Catherine Barrera

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Intra- and interprotamine cross-linking by disulphide bonds are the main factors responsible for the highly compact and stable structure of chromatin in mammalian spermatozoa. Unfixed or methanol fixed smears of human sperm and sperm suspensions from fertile donors and oligospermic patients were subjected to a reductive cleavage of disulphide bonds by using(More)
Protamine crosslinking by disulphide (-SS-) bonds in the main factor responsible for the stability of chromatin structure in mammalian spermatozoa. Sperm chromatin containing arginine/cysteine-rich protamines shows a deeply modified cytochemical reactivity (e.g. basophilia) when compared with somatic chromatic. After methanol or ethanol-acetic acid fixation(More)
Experimental autoimmune orchitis (EAO) has been extensively studied in spite of which its pathogenic mechanisms are still poorly understood. It has been mostly induced in guinea pigs using spermatozoa or a testicular homogenate plus adjuvants. Initially, the aim of our work was to establish if non-spermatic antigens, such as extracellular components of the(More)
Semen samples from 279 infertility patients attending an Immunological Centre were analysed to evaluate the relationship between the populations of leucocytes, seminal quality, antisperm antibodies, and seminal vesicle function. The most frequent finding between leucocytospermic samples was asthenozoospermia (57%), whereas in non-leucocytospermic samples(More)
Occupational Health is increasingly recognized as an area of importance in Latin American public health. In the agricultural sector of the region, the concentration of arable land into large holdings devoted to the production of export crops has resulted in the formation of a large migrant work force and greatly increased use of pesticides. The(More)
Trends in female migration in Latin America are analyzed, using the example of migration from Colombia to Venezuela since the 1950s. Consideration is given to the causes of this migration, the economic role of female migrants, and the concept of migration as a survival strategy. Data are from a survey of migrant origin carried out in 1980 in major(More)
I present an integrated model of occupation choice, spouse choice, family labor supply, and fertility that unifies an extensive empirical literature on career and family and provides predictions on the relationship among career, family, and marriage market outcomes. Two key assumptions of the model are that occupations differ both in wages and in an amenity(More)