***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: BACKGROUND Glutathione ( GSH ) deficiency is common in HIV-infected individuals and is associated with impaired T cell function and impaired survival . N-acetylcysteine ( NAC ) is used to replenish GSH that has been depleted by acetaminophen overdose . Studies here test oral administration of NAC for safe and effective GSH replenishment in HIV infection . DESIGN Oral NAC administration in a r and omized , 8-week double-blind , placebo-controlled trial followed by optional open-label drug for up to 24 weeks . SUBJECTS HIV-infected , low GSH , CD4 T cells < 500 micro L(-1 ) , no active opportunistic infections or other debilitation ; n = 81 . Study conducted prior to introduction of protease inhibitors .  RESULTS Whole blood GSH levels in NAC arm subjects significantly increased from 0.88 mM to 0.98 mM , bringing GSH levels in NAC-treated subjects to 89 % of uninfected controls ( P = 0.03 ) . Baseline GSH levels in the placebo group ( 0.91 ) remained essentially the same during the 8 week placebo-controlled trial . T cell GSH , adjusted for CD4 T cell count and beta2-microglobulin levels , also increased in the NAC-treated subjects ( P = 0.04 ) . Adverse effects were minimal and not significantly associated with NAC ingestion . CONCLUSION NAC treatment for 8 weeks safely replenishes whole blood GSH and T cell GSH in HIV-infected individuals . Thus , NAC offers useful adjunct therapy to increase protection against oxidative stress , improve immune system function and increase detoxification of acetaminophen and other drugs . These findings suggest that NAC therapy could be valuable in other clinical situations in which GSH deficiency or oxidative stress plays a role in disease pathology , e.g. rheumatoid arthritis , Parkinson 's disease , hepatitis , liver cirrhosis , septic shock and diabetes OBJECTIVE We aim ed to evaluate the efficacy of low dose N-acetylcysteine ( NAC ) against myocardial ischemia-reperfusion damage in coronary artery bypass surgery accompanied by cardiopulmonary bypass ( CPB ) . METHODS Thirty patients operated due to triple coronary artery disease were enrolled into this prospect i ve r and omized study ( control group -n=15 and NAC group - n=15 ) . N-acetylcysteine was added to induction cardioplegia solution in dose of 4 mmol/l and in dose of 2 mmol/l to maintenance cardioplegia solution in the NAC group . Hemodynamic measurements were performed before and after anesthesia with different intervals . Creatine kinase-MB ( CK-MB ) levels were analyzed during 24 hours postoperatively . Blood sample s were obtained from coronary sinus before CPB ( T1 ) , just before the cross-clamp removed ( T2 ) and 30 minutes later ( T3 ) . Malondialdehyde ( MDA ) , glutathione peroxidase ( GSH-Px ) , nitric oxide ( NO ) levels and neutrophil percentage were determined . Statistical analysis was performed using student 's t test , Chi-square and two-way ANOVA tests . RESULTS There were no significant differences between the two groups with regard to the hemodynamic parameters , and CK-MB levels . The MDA levels were significantly lower in NAC group than in control group during reperfusion period ( 0.75 nmol/l vs 0.88 nmol/l , p<0.05 ) . Neutrophil percentage in coronary sinus blood was significantly lower in NAC group than in control group during the reperfusion period ( 77.6 % vs 82.7 % , p<0.05 ) . The GSH-Px and NO levels were also not statistically different between groups . CONCLUSION Low dose NAC as an adjunct to cardioplegic solutions effectively reduces myocardial oxidative stress in coronary bypass surgery with cardiopulmonary bypass , but may not restore the myocardial injury In a r and omized , double – blind study , 131 consecutive patients , subjected to elective upper laparotomy , were prophylactically given the recommended dose of N – acetylcysteine ( NAC ) ( Mucomyst , ASTRA ) ( 200 mg × 3 ) or placebo against postoperative pulmonary complications . The effect was evaluated by lung function tests ( VC and FEV1 ) , arterial blood gas analyses and chest x – ray . No benefit could be demonstrated , either to postoperative pulmonary function or in the frequency of atelectasis in the recommended dose . However , no patients with preoperative bronchopulmonary disease dem and ing treatment with bronchodilatators were included in the study . A positive effect of NAC in this category of patients could not be excluded OBJECTIVE --To see whether intravenous acetylcysteine would improve outcome in patients with fulminant hepatic failure after paracetamol overdose . DESIGN --A prospect i ve r and omised controlled study . SETTING --The Institute of Liver Studies , King 's College Hospital , London . PATIENTS --50 consecutive patients ( 21 male ) aged 16 - 60 with fulminant hepatic failure after paracetamol overdose who had not previously received acetylcysteine . INTERVENTIONS --Conventional intensive liver care plus either acetylcysteine ( 25 patients ) in the same dose regimen as used early after a paracetamol overdose , except that the infusion was continued until recovery from encephalopathy or death , or an equivalent volume of 5 % dextrose ( 25 patients ) . MAIN OUTCOME MEASURES --Survival ; incidence of cerebral oedema , renal failure , and hypotension requiring inotropic support ; liver function as assessed by prolongation of the prothrombin time ; and degree of encephalopathy . RESULTS --The rate of survival was significantly higher in the acetylcysteine treated group than in the controls ( 48 % ( 12/25 patients ) v 20 % ( 5/25 ) ; p = 0.037 , 95 % confidence interval for difference in proportions surviving 3 % to 53 % ) . Acetylcysteine treated patients had a lower incidence of cerebral oedema ( 40 % ( 10/25 ) v 68 % ( 17/25 ) ; p = 0.047 , 95 % confidence interval for difference in incidence 2 % to 54 % ) , and fewer developed hypotension requiring inotropic support ( 48 % ( 12/25 ) v 80 % ( 20/25 ) ; p = 0.018 , 95 % confidence interval 7 % to 57 % ) . Rates of deterioration and recovery of liver function , however , were similar in the two groups . No adverse reactions to acetylcysteine were seen . CONCLUSIONS --Acetylcysteine is safe and effective in fulminant hepatic failure after paracetamol overdose The role of N-acetylcystein ( NAC ) administration on the oxidative response of neutrophils  during cardiopulmonary bypass ( CPB ) was evaluated in a double-blind study . Twenty-four adult patients undergoing coronary artery bypass were included in the study . Twelve patients received NAC as a bolus of 100 mg/kg followed by a continuous infusion of 20 mg/kg/h in the bypass circuit from the beginning to the end of bypass . A further 12 patients received placebo . Citrated blood sample s for measurement of oxidative burst response of neutrophils were obtained at different time points during bypass . The oxidative burst response of neutrophils in the patients receiving NAC was significantly low at all times during bypass . Based on these findings NAC appears to act as an oxygen free radical scavenger during open-heart surgery BACKGROUND & AIMS N-acetylcysteine ( NAC ) , an antidote for acetaminophen poisoning , might benefit patients with non-acetaminophen-related acute liver failure . METHODS In a prospect i ve , double-blind trial , acute liver failure patients without clinical or historical evidence of acetaminophen overdose were stratified by site and coma grade and assigned r and omly to groups that were given NAC or placebo ( dextrose ) infusion for 72 hours . The primary outcome was overall survival at 3 weeks . Secondary outcomes included transplant-free survival and rate of transplantation . RESULTS A total of 173 patients received NAC  ( n = 81 ) or placebo ( n = 92 ) . Overall survival at 3 weeks was 70 % for patients given NAC and 66 % for patients given placebo ( 1-sided P = .283 ) . Transplant-free survival was significantly better for NAC patients ( 40 % ) than for those given placebo ( 27 % ; 1-sided P = .043 ) . The benefits of transplant-free survival were confined to the 114 patients with coma grade s I-II who received NAC ( 52 % compared with 30 % for placebo ; 1-sided P = .010 ) ; transplant-free survival for the 59 patients with coma grade s III-IV was 9 % in those given NAC and 22 % in those given placebo ( 1-sided P = .912 ) . The transplantation rate was lower in the NAC group but was not significantly different between groups ( 32 % vs 45 % ; P = .093 ) . Intravenous NAC generally was well tolerated ; only nausea and vomiting occurred significantly more frequently in the NAC group ( 14 % vs 4 % ; P = .031 ) . CONCLUSIONS Intravenous NAC improves transplant-free survival in patients with early stage non-acetaminophen-related acute liver failure . Patients with advanced coma grade s do not benefit from NAC and typically require emergency liver transplantation Objective : Markers of oxidative stress are reported to be increased in severe malaria . It has been suggested that the antioxidant N-acetylcysteine ( NAC ) may be beneficial in treatment . We studied the efficacy and safety of parenteral NAC as an adjunct to artesunate treatment of severe falciparum malaria . Design : A r and omized , double-blind , placebo-controlled trial on the use of high-dose intravenous NAC as adjunctive treatment to artesunate . Setting : A provincial hospital in Western Thail and and a tertiary referral hospital in Chittagong , Bangladesh . Patients : One hundred eight adult patients with severe falciparum malaria . Interventions : Patients were r and omized to receive NAC or placebo as an adjunctive treatment to intravenous artesunate . Measurements and Main Results : A total of 56 patients were treated with NAC and 52 received placebo . NAC had no significant effect on mortality , lactate clearance times ( p = 0.74 ) , or coma recovery times ( p = 0.46 ) . Parasite clearance time was increased from 30 hours ( range , 6–144 hours ) to 36 hours ( range , 6–120 hours ) ( p = 0.03 ) , but this could be explained by differences in admission parasitemia . Urinary F2-isoprostane metabolites , measured as a marker of oxidative stress , were increased in severe malaria compared with patients with uncomplicated malaria and healthy volunteers . Admission red cell rigidity correlated with mortality , but did not improve with NAC . Conclusion : Systemic oxidative stress is increased in severe malaria . Treatment with NAC had no effect on outcome in patients with severe falciparum malaria in this setting OBJECTIVE To determine the effects of intravenous N-acetylcysteine ( NAC ) on the development of severe adult respiratory distress syndrome ( ARDS )  and mortality rate  in patients with mild-to-moderate acute lung injury and to analyze the duration of ventilatory support and FIO2 required as well as the evolution of the lung injury score . SETTING Three university hospital ICUs and one regional ICU in Switzerl and . PATIENTS Sixty-one adult patients presenting with mild-to-moderate acute lung injury and various predisposing factors for ARDS received either NAC , 40 mg/kg/d , or placebo intravenously for 3 days . MEASUREMENTS Respiratory dysfunction was assessed daily according to the need for mechanical ventilation and FIO2 , the evolution of the lung injury score , and the PaO2/FIO2 ratio . The cardiovascular state , liver function , and kidney function were also monitored . Data were collected at admission ( day 0 ) , during the first 3 days , and on the day of discharge from the ICU . RESULTS The NAC and placebo groups ( 32 and 29 patients , respectively ) were comparable at ICU admission for severity of illness assessed by the simplified acute physiology score ( SAPS ) ( 10.8 + /- 4.6 vs 10.9 + /- 4.8 ) and lung injury score ( LIS ) ( 1.39 + /- 0.95 vs 1.11 + /- 1.08 ) ( mean + /- SD ) . Three patients in each group developed ARDS . The 1-month mortality rate was 22 percent for the NAC group and 35 percent for the placebo group ( difference not statistically significant ) . At admission , 22 of 32 patients ( 69 percent ) in the NAC group were mechanically ventilated compared with 22 of 29 ( 76 percent ) in the place 
    Output:
    
Early application of N-acetylcysteine to prevent the development of an oxidato-inflammatory response did not affect the outcome , nor did late application that is after 24 hours of developing symptoms .
Late application was associated with cardiovascular instability .
AUTHORS ' CONCLUSIONS Overall , this meta- analysis puts doubt on the safety and utility of intravenous N-acetylcysteine as an adjuvant therapy in SIRS and sepsis .
At best , N-acetylcysteine is ineffective in reducing mortality and complications in this patient population .
At worst , it can be harmful , especially when administered later than 24 hours after the onset of symptoms , by causing cardiovascular depression .