Immunoaffinity column clean-up techniques in food analysis: A review

This review provides a critical assessment of the applications of immunoaffinity columns for sample clean-up in the field of food safety. The performance of immunoaffinity columns are compared in terms of specificity, binding capacity and recovery, and commercial disposable columns are contrasted with home-made columns. Areas covered include multiple-use of columns, multiple-analyte columns, use with automated systems and validation of IAC methods. Publications illustrating the many varied applications of IAC for sample clean-up in the areas of mycotoxins, veterinary drug residues, pesticide residues, environmental contaminants and vitamins have been compiled, comparing extraction methods, achievable recovery, and illustrating the variety of end-detection methods that have been employed.     

The effect of lipoic acid on wound healing in a full thickness uterine injury model in rats

Aim of this study was to investigate the effects of lipoic acid on uterine wound healing by immunohistochemical and biochemical assay in a rat uterine horn model with full thickness injury. Thirty-two female Wistar albino rats were randomised into five groups: Control group, with no intervention; uterine scar group 15days (US15d), uterine scar group 15 days + alpha lipoic acid (ALA) (US15d + ALA), uterine scar group 30 days (US30d) and uterine scar group 30 days + ALA (US30 days + ALA). After uterine incision 100 mg/kg of ALA was administered by oral gavage for either 15 or 30 days. Vascular endothelial growth factor (VEGF) and alpha smooth muscle actin (α-SMA) distribution were evaluated by immunohistochemical methods in tissue and ELISA methods in tissue homogenate. The percentage of α-SMA positive area in US15d + ALA and US30d + ALA groups was significantly higher than US15 and US30d groups. The percentage of VEGF positive area in US15d + ALA group was significantly higher than US15d group and US30d + ALA group was significantly higher than US30d group. Biochemically, α-SMA was significantly higher in the US15d + ALA group when compared to US15d group and higher in US30d + ALA group when compared to US30d group. VEGF was significantly higher in US15d + ALA and US30d + ALA groups when compared to US15 and US30d groups. In conclusion, ALA was found to be effective in enhancing wound healing in uterine full thickness injury.     

Calcium, magnesium, and zinc status in experimental hypothyroidism

In this study, experimental hypothyroidism was established and used to investigate possible alterations in the calcium, magnesium, and zinc homeostasis by assessing their concentration in plasma and erythrocytes. Hypothyroidism was induced by administration of methimazole an iodine blocker at a dose of 75 mg/100 g food for 3 wk. In the methimazole-induced hypothyroid state, the experimental animals showed a significant decrease in plasma zinc concentration, whereas a significant increase in plasma magnesium concentration occurred. No change was observed in plasma calcium concentration. The erythrocyte zinc and calcium concentrations were found to be increased, whereas magnesium concentration decreased. Erythrocyte magnesium concentration showed a significant positive correlation with T₄ values. The study provides evidence for marked alterations in homeostatis of zinc, magnesium, and calcium.     

Reversible lysozyme immobilization onto N,N′-bis-(3-(4-morpholino)-propyl)-3,4,9,10-perylenetetracarboxylic acid dimide (MPPDI) attached polymeric nanospheres

Novel hydrophobic nanospheres with an average size of 200 nm utilizing N,N′-bis-(3-(4-morpholino)-propyl)-3,4,9,10-perylenetetracarboxylic acid dimide (MPPDI) as a monomer were prepared by surfactant free emulsion polymerization of 2-hydroxyethyl methacrylate (HEMA) and MPPDI conducted in an aqueous dispersion medium. The nanospheres were used for the adsorption of lysozyme. The system parameters, such as effect of the adsorption conditions (i.e. enzyme concentration, medium pH, and temperature) and the reusability of the support were studied. Specific surface area of the nonporous nanospheres was found 664 m²/g. Poly(HEMA–MPPDI) nanospheres were characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis and scanning electron microscopy (SEM). Then, poly(HEMA–MPPDI) nanospheres were used in the adsorption of lysozyme in batch system. Using an optimized adsorption protocol, 400 mg lysozyme/g nanosphere loading capacity was obtained. The adsorption phenomena appeared to follow a typical Langmuir isotherm. Lysozyme could be repeatedly adsorbed and desorbed with poly(HEMA–MPPDI) nanospheres without noticeable loss in the adsorption capacity.     

Analysis of the Alpha-1-Antitrypsin Deficient Alleles M3S, MZ, and ZZ by Biochemical and Molecular Methods: A Family Study

Deficiency of alpha-1-antitrypsin (α₁-AT, a major protease inhibitor controlling tissue degradation) is a genetic disorder transmitted in a codominant autosomal form. It has more than 100 genetically determined variants. This study attempted to determine the degree of association between serum α₁-AT levels and phenotypes and to provide a strategy for reliable laboratory evaluation of deficiencies. The study group consisted of a 38-year-old male proband with clinical features of emphysema, his first-degree relatives, and healthy controls. Family history revealed a four-generation pedigree. Genomic DNA was isolated from peripheral blood leukocytes. Alpha-1-AT levels were determined from human serum by immunonephelometry. Phenotypes were determined by isoelectric focusing of blood samples. DNA sequences of coding exons were analyzed by the amplification DNA technique and direct sequencing. Inheritance and plasma levels of the ZZ, MM, M3S, and MZ phenotypes were confirmed by the family study. In the family members with deficiencies, plasma concentrations were 22.55% ± 5.15 (ZZ), 84.18% ± 5.18 (M3S), and 61.06% ± 7.15 (MZ) of the normal MM level. We found a close association between α₁-AT level and genotype. A combination of genotyping, quantification, and phenotyping is the optimal strategy for the laboratory evaluation of α₁-AT deficiency.