ABSTRACT
SUMMARY Cadmium (Cd2+) is a nonessential heavy metal that possesses a high capacity of bioaccumulation and exhibits toxic characteristics even at low concentrations. This study evaluated the genotoxicity and cytotoxicity in human leukocytes in vitro after exposure to a lower range of Cd2+concentration (1-25 (g/mL) using an unprecedented strategy by correlating between intracellular Cd2+ levels after exposure and cellular damage. Results demonstrated that Cd2+exposure from 5 to 25 fig/mL significantly increased the unviability of leukocytes, as well as the DNA damage, which was dose-dependent. The intracellular Cd2+ levels in leukocytes ranged from 9.85 to 94.38 pg/cell, and cytotoxicity and genotoxicity were induced at a concentration of24.22 pg/cell. The relationship between exposure concentration and intra-cellular Cd2+ levels suggests that its influx occurs in human leukocytes under zero-order kinetics.
RESUMEN El cadmio (Cd2+) es un metal pesado no esencial que posee una alta capacidad de bioacumulación y presenta características tóxicas incluso en bajas concentraciones. Este estudio evaluó la genotoxicidad y la citotoxicidad en leucocitos humanos in vitro después de la exposición a un rango inferior de concentración de Cd2+ (1-25 (g / mL) mediante una estrategia sin precedentes al correlacionar los niveles intracelulares de Cd2+ después de la exposición y el daño celular. Los resultados demostraron que la exposición a Cd2+ de 5 a 25 (g/mL aumentó significativamente la inviabilidad de los leucocitos, así como el daño en el ADN, que era dependiente de la dosis. Los niveles intracelulares de Cd2+ en leucocitos oscilaron entre 9,85 y 94,38 pg/célula, y se indujo la citotoxicidad y la genotoxicidad a una concentración de 24,22 pg/ célula. La relación entre la concentración de la exposición y los niveles intracelulares de Cd2+ sugiere que su influjo se produce en leucocitos humanos bajo una cinética de orden cero.
ABSTRACT
Nos últimos anos, após a epidemia de aids (síndrome da imunodeficiência adquirida), o estudo dos mecanismos de defesa vaginal têm se revestido de especial importância para a compreensão da fisiopatogênese das infecções genitais femininas. A resposta imune celular é talvez um dos principais mecanismos de proteção da mucosa vaginal mediante desenvolvimento de resposta imune local. Na placa basal do epitélio vaginal existem células de defesa (macrófagos, linfócitos, plasmócitos, células de Langerhans, eosinófilos e mastócitos) prontas para atuar. Os linfócitos são as principais células de defesa que migram pelos canais intercelulares, precedidos pelas células de Langerhans e pelos macrófagos para erradicar o microorganismo invasor. As células de defesa controlam o crescimento bacteriano e fúngico, mediante ativação de mecanismos de fagocitose. Havendo falha da imunidade celular, com a exposição da mucosa vaginal aos antígenos, pode ocorrer o desenvolvimento de infecções vaginais. Os autores revisam o tema enfatizando a importância da resposta imune adequada na manutenção do equilíbrio vaginal.
After the aids (acquired immunodeficiency syndrome) epidemic, the mechanisms of vaginal defense have been coated with special importance in the study of the genital feminine infections. The cellular immune response is perhaps one of the main protection mechanisms of the vaginal mucosa by means development of local immune response. There are many different defense cells (macrophages, lymphocytes, Langerhans cells, eosinophils and mastocytes) in the vaginal epithelium ready to be elicited. The lymphocytes are the main defense cells; they come from the basal plaque crossing the intercellular canals, preceded only by Langerhans cells and macrophages, in order to eradicate the invasive microorganisms. The defense cells control the bacterial and fungi growth, by means of phagocytosis activation. If the cellular immune response fails, vaginal infections can occur. The authors revise the theme emphasizing the importance of the adequate immune response in the vaginal equilibrium.
Subject(s)
Humans , Female , Vulvovaginitis , Immunity, Mucosal , Immunity, Cellular , Langerhans CellsABSTRACT
Undernutrition in early life is associated with a number of acute and chronic sequelae, and recovering is a controversial issue. Even if undernutrition in Brazil is declining, studies have shown that about 31% of brazilian children still present severe or moderate malnutrition. The present study goal was to induce early malnutrition in rats and observe short- (undernourished) and long-term (after recovered) effects on defense cells involved in wound healing. Undernutrition was produced by separating the pups from the mother for 10 hours/day during the suckling period (21 days after birth). As controls were used rats at same age not submitted to suckling restriction. Undernutrition and recovering states were assessed by body weight. Skin wounds were made on the shaved backs of all, undernourished, recovered and their controls, under tribromoethanol anesthesia. Aninals were sacrificed 1, 3, 7 and 14 days after surgery and the tissues were properly prepared and observed under light microscopy. Our results showed that: 1) neutrophils, lymphocytes and macrophages couting in healing area were lower in undernourished and in recovered animals as compared with their controls; 2) there were a basal deficiency in lymphocytes and macrophages numbers in recovered animals but not in those acutelly undernourished. These results allow us to conclude that post-nattally undernourished animals submitted to a nutritional rescue time showed a complete recovery in physical weight, but in spite of the physical recovery, the wound healing showed less defense cell density in healing areas suggesting long-term sequelae of early undernutrition.
La desnutrición postnatal está asociada a un conjunto de secuelas agudas y crónicas, y su recuperación es aún asunto controvertido. En Brasil, a pesar de estar disminuyendo la desnutrición, algunos estudios han demostrado que alrededor del 31% de los niños presentan malnutrición moderada o severa. El objetivo del presente estudio fue inducir una desnutrición precoz en ratas y observar los efectos inmediatos (desnutrición) y permanentes (depués de la recuperación) sobre las células de defensa involucradas en la cicatrización. La desnutrición fue provocada separando las crías de sus madres, por 10 horas diarias, durante el periodo de lactancia (21 días de nacidos). Como contoles fueron usadas ratas de la misma edad no sometidas a restrición láctea. Los estados de desnutrición y de recuperación fueron evaluados por el peso corporal. Las heridas fueron realizadas en la piel rasurada del dorso de los animales desnutridos, recuperados y controles, bajo anestesia con tribromoetanol. Los animales fueron sacrificados 1, 3, 7 y 14 días después de la cirugía y los tejidos de la región cicatricial fueron procesados histológicamente y examinados al microscopio óptico. Los resultados mostraron que: 1) el número de neutrófilos, linfocitos y macrófagos en la área de cicatrización, fue menor en los animales desnutridos y en recuperación que en los controles; 2) enlos animales recuperados hubo una deficiencia basal en el número de linfocitos y macrófagos, lo que no ocurrió en los animales con desnutrición aguda. Estos resultados permitieron concluir que los animales sometidos a desnutrición postnatal mostraron una recuperación completa en el peso físico después del periodo de recuperación nutricional, pero que la región de cicatrización mostró menor densidad de células de defensa, sugiriendo secuelas permanentes de la desnutrición postnatal.