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The levels of polyamines (PAs) in urine are an important biomarker of physiological and pathological phenomena for humans.Due to its importance, the validation of a PAs determination methodology was validated for (Putrescine (Pu), Cadaverine(Cdv), Spermidine (Spd), Spermine (Spm), Epinephrine (Epf) and Histamine (Hst) in urine by Reversed-phase HighPerformance Liquid Chromatography (RP-HPLC) with pre- column derivatization using dansyl chloride and UV detection at254 nm. To this aim, selectivity, working range and linearity, detection /quantification limit were determined. The precision (asrepeatability and precision under intermediate conditions), accuracy (measured as recovery) and robustness were established.The methodology was adapted from the Chilean Standard for the detection of histamine and other biogenic amines in fish andshellfish ME-711.O4-070, 2014, so it was necessary to implement adjustments for its application in urine. The results showedthat amino acids (AAs) did not cause interference in the analysis of PAs, and allow determination of concentrations in thelinear range between 4 and 28 μg/mL. However, good recovery (accuracy) was not obtained in the experiment, possiblybecause the standards used were not acetylated (42.6% Pu and 69% Cdv). The present methodology allows determining thelevels of Pu, Cdv, Spd, Spm Hst and Efd in urine samples from humans and other mammalian species.

The Mexican Regulations on milk classifies a product as adulterated when it has either undergone treatment that conceals its alteration and/or defects in its process or in the sanitary quality of the raw materials, among other criteria. The principal, most widely known adulterants incorporated into milk, include those added to increase milk volume and mask acidification. Milk should also test negative for the presence of inhibitors,e.g. antibiotics or disinfectants. The objective of this work was to determine the LOD for starches, sucrose, gelatin, chlorinated disinfectants; oxidants, quaternary ammonium and 14 most widely used microbial growth inhibitors in milk. This is because although the prohibition of these substances is clearly established, the detection limits (LOD) are not declared in the current regulation. With this finality, qualitative chemical analytical methodologiesfor detection of adulterants described in the Mexican Standards were implemented, as well as for the Yogurt Inhibition Test. Microbiological quality skim milk powder was used as a negative control, and the commercial culture YO-MIX ™ was used for the Yogurt Inhibition Test. The following LOD were obtained by chemical methods for starches (125and250 mg/kg), gelatin (250 mg/kg), hydrogen peroxide (6 mg/kg), sodium hypochlorite (25 mg/kg), benzalkonium chloride (12 mg/kg), N-Alkyl (C12,16) -N, N-dimethyl-N-benzylammonium (6 mg/kg). The yogurt test showed higher LOD for the disinfectants: 25,000 mg/kg for sodium hypochlorite and 60 mg/kg for the quaternary ammonium compounds. On the other hand, although oxidants were not detectable the yogurt testwas sufficiently sensitive to detect the Maximum Residue Limits (MRLs) for the 14 antimicrobials tested. Carrying out both types of tests, chemical and yogurt, to determine disinfectants and inhibitors at the levels of interest in milk is recommended.

Proposing animal models that allow predicting results in humans becomes critical when the analogies in physiology between both entities are reviewed. About heart disease, the heart rate in humans is more similar to that of chickens than that of the mouse, rat or other mammalian models generally used to study this disease. In the present work, the ethology on the attraction of chickens to earthworms as a food source was reviewed, in addition hematological, organ and urological parameters were measured in chickens fed with double and triple the protein percentage supplied with Eisenia foetida live added to the feed. commercial for the Cobb500 line. The results show a marked attraction depending on the nutritional status of the birds for Eisenia foetida and differences in hematological parameters, but not for urological parameters. The morphological characteristics of the heart showed a clear association between three times the protein load in the food and cardiac damage in 2 of 7 animals fed during 7 weeks of study. The present work represents the first contribution with the animal model approach in chickens to study cardiac damage and its possible prediction for humans.

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