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Biomedical subjects

E Lorenzo

Publications and source records attributed to E Lorenzo.

24 records · Page 2Linked to original sources
PubMed1996

Enzyme support systems for biosensor applications based on gold-coated nylon meshes.

A novel experimental protocol for enzyme immobilization based on the use of a very permeable support is described and applied to the development of an acetylcholinesterase (AChE) based biosensor. In this system, the enzyme was immobilized onto a gold-coated nylon mesh via a self-assembled monolayer of a bifunctional reagent, cystamine, preadsorbed onto the gold surface. This support has been characterized by optical microscopy and electrochemical measurements of permeability. In the assembled biosensor, the AChE modified mesh was placed over a glassy carbon electrode and the response to 4-aminophenylacetate, used as substrate, was monitored via the enzymatic reaction product, 4-aminophenol, by oxidation at +0.25 V vs. SSCE. This approach to biosensor design has been extended to the determination of organophosphorus and carbamate pesticides by their inhibition of AChE enzymatic activity.

Acetylcholinesterase↗
PubMed1995

[Health education in school].

OBJECTIVES: To discover the contents of health education taught at present in the EGB (basic) schools of Castelldefels, the opinions of teachers on health education in schools, and to stimulate reflection among teachers and health-workers on health education at school. DESIGN: A crossover study using a self-administered questionnaire. SETTING: EGB schools in the town of Castelldefels. PARTICIPANTS: All the EGB teachers in Castelldefels (n = 261). MEASUREMENTS AND MAIN RESULTS: 148 teachers (57%) replied to the survey. Health education was considered necessary by 56.8% and essential by 33.1%. They needed technical support and adequate material to carry it through. Integration of health education into the teaching programmes of the school syllabus's different subjects was the best way of carrying it out, in the view of the majority. The advantage of different subjects coincided with those described in the "Health Plan for Catalonia". CONCLUSIONS: Given that we consider teachers to be the professionals best-placed to carry out health education at school, it is useful to confirm their awareness of its importance. As health education is also an objective of the primary care teams, these should be the reference and support point for teachers' demands for technical help.

Adult↗
PubMed1990

Dormancy in Peach (Prunus persica L.) Flower Buds : I. Floral Morphogenesis and Endogenous Gibberellins at the End of the Dormancy Period.

Flower buds of peach (Prunus persica L.) trees, cv Novedad de Cordoba (Argentina), were collected near the end of the dormant period and immediately before anthesis. After removal of scale leaves, morphological observations of representative buds, made on transverse and longitudinal microtome sections, showed that all verticils making up the flower are present in an undifferentiated form during the dormant period (June). Flower buds collected at the end of dormant period (August) showed additional growth and differentiation, at which time formation of two ovules was beginning in the unicarpelar gynoecium. Dehiscence of anthers had not yet occurred 10 days before full bloom, and the ovules were still developing. Free endogenous gibberellin (GA)-like substances were quantified by bioassay (Tan-ginbozu dwarf rice microdrop) after SiO(2) partition column chromatography, reversed phase C18-high performance liquid chromatography, and finally Nucleosil [N(CH(3))(2)]high performance liquid chromatography. Bioactive fractions were then subjected to capillary gas chromatography-mass spectrometry-selected ion monitoring (GC-MS-SIM). Gibberellins A(1), A(3), and A(8) were tentatively identified in peach flower buds using GC-SIM and Kovat's retention indices, and relative amounts approximated by GC-SIM (2:8:6 for GA(1), GA(3), and GA(8), respectively). The highest concentration (330 nanograms per gram dry weight) of free GA(1)/GA(3) was found in dormant buds (June) and diminished thereafter. The concentration free of GA(1)/GA(3) did not increase immediately prior to bud break. However, high GA(1)/GA(3) concentrations occurred during stages where rate of growth and cellular differentiation of (mainly fertile) verticils can be influenced.

Journal Article↗