The initial rate of Fe(2+) movement across the inner envelope membrane of pea (Pisum sativum) chloroplasts was directly measured by stopped-flow spectrofluorometry using membrane vesicles loaded with the Fe(2+)-sensitive fluorophore, Phen Green SK. The rate of Fe(2+) transport was rapid, coming to equilibrium within 3s. The maximal rate and concentration dependence of Fe(2+) transport in predom...

This simplified determination of serotonin in human plasma involves "high-performance" liquid chromatography with electrochemical detection. Deproteinated samples of platelet-poor plasma are injected directly into the chromatograph without preliminary chromatographic purification. The limit of quantitative detection of serotonin in plasma is 5 nmol/L (equivalent to 250 fmol injected). Intra- an...

The effects of pneumolysin on the proinflammatory activity of human neutrophils, as well as on cation fluxes in these cells, have been investigated. Superoxide production, release of elastase, CR3 expression, phospholipase A2 activity, and alterations in membrane potential were measured by use of lucigenin-enhanced chemiluminescence and colorimetric, flow cytometric, radiometric, and spectroflu...

20 Determining the concentration and composition of dissolved organic carbon (DOC) in glacial 21 ecosystems is important for assessments of in situ microbial activity and contributions to 22 wider biogeochemical cycles. Nonetheless, there is limited knowledge of the abundance and 23 character of DOC in basal ice and the subglacial environment and a lack of quantitative data 24 on low molecular ...

STUDY OBJECTIVES We performed a clinical trial of laser-induced fluorescence endoscopy (LIFE) for detection of precancerous lesions and cancer including carcinoma in situ (CIS), which are difficult to detect by white-light bronchoscopy. DESIGN Results with LIFE were compared with the criterion standard, white-light bronchoscopy. The evaluation of these endoscopic results spectrofluorometrical...

We have developed a set of simple modifications of the green fluorescent protein (GFP)fragment reassembly assay in bacteria that permits: (i)fluorescent microscopy visualization of GFP reassembly only 1-2 h after induction of protein expression, thus approximating the detection of GFP reassembly to the real-time dynamics of protein complex formation in living cells; (ii) spectrofluorometric det...

The interaction of a food colourant, quinoline yellow (Qy), and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorometry, FT-IR and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the dye was a static procedure. Various binding parameters were evaluated. The negative value of ΔH, negative value of ΔS and t...

AIM To assess the effects of oleic acid treatment on subcellular distribution of indium gallium phosphide-zinc sulfide (InGaP/ZnS) nanoparticles in microglia and astrocytes. MATERIALS & METHODS The extent of colocalization between the nanoparticles and organelles was assessed by confocal microscopy, spectrofluorometry and cell sorting. RESULTS Cell treatment with a common fatty acid (oleic ...

We have recently shown that a large proproportion of earthworm coelomocytes exhibit strong autofluorescence in some species (Dendrobaena veneta, Allolobophora chlorotica, Dendrodrilus rubidus, Eisenia fetida, and Octolasion spp.), while autofluorescent coelomocytes are very scarce in representatives of Lumbricus spp. and Aporrectodea spp. Riboflavin (vitamin B2) was identified as a major fluoro...

Fluorescein-labeled immunoglobulin G (IgG) fractions of serum from patients with acute poststreptococcal glomerulonephritis stained parts of the glomerular basement membrane and mesangium of kidney tissue obtained from the same patients during the early phase of the disease. Renal tissue obtained from normal individuals and from patients with other kidney diseases failed to stain with these IgG...