BACKGROUND: Cellular blood components are irradiated to prevent graft- versus-host disease in transfusion recipients at risk for this syndrome. Because gamma radiation can result in the production of reactive oxygen species, the role of reactive oxygen species was investigated in radiation-induced red cell damage. STUDY DESIGN AND METHODS: Whole blood from normal donors was exposed to various doses of t-butyl hydroperoxide (0-1 mM) and/or to gamma-radiation (0-50 Gy). Oxidative damage was assessed by the extent of lipid peroxidation (measured by thiobarbituric acid-reactive substances [TBARS]) and hemoglobin oxidation. Fresh blood was divided into three parts-one initially irradiated and stored, another stored with portions irradiated weekly, and a third stored without irradiation. TBARS and hemoglobin oxidation were measured weekly. RESULTS: As expected, t- butyl hydroperoxide induced TBARS formation and hemoglobin oxidation in a dose-dependent fashion. The gamma-radiation not only increased hemoglobin oxidation and TBARS formation, but also enhanced the t-butyl hydroperoxide effect on red cells. Red cell storage increased TBARS generation and hemoglobin oxidation in a time-dependent fashion. When radiation was administered either initially or after weekly storage, TBARS production and hemoglobin oxidation were increased over that measured in unirradiated paired controls. CONCLUSION: Gamma radiation at clinically used doses increases lipid peroxidation and hemoglobin oxidation in human red cells. The effect of gamma-radiation is accentuated by blood storage and induces damage independent of time of storage. 相似文献
SUMMARY Atopy development cannot yet be predicted with certainty, and primary prophylaxis has to be directed at every ‘at-risk’ infant. However, substantial progress has been made in identifying environmental factors associated with allergic disorders. The process of sensitisation to common allergens may begin in utero. The influence of adjuvants, especially passive smoking, is considerable in individuals with established atopic disease. This article examines the role of intervention during pregnancy and the first year of life in the primary prevention of atopy and suggests a number of measures based on the current evidence. 相似文献
The power and nociceptive intensity of shock waves generated by the Dornier HM3 extracorporeal shock wave lithotripter (ESWL) are voltage dependent and suited to algesimetry in a controllable voltage range of 8–30 kV. Fidelity of the HM3 as an algesimeter was tested by:
1. (1) In vitro measurements of shock pressure at voltages between 14 and 30 kV were recorded by a force transducer at the point of clinical focus.
2. (2) Unanaesthetized volunteer (n = 5) assessment and VAS pain scores of shocks in the range of 10–24 kV, yielding highly significant correlations between blinded randomized shock voltage (r = 0.88), and VAS scores (r = 0.84).
3. (3) Voltage-tolerance curves generated from 33 ASA class 1 or 2 patients undergoing ESWL treatment under epidural analgesia with 0.125% bupivacaine, fortified with a bolus epidural dose of 100 μg fentanyl if pain arose during treatment. Voltage tolerance was increased by 50% after an epidural bolus of 100 μg fentanyl (P < 0.001). The respiratory consequences of epidural fentanyl were assessed by changes of respiratory rate and rhythm recorded from capnographic tracings of expired carbon dioxide.
This study indicates that the Dornier HM3 system provides a valuable opportunity to conduct precise, quantitative measurements of induced deep truncal pain, as well as the effectiveness and respiratory cost of analgesic interventions directly applicable to the safe management of acute pain. 相似文献
Dantrolene (2.45 mg/kg body weight, range 2 to 4) was administered iv in eight heat stroke (HS) patients and compared with a control group of 12 patients of similar age, weight, and temperature range (41.9 degrees to 44 degrees C). Body surface cooling was conducted in air conditioned rooms at temperatures of 18 degrees to 23 degrees C. Mean cooling time in the dantrolene group was 49.7 +/- 4.4 (SEM) min, whereas cooling time in the control group was 69.2 +/- 4.8 min. The decrease in temperature was significantly greater in the dantrolene group, for whom the cooling time was decreased by about 19.5 min (p less than .01). Although cooling time was significantly shorter in the dantrolene group, there was no difference in the recovery of both groups. Dantrolene is an expensive drug and justification for its routine use in HS remains to be evaluated. 相似文献
BACKGROUND: Expensive devices have been developed for the collection and transfusion of blood salvaged after hip or knee arthroplasty. STUDY DESIGN AND METHODS: The volume of salvaged red cells was measured for the first 6 hours after operation. This volume was compared to total red cell loss during hospitalization and to the volume of allogeneic red cells transfused. RESULTS: Mean postoperative red cell loss in 31 patients following hip replacement was 55 +/− 29 mL and that in 20 patients following knee replacement was 121 +/− 50 mL. The 6-hour wound drainage represented 8.7 and 16.8 percent of overall red cell loss during hospitalization for hip and knee replacement, respectively. The transfusion of postoperatively salvaged red cells would have supplanted transfusion of less than one-third of a unit of allogenic blood after hip replacement and two-thirds of a unit after knee replacement. Only three patients (5.9%) lost red cell volume in the drainage equivalent to or in excess of 1 unit of red cells (180 mL). The volume of red cells salvaged postoperatively bore no relationship to perioperative red cell losses as a whole. CONCLUSION: The relatively small red cell loss in the postoperative period in most arthroplasty patients does not appear to justify the routine use of this technique for the recovery of autologous blood. 相似文献