Elena Real Rodríguez

Detection of cows' milk in ewes' milk and cheese by an indirect enzyme-linked immunosorbent assay (ELISA)

An indirect enzyme-linked immunosorbent assay was successfully developed for the detection of defined amounts of cows milk (1-50%) in sheeps milk and cheese. The assay used polyclonal antibodies raised in rabbits against bovine caseins (BC). The anti-BC antibodies were recovered from the crude antiserum by immunoadsorption and elution from a column containing BC. The antibodies were biotinylated and rendered cows milk specific by mixing them with lyophilized ovine and caprine caseins. ExtrAvidin-peroxidase was used to detect the biotinylated anti-BC antibodies bound to BC immobilized on 96-well plates. Subsequent enzymic conversion of substrate gave clear absorbance differences when assaying mixtures of sheeps milk and cheese containing variable amounts of cows milk.

Synthesis of methyl 4-aryl-6-methyl-4,7-dihydro-1H-pyrazolo-[3,4-b]pyridine-5-carboxylates from methyl 4-aryl-6-methyl-2-oxo-1,2,3,4-tetrahydropyridine-5-carboxylates

Novel methyl 4,7-dihydro-1H-pyrazolo[3,4-b]pyridine-5-carboxylates 3a–e have been prepared in a two step procedure from the readily available 2-oxo-1,2,3,4-tetrahydropyridine-5-carboxylates 1a–e by treatment with the Vilsmeier–Haack reagent. Further treatment of the novel o-chloroformyl substituted methyl 1,4-dihydropyridine-5-carboxylates 2a–e with hydrazine affords the corresponding methyl pyrazolo[3,4-b]pyridine-5-carboxylates in good yields. Semiempirical calculations reveal a favoured geometry with a boat conformation in the dihydropyridine system and a planar pyrazole ring.

Development of a cows' milk identification test (COMIT) for field use

A cows milk identification test (COMIT) has been successfully developed for the detection of defined amounts of cows milk (3-100%) in ewes milk. The assay uses polyclonal antibodies raised in goats against bovine whey proteins. The test, an agar-gel immunodiffusion technique, uses agar plates with a printed template for correct placement of the test components (antisera discs, positive and negative milk reference discs and sample discs). The presence of cows milk in the sample was recorded as positive when the precipitin lines appearing between the sample disc and the antisera disc fuse completely with those from the positive cows milk reference disc. This test is reliable, practical and easy to perform in the field and in dairy factories. Furthermore, the nature and stability of the components of the test make it suitable for commercial development into kits which should be highly practical in any kind of inspection programme concerned with milk species identification.

Sandwich ELISA for detection of goats’ milk in ewes’ milk and cheese

A sandwich ELISA has been developed for the detection of defined amounts of goats’ milk (1–100%) in ewes’ milk and cheese. Polyclonal antibodies were raised in rabbits against goat caseins (GC). The resultant antibodies were affinity purified by immunoadsorption of the crude antiserum on to columns containing immobilized cow, ewe and goat caseins, followed by elution of the goats’ milk‐specific antibodies (anti‐GC) from the column containing the goat caseins. The anti‐GC antibodies bound to the wells of a microtiter plate were used to capture the goats’ caseins from milk or cheese mixtures. Further immunorecognition of the captured proteins was achieved with the same antibodies conjugated to biotin. ExtrAvidin‐peroxidase was used to detect biotinylated antibodies bound to their specific antigens. Subsequent enzymic conversion of the substrate gave clear absorbance differences when assaying mixtures of ewes’ milk and cheese containing variable amounts of goats’ milk.

Detection of Bovine Milk in Ovine Milk by a Sandwich Enzyme-Linked Immunosorbent Assay (ELISA)

A sandwich ELISA (enzyme-linked immunosorbent assay) was developed for the detection of defined amounts of bovine milk (1-30%) in ovine milk. Polyclonal antibodies were raised in rabbits against bovine whey proteins (BWP). Resultant antibodies were affinity purified by immunoadsorption of the crude antiserum onto columns containing immobilized ovine, caprine, and BWP, followed by elution of the bovine milk specific antibodies (anti-BWP) from the column containing the bovine proteins. The specific anti-BWP antibodies bound to the wells of a microtiter plate were used to capture the BWP from milk mixtures. Further immunorecognition of the captured proteins was attained with the same specific antibodies conjugated to biotin. ExtrAvidin-peroxidase was used to detect the biotinylated antibodies bound to their specific antigens. Subsequent enzymic conversion of substrate gave clear optical density differences when assaying mixtures containing variable amounts of bovine milk.

RIAM (Rap1-interacting adaptor molecule) regulates complement-dependent phagocytosis

Phagocytosis mediated by the complement receptor CR3 (also known as integrin αMß2 or Mac-1) is regulated by the recruitment of talin to the cytoplasmic tail of the ß2 integrin subunit. Talin recruitment to this integrin is dependent on Rap1 activation. However, the mechanism by which Rap1 regulates this event and CR3-dependent phagocytosis remains largely unknown. In the present work, we examined the role of the Rap1 effector RIAM, a talin-binding protein, in the regulation of complement-mediated phagocytosis. Using the human myeloid cell lines HL-60 and THP-1, we determined that knockdown of RIAM impaired αMß2 integrin affinity changes induced by stimuli fMLP and LPS. Phagocytosis of complement-opsonized RBC particles, but not of IgG-opsonized RBC particles, was impaired in RIAM knockdown cells. Rap1 activation via EPAC induced by 8-pCPT-2′-O-Me-cAMP resulted in an increase of complement-mediated phagocytosis that was abrogated by knockdown of RIAM in HL-60 and THP-1 cell lines and in macrophages derived from primary monocytes. Furthermore, recruitment of talin to ß2 integrin during complement-mediated phagocytosis was reduced in RIAM knockdown cells. These results indicate that RIAM is a critical component of the phagocytosis machinery downstream of Rap1 and mediates its function by recruiting talin to the phagocytic complement receptors.

Detection of goats’ milk in ewes’ milk by an indirect elisa

An indirect ELISA has been developed successfully for the detection of defined amounts of goats’ milk (1–100%) in ewes’ milk. The assay uses polyclonal antibodies against goats’ whey proteins (GWP) raised in rabbits. The anti‐GWP antibodies were recovered from the crude antiserum by immunoadsorption and elution from a column containing immobilized GWP. The anti‐GWP antibodies were biotinylated and rendered goats’ milk‐specific by mixing them with lyophilized cows’ and ewes’ whey proteins. ExtrAvidin‐peroxidase was used to detect the specific anti‐GWP antibodies bound to goats’ milk proteins immobilized on 96‐well plates. Subsequent enzymic conversion of substrate resulted in discernible differences in optical density between mixtures of ewes’ milk containing variable amounts of goats’ milk.

Determination of the herbicide desmetryne in organised media by adsorptive stripping voltammetry

An electroanalytical method for the determination of the herbicide desmetryne at nanomolar levels in dispersed media, based on adsorptive stripping voltammetry, is reported. The adsorption of desmetryne at the hanging mercury drop electrode was checked both in micellar solutions, where the anionic surfactant sodium pentanesulphonate was chosen as the most suitable surfactant agent, and in oil-in-water emulsions prepared with ethyl acetate as the organic solvent. In a micellar medium formed with 0.02% sodium pentanesulphonate and with 0.1 mol l(-1) Britton-Robinson buffer (pH 1.5), the herbicide could be determined over the 1.0 x 10(-8)-4.0 x 10(-7) mol l(-1) concentration range, when an accumulation potential of -0.70 V was applied for 50 s. On the other hand, in an oil-in-water emulsion formed with 2% ethyl acetate and 0.04% sodium pentanesulphonate as emulsifying agent in 0.1 mol l(-1) HClO(4), desmetryne could be determined over the 2.0 x 10(-9)-1.0 x 10(-7) mol l(-1) concentration range. The limits of detection were 2.4 x 10(-9) and 4.2 x 10(-10) mol l(-1) in micellar and emulsified media, respectively, with R.S.D.s (n=10) 3.6 and 3.7%. The degree of interference from some other s-triazines on the desmetryne differential pulse response was also evaluated. Finally, the method developed in emulsified medium was applied to the determination of desmetryne in spiked apple juice.

Indirect enzyme‐linked Immunosorbent assay for detection of cow's milk in goat's milk

An indirect enzyme‐linked immunosorbent assay (ELISA) has been developed for the specific detection of cows milk (1–25%) in goats milk. The test uses polyclonal antibodies raised in rabbits against bovine whey proteins (BWP). The anti‐BWP antibodies were recovered from the crude antiserum by immunoadsorption and elution from a column containing immobilized BWP. The anti‐BWP antibodies were biotinylated and rendered cows milk specific by mixing them with lyophilized ovine and caprine whey proteins. Streptavidin‐peroxidase was used to detect the biotinylated anti‐BWP antibodies bound to bovine milk proteins immobilized on 96‐well plates. The colour developed by the subsequent enzymic conversion of the substrate gave clear absorbance differences when assaying mixtures of goats milk containing variable amounts of cows milk.

Algunos interrogantes en torno a los estudios de Periodismo ante el nuevo Espacio Europeo de Educación Superior

Este articulo expone ciertas cuestiones que se le plantean a los estudios de Periodismo ante su proxima adaptacion al nuevo escenario educativo que supone el denominado Espacio Europeo de Educacion Superior. El acercamiento de los sistemas de formacion de los distintos paises de la Union Europea, encaminado a procurar una mayor “comparabilidad” y “compatibilidad” que fomente la movilidad de estudiantes y profesores y que, a largo plazo, facilite tambien las dificultades que aun se presentan en la libre circulacion de profesiones, podria generar ciertos cambios en la forma en como esta disenada en la actualidad esta carrera en nuestro pais.