Browsing by Author "Torres, C"

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    Bioactivity of prolactin isoforms
    (1999) Campino, C; Torres, C; Ampuero, S; Díaz, S; González, GB; Serón-Ferré, M
    To assess whether plasma prolactin (PRL) characteristics relate to lactogenesis and absence or presence of menstrual cycles, we measured bioactive PRL (BIO;PRL) using the Nb2 assay, immunoreactive PRL (TR-PRL) by radioimmunoassay, calculated equations describing the BIO-PRL-IR-PRL relationship and separated charged PIiL isoforms (by chromatofocusing) in five amenorrhoeic and five cycling nursing women at 6 months postpartum and in 10 cycling non-nursing women, Plasma samples were drawn before and 30 min after a suckling episode at 0800, 1600 and 2400 h in nursing women and at the same hours ih non-nursing women. BIO-PRL and IR-PRL concentrations were highest in amenorrhoeic nursing women, intermediate in cycling nursing women and lowest in cycling non-nursing women. The BIO-PRL-IR-PRL relationship shows that a given amount of IR-PRL corresponds to equivalent amounts of BIO-PRL in cycling nursing and cycling nonnursing women, and to a larger extent in amenorrhoeic nursing women. IR-PRL was present In plasma as several charge isoforms, Bioactive isoforms eluting at PH 6.0-5.1 were found in amenorrhoeic and cycling nursing women, reaching similar concentrations after suckling. Bioactive isoforms eluting at pH 7.0-6.1 were found only in amenorrhoeic nursing women. We speculate that isoforms eluting at pH 6.0-5.1 may play a role in lactation and isoforms eluting at pH 7.0-6.1, in lactational amenorrhoea.
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    Epoxidation of quinones with urea hydrogen peroxide
    (PERGAMON-ELSEVIER SCIENCE LTD, 2003) Valderrama, JA; Gonzalez, MF; Torres, C
    Quinones reacted with urea-hydrogen peroxide complex in the presence of a base at room temperature, to give the corresponding quinone epoxides in 22-92% yields. The advantages of this new quinone epoxidation procedure are the requirement of organic solvent media, a easily handled solid reagent and a simple workup procedure.
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    Sun exposure behaviors and knowledge among Chileans
    (SOC MEDICA SANTIAGO, 2005) Molgo, M; Castillo, C; Valdes, R; Romero, W; Jeanneret, V; Cevo, T; Torres, C; Silva, P; Flores, L; Riquelme, A; Ayala, MF; Gonzalez, F; Hasbun, MT; Baladron, MJ
    Background: Ultraviolet light exposure has a pathogenic effect on the development of skin cancer whose prevalence increases worldwide. In Chile and the rest of the world, preventive educational campaigns are carried out to change high risk sun exposure behaviors. Aim To study the behavior of the Chilean population towards skin cancer prevention and to identify erroneous preventive practices and concepts. Material and methods: A survey containing 17 questions about sun exposure behaviors, photoprotective measures and knowledge about ultraviolet radiation and skin cancer was used. It was applied during January and February 2004, to 1,143 subjects (mean age 30 years, 409 males), taking vacations in beach resorts in Chile. Results: The hours of higher sun, exposure ranged from 12 AM to 4 PM. Thirty seven percent of subjects were exposed more than 2 hours during this high risk lapse. Women and subjects aged less than 25 years were Those with the riskiest behaviors. Fifty four percent used some type of photoprotection and 50% used ocular protection. Seventy percent used creams with sun screen and 74% used a sun protection factor higher than 15. Seventy percent applied The sun screen as recommended. Thirty eight percent had at least one sun burn in the last two years. More than 90% of subjects were aware of the relationship between sun exposure and skin cancer but 60% did not know the hours of higher ultraviolet radiation. The information about sun exposure was obtained from television in 57% of surveyed individuals. Conclusions: More educational campaigns about the risk of sun exposure are needed to reduce risky behaviors in the Chilean population.