Galectins are a family of animal lectins defined by two properties: shared amino acid sequences in their carbohydrate-recognizing domain, and beta-galactoside affinity. A wide variety of biological phenomena are related to galectins, i.e., development, differentiation, morphogenesis, tumor metastasis, apoptosis, RNA splicing, and immunoregulatory function. In this review, we will focus on galectin-1 receptors, and some of the mechanisms by which this lectin affects different cell types. Several galectin-1 receptors are discussed such as CD45, CD7, CD43, CD2, CD3, CD4, CD107, CEA, actin, extracellular matrix proteins such as laminin and fibronectin, glycosaminoglycans, integrins, a beta-lactosamine glycolipid, GM1 ganglioside, polypeptide HBGp82, glycoprotein 90 K/MAC-2BP, CA125 cancer antigen, and pre-B cell receptor.

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Lead is a multiple-source pollutant, well known for its toxicity, of great risk both for the environment and human health. The main target organs of lead are the hematopoietic, nervous, and renal systems; there are also reports in support of its impairment effects on the reproductive and immune systems. It is well known that most of the metal is accumulated in the blood cells and that many of the deleterious effects are related to its circulating concentrations. These adverse effects have been described not only in humans but also in a number of other vertebrates such as fish and birds. The purpose of the present work was to evaluate the effects of weekly administration of sublethal Pb (as acetate, 50 mg x kg(-1)) during 6 weeks on the profile of the serum proteins and blood cell counts of the adult South American toad, Bufo arenarum (Anura: Bufonidae). The electrophoretic patterns of serum proteins pointed out the presence of four fractions; the metal provoked a significant decrease in both total proteins and albumin fraction; among the globulin fractions, the G3 resulted augmented. These findings may be related to the impact of lead on the toads' hepatic cells and immune system. The number of total red blood cells (RBC) showed a tendency to decrease after the injections of the metal, whereas the number of white blood cells (WBC) increased significantly; the differential leukocyte counts showed a statistically significant increase in the absolute number and in the relative percentage of blast-like cells. The decrease in RBC was attributed to the negative impact of the metals on the hemoglobin synthesis. The increasing of the WBC counts may be interpreted as a consequence of the induction of proliferation of pluripotential hematopoietic cells.

Abbreviations: A absorbance; EIA enzyme-linked immunoassay; EPO erythropoietin; Hb hemoglobin.The measurement of erythropoietin (EPO) is useful for diagnosis and follow up of several pathologies which produce anemia. It can be also used in the differentiation of primary and secondary polycythemias. Simple cost-effective and sensitive methodologies for the EPO determination in clinical laboratories have been developed in the last two decades (1, 2). In our laboratory we have evaluated some previously described (3) performance characteristics of an EPO enzyme-linked immunoassay (EPO-EIA) alkaline phosphatase conjugate, marketed by JCL Clinical Research (Knowxville, USA; Cat. N° JCL 2-500MCT). We have also verified the manufacturer's reference interval.Three kits (Lot. N° 700138) were used. Tests were done by duplicates as recommended by the manufacturer (4), and the absorbance (A) was measured at 410 nm in an E-max ELISA reader (Molecular Device Corporation, Sunnyvale, USA). To verify that the reader functioned correctly, the photometric linearity at 405 nm was assessed with reference solutions of p-nitrophenol at four different concentrations. These data (A: 0.210, 0.420, 0.833, and 1.633) correlated with the A values (0.193, 0.390, 0.771 and 1.520) obtained in a diode array Hewlett Packard spectrophotometer (correlation coefficient r = 0.99995). Each EIA duplicate was within ± 0.022 AU. Variation was lower than that claimed by the manufacturer (± 0.05 AU). Calibration curves with the five standards included in the kit were determined. Results are shown in Table 1. Our CV which illustrate plate-to-plate and day-to-day variability (intralaboratory assay data) were higher than those described previously (12.8, 6.6, 9.5, 12.0, and 10.9% for 1, 10, 50, 100, and 500 mIU/ml, respectively) (3). We also assayed an EPO control kit with low (L), mid (M) and elevated (E) concentrations (Cat. N° JCL 1-101; Lot. N° 000443), in the same conditions as standards and specimens (Table 1). In both the calibration curve standards as well as the L and E controls, values were lower than those described in JCL brochures, which indicate a defect in the calibration or in the standards employed. The latter seems less probable as it is claimed that the preparations have been checked against laboratory preparations of EPO previously calibrated against the International Reference Preparation IRP # 1 (Standard B) for erythropoietin. We also introduced an internal control (normal serum); a CV of 7.2% was obtained which, as expected, is lower than those from commercial controls.Subsequently, we verified the manufacturer's reference interval (range: 22-54 mIU/ml, 150 individuals). For this purpose we obtained serum samples from 41 Tab.

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