THE FLUORIMETRIC MICRODETERMINATION OF GLYOXYLIC ACID IN BLOOD, URINE AND BACTERIAL EXTRACTS.
Ontology highlight
ABSTRACT:
SUBMITTER: ZAREMBSKI PM
PROVIDER: S-EPMC1206925 | biostudies-other | 1965 Jul
REPOSITORIES: biostudies-other
Similar Datasets
Project description:1. Oxalic acid is separated from interfering substances by extraction with tri-n-butyl phosphate followed by co-precipitation with calcium sulphate. The precipitated oxalic acid is then reduced to glyoxylic acid, which is coupled with resorcinol to form a coloured fluorescent complex. 2. The spectrofluorometric method described is sensitive and highly specific, the minimum detectable amount of oxalic acid being 0.9mumole under the recommended conditions. 3. The concentration of oxalic acid in blood from 15 normal adults was 200-320mug./100ml. For serum the range was 135-280mug./100ml. The urinary excretion of oxalic acid by 60 normal adults on a normal diet was 9.0-28.5mg./24hr.
| S-EPMC1207208 | biostudies-other
Project description:In the present study, the determination of histidine (HIS) by an on-line flow method based on the concept of zone fluidics is reported. HIS reacts fast with o-phthalaldehyde at a mildly basic medium (pH 7.5) and in the absence of additional nucleophilic compounds to yield a highly fluorescent derivative (?ex/?em = 360/440 nm). The flow procedure was optimized and validated, paying special attention to its selectivity and sensitivity. The LOD was 31 nmol·L-1, while the within-day and day-to-day precisions were better than 1.0% and 5.0%, respectively (n = 6). Random urine samples from adult volunteers (n = 7) were successfully analyzed without matrix effect (<1%). Endogenous HIS content ranged between 116 and 1527 ?mol·L-1 with percentage recoveries in the range of 87.6%-95.4%.
| S-EPMC7180633 | biostudies-literature
Project description:A high-throughput fluorimetric assay for histidine was developed, using a 96-well plates platform. The analyte reacts selectively with o-phthalaldehyde under mild alkaline conditions to form a stable derivative. Instrumental-free detection was carried out using a smartphone after illumination under UV light (365 nm). The method was proved to be linear up to 100 μM histidine, with an LLOQ (lower limit of quantification) of 10 μM. The assay was only prone to interference from glutathione and histamine that exist in the urine samples at levels that are orders of magnitude lower compared to histidine. Human urine samples were analyzed following minimum treatment and were found to contain histidine in the range of 280 to 1540 μM. The results were in good agreement with an HPLC corroborative method.
| S-EPMC10488697 | biostudies-literature
Project description:1. A sensitive fluorimetric procedure for the assay of d-amino acid oxidase has been developed. 2. The method depends on the formation of a fluorescent derivative, 2-hydroxy-3-methylquinoxaline, on condensation of pyruvate with o-phenylenediamine in acid medium. 3. 2-Hydroxy-3-methylquinoxaline fluoresces strongly in 50% (v/v) sulphuric acid after excitation at 375mmu. A single emission peak is observed at 480mmu. 4. Formation of the quinoxaline is dependent on time, temperature, acidity and relative concentration of reactants. 5. A particulate preparation from mouse kidney required FAD for optimum activity at pH8.5; K(m) was 3.8x10(-3)m; K(FAD) was 1.4x10(-7)m and the reaction was strongly inhibited by p-chloromercuribenzoate and phenylmercuric acetate. 6. Subcellular fractionation on a sucrose density gradient confirmed that the d-amino acid oxidase was localized on small granules.
| S-EPMC1270418 | biostudies-other
Project description:Urine is an acceptable, non-invasive sample for investigating the human urogenital microbiota and for the diagnosis of sexually transmitted infections. However, low quantities of bacterial DNA and PCR inhibitors in urine may prevent efficient PCR amplification for molecular detection of bacteria. Furthermore, cold temperatures used to preserve DNA and bacteria in urine can promote precipitation of crystals that interfere with DNA extraction. Saline, Dulbecco's Phosphate Buffered Saline, or Tris-EDTA buffer were added to urine from adult men to determine if crystal precipitation could be reversed without heating samples beyond ambient temperature. Total bacterial DNA concentrations and PCR inhibition were measured using quantitative PCR assays to compare DNA yields with and without buffer addition. Dissolution of crystals with Tris-EDTA prior to urine centrifugation was most effective in increasing bacterial DNA recovery and reducing PCR inhibition. DNA recovery using Tris-EDTA was further tested by spiking urine with DNA from bacterial isolates and median concentrations of Lactobacillus jensenii and Escherichia coli 16S rRNA gene copies were found to be higher in urine processed with Tris-EDTA. Maximizing bacterial DNA yield from urine may facilitate more accurate assessment of bacterial populations and increase detection of specific bacteria in the genital tract.
| S-EPMC6759279 | biostudies-literature
Project description:Bloodstream infections are a significant cause of morbidity and mortality in critically ill dogs, but due to cost and difficulties in sample acquisition, blood cultures are infrequently obtained. In ill dogs, urine cultures may be recommended as surrogates for blood cultures. In order to determine the outcome agreement between parallel urine and blood cultures, we retrospectively analyzed parallel blood and urine specimens submitted for culture from dogs at the NC State Veterinary Hospital between 2011 and 2016. Positive cultures were reported from 15% of the submitted blood specimens and 23% of the submitted urine specimens. A total of 295 urine and blood samples were submitted in parallel, with positive growth demonstrated in 14 concordant and five discordant pairs. A kappa statistic comparing blood and urine culture outcomes was 0.266 (fair) when all parallel growth was included, including concordant and discordant results, and 0.170 (poor) when restricted to parallel concordant growth. The sensitivity of urine to reflect concordant bloodstream bacterial organisms was 30%, with a specificity of 87%. The positive and negative predictive values were 30% and 88%, respectively. Of dogs with both specimens positive on bacterial culture, 7 of 7 (100%) with suspected urogenital infection sources were concordant. All dogs with discordant bloodstream and urinary infections were immunosuppressed. Urinary coagulase-positive Staphylococcus isolates were most likely to be concordant with bloodstream infections. In conclusion, we found that urine culture is neither a substitute nor a screen for blood culture. Blood cultures should be performed in any potentially septic animal, especially those that are considered immunosuppressed.
| S-EPMC6113489 | biostudies-literature
Project description:BackgroundDecreased galactocerebrosidase (GALC) enzyme activity is causative for Krabbe disease, a lysosomal storage disorder with devastating neurodegenerative consequences. Quantitative fluorimetric assays for GALC activity in isolated blood and skin cells have been described; however, no such assay has been described using dried blood spot (DBS) specimens.MethodsGALC enzyme activity was measured quantitatively using fluorescence from a novel glycosidic substrate: carboxy derived from 6-hexadecanoylamino-4-methylumbelliferone. GALC activity was demonstrated on newborn DBS specimens, known Krabbe disease patient specimens, proficiency testing and quality control samples.ResultsWe present data on characterization of the novel substrate and assay, including pH optimization and enzyme kinetics using a fluorimetric profile. Single and multi-day precision analyses revealed tight analytical measurements with %CV ranging from 5.2% to 14.1%. GALC enzyme activity was linear over the range of 0.31 - 12.04 μmol/l/h with a limit of detection of 0.066 μmol/l/h. Our results with this assay show a clear discrimination between GALC activities in samples from Krabbe disease patients versus presumed normal newborn samples.ConclusionsA fluorimetric assay for GALC enzyme activity measurement on dried blood spot specimens is feasible. Improvements to the assay including novel substrate design, increased substrate concentration and removal of sodium chloride maximize the specificity of the assay and minimize interference from β-galactosidase.
| S-EPMC6838535 | biostudies-literature
Project description:Urine from mutant mice which lack D-amino-acid oxidase contained a large amount of D-alanine. The alanine content was not changed by changes in the dietary composition or by starvation. However, oral administration of an antibiotic, amoxicillin, decreased the urinary alanine to the normal level. These results suggest that the D-alanine is not of dietary origin but of intestinal bacterial origin.
| S-EPMC1131426 | biostudies-other
Project description:Bearing in mind the interest in the development and application of amino acids/peptides as bioinspired systems for sensing, a series of new phenylalanine derivatives bearing thiosemicarbazone and hydrazone units at the side chain were synthesised and evaluated as fluorimetric chemosensors for ions. Thiosemicarbazone and hydrazone moieties were chosen because they are considered both proton-donor and proton-acceptor, which is an interesting feature in the design of chemosensors. The obtained compounds were tested for the recognition of organic and inorganic anions (such as AcO-, F-, Cl-, Br-, I-, ClO4-, CN-, NO3-, BzO-, OH-, H2PO4- and HSO4-) and of alkaline, alkaline-earth, and transition metal cations, (such as Na+, K+, Cs+, Ag+, Cu+, Cu2+, Ca2+, Cd2+, Co2+, Pb2+, Pd2+, Ni2+, Hg2+, Zn2+, Fe2+, Fe3+ and Cr3+) in acetonitrile and its aqueous mixtures in varying ratios via spectrofluorimetric titrations. The results indicate that there is a strong interaction via the donor N, O and S atoms at the side chain of the various phenylalanines, with higher sensitivity for Cu2+, Fe3+ and F- in a 1:2 ligand-ion stoichiometry. The photophysical and metal ion-sensing properties of these phenylalanines suggest that they might be suitable for incorporation into peptide chemosensory frameworks.
| S-EPMC10650509 | biostudies-literature
Project description:Patients enrolled in the African American Study of Kidney Disease and Hypertension (AASK) Cohort Study who exhibited overt proteinuria have been reported to show high nonalbumin proteinuria (NAP), which is characteristic of a tubulopathy. To determine whether African American Study of Kidney Disease and Hypertension nephropathy (AASK-N) is a tubulopathy, we obtained urine samples of 37 patients with AASK-N, with 24-hour protein-to-creatinine ratios (milligrams per milligram) ranging from 0.2 to 1.0, from the National Institute of Diabetes and Digestive Kidney Diseases repository and tested for seven markers of tubular proteinuria. By protocol, each sample had been collected in acetic acid (0.5%; mean final concentration). Compared with samples from patients with lupus nephritis or healthy black controls, AASK-N samples had lower amounts of six markers. Four markers (albumin, β-2-microglobulin, cystatin C, and osteopontin) were undetectable in most AASK-N samples. Examination by SDS-PAGE followed by protein staining revealed protein profiles indicative of severe protein degradation in 34 of 37 AASK-N urine samples. Treatment of lupus nephritis urine samples with 0.5% acetic acid produced the same protein degradation profile as that of AASK-N urine. We conclude that the increased NAP in AASK-N is an artifact of acetic acid-mediated degradation of albumin. The AASK-N repository urine samples have been compromised by the acetic acid preservative.
| S-EPMC5407732 | biostudies-literature