RESUMEN
Human spaceflight is associated with the loss of body protein. On Earth, insulin is an important factor in the regulation of muscle protein synthesis and breakdown. The objectives of this study were to determine whether insulin resistance occurs in spaceflight, and if the development of insulin resistance is related to the protein loss. The urinary C-peptide excretion rate was used as a marker for insulin secretion. The experiment was conducted before, during and after the 1991 9.5-d SLS-1 (Columbia) Space Shuttle mission. Dietary intake and urine output were monitored continuously for the four payload crewmembers from 11 d before launch to 7 d after landing for a total of 27 d. Data were obtained on the four payload crewmembers. Results were as follows: 1) the mean inflight C-peptide excretion rates were significantly lower than either the pre- or postflight rates (p < 0.05); and 2) the inflight nitrogen balance decreased as C-peptide excretion increased.
Asunto(s)
Astronautas , Péptido C/orina , Resistencia a la Insulina/fisiología , Vuelo Espacial , Adulto , Reposo en Cama , Glucemia/metabolismo , Índice de Masa Corporal , Péptido C/sangre , Estudios de Casos y Controles , Creatinina/orina , Ingestión de Energía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Musculares/metabolismoRESUMEN
Autobiographical case studies of two male-to-female transsexuals reveal a pattern of strong female identity couples with lesbian sexual-affectional preference and feminist value orientation. For both informants there is evidence of social concern and activism from an early age, which led them to perceive their gender dilemmas in a political as well as personal way. This case material challenge the notion that transsexuals are necessarily "sexualy Uncle Toms" and demonstrated that male-to-female transsexuals (like genetic women) can achieve an affirmative lesbian identity; it suggests more generally that the development of sexual identity is an ongoing, lifelong process.