Determination of Lead in Bee Products by Solid Surface Fluorescence Using Complexation and Coacervation at Room Temperature Processes. An Environmental Friendly Methodology.

An accurate, economic and green methodology for Pb(II) monitoring in bee products is proposed. Complexed metal traces were preconcentrated on Nylon membranes using the coacervation phenomenon based on room temperature reaction between the cationic surfactant hexadecyltrimethylammonium bromide and the bile salt sodium cholate. The increase in solid surface fluorescence signal of dyes 8-hydroxyquinoleine and o-phenanthroline due to Pb(II) presence was used for the metal quantification.

Sonochemical Synthesized Manganese Oxide Nanoparticles as Fluorescent Sensor for Selenium (IV) Quantification. Application to Food and Drink Samples.

Manganese oxide nanoparticles (MnO Nps), sonochemical synthesized and characterized in our laboratory, are proposed as fluorescent sensor for selenium (Se) determination. The new methodology has been developed based on the enhancing effect of the Se(IV) on fluorescent emission of MnO Nps. Experimental variables that influence on fluorimetric sensitivity were optimized.

Copper Traces Quantification in Bee's Products by Solid Surface Fluorescence. A Green Analytical Proposal.

A new methodology based on the fluorescence of Cu(II) ternary system with o-phenanthroline (o-Phen) and eosin (Eo) dyes is proposed. The metal was selectively retained on Nylon membranes and the solid surface fluorescence (SSF) was used for anayte quantification. Experimental variables that influence the formation of Cu(II)-o-Phen-eo system and retention step were studied and optimized.

Determination of lead traces in honey using a fluorimetric method.

Heavy traces metals may be present in honey being their detection very important for the quality control and it also serves as an indicator of environmental pollution. A new methodology for lead traces determination has been developed based on the quenching effect of the metal on fluorescent emission of 8-hydroxyquinoline and o-phenanthroline at λ = 360 nm (λ = 250 nm). Experimental variables that influence on fluorimetric sensitivity were optimized by uni-variation assays.

Novel method for metalloproteins determination in human breast milk by size exclusion chromatography coupled to inductively coupled plasma mass spectrometry.

Levels of essential metals in human breast milk (HBM) have been determined by different analytical techniques, but there is few woks about human whey milk fractions. However, the current trend lies in metalloproteomic and identification of different metalloproteins. In this sense, native separative techniques (N-PAGE and SEC) coupled to ICP-MS provide us with valuable information.

Evaluation of nitroxyl donors' effect on mycobacteria.

Nitroxyl (HNO) is a highly elusive and reactive molecule. Nitroxyl biological effects and pharmacological potential are becoming increasingly relevant. Mycobacterium tuberculosis infection needs new and more efficient drugs.

Sequential determination of nickel and cadmium in tobacco, molasses and refill solutions for e-cigarettes samples by molecular fluorescence.

In this work, a new procedure was developed for separation and preconcentration of nickel(II) and cadmium(II) in several and varied tobacco samples. Tobacco samples were selected considering the main products consumed by segments of the population, in particular the age (youth) and lifestyle of the consumer. To guarantee representative samples, a randomized strategy of sampling was used.

ICPMS analysis of proteins separated by Native-PAGE: Evaluation of metaloprotein profiles in human synovial fluid with acute and chronic arthritis.

The role of trace elements bound to proteins in the etiology and pathogenesis of rheumatoid arthritis (RA) remains unclear. In this sense, the identification and detection of metalloproteins has a strong and growing interest. Metalloprotein studies are currently carried out by polyacrylamide gel electrophoresis (PAGE) associated to inductively coupled plasma mass spectrometry (ICPMS), and despite that complete information can be obtained for metals such as Fe, Cu and Zn, difficulties due to poor sensitivity for other trace elements such as Sn, As, etc, are currently faced.

Role of macrophage secretions on rat polycystic ovary: its effect on apoptosis.

Polycystic ovarian syndrome is the most common endocrine disorder among women of reproductive age. Little is known about its etiology, although the evidence suggests an intrinsic ovarian abnormality in which endocrine, metabolic, neural and immune factors would be involved. In this work, the effects of macrophage (MO) secretion on ovarian apoptosis in a polycystic ovary syndrome rat model (PCO rat) induced by estradiol valerate are studied.

New solid surface fluorescence methodology for lead traces determination using rhodamine B as fluorophore and coacervation scheme: Application to lead quantification in e-cigarette refill liquids.

A new environmental friendly methodology based on fluorescent signal enhancement of rhodamine B dye is proposed for Pb(II) traces quantification using a preconcentration step based on the coacervation phenomenon. A cationic surfactant (cetyltrimethylammonium bromide, CTAB) and potassium iodine were chosen for this aim. The coacervate phase was collected on a filter paper disk and the solid surface fluorescence signal was determined in a spectrofluorometer.

Novel method for determination of zinc traces in beverages and water samples by solid surface fluorescence using a conventional quartz cuvette.

A new method for zinc pre-concentration/separation and determination by molecular fluorescence is proposed. The metal was complexed with o-phenanthroline and eosin at pH 7.5 in Tris; a piece of filter paper was used as a solid support and solid fluorescent emission measured using a conventional quartz cuvette.

Sequential determination of lead and cobalt in tap water and foods samples by fluorescence.

In this work, a new procedure was developed for the separation and preconcentration of lead(II) and cobalt(II) in several water and foods samples. Complexes of metal ions with 8-hydroxyquinolein (8-HQ) were formed in aqueous solution. The proposed methodology is based on the preconcentration/separation of Pb(II) by solid-phase extraction using paper filter, followed by spectrofluorimetric determination of both metals, on the solid support and the filtered aqueous solution, respectively.

Protective effect of soybeans as protein source in the diet against cadmium-aorta redox and morphological alteration.

We investigated the effects of cadmium exposition on thoracic aorta redox status and morphology, and the putative protective effect of soybeans in the diet. Male Wistar rats were separated into 6 groups: 3 fed with a diet containing casein and 3 containing soybeans, as protein source. Within each protein group, one was given tap water (control) and the other two tap water containing 15 and 100 ppm of Cd(2+), respectively, for two months.

Caffeine monitoring in biological fluids by solid surface fluorescence using membranes modified with nanotubes.

Background: In this work, a new methodology based upon enhancement of rhodamine B fluorescent signal is proposed for the quantification of caffeine traces.

Methods: Membrane filters treated with multiple wall carbon nanotubes were employed as solid support for determination step by solid surface fluorescence.

Results: Experimental variables that influence the preconcentration step and fluorimetric sensitivity have been optimized using uni-variation assays, presenting linearity from 1.

Determination of cadmium in tobacco by solid surface fluorescence using nylon membranes coated with carbon nanotubes.

A new methodology based on fluorescent signal enhancement of o-cresolphthalein (o-CPT) for traces of cadmium determination is proposed. The dye was retained on membrane filters in the presence of a micellar surfactant solution of carbon nanotubes (CNTs). All the experimental variables that influence both the preconcentration procedure and the fluorimetric sensitivity were carefully optimized.

Cellular associations of pituitary gonadotrophs in a rodent (Lagostomus maximus maximus) with photoperiod-dependent reproduction.

The morphological characteristics and percentage of the cellular associations between gonadotrophs (LH- and FSH-secreting cells) and other cellular types were studied in pituitary pars distalis of adult male viscachas (Lagostomus maximus maximus) by double immunohistochemistry using specific antibodies to LH, FSH, PRL, GH, ACTH, TSH and S-100 protein (by folliculostellate cells; FSC), during long and short photoperiods. Bihormonal gonadotrophs were observed in ventro-medial and dorsal regions, interspersed between monohormonal gonadotrophs, and their number increased in short photoperiod. LH- and FSH-gonadotrophs were found around lactotrophs, enclosed by somatotrophs in the dorsal region, and associated with irregular corticotrophs.

Effect of the photoperiod and administration of melatonin on folliculostellate cells of the pituitary pars distalis of adult male viscacha (Lagostomus maximus maximus).

Numerous reports have shown the effect of photoperiod and melatonin administration on the different hormone secreting cell types in the pituitary pars distalis. The viscacha (Lagostomus maximus maximus) is a rodent with photoperiod-dependent seasonal reproduction. The aim of this study was to examine the effect of photoperiod seasonal variations and melatonin administration on the folliculostellate cells in pituitary pars distalis of viscacha.

Folliculostellate cells in pituitary pars distalis of male viscacha: immunohistochemical, morphometric and ultrastructural study.

Unlabelled: Folliculostellate cells (FSC) have been reported in pituitary of several mammalian species. FSC morphology and secreted substances have been instrumental to the understanding of their function. The purpose of this work was to perform an immunohistochemical, morphometric and ultrastructural study of the pituitary pars distalis FSC in adult male viscacha and to analyze their relation with hormone secreting cells.

Cadmium exposure modifies lactotrophs activity associated to genomic and morphological changes in rat pituitary anterior lobe.

Cadmium (Cd) is widely used in industrial applications and is an important contaminant of agricultural products. As an endocrine disruptor, Cd modifies the hormone release of pituitary anterior lobe (PAL). This work was undertaken to evaluate a possible association between phospholipase D (PLD) and prolactin mRNA expressions and the activity of lactotrophs and folliculostellate cells (FSC) in PAL of Cd exposed adult male Wistar rats (Cd, 0.

Pituitary pars intermedia of male viscacha (Lagostomus maximus maximus): a morphometric study of seasonal and age-related changes in immunohistochemistry.

The aim of this work was to study the pituitary pars intermedia in seasonally captured adult male and immature viscachas by immunohistochemistry and image analysis. The pituitary pars intermedia exhibited a well-developed parenchyma with scarce connective tissue and vascularization. It was formed by a close association of melanotrophs and folliculostellate cells.