Metaphase and anaphase analysis of V79 cells exposed to erionite, UICC chrysotile and UICC crocidolite

The cytogenetic effects of erionite treatment of V79 cells werecompared with those of UICC crocidolite and UICC chrysotiletreatment. A significant reduction in diploid cells with anaccompanying increase in aneuploid and polyploid cells was observedwith all three treatments. In the erionite-treated cultures,an increase in aneuploid was observedy at all dose levels rangingfrom 10 to 100 µg/ml, whereas in the crocidolite- andchrysotile-treated cultures, significant increases in aneuploidywere observed at all dose levels except the low dose, 10 µg/ml.Chromatid aberrations were observed in cultures treated withcrocidolite and chrysotile and were especially pronounced atdose 100 µg/ml of chrysotile. The clastogenic effect oferionite was weaker but statistically significant at dose 100µg/ml. An extrapolation of these cytogenetic changes overdose in number of fibers suggests that erionite was more reactivethan the other two minerals in producing aneuploidy. The numberof fibers required to produce a similar degree of cytogeneticeffects was several orders of magnitude higher for chrysotileand crocidolite than erionite. These results correlate withthe higher tumorigenic potency of erionite. In general, fewercells treated with erionite entered anaphase than those treatedwith the other two minerals. As a result, abnormal anaphasesrepresenting chromosomal mis-segregation were observed onlyin the chrysotile- and crocidolite-treated cultures. To ourknowledge, this is the first report on cytogenetic effects oferionite.     

Dopamine compared with dobutamine in experimental septic shock: relevance to fluid administration

The hemodynamic effects of dopamine and dobutamine (at doses of 6 micrograms X kg-1 X min-1) were compared during fluid resuscitation from septic shock induced by endotoxin (3 mg/kg) in the dog. In the first part of the study, when a standard amount of saline solution was infused (in 24 dogs), dopamine infusion resulted in higher cardiac filling pressures than did dobutamine infusion, whereas dobutamine infusion resulted in higher cardiac output. In the second part of the study, when fluid infusion was titrated to maintain pulmonary artery balloon-occluded pressure at constant level (in 24 dogs), the total amount of fluids was significantly greater with dobutamine than when dopamine was used (109 +/- 13 vs 71 +/- 10 ml/kg). The combination of dobutamine with fluids resulted in significantly greater stroke volume (39.6 +/- 3.8 vs 21.0 +/- 4.0 ml, P less than 0.05) and oxygen consumption (194 +/- 18 vs 144 +/- 8 ml/min, P less than 0.05). The different effects of dopamine and dobutamine on cardiac filling pressures can be due to differences in effects on myocardial contractility, ventricular afterload, and cardiac compliance. This experimental study indicates that when fluid therapy is combined with adrenergic agents in resuscitation from septic shock, dobutamine can be associated with higher cardiac output and oxygen transport and can result in higher tissue oxygen consumption than dopamine.     

L’électroencéphalogramme n’est pas un examen légitime pour la confirmation du diagnostic de mort cérébrale

PURPOSE: In France, legislation mandates that the clinical diagnosis of brain death be confirmed by one paraclinical test before organ donation is allowed. That test may be either the electroencephalogram (EEG) or cerebral angiography. We report a case in which the clinical diagnosis of brain death was first confirmed by two EEGs performed according to the French guidelines, but ruled out by cerebral angiography. Considering that the EEG is no longer recommended to establish the diagnosis of brain death, we discuss the relevance of maintaining the EEG for brain death diagnosis in France. CLINICAL FINDINGS: A 58 yr-old man was admitted to the intensive care unit because of coma secondary to a massive subarachnoid hemorrhage with herniation below the falx shown by computed tomography. Clinical criteria of brain death were rapidly present. Two EEGs first confirmed the diagnosis but a four-vessel cerebral angiography was finally performed because the patient moved spontaneously. This cerebral angiography showed flow in the right internal carotid artery. A computed tomography performed the next day definitely confirmed the absence of brain death and organ donation did not occur. CONCLUSIONS: This case demonstrates the limitations of the EEG for this indication and suggests that angiography should be preferred. French legislation is probably maladjusted and would benefit by incorporating guidelines of other countries like Canada. International harmonization of criteria for brain death diagnosis would also be welcome.     

The value of bacterial culture during clean orthopedic surgery: a prospective study of 1,036 patients.

OBJECTIVE: To determine whether bacterial cultures of the wounds of patients undergoing clean orthopedic surgery would help predict infection. METHODS: During 1 year, 1,256 cultures were performed for 1,102 patients who underwent clean orthopedic surgery. Results were analyzed to evaluate their ability to predict postoperative infection. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of the cultures were 38%, 92%, 7%, and 99%, respectively. CONCLUSIONS: Cultures performed during clean orthopedic surgery were not useful for predicting postoperative infection.