled plasma mass spectrometry (ICP-MS) and solution based inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis of selected food and drink materials (pork, wine, tea, coffee and olive oil).Quantitative determination of up to 55 elements was undertaken using solution based ICP-MS and AES while counts per second data for 49 elements was used for samples analyzed using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS).ICP-AES was used to determine the concentrations of Na, K, Ca, Mg and Fe where appropriate.A quantitative analytical methodology for LA-ICP-MS analysis of olive oil was also developed and preliminary trials undertaken.Additional information, to establish more detailed geographic resolution in provenance determination, especially for tea and coffee (plantation of origin), was provided by the incorporation of data for light stable isotope distribution patterns ( 2 H (D), 13 C and 15 N).LA-ICP-MS was used for the direct analysis of olive oil and coffee beans.The use of laser ablation for the analysis of olive oil has the potential to overcome problems associated with both acid dissolution and thermal oxidation of this material, which are the traditional methods of sample dissolution and which either introduce significant contamination or cause the loss of volatile organo-metallic compounds that may be indicative for provenance determination.Results from the overall study indicated that it was possible not only to establish country of origin of the study materials but also in some cases to improve resolution of provenance to state of origin (wine and pork), and even plantation of origin (tea and coffee).
Two microwave-assisted digestion procedures, followed by inductively coupled plasma mass spectrometry (ICP-MS) analysis, were evaluated for the determination of trace elements in fine atmospheric aerosols (PM 2.5 ) for air monitoring purposes.The first procedure used 40%(v/v) HNO 3 and a digestion program with a maximum temperature of 175 o C. The second digestion procedure provided the dissolution of silicate matrix through the use of a mixture of HNO 3 /HF/H 3 BO 3 at 200 o C. Both digestion procedures employed microvessels (MicroVessel TM ), which significantly reduced the amount of reagents needed, and increased the sample throughput by two-fold.The effectiveness of both digestion procedures was studied through the analysis of NIST standard reference materials (SRM), namely SRM 2783 (PM 2.5 Air Particulate Matter deposited on a polycarbonate filter membrane), and SRM 1648 (Urban Particulate Matter).The accuracy was also checked through the analysis of co-located ambient PM 2.5 samples collected within the Canadian National Air Pollution Surveillance (NAPS) network.Comparison of analytical results for PM 2.5 samples showed that 40% (v/v) HNO 3 could dissolve most of the metals of interest to the same degree as the HNO 3 /HF/H 3 BO 3 mixture.Good agreement was also obtained by comparison with Energy Dispersive X-ray Fluorescence Spectrometry (ED-XRF).The efficiency of the simple microwave digestion procedure (no HF) was not dependent on the origin, mass loading, or elemental composition of the analyzed samples, thus it is quite suitable for monitoring purposes.However, the total dissolution of several trace elements such as Ti, Cr and U in PM 2.5 , and Ti, Cr, Al, lanthanides, and Sb in coarse fractions of PM (PM 10 -2.5 ) would require digestion in the presence of HF.
