Plasma and wound fluids from trauma patients suppress neutrophil extracellular respiratory burst.

BACKGROUND: Trauma increases susceptibility to secondary bacterial infections. The events suppressing antimicrobial immunity are unclear. Polymorphonuclear neutrophils (PMNs) migrate toward bacteria using chemotaxis, trap them in extracellular neutrophil extracellular traps, and kill them using respiratory burst (RB). We hypothesized that plasma and wound fluids from trauma patients alter PMN function. METHODS: Volunteer PMNs were incubated in plasma or wound fluids from trauma patients (days 0 and 1, days 2 and 3), and their functions were compared with PMNs incubated in volunteer plasma. Chemotaxis was assessed in transwells. Luminometry assessed total and intracellular RB responses to receptor-dependent and independent stimulants. Neutrophil extracellular trap formation was assessed using elastase assays. The role of tissue necrosis in creating functionally suppressive systemic PMN environments was assessed using a novel pig model where PMNs were incubated in uninjured pig plasma or plasma from pigs undergoing intraperitoneal instillation of liver slurry. RESULTS: Both plasma and wound fluids from trauma patients markedly suppress total PMN RB. Intracellular RB is unchanged, implicating suppression of extracellular RB. Wound fluids are more suppressive than plasma. Biofluids suppressed RB maximally early after injury and their effects decayed with time. Chemotaxis and neutrophil extracellular trap formation were suppressed by biofluids similarly. Lastly, plasma from pigs undergoing abdominal liver slurry instillation suppressed PMN RB, paralleling suppression by human trauma biofluids. CONCLUSION: Trauma plasma and wound fluids suppress RB and other key PMNs antimicrobial functions. Circulating suppressive signals can be derived from injured or necrotic tissue at wound sites, suggesting a key mechanism by which tissue injuries can put the host at risk for infection.

Efectos del nivel plasmático de calcio durante el embarazo y la lactancia sobre el remodelado óseo y la resorción / Effect of the level plasma of calcium during the pregnancy and the location bone and the alveolar loss

El propósito de esta investigación fue evaluar el comportamiento de los marcadores sanguíneos del remodelado óseo en el embarazo y la lactancia, y sus efectos sobre el remodelado alveolar y la resorción radicular en el movimiento dental ortodóncico. Se usaron ratas Wistar: 50 hembras de 3 meses de edad y 12 machos de 4 meses de edad. Se establecieron 4 Grupos experimentales: Grupo A (grupo control), Grupo B (Grupo con aparatología ortodóncica), Grupo C (Grupo de gestación y lactancia), Grupo D (Grupo de gestación y lactancia más aparatología ortodóncica). Los Grupos de gestación y lactancia se evaluaron a los 5, 12 y 18 días de gestación y 21 días de lactancia, días que representan las diferentes etapas de cada proceso. A los grupos de aparatología se les colocó un loop ortodóncico durante 3 días, para estudiar la primera fase del movimiento dental. En cuanto a la Bioquímica Sanguínea, se obtuvo que los iones de Calcio, Magnesio y Fósforo disminuyeron en los grupos B, C y D. La actividad enzimática de la fosfatasa alcalina disminuyó en los grupos B y D; aumentó en el Grupo C. En cuanto al análisis histológico, el número de cementoclastos y de vasos sanguíneos disminuyó en el Grupo D. Igualmente el área del ligamento periodontal y de las lagunas de reabsorción disminuyó en el Grupo D. Los resultados demuestran que: 1) la gestación y la lactancia no constituyen estadios fisiológicos contraindicados para la realización del tratamiento de ortodoncia. 2) Los niveles de los marcadores sanguíneos del remodelado óseo varían en cada etapa de gestación y lactancia y disminuyen sus concentraciones con la colocación de aparatología ortodóncica. 3) La gestación y la lactancia aceleran el remodelado óseo lo que favorece el movimiento dental. 4) La resorción radicular es imperceptible en los estadios de gestación y lactancia

Carbohydrate beverage ingestion and neutrophil degranulation responses following cycling to fatigue at 75% VO2 max.

Carbohydrate (CHO) beverage ingestion appears to influence neutrophil functional responses to prolonged exercise of a fixed duration. The aim of this randomised study was to examine the effect of CHO (5% w/v) beverage ingestion on lipopolysaccharide (LPS)-stimulated neutrophil degranulation responses in nine recreationally active males who cycled at 75% VO2 max until fatigue. On two separate occasions, subjects ingested either placebo (PLA) or CHO beverages before and at 15 min intervals during the exercise. Subjects exercised for 31% longer on the CHO trial compared with the PLA trial (P < 0.05). At fatigue plasma glucose concentration was significantly lower on the PLA trial compared with the CHO trial (P < 0.05). Plasma cortisol concentrations had increased similarly on both trials at this time. A marked neutrophilia was evident at fatigue and throughout the 4 h recovery period, the magnitude of which was similar on both trials. At fatigue LPS-stimulated elastase release per neutrophil had fallen similarly on both trials compared with pre-exercise values (47% and 50% on the PLA and CHO trials, respectively). In conclusion, our results suggest that CHO beverage ingestion has negligible influence on the hormonal, circulating neutrophil and LPS-stimulated neutrophil degranulation responses when exercise is performed to fatigue.