Identifican proteínas espermáticas involucradas en la fecundación humana

La presencia de anticuerpos antiespermáticos en diferentes fluidos biológicos puede afectar la interacción entre el espermatozoide y el ovocito y causar infertilidad. En trabajos previos de nuestro grupo se demostró que los fluidos foliculares de pacientes participantes de un programa de fecundación in vitro contienen inmunoglobulinas (IgGFF) con capacidad de alterar la función espermática, esto es, tanto inhibir la unión de los espermatozoides a la matriz extracelular del ovocito como inducir la liberación de las enzimas acrosomales (Marín Briggiler et al, Am J Reprod Immunol, 2003). El objetivo del presente estudio fue utilizar dichos anticuerpos para identificar proteínas espermáticas involucradas en la interacción de los gametos humanos. Se llevaron a cabo ensayos de Western immunoblotting en los que proteínas extraídas de espermatozoides humanos incubados en condiciones capacitantes fueron separadas por electroforesis en geles de poliacrilamida de una dimensión, transferidas a membranas de nitrocelulosa y expuestas a fluidos foliculares individuales y anticuerpos anti-IgG humana. Tres de las IgGFF capaces de alterar los eventos relacionados con la interacción de los gametos reconocieron proteínas espermáticas de 78 ± 1, 58 ± 2 y 15 ± 1 kDa. La caracterización bioquímica y molecular de estos polipéptidos permitirá confirmar su participación en la interacción espermatozoide-ovocito. Estos estudios contribuirían a dilucidar las bases moleculares del proceso de fecundación y conducirían a proponer métodos alternativos para el diagnóstico y tratamiento de la infertilidad, así como nuevas estrategias para la regulación de la natalidad.Presence of antisperm antibodies in biological fluids can alter sperm-egg interaction and cause infertility. Previous studies from our group have demonstrated that follicular fluids obtained from patients participating in an in vitro fertilization program contain immunoglobulins (FFIgG) with the ability to affect sperm function, i.e. to inhibit sperm binding to the egg extracellular matrix and/or to induce the release of acrosomal enzymes (Marín Briggiler et al, Am J Reprod Immunol, 2003). The objective of the present study was to use these antibodies to identify sperm proteins involved in human gamete interaction. Western immunoblot assays were carried out in which proteins extracted from human sperm previously incubated under capacitating conditions were separated by one dimensional polyacrylamide gel electrophoresis, transferred to nitrocellulose membranes and exposed to individual follicular fluids and anti human IgG antibodies. Three of the FFIgG with the capacity of altering gamete interaction-related events recognized sperm proteins of 78 ± 1, 58 ± 2 and 15 ± 1 kDa. Biochemical and molecular characterization of these polypeptides will confirm their participation in sperm-egg interaction. These studies would contribute to elucidate the molecular basis of the fertilization process, and would lead to propose alternative methods for infertility diagnosis and treatment, as well as new strategies for fertility regulation.Fil: Marin Briggiler, Clara Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Gonzalez Echeverría, María Fernanda. Centro Médico Fertilab; ArgentinaFil: Blaquier, Jorge. Centro Médico Fertilab; ArgentinaFil: Tezon, Jorge Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Vazquez, Monica Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Development of the magnesium alloy industry in Colombia - an opportunity [Desarrollo de la industria de aleaciones de magnesio en Colombia - una oportunidad]

Magnesium and its alloys are some of the materials that have had notable growing progress in recent years. This interest in magnesium base alloys is due to both, its physical and mechanical properties, as well as the search for alternatives to less polluting materials. In order to provide an overview of the possibilities that the use of this material has in the domestic industry, this work gives a look at the basic aspects of the material and the processes of obtaining; its most promising applications and with potential to be developed in Colombia. Finally, the authors discuss their research and results on this material, seeking to be employed as inputs for the implementation of processes and products at the commercial level. © The author; licensee Universidad Nacional de Colombia

Calcium requirements for human sperm function in vitro

To determine extracellular calcium (Ca(2+)) requirements for the maintenance of human sperm function in vitro. Prospective study. Spermatozoa were incubated for </=18 hours in media containing different CaCl(2) concentrations (maximum, 2.5 mM [control]).Fil: Marin Briggiler, Clara Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Gonzalez Echeverría, Fernanda. Fertilab; ArgentinaFil: Buffone, Mariano Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Calamera, Juan Carlos. Laboratorio de Estudios en Reproducción; ArgentinaFil: Tezon, Jorge Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Vazquez, Monica Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Diminishing benefits of urban living for children and adolescents’ growth and development

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified