scholarly journals Surface Adsorption of the Cancer Biomarker Lysophosphatidic Acid in Serum Studied by Acoustic Wave Biosensor

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4158
Author(s):  
Brian De La Franier ◽  
Michael Thompson
Keyword(s):  
Acoustic Wave ◽  
Lysophosphatidic Acid ◽  
Electrode Surface ◽  
Biological Fluids ◽  
Thiol Group ◽  
Cancer Biomarker ◽  
Specific Adsorption ◽  
Shear Mode ◽  
Serum Samples ◽  
Fouling Reduction

The thickness shear mode acoustic wave device is of interest for the sensing of biomarkers for diseases in various biological fluids, but suffers from the issue of non-specific adsorption of compounds other than those of interest to the electrode surface, thus affecting the device’s output. The aim of this present study was to determine the level of non-specific adsorption on gold electrodes from serum samples with added ovarian cancer biomarker lysophosphatidic acid in the presence of a surface anti-fouling layer. The latter was an oligoethylene molecule with thiol group for attachment to the electrode surface. It was found that the anti-fouling layer had a minimal effect on the level of both adsorption of components from serum and the marker. This result stands in sharp contrast to the analogous monolayer employed for anti-fouling reduction on silica.

Poly N-(2-cyanoethyl)pyrrole as a selective film for the thickness-shear-mode acoustic wave sensor

1995 ◽  
Vol 73 (9) ◽  
pp. 1427-1435 ◽  
Author(s):  
Zhiping Deng ◽  
David C. Stone ◽  
Michael Thompson
Keyword(s):  
Acoustic Wave ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Polymerization ◽  
Shear Mode ◽  
Polymeric Coatings ◽  
Thickness Shear Mode ◽  
X Ray ◽  
Acoustic Wave Sensor ◽  
Polypyrrole Film ◽  
Thickness Shear

Poly N-(2-cyanoethyl)pyrrole films have been synthesized by electrochemical polymerization and characterized by cyclic voltammetry, scanning electron microscopy, and X-ray photoelectron spectroscopy. Polymeric coatings prepared on the surface of a thickness-shear-mode acoustic wave sensor have been used to examine response selectivity to a number of gas-phase probe molecules. The responses of the poly N-(2-cyanoethyl)pyrrole based sensor are compared with the parent polypyrrole device and rationalized in terms of the molecular interactions between probes and polymer films. The polar cyano functionality enhances interactions with analytes such as acetonitrile. Keywords: gas sensor, thickness-shear-mode acoustic wave sensor, poly N-(2-cyanoethyl)pyrrole film, polypyrrole film, conducting polymer.

Development of an HPLC method for measuring orally administered 1-substituted 2-alkyl-3-hydroxypyrid-4-one iron chelators in biological fluids

1990 ◽  
Vol 36 (1) ◽  
pp. 5-8 ◽  
Author(s):  
J G Goddard ◽  
G J Kontoghiorghes
Keyword(s):  
High Performance ◽  
Biological Fluids ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Iron Chelators ◽  
Serum Samples ◽  
Thalassemic Patient ◽  
Serum And Urine

Abstract "High-performance" liquid-chromatographic (HPLC) methods have been developed for identifying 1-substituted 2-alkyl-3-hydroxypyrid-4-one iron chelators in serum and urine. Ion pairing with heptane- or octanesulfonic acid in pH 2.0-2.2 phosphate buffer and reversed-phase chromatography were required to separate these compounds from endogenous compounds in both biological fluids. In both the 2-methyl and 2-ethyl series of 1-substituted compounds (H, methyl, ethyl, or propyl) the elution times increased in accordance with the n-octanol/water partition coefficients (propyl greater than ethyl greater than H greater than methyl). Urine samples were filtered (0.4 microns pore size) and injected either undiluted or after dilution with elution buffer. After the addition of internal standard, the plasma or serum samples were deproteinized by treatment with HCIO4, 0.5 mol/L, centrifuged, and the supernates were injected directly onto the HPLC. Using these procedures, we could identify 1,2-dimethyl-3-hydroxypyrid-4-one (L1) in the serum and urine of a thalassemic patient who had received a 3-g dose of the drug and in the urine of other patients who had received the same dose. One or more possible metabolites were also observed in the chromatograms of both urine and serum. The 24-h urinary output of L1 (0.22-2.37 g) and iron (10.6-71.5 mg) varied but there was no correlation between the two with respect to quantity or concentration. Instead, urinary iron output was higher in patients with a greater number of transfused units of erythrocytes. This is the first study in humans to show that L1 is absorbed from the gut, enters the circulation, and is excreted in the urine.

Acoustic wave flow sensor using quartz thickness shear mode resonator

2009 ◽  
Vol 56 (9) ◽  
pp. 1945-1954 ◽  
Author(s):  
Lifeng Qin ◽  
Zijing Zeng ◽  
Hongbin Cheng ◽  
Qing-ming Wang
Keyword(s):  
Acoustic Wave ◽  
Flow Sensor ◽  
Wave Flow ◽  
Shear Mode ◽  
Thickness Shear Mode ◽  
Thickness Shear ◽  
Mode Resonator

Biotin radioligand assay with an 125I-labeled biotin derivative, avidin, and avidin double-antibody reagents.

1987 ◽  
Vol 33 (11) ◽  
pp. 1983-1988 ◽  
Author(s):  
E Livaniou ◽  
G P Evangelatos ◽  
D S Ithakissios
Keyword(s):  
Pregnant Women ◽  
Binding Protein ◽  
Biological Fluids ◽  
Normal Subjects ◽  
Chronic Hemodialysis ◽  
Serum Samples ◽  
Radioligand Assay ◽  
Double Antibody ◽  
Low Concentrations ◽  
High Concentrations

Abstract We describe a new radioligand assay for determining biotin in biological fluids by using a mixture of N-[beta-(4-OH-3-125I-phenyl)ethyl]- and N-[beta-(4-OH-3,5-di-125I-phenyl)ethyl]biotinamides as radiotracer, avidin as a binding protein, and an avidin double-antibody as a separation reagent. The radiotracer is synthesized by coupling (at pH 8.5, 20-22 degrees C, 90 min) N-hydroxysuccinimidobiotin to radioiodinated tyramine. The assay curve is linear and the assay itself is sensitive (less than 10 ng/L), reproducible (intra- and interassay CVs 4.1% and 7.0%, respectively), and allows the simultaneous handling of more than 100 samples in less than 4 h. Serum samples from apparently normal subjects contained 100-840 ng of biotin per liter (mean 340 ng/L). Pregnant women had low concentrations of biotin (100-300 ng/L) in their serum. Patients undergoing chronic hemodialysis treatment showed high concentrations (0.5-3.0 micrograms/L), which may be ascribable to the inability of avidin, which was used as the assay binding protein, to distinguish biotin from biotinyl derivatives with an intact ureido ring.

Measuring swainsonine in serum of cancer patients: phase I clinical trial

1994 ◽  
Vol 40 (3) ◽  
pp. 426-430 ◽  
Author(s):  
J A Baptista ◽  
P Goss ◽  
M Nghiem ◽  
J J Krepinsky ◽  
M Baker ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Phase I ◽  
Cancer Patients ◽  
Biological Fluids ◽  
Competitive Inhibitor ◽  
Phase I Clinical Trial ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Liquid Chromatography ◽  
Serum Samples ◽  
Internal Standards

Abstract Swainsonine, an indolizidine alkaloid and competitive inhibitor of Golgi alpha-mannosidase II (EC 3.2.1.114), reduces tumor growth and stimulates immune function in mice. On the basis of these observations, a phase I clinical trial was initiated to determine whether swainsonine could be administered safely to cancer patients. We describe a method for extraction, acetylation, and quantification of swainsonine in human serum samples. Methyl alpha-D-mannopyranoside and methyl beta-D-galactopyranoside were added to serum samples as internal standards and, after sequential extraction of lipids and proteins with chloroform and acetonitrile, respectively, samples were acetylated with acetic anhydride and 4-dimethylaminopyridine and separated by gas-liquid chromatography. The identity of swainsonine and the internal standards after their extraction from serum and acetylation was confirmed by gas chromatography/mass spectrometry. Swainsonine was recovered at an efficiency of 90%, relative to internal standards, and calibration graphs were rectilinear from 3 to 18 mg/L with a detection limit of approximately 0.1 mg/L. The CV for multiple samples was < or = 6.7%. In patients receiving swainsonine (50-550 micrograms/kg per day) continuously for 5 days by intravenous infusion, serum concentrations of the drug reached 3-11.8 mg/L, 100 to 400 times greater than the 50% inhibitory concentration for Golgi alpha-mannosidase II and lysosomal alpha-mannosidases. Accurate measurements of swainsonine in biological fluids with this method should facilitate further clinical studies with the drug.

scholarly journals MicroRNA profiles in serum samples from Acute-On-Chronic Liver Failure patients and miR-25-3p as a potential biomarker for survival prediction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Júlia Cisilotto ◽  
Alex Evangelista do Amaral ◽  
Daiane Rosolen ◽  
Michele Patrícia Rode ◽  
Adny Henrique Silva ◽  
...  
Keyword(s):  
Liver Failure ◽  
Biological Fluids ◽  
Chronic Liver ◽  
Survival Prediction ◽  
Chronic Liver Failure ◽  
Serum Samples ◽  
Rna Molecules ◽  
Potential Biomarker ◽  
Acute Decompensation ◽  
The Difference

AbstractAcute-on-chronic liver failure (ACLF) is a condition characterized by acute decompensation of cirrhosis, associated with organ failure(s), and high short-term mortality. The microRNAs or miRNAs are small non-coding RNA molecules, stable in circulating samples such as biological fluids, and the difference in expression levels may indicate the presence, absence and/or stage of the disease. We analyzed here the miRNA profiling to identify potential diagnostic or prognostic biomarkers for ACLF. The major miRNAs discovered were validated in a cohort of patients with acute decompensation of cirrhosis grouped in no ACLF or ACLF according to EASL-CLIF definition. Relationship between serum miRNAs and variables associated with liver-damage and survival outcomes were verified to identify possible prognostic markers. Our results showed twenty altered miRNAs between no ACLF and ACLF patients, and twenty-seven in patients who died in 30 days compared with who survived. In validation phase, miR-223-3p and miR-25-3p were significantly altered in ACLF patients and in those who died in 30 days. miR-223-3p and miR-25-3p expression were associated with the lowest survival in 30 days. The decrease in miR-223-3p and miR-25-3p expression was associated with the presence of ACLF and poor prognosis. Of these, miR-25-3p was independently related to ACLF and 30-day mortality.

scholarly journals Semiautomated microtiter plate assay for monitoring peptidylprolyl cis/trans isomerase activity in normal and pathological human sera

1998 ◽  
Vol 44 (3) ◽  
pp. 502-508 ◽  
Author(s):  
Gerhard Küllertz ◽  
Sabine Lüthe ◽  
Gunter Fischer
Keyword(s):  
Biological Fluids ◽  
Microtiter Plate ◽  
Serum Samples ◽  
Ppiase Activity ◽  
Microtiter Plate Assay ◽  
Isomerase Activity ◽  
Microtiter Plates ◽  
Activity Factor ◽  
Healthy Donors ◽  
Human Sera

Abstract An UV/VIS spectrophotometric assay technique was developed that was able to routinely monitor peptidylprolyl cis/trans isomerase (PPIase) activity of biological fluids in 96-well microtiter plates. The assay, based on monitoring the cis-to-trans isomerization of succinyl-Phe-cisPro-Phe-4-nitroanilide as substrate in a chymotrypsin-coupled reaction, yields a throughput of 96 samples per 30 min. The assay’s capacity was exemplified by dealing with the PPIase activity in several normal and pathological human sera. Reference values of 151 healthy subjects (83 females, 69 males, 17 to 60 years old) were found to possess significant sex-specific differences. PPIase activity factor K of the sera was significantly greater in males (5th, 50th, 95th percentiles: 17, 36, 55 K) than females (14, 30, 48 K). PPIase activities of sera from healthy donors (n = 151) were significantly higher (Mann–Whitney rank-sum test P <0.0001) than those of patients (n = 47). PPIase activity in serum samples stored at 4 °C was stable for at least 20 h.

scholarly journals Interfacial slip on a transverse-shear mode acoustic wave device

2003 ◽  
Vol 94 (12) ◽  
pp. 7856 ◽  
Author(s):  
Jonathan S. Ellis ◽  
Gordon L. Hayward
Keyword(s):  
Acoustic Wave ◽  
Transverse Shear ◽  
Shear Mode ◽  
Interfacial Slip ◽  
Acoustic Wave Device ◽  
Wave Device
Sign in / Sign up

Export Citation Format

Share Document