human
***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The wide use of antibiotics for treatment of exacerbations of chronic obstructive pulmonary disease ( COPD ) lacks evidence . The efficacy is debatable , and bacterial involvement in exacerbation is difficult to verify . The aim of this prospect i ve study was to identify factors that can help to estimate the probability that a microorganism is involved in exacerbation of COPD and , therefore , predict the success of antibiotic treatment . METHODS Clinical data and sputum sample s were obtained from 116 patients during exacerbation of COPD . Bacterial infection was defined by the abundant presence of > or=1 potential pathological microorganism in relation to the normal flora in sputum . RESULTS Of 116 exacerbations , 22 ( 19 % ) had bacterial involvement . The combination of a negative result of a sputum Gram stain , a relevant non clinical decrease in lung function ( compared with baseline measurements ) , and occurrence of < 2 exacerbations in the previous year were 100 % predictive of a nonbacterial origin of the exacerbation . The presence of all 3 of these clinical characteristics yielded a positive predictive value of 67 % for a bacterial exacerbation . CONCLUSIONS Patients presenting with an exacerbation who have a negative result of sputum Gram stain , do not have a clinical ly relevant decrease in lung function , and have experienced < 2 exacerbations of COPD in the previous year do not require antibiotic treatment [ corrected ] . A treatment protocol taking into account these variables might lead to a 5%-24 % reduction in unnecessary treatment with antibiotics , depending on actual prescription rates Antibiotic therapy for acute episodes of chronic obstructive pulmonary disease ( COPD ) is a controversial issue still not clarified . In order to evaluate the effectivity of the antibiotic therapy , we design ed a double-blind controlled and r and omized clinical trial , in which 90 patients hospitalized due to an acute episode of COPD were divided into three groups : group I , cotrimoxazole ( 29 patients ) ; group II , amoxicillin-clavulanic acid ( 32 patients ) and group III , placebo ( 29 patients ) . Gasometric and spirometric measures were taken in addition to clinical evaluation at hospital admission and discharge using a numerical valoration system . All patients were treated with common bronchodilators . The three groups were homogeneous at their admission and there were no statistical differences at their discharge . We conclude that antibiotics do not play a relevant role in the improvement of acute episodes of COPD The effects of broad-spectrum antibiotic and placebo therapy in patients with chronic obstructive pulmonary disease in exacerbation were compared in a r and omized , double-blinded , crossover trial . Exacerbations were defined in terms of increased dyspnea , sputum production , and sputum purulence . Exacerbations were followed at 3-day intervals by home visits , and those that resolved in 21 days were design ated treatment successes . Treatment failures included exacerbations in which symptoms did not resolve but no intervention was necessary , and those in which the patient 's condition deteriorated so that intervention was necessary . Over 3.5 years in 173 patients , 362 exacerbations were treated , 180 with placebo and 182 with antibiotic .  The success rate with placebo was 55 % and with antibiotic 68 % . The rate of failure with deterioration was 19 % with placebo and 10 % with antibiotic . There was a significant benefit associated with antibiotic .  Peak flow recovered more rapidly with antibiotic treatment than with placebo .  Side effects were uncommon and did not differ between antibiotic and placebo BACKGROUND --Bacterial infections of the lower airways during an exacerbation in patients with asthma or chronic obstructive pulmonary disease ( COPD ) may be the cause of an exacerbation or the consequence of a viral infection or an increase in airways limitation . To determine whether bacterial infection is an important component in the pathogenesis of an exacerbation , the effects of antimicrobial treatment must be studied . METHODS -- Patients with asthma or COPD seen in general practice were studied in a double blind r and omised manner to investigate whether the antimicrobial drugs amoxicillin ( 500 mg three times daily ) , cotrimoxazole ( 960 mg twice daily ) , or a placebo , each when added to a short course of oral corticosteroids , can accelerate recovery from exacerbations . Patients were instructed to contact their own physician early in the morning when complaints of increased shortness of breath , wheezing , or exacerbations of cough with or without sputum production occurred . Treatment effects were evaluated over the next 14 days by study ing symptom scores ( wheeze , dyspnoea , cough with and without mucus production , and awakening with dyspnoea ) , peak expiratory flow values ( PEF , expressed as % predicted ) , and sublingual temperature . Bacteriological study of the sputum was made at the onset of an exacerbation and 7 , 21 and 35 days afterwards . RESULTS --Of 195 patients enrolled 71 ( 36 % ) contacted their physician for symptoms of an exacerbation . Symptoms improved in all three groups , improvements ranging from 0.54 to 0.75 points per day on a four point scale . PEF% predicted showed improvements in the three groups after the exacerbation , ranging from 0.34 % to 0.78 % predicted per day , finally returning to baseline values . Sublingual temperature did not change . Six of 71 patients consulted their physician because of a relapse between four and 24 days after the start of treatment . In only two of the 50 sputum sample s , collected during an exacerbation , and which contained > or = 10(5 ) bacteria in culture sensitive to the chosen antibiotic given , did any benefit from antimicrobial treatment occur . During the recovery period sputum purulence improved irrespective of antibiotic treatment . CONCLUSIONS --Antibiotics given with a short course of oral prednisolone during an exacerbation do not accelerate recovery as measured by changes in peak flow and symptom scores in ambulatory patients with mild to moderate asthma or COPD when treated by their general practitioners . Moreover , antibiotics do not reduce the number of relapses after treating an exacerbation The aim of the study was to evaluate whether a broad-spectrum penicillin , amoxicillin , was superior to placebo in resolving symptoms of acute exacerbations of chronic bronchitis in patients from general practice . 131 general practitioners included 278 patients over a period of 30 months . The patients were r and omly assigned to treatment with amoxicillin 750 mg b.i.d . or corresponding placebo for 7 days . Patients with pneumonia , a temperature above 38.5 degrees C or heart rate over 100 were excluded for safety reasons . The main effect parameter -- the doctors ' overall evaluation of the treatment -- did not demonstrate any statistically significant difference between amoxicillin or placebo , 63 % versus 64 % of the patients . Resolution of symptoms was obtained by 19 % ( 25/132 ) of the patients in the amoxicillin group compared with 10 % ( 13/136 ) of the patients in the placebo group , P = 0.03 . The present findings do not favour routine use of antibiotics in an attempt to improve the course of acute exacerbations as defined in this study in patients with chronic bronchitis The diagnostic significance of  procalcitonin  concentrations in lower respiratory tract infections and tuberculosis is not known . A prospect i ve analysis was , therefore , performed in patients with acute exacerbation of chronic bronchitis ( AECB ) , community-acquired pneumonia ( CAP ) , hospital-acquired pneumonia ( HAP ) and tuberculosis and their procalcitonin levels compared with those of patients with noninfectious lung diseases ( controls ) . In addition , st and ard inflammatory parameter data were collected . A prospect i ve clinical study was performed with four different groups of patients and a control group that consisted of patients with noninfectious lung diseases . A total of 129 patients were included : 25 with HAP , 26 CAP , 26 AECB , 27 tuberculosis , and 25 controls . C-reactive protein level , blood cell counts and procalcitonin concentration were evaluated on the first day after onset of clinical and inflammatory symptoms prior to treatment . The median procalcitonin concentrations in HAP , CAP , AECB and tuberculosis were not elevated in relation to the cut-off level of 0.5 ng·mL−1 . In the HAP group , in four of five patients who subsequently died , procalcitonin concentrations of > 0.5 ng·mL−1 were found . In acute lower respiratory infections , such as HAP , CAP and AECB , significantly elevated levels were found in comparison to the control group , but below the usual cut-off level . No differences were observed between tuberculosis and the control group . Relative to the current cut-off level of 0.5 ng·mL−1 , procalcitonin concentration is not a useful parameter for diagnosis of lower respiratory tract infections . However , compared to the control group , there were significantly elevated levels in patients with hospital-acquired pneumonia , community-acquired pneumonia and acute exacerbation of chronic bronchitis below the current cut-off level , which should be further investigated Purulent exacerbations of chronic bronchitis are usually treated with antibiotics . Tetracycline , penicillin with strepto mycin , and ampicillin are those most often used . Though innumerable courses of these drugs have been given in this illness , no comparative trial of their efficacy has ever been made ( Stuart-Harris , 1966 ) . We report a r and omized and " blindly " assessed comparison of these antibiotics in hospital in patients , all of whom were moderately or severely ill BACKGROUND Lower respiratory tract infections are often treated with antibiotics without evidence of clinical ly relevant bacterial disease . Serum calcitonin precursor concentrations , including procalcitonin , are raised in bacterial infections . We aim ed to assess a procalcitonin-based therapeutic strategy to reduce antibiotic use in lower respiratory tract infections with a new rapid and sensitive assay . METHODS 243 patients admitted with suspected lower respiratory tract infections were r and omly assigned st and ard care ( st and ard group ; n=119 ) or procalcitonin-guided treatment ( procalcitonin group ; n=124 ) . On the basis of serum procalcitonin concentrations , use of antibiotics was more or less discouraged ( < 0.1 microg/L or < 0.25 microg/L ) or encouraged ( > or = 0.5 microg/L or > or = 0.25 microg/L ) , respectively . Re-evaluation was possible after 6 - 24 h in both groups . Primary endpoint was use of antibiotics and analysis was by intention to treat . FINDINGS Final diagnoses were pneumonia ( n=87 ; 36 % ) , acute exacerbation of chronic obstructive pulmonary disease ( 60 ; 25 % ) , acute bronchitis ( 59 ; 24 % ) , asthma ( 13 ; 5 % ) , and other respiratory affections ( 24 ; 10 % ) . Serological evidence of viral infection was recorded in 141 of 175 tested patients ( 81 % ) . Bacterial cultures were positive from sputum in 51 ( 21 % ) and from blood in 16 ( 7 % ) . In the procalcitonin group , the adjusted relative risk of antibiotic exposure was 0.49 ( 95 % CI 0.44 - 0.55 ; p<0.0001 ) compared with the st and ard group . Antibiotic use was significantly reduced in all diagnostic subgroups . Clinical and laboratory outcome was similar in both groups and favourable in 235 ( 97 % ) . INTERPRETATION Procalcitonin guidance substantially reduced antibiotic use in lower respiratory tract infections . Withholding antimicrobial treatment did not compromise outcome . In view of the current overuse of antimicrobial therapy in often self-limiting acute respiratory tract infections , treatment based on procalcitonin measurement could have important clinical and financial implication BACKGROUND The role of antibiotics in treatment of patients with moderate exacerbations of chronic obstructive pulmonary disease ( COPD ) is uncertain , but such treatment might be useful in very severe episodes . Our objective was to assess the effects of ofloxacin in patients with exacerbations of COPD who required mechanical ventilation . METHODS We did a prospect i ve , r and omised , double-blind , placebo-controlled trial in 93 patients with acute exacerbation of COPD who required mechanical ventilation . Patients were r and omly assigned to receive oral ofloxacin 400 mg once daily ( n=47 ) or placebo ( 46 ) for 10 days . Primary endpoints were death in hospital and need for an additional course of antibiotics  , both separately and in combination . Analysis was by intention to treat . FINDINGS Three patients dropped out of the study . Two ( 4 % ) patients receiving ofloxacin died in hospital and ten ( 22 % ) did so in the placebo group ( absolute risk reduction 17.5 % , 95 % CI 4.3 - 30.7 , p=0.01 ) . Treatment 
    Output:
    
agent
***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The wide use of antibiotics for treatment of exacerbations of chronic obstructive pulmonary disease ( COPD ) lacks evidence . The efficacy is debatable , and bacterial involvement in exacerbation is difficult to verify . The aim of this prospect i ve study was to identify factors that can help to estimate the probability that a microorganism is involved in exacerbation of COPD and , therefore , predict the success of antibiotic treatment . METHODS Clinical data and sputum sample s were obtained from 116 patients during exacerbation of COPD . Bacterial infection was defined by the abundant presence of > or=1 potential pathological microorganism in relation to the normal flora in sputum . RESULTS Of 116 exacerbations , 22 ( 19 % ) had bacterial involvement . The combination of a negative result of a sputum Gram stain , a relevant non clinical decrease in lung function ( compared with baseline measurements ) , and occurrence of < 2 exacerbations in the previous year were 100 % predictive of a nonbacterial origin of the exacerbation . The presence of all 3 of these clinical characteristics yielded a positive predictive value of 67 % for a bacterial exacerbation . CONCLUSIONS Patients presenting with an exacerbation who have a negative result of sputum Gram stain , do not have a clinical ly relevant decrease in lung function , and have experienced < 2 exacerbations of COPD in the previous year do not require antibiotic treatment [ corrected ] . A treatment protocol taking into account these variables might lead to a 5%-24 % reduction in unnecessary treatment with antibiotics , depending on actual prescription rates Antibiotic therapy for acute episodes of chronic obstructive pulmonary disease ( COPD ) is a controversial issue still not clarified . In order to evaluate the effectivity of the antibiotic therapy , we design ed a double-blind controlled and r and omized clinical trial , in which 90 patients hospitalized due to an acute episode of COPD were divided into three groups : group I , cotrimoxazole ( 29 patients ) ; group II , amoxicillin-clavulanic acid ( 32 patients ) and group III , placebo ( 29 patients ) . Gasometric and spirometric measures were taken in addition to clinical evaluation at hospital admission and discharge using a numerical valoration system . All patients were treated with common bronchodilators . The three groups were homogeneous at their admission and there were no statistical differences at their discharge . We conclude that antibiotics do not play a relevant role in the improvement of acute episodes of COPD The effects of broad-spectrum antibiotic and placebo therapy in patients with chronic obstructive pulmonary disease in exacerbation were compared in a r and omized , double-blinded , crossover trial . Exacerbations were defined in terms of increased dyspnea , sputum production , and sputum purulence . Exacerbations were followed at 3-day intervals by home visits , and those that resolved in 21 days were design ated treatment successes . Treatment failures included exacerbations in which symptoms did not resolve but no intervention was necessary , and those in which the patient 's condition deteriorated so that intervention was necessary . Over 3.5 years in 173 patients , 362 exacerbations were treated , 180 with placebo and 182 with antibiotic .  The success rate with placebo was 55 % and with antibiotic 68 % . The rate of failure with deterioration was 19 % with placebo and 10 % with antibiotic . There was a significant benefit associated with antibiotic .  Peak flow recovered more rapidly with antibiotic treatment than with placebo .  Side effects were uncommon and did not differ between antibiotic and placebo BACKGROUND --Bacterial infections of the lower airways during an exacerbation in patients with asthma or chronic obstructive pulmonary disease ( COPD ) may be the cause of an exacerbation or the consequence of a viral infection or an increase in airways limitation . To determine whether bacterial infection is an important component in the pathogenesis of an exacerbation , the effects of antimicrobial treatment must be studied . METHODS -- Patients with asthma or COPD seen in general practice were studied in a double blind r and omised manner to investigate whether the antimicrobial drugs amoxicillin ( 500 mg three times daily ) , cotrimoxazole ( 960 mg twice daily ) , or a placebo , each when added to a short course of oral corticosteroids , can accelerate recovery from exacerbations . Patients were instructed to contact their own physician early in the morning when complaints of increased shortness of breath , wheezing , or exacerbations of cough with or without sputum production occurred . Treatment effects were evaluated over the next 14 days by study ing symptom scores ( wheeze , dyspnoea , cough with and without mucus production , and awakening with dyspnoea ) , peak expiratory flow values ( PEF , expressed as % predicted ) , and sublingual temperature . Bacteriological study of the sputum was made at the onset of an exacerbation and 7 , 21 and 35 days afterwards . RESULTS --Of 195 patients enrolled 71 ( 36 % ) contacted their physician for symptoms of an exacerbation . Symptoms improved in all three groups , improvements ranging from 0.54 to 0.75 points per day on a four point scale . PEF% predicted showed improvements in the three groups after the exacerbation , ranging from 0.34 % to 0.78 % predicted per day , finally returning to baseline values . Sublingual temperature did not change . Six of 71 patients consulted their physician because of a relapse between four and 24 days after the start of treatment . In only two of the 50 sputum sample s , collected during an exacerbation , and which contained > or = 10(5 ) bacteria in culture sensitive to the chosen antibiotic given , did any benefit from antimicrobial treatment occur . During the recovery period sputum purulence improved irrespective of antibiotic treatment . CONCLUSIONS --Antibiotics given with a short course of oral prednisolone during an exacerbation do not accelerate recovery as measured by changes in peak flow and symptom scores in ambulatory patients with mild to moderate asthma or COPD when treated by their general practitioners . Moreover , antibiotics do not reduce the number of relapses after treating an exacerbation The aim of the study was to evaluate whether a broad-spectrum penicillin , amoxicillin , was superior to placebo in resolving symptoms of acute exacerbations of chronic bronchitis in patients from general practice . 131 general practitioners included 278 patients over a period of 30 months . The patients were r and omly assigned to treatment with amoxicillin 750 mg b.i.d . or corresponding placebo for 7 days . Patients with pneumonia , a temperature above 38.5 degrees C or heart rate over 100 were excluded for safety reasons . The main effect parameter -- the doctors ' overall evaluation of the treatment -- did not demonstrate any statistically significant difference between amoxicillin or placebo , 63 % versus 64 % of the patients . Resolution of symptoms was obtained by 19 % ( 25/132 ) of the patients in the amoxicillin group compared with 10 % ( 13/136 ) of the patients in the placebo group , P = 0.03 . The present findings do not favour routine use of antibiotics in an attempt to improve the course of acute exacerbations as defined in this study in patients with chronic bronchitis The diagnostic significance of  procalcitonin  concentrations in lower respiratory tract infections and tuberculosis is not known . A prospect i ve analysis was , therefore , performed in patients with acute exacerbation of chronic bronchitis ( AECB ) , community-acquired pneumonia ( CAP ) , hospital-acquired pneumonia ( HAP ) and tuberculosis and their procalcitonin levels compared with those of patients with noninfectious lung diseases ( controls ) . In addition , st and ard inflammatory parameter data were collected . A prospect i ve clinical study was performed with four different groups of patients and a control group that consisted of patients with noninfectious lung diseases . A total of 129 patients were included : 25 with HAP , 26 CAP , 26 AECB , 27 tuberculosis , and 25 controls . C-reactive protein level , blood cell counts and procalcitonin concentration were evaluated on the first day after onset of clinical and inflammatory symptoms prior to treatment . The median procalcitonin concentrations in HAP , CAP , AECB and tuberculosis were not elevated in relation to the cut-off level of 0.5 ng·mL−1 . In the HAP group , in four of five patients who subsequently died , procalcitonin concentrations of > 0.5 ng·mL−1 were found . In acute lower respiratory infections , such as HAP , CAP and AECB , significantly elevated levels were found in comparison to the control group , but below the usual cut-off level . No differences were observed between tuberculosis and the control group . Relative to the current cut-off level of 0.5 ng·mL−1 , procalcitonin concentration is not a useful parameter for diagnosis of lower respiratory tract infections . However , compared to the control group , there were significantly elevated levels in patients with hospital-acquired pneumonia , community-acquired pneumonia and acute exacerbation of chronic bronchitis below the current cut-off level , which should be further investigated Purulent exacerbations of chronic bronchitis are usually treated with antibiotics . Tetracycline , penicillin with strepto mycin , and ampicillin are those most often used . Though innumerable courses of these drugs have been given in this illness , no comparative trial of their efficacy has ever been made ( Stuart-Harris , 1966 ) . We report a r and omized and " blindly " assessed comparison of these antibiotics in hospital in patients , all of whom were moderately or severely ill BACKGROUND Lower respiratory tract infections are often treated with antibiotics without evidence of clinical ly relevant bacterial disease . Serum calcitonin precursor concentrations , including procalcitonin , are raised in bacterial infections . We aim ed to assess a procalcitonin-based therapeutic strategy to reduce antibiotic use in lower respiratory tract infections with a new rapid and sensitive assay . METHODS 243 patients admitted with suspected lower respiratory tract infections were r and omly assigned st and ard care ( st and ard group ; n=119 ) or procalcitonin-guided treatment ( procalcitonin group ; n=124 ) . On the basis of serum procalcitonin concentrations , use of antibiotics was more or less discouraged ( < 0.1 microg/L or < 0.25 microg/L ) or encouraged ( > or = 0.5 microg/L or > or = 0.25 microg/L ) , respectively . Re-evaluation was possible after 6 - 24 h in both groups . Primary endpoint was use of antibiotics and analysis was by intention to treat . FINDINGS Final diagnoses were pneumonia ( n=87 ; 36 % ) , acute exacerbation of chronic obstructive pulmonary disease ( 60 ; 25 % ) , acute bronchitis ( 59 ; 24 % ) , asthma ( 13 ; 5 % ) , and other respiratory affections ( 24 ; 10 % ) . Serological evidence of viral infection was recorded in 141 of 175 tested patients ( 81 % ) . Bacterial cultures were positive from sputum in 51 ( 21 % ) and from blood in 16 ( 7 % ) . In the procalcitonin group , the adjusted relative risk of antibiotic exposure was 0.49 ( 95 % CI 0.44 - 0.55 ; p<0.0001 ) compared with the st and ard group . Antibiotic use was significantly reduced in all diagnostic subgroups . Clinical and laboratory outcome was similar in both groups and favourable in 235 ( 97 % ) . INTERPRETATION Procalcitonin guidance substantially reduced antibiotic use in lower respiratory tract infections . Withholding antimicrobial treatment did not compromise outcome . In view of the current overuse of antimicrobial therapy in often self-limiting acute respiratory tract infections , treatment based on procalcitonin measurement could have important clinical and financial implication BACKGROUND The role of antibiotics in treatment of patients with moderate exacerbations of chronic obstructive pulmonary disease ( COPD ) is uncertain , but such treatment might be useful in very severe episodes . Our objective was to assess the effects of ofloxacin in patients with exacerbations of COPD who required mechanical ventilation . METHODS We did a prospect i ve , r and omised , double-blind , placebo-controlled trial in 93 patients with acute exacerbation of COPD who required mechanical ventilation . Patients were r and omly assigned to receive oral ofloxacin 400 mg once daily ( n=47 ) or placebo ( 46 ) for 10 days . Primary endpoints were death in hospital and need for an additional course of antibiotics  , both separately and in combination . Analysis was by intention to treat . FINDINGS Three patients dropped out of the study . Two ( 4 % ) patients receiving ofloxacin died in hospital and ten ( 22 % ) did so in the placebo group ( absolute risk reduction 17.5 % , 95 % CI 4.3 - 30.7 , p=0.01 ) . Treatment 
    Output:
    