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Biomedical subjects

C Hidalgo

Publications and source records attributed to C Hidalgo.

97 records · Page 6Linked to original sources
PubMedDate not supplied

Complement fixation by Rh blood group antibodies.

Rh blood group antibodies normally do not fix complement. Rh positive intact red blood cells treated with papain do not lyse when incubated with corresponding antibody and complement. This study was done to determine if complement fixation occurs when antibodies were combined with Rh positive red blood cell ghosts untreated or treated with papain. Complement fixation was observed with IgG anti-D, anti-DC and anti-c when papain treated ghosts were used. No complement fixation or a smaller degree of it was observed in the case of untreated Rh positive red blood cell ghosts when incubated with similar anti-Rh antibodies. It is concluded that the papain treatment of Rh positive red blood cell ghosts, possibly by inducing aggregation of antigen sites, allowed complement binding by Rh antibodies.

Animals↗
PubMedDate not supplied

Determination of glyphosate residues in plants by precolumn derivatization and coupled-column liquid chromatography with fluorescence detection.

A rapid method was developed for the trace-level determination of glyphosate in olives. After extraction of the glyphosate with water-dichloromethane and simultaneous removal of the olive oil, an aliquot of the aqueous extract is derivatized with 9-fluoroenylmethyl chloroformate (9-fluorenylmethoxycarbonyl chloride; FMOC-CI) to produce a highly fluorescent derivative. A 2 mL aliquot of this extract is injected directly into a coupled-column liquid chromatography system with fluorimetric detection (LC/LC-FD). The procedure was validated by recovery experiments at 3 spiking levels; recoveries ranged from 80 to 97% with relative standard deviations of 3-6%. The limits of detection and quantitation were estimated to be 0.01 and 0.05 mg/kg, respectively. The method was also applied to other plant materials, i.e., tomato plants, strawberry plants, and pear trees (branches, leaves, and fruits) suspected to be contaminated by glyphosate. In all these cases, the extraction was performed in aqueous media. The derivatization reaction was modified by increasing the FMOC-CI concentration, to ensure a quantitative reaction between analyte and reagent in the presence of high levels of coextractives, which also react with FMOC-CI. The final determination was by LC/LC-FD, yielding a rapid, selective, and sensitive method for the determination of glyphosate residues in these samples. The method was tested with real-world samples after application of glyphosate to the surrounding area of crops.

Chromatography, Liquid↗