An enzyme immunoassay to determine human chorionic gonadotropin (HCG) in serum and urine samples using an ultra-microanalytical system.

The determination of Human Chorionic Gonadotropin (HCG) in biological fluids is of great interest in the early pregnancy diagnostics, the evaluation of pregnancy disorders, as a tumor marker, as a screening procedure for anti-doping control, and many other purposes. A simple sandwich-type UltraMicro Enzyme-Linked ImmunoSorbent Assay (UMELISA) has been developed for the measurement of HCG in serum and urine samples. Strips coated with a high affinity MAb directed against HCG are used as solid phase, to ensure the specificity of the assay. The HCG assay was completed in 1.5 h, with a measuring range of 0.76-400 mIU/mL. The intra- and inter-assay coefficients of variation were lower than 10 %, depending on the HCG concentrations evaluated. Recovery percentages were 96.43-97.16 % (serum) and 98.10-99.04 % (urine). The assay detected intact HCG, nicked HCG, HCG ß, and nicked HCG ß, and did not recognize any of the interfering molecules tested. Regression analysis showed a good correlation with Elecsys in serum (n = 1459, r = 0.952, ρc = 0.948) and urine (n = 869, r = 0.988, ρc = 0.978). A good correlation was also found with 84 RIQAS samples analyzed with the kits Elecsys (r = 0.969, ρc = 0.957), Architect (r = 0.982, ρc = 0.970), Dimension (r = 0.989, ρc = 0.977), and Bioscience (r = 0.992, ρc = 0.980), all with a p < 0.01. Comparison with transvaginal ultrasonography in early pregnancy detection showed a specificity and a sensitivity of 100 % (n = 2385, κ = 1). The analytical performance characteristics of UMELISA HCG endorse its use for the quantification of HCG in serum and urine samples. This assay will make a cost-effective diagnostic kit accessible to low-income countries and is now available in the Cuban Public Health System.

Virulencia, inmunogenicidad y capacidad de colonización de cepas atenuadas de vidrio cholerae administradas de forma simultáneas en modelos animales / Virulence, immunogenecity and colonizing capability of vidrio cholerae-attenuated strains simultaneously administered in animal models

Disponer de una vacuna eficaz y segura contra el cólera, continúa siendo la mejor alternativa para el control de la enfermedad. En Cuba se ha obtenido un grupo de cepas atenuadas de V. Cholerae y una de ellas-la cepa 638- ha sido evaluada en voluntarios inoculados por vía oral. en el presente trabajo se realizó la evaluación preclínica de virulencia, inmunogenicidad y capacidad colonizadora de las cepas 638 y 413 de V. Cholerae de los serotipos Ogawa e Inaba respectivamente, administradas simultáneamente en animales de experimentación. Ambas cepas mostrarón un nivel de atenuación aceptable y una capacidad colonizadora comparable entre ellas y con las de las cepas salvajes utilizadas como control. Además lograrón niveles de seroconversión apreciable a los 7 días de inoculados y altos títulos de anticuerpos específicos contra antígenos de V. Cholerae(AU)