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Recent Advances in Analytical Techniques is a series of updates in techniques used in chemical analysis. Each volume presents a selection of chapters that explain different analytical techniques and their use in applied research. Readers will find updated information about developments in analytical methods such as chromatography, electrochemistry, optical sensor arrays for pharmaceutical and biomedical analysis. The third volume of the series features seven reviews on a variety of techniques: Chiral Analysis of Methamphetamine and Related Controlled Substances in Forensic Science Low-cost feedstocks for biofuels and high value added products production: Using multi-parameter flow cytometry as a tool to enhance the process efficiency Recent Trends in the Application of Ionic Liquids for Micro Extraction Techniques Electrospun Nanofibers: Functional and Attractive Materials for the Sensing and Separation Approaches in Analytical Chemistry Neutron Activation Analysis: An Overview Non-commercial Polysaccharides-based Chiral Selectors in Enantioselective Chromatography Ru(II)-polypyridyl Complexes as Potential Sensing Agents for Cations and Anions

Recent Advances in Analytical Techniques is a collection of updates in techniques used in chemical analysis. This volume presents information about a selection of analytical techniques. Readers will find information about: New methods of sample preparation in biological and environmental analysis Developments in electrochemical sensors In vivo cytometry for detection of tumor cells Flow discharge spectroscopy for depth profile analysis Advances in photodynamic therapy New methods to analyze volatility in alcoholic beverages

Glucose and glutamine are essential energy metabolites for brain tumor growth and survival under both normoxic and hypoxic conditions. Both metabolites can contribute their carbons to lipid biosynthesis. We used uniformly labeled [¹⁴C]-U-D-glucose and [¹⁴C]-U-L-glutamine to examine the profile of de novo lipid biosynthesis in the VM-M3 murine glioblastoma cells. The major lipids synthesized included phosphatidylcholine (PtdCho), phosphatidylethanolamine (EtnGpl), phosphatidylinositol (PtdIns), phosphatidylserine (PtdSer), sphingomyelin (CerPCho), bis(monoacylglycero)phosphate (BMP)/phosphatidic acid (PtdOH), cholesterol (C), cardiolipin (Ptd₂Gro), and gangliosides. Endogenous lipid synthesis, using either glucose or glutamine, was greater in media without fetal bovine serum (FBS) than in media containing 10 % FBS under normoxia. De novo lipid synthesis was greater using glucose carbons than glutamine carbons under normoxia. The reverse was observed for most lipids under hypoxia suggesting an attenuation of glucose entering the TCA cycle. Lactate was produced largely from glucose carbons with minimal lactate derived from glutamine under either normoxia or hypoxia. Accumulation of triacylglycerols (TAG), containing mostly saturated and mono-unsaturated fatty acids, was observed under hypoxia using carbons from either glucose or glutamine. The data show that the incorporation of labeled glucose and glutamine into most synthesized lipids was dependent on the type of growth environment, and that the VM-M3 glioblastoma cells could acquire lipids, especially cholesterol, from the external environment for growth and proliferation.

Rissin et al . increase the sensitivity of sandwich ELISA by segregating beads bearing a single enzyme-labeled immunoconjugate into femtoliter-volume reaction chambers. As the small volume of each well permits detection of extremely low levels of fluorescence, protein abundance is determined by counting the number of fluorescent wells as a percentage of the number of wells containing beads. The ability to detect single protein molecules 1 , 2 in blood could accelerate the discovery and use of more sensitive diagnostic biomarkers. To detect low-abundance proteins in blood, we captured them on microscopic beads decorated with specific antibodies and then labeled the immunocomplexes (one or zero labeled target protein molecules per bead) with an enzymatic reporter capable of generating a fluorescent product. After isolating the beads in 50-fl reaction chambers designed to hold only a single bead, we used fluorescence imaging to detect single protein molecules. Our single-molecule enzyme-linked immunosorbent assay (digital ELISA) approach detected as few as ∼10–20 enzyme-labeled complexes in 100 μl of sample (∼10 −19 M) and routinely allowed detection of clinically relevant proteins in serum at concentrations (<10 −15 M) much lower than conventional ELISA 3 , 4 , 5 . Digital ELISA detected prostate-specific antigen (PSA) in sera from patients who had undergone radical prostatectomy at concentrations as low as 14 fg/ml (0.4 fM).

An update to the American Cancer Society (ACS) guideline regarding screening for the early detection of cervical precancerous lesions and cancer is presented. The guidelines are based on a systematic evidence review, contributions from 6 working groups, and a recent symposium cosponsored by the ACS, the American Society for Colposcopy and Cervical Pathology, and the American Society for Clinical Pathology, which was attended by 25 organizations. The new screening recommendations address age-appropriate screening strategies, including the use of cytology and high-risk human papillomavirus (HPV) testing, follow-up (eg, the management of screen positives and screening intervals for screen negatives) of women after screening, the age at which to exit screening, future considerations regarding HPV testing alone as a primary screening approach, and screening strategies for women vaccinated against HPV16 and HPV18 infections.

Background and AimThe study of CD44/CD24 and ALDH1 expression is the most accurate method to identify cancer stem cells (CSC) from breast cancer populations. However, the overlap between CD44+CD24−/low and ALDH1high CSC phenotypes in breast cancer seems to be very small, as well as their distribution among intrinsic breast cancer subtypes. Due to this discrepancy, it is imperative to improve the understanding of breast CSC marker distribution.Methods466 invasive breast carcinomas and eight breast cancer cell lines were analysed for the expression of CD44, CD24 and ALDH1, to evaluate their distribution among the distinct molecular subtypes.ResultsBasal-like tumours (76.5%) contained the higher percentage of cells with the CSC phenotype CD44+CD24−/low (p<0.0001). From ALDH1-positive cases, 39.4% were also basal-like tumours (p<0.0001). The analysis of breast cancer cell lines indicated that luminal cell lines are mainly enriched in a CD44−/lowCD24+ cell population, basal/mesenchymal breast cancer cell lines are enriched in the CD44+CD24−/low phenotype, whereas the remaining basal/epithelial cell lines are mainly positive for both markers. ALDH1 activity was mainly found in HER-OE and basal/epithelial breast cancer cell.ConclusionsCD44+CD24−/low and ALDH1+ phenotypes seem to identify CSC with distinct levels of differentiation. It seems that the paramount method and biomarkers that identify breast CSC within the distinct molecular subtypes need to be better explored, because it is pivotal to translate the CSC concept to clinical practice. In the future, the recognition of reliable markers to distinguish the CSC pool in each molecular subtype will be decisive for the development of specific target therapies.

Optical imaging in vivo with molecular specificity is important in biomedicine because of its high spatial resolution and sensitivity compared with magnetic resonance imaging. Stimulated Raman scattering (SRS) microscopy allows highly sensitive optical imaging based on vibrational spectroscopy without adding toxic or perturbative labels. However, SRS imaging in living animals and humans has not been feasible because light cannot be collected through thick tissues, and motion-blur arises from slow imaging based on backscattered light. In this work, we enable in vivo SRS imaging by substantially enhancing the collection of the backscattered signal and increasing the imaging speed by three orders of magnitude to video rate. This approach allows label-free in vivo imaging of water, lipid, and protein in skin and mapping of penetration pathways of topically applied drugs in mice and humans.

BackgroundPatients with non-alcoholic steatohepatitis (NASH) have increased mortality and liver-related complications. In contrast, simple steatosis is considered benign and non-progressive.ObjectiveTo investigate disease progression in patients with different degrees of non-alcoholic fatty liver disease (NAFLD) activity.DesignProspective longitudinal hospital-based cohort study.PatientsFifty-two patients (age 44±9 years) with biopsy-proven NAFLD had liver biopsies repeated at month 36.ResultsAmong 13 patients with simple steatosis at baseline, 2 (15%) had a normal liver at month 36, 3 (23%) continued to have simple steatosis, 5 (39%) developed borderline NASH and 3 (23%) developed NASH. Among 22 patients with borderline NASH at baseline, 4 (18%) had simple steatosis and 13 (59%) had borderline NASH at month 36, while 5 (23%) developed NASH. Among 17 patients with NASH at baseline, 10 (59%) continued to have NASH and 6 (35%) had borderline NASH at month 36. Only 1 (6%) patient regressed to simple steatosis. Overall, 14 (27%) patients had fibrosis progression, 25 (48%) had static disease, and 13 (25%) had fibrosis regression. Reduction in body mass index and waist circumference was independently associated with non-progressive disease activity and fibrosis. The baseline serum levels and month 36 changes in adiponectin, tumour necrosis factor α, interleukin 6 and leptin were not associated with disease progression. Serum cytokeratin-18 fragment level reflected disease activity and its change correlated with the change in NAFLD activity score (R=0.51, p<0.001).ConclusionsPatients with simple steatosis may still develop NASH and fibrosis progression. Weight reduction is associated with non-progressive disease. All patients with NAFLD should undergo periodic assessment and lifestyle modification.