***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: All newborn infants in East Anglia are screened for cystic fibrosis by blood immunoreactive trypsin assay at 7 days . Thirty eight infants with cystic fibrosis were r and omised to treatment with either continuous oral flucloxacillin 250 mg/day ( group P , n = 18 ) or with episodic antimicrobials as clinical ly indicated ( group E , n = 20 ) . Their progress was monitored from diagnosis to 24 months by a nurse coordinator who visited all infants regularly , at home and in hospital , to collect anthropometric , dietary , clinical , and microbiological data . Mean ( range ) age of confirmation of diagnosis was 5.7 weeks ( 1 - 14 weeks ) . There was no significant difference in birth weight , genotype , immunoreactive trypsin concentration , neonatal history , symptoms at diagnosis , pancreatic enzyme supplementation , or parental smoking history between the groups . Infants in group E had more frequent cough and a greater number of Staphylococcus aureus isolates than infants in group P. More infants of group E were admitted to hospital , had higher admission rates during the second year ( 19 v 5 ) , for longer periods ( 6.4 v 2.2 days ) , despite receiving more than double the number of courses of antibiotics than group P infants ( in addition to flucloxacillin ) . Continuous prophylactic flucloxacillin from early diagnosis of cystic fibrosis is associated with improved clinical progress during the first two years of life The nature and timing of lower respiratory infections in infants with cystic fibrosis is largely unknown1 because infants do not produce sputum and throat cultures may not predict lower respiratory pathogens.2 We performed a prospect i ve cross sectional study of an unselected cohort of infants with cystic fibrosis in which bronchoalveolar lavage was used to determine lower respiratory infection and inflammation during the first three months of life . The state of Victoria , Australia ( 66000 births per year ) has a cystic fibrosis screening programme , all patients being managed by one centre . Between February 1992 and September 1994 we recruited 45 ( 27 boys ) of the 52 infants with newly diagnosed disease ; 32 were identified by screening , 12 from meconium ileus , and one by failure to thrive , and all cases were confirmed by sweat testing . Sixteen infants had respiratory symptoms , and seven of them were receiving oral antibiotics when bronchoalveolar lavage was performed at a mean age of 2.6 ( SD 1.6 ) months . Nine otherwise healthy infants ( five boys ) aged ABSTRACT Linezolid is a treatment option for  methicillin-resistant Staphylococcus aureus ( MRSA ) infections in cystic fibrosis ( CF ) patients . Little is known , however , about its pharmacokinetics in this population . Eight adults with CF were r and omized to receive intravenous ( i.v . ) and oral linezolid at 600 mg twice daily for 9 doses in a crossover design with a 9-day washout . Plasma sample s were collected after the first and ninth doses of each phase . Population pharmacokinetic analyses were performed by nonlinear mixed-effects modeling using a previously described 2-compartment model with time-dependent clearance inhibition . Monte Carlo simulation was performed to assess the activities of the linezolid dosing regimens against 42 contemporary MRSA isolates recovered from CF patients . The following pharmacokinetic parameter estimates were observed for the population : absorption rate constant , 1.91 h−1 ; clearance , 9.54 liters/h ; volume of central compartment , 26.8 liters ; volume of peripheral compartment , 17.3 liters ; and intercompartmental clearance , 104 liters/h . Linezolid  demonstrated nonlinear clearance after 9 doses , which was reduced by a mean of 38.9 % ( range , 28.8 to 59.9 % ) . Mean bioavailability was 85 % ( range , 47 to 131 % ) . At steady state , 600 mg given twice daily produced 93.0 % and 87.2 % probabilities of obtaining the target pharmacodynamic exposure against the MRSA isolates for the i.v . and oral formulations , respectively . Thrice-daily dosing increased the probabilities to 97.0 % and 95.6 % , respectively . Linezolid pharmacokinetics in these adults with CF were well described by a 2-compartment model with time-dependent clearance inhibition . St and ard i.v . and oral dosing regimens should be sufficient to reliably attain pharmacodynamic targets against most MRSA isolates ; however , more frequent dosing may be required for isolates with MICs of ≥2 μg/ml RATIONALE Better underst and ing of evolution of lung function in infants with cystic fibrosis ( CF ) and its association with pulmonary inflammation and infection is crucial in informing both early intervention studies aim ed at limiting lung damage and the role of lung function as outcomes in such studies . OBJECTIVES To describe longitudinal change in lung function in infants with CF and its association with pulmonary infection and inflammation . METHODS Infants diagnosed after newborn screening or clinical presentation were recruited prospect ively .  FVC , forced expiratory volume in 0.5 seconds ( FEV(0.5 ) ) , and forced expiratory flows at 75 % of exhaled vital capacity ( FEF(75 ) ) were measured using the raised-volume technique , and z-scores were calculated from published reference equations . Pulmonary infection and inflammation were measured in bronchoalveolar lavage within 48 hours of lung function testing . MEASUREMENTS AND MAIN RESULTS Thirty-seven infants had at least two successful repeat lung function measurements . Mean ( SD ) z-scores for FVC were -0.8 ( 1.0 ) , -0.9 ( 1.1 ) , and -1.7 ( 1.2 ) when measured at the first visit , 1-year visit , or 2-year visit , respectively . Mean ( SD ) z-scores for FEV(0.5 ) were -1.4 ( 1.2 ) , -2.4 ( 1.1 ) , and -4.3 ( 1.6 ) , respectively . In those infants in whom free neutrophil elastase was detected , FVC z-scores were 0.81 lower ( P=0.003 ) , and FEV(0.5 ) z-scores 0.96 lower ( P=0.001 ) , respectively . Significantly greater decline in FEV(0.5 ) z-scores occurred in those infected with Staphylococcus aureus ( P=0.018 ) or Pseudomonas aeruginosa ( P=0.021 ) . CONCLUSIONS In infants with CF , pulmonary inflammation is associated with lower lung function , whereas pulmonary infection is associated with a greater rate of decline in lung function . Strategies targeting pulmonary inflammation and infection are required to prevent early decline in lung function in infants with CF The effect of prophylactic antibiotics on bacterial colonization of the respiratory tract and on general progression of  cystic fibrosis  was studied in a two-year prospect i ve study of 47 mildly to moderately affected patients . One group of patients received inhaled cephaloridine and the other received no inhaled antibiotic ; both groups received cloxacillin orally .  Carriage of Haemophilus influenzae was greater in the group not receiving inhaled antibiotic ( 55 % vs 20 % ) . Rates of carriage of Staphylococcus aureus ( 23 % ) . Pseudomonas aeruginosa ( greater than 90 % ) . Pseudomonas cepacia ( 45 % ) , and other organisms were similar in both groups . There were no significant differences between the two groups in incidence of respiratory tract infections or hospital admissions , clinical scores , radiologic scores , or rate of change of pulmonary function . Although continuous antistaphylococcal antibiotic prophylaxis may be successful in suppressing colonization with S. aureus , it may also contribute to the high rates of carriage of Ps . aeruginosa and Ps . cepacia observed in patients with cystic fibrosis On the basis of their answers to a self-administered question naire , 697 nonsmoking healthy subjects were chosen from a r and omly selected sample representative of the white non-Mexican-American population of Tucson , Arizona , enrolled in a longitudinal study of respiratory health . For each subject , the first satisfactory set of flow-volume data obtained during the first 3 consecutive surveys was selected for analysis . For forced vital capacity ( FVC ) and forced expiratory volume in one second ( FEV1 ) , the single best value for each subject was selected . Other flow-volume measurements were derived from the single test with the best sum FEV , plus FVC . These data were used to derive improved prediction equations for each sex by age group for 5 spirometric and flow-volume variables . The result ing predicted values demonstrate the effects of development , maturation , and senescence on ventilatory function . " Normal " limits are proposed that take into consideration the between-subject variability and non-Gaussian distribution of the various measurements Since 1982 all infants born within the East Anglian Regional Health Authority have been screened for cystic fibrosis . Between April 1985 and April 1992 infants identified in this way have been entered into a r and omised prospect i ve controlled trial of antibiotic prophylaxis . Approximately half the infants received continuous oral flucloxacillin and the remainder received antibiotics when clinical ly indicated . Infants underwent tests of respiratory function at 3 - 4 months and at 1 year of age . Measurements of thoracic gas volume and airway conductance were made with an infant whole body plethysmograph , and maximum expiratory flow by the ' squeeze ' technique . A total of 73 tests was performed of 42 infants . To facilitate comparisons , measurements were expressed as scores . The mean values of the scores for the two groups of infants fell within normal limits . There was no difference between the treatment groups at either age . A reduction in airways conductance was observed between the two tests The effects of oral administration of cephalexin were evaluated in a double-blind , placebo-controlled , crossover study in 17 patients with mild to moderate pulmonary disease due to cystic fibrosis . For two years , four-month periods with cephalexin were alternated with four-month placebo periods . Thus , patients served as their own control subjects . Fungal vulvovaginitis occurred in two patients and a cephalexin-resistant Enterobacter cloacae was acquired in the sputum of another patient during cephalexin therapy . During the 2 years of study , the rate of colonization with mucoid strains of Pseudomonas aeruginosa increased and disease severity deteriorated in patients initially colonized with P. aeruginosa . Short-term courses of sputum culture-specific antibiotics improved the course of some patients with mild to moderate pulmonary disease due to cystic fibrosis . Treatment with cephalexin decreased the frequency of respiratory illnesses , respiratory illnesses requiring antibiotics , and hospitalizations for respiratory illnesses in patients initially colonized with Staphylococcus aureus and /or Haemophilus influenzae , and also reduced colonization with these organisms . Improved weight gain in 16 of 17 patients was associated with periods of cephalexin therapy . Pulmonary function tests remained stable or improved in 10 of 14 patients . Disease severity improved in patients not colonized with P. aeruginosa OBJECTIVES To evaluate whether antistaphylococcal prophylaxis in infants and young children with cystic fibrosis ( CF ) would suppress the acquisition of Staphylococcus aureus and delay the onset of the manifestations of bronchopulmonary disease . STUDY DESIGN A 7-year , multicenter , double-blind , placebo-controlled study of continuous antistaphylococcal therapy .  Otherwise healthy children < 2 years of age with CF were r and omly assigned to be treated with daily cephalexin ( 80 - 100 mg/kg/day ) or placebo .  Clinical , microbiologic , laboratory , radiographic , and anthropometric outcomes were evaluated . RESULTS Of 209 children enrolled , 119 completed a 5- to 7-year course of therapy . Mean age at enrollment was 15.6 and 14.1 months in the cephalexin and placebo groups , respectively . Respiratory cultures from children treated with cephalexin were significantly less likely to be positive for S aureus ( 6.0 % vs 30.4 % ; P < .001 ) . They were , however , much more likely to be positive for Pseudomonas aeruginosa ( 25.6 % vs 13.5 % ; P < .009 ) . These differences became apparent in the first year after enrollment and persisted over the duration of the study . In contrast to these microbiologic differences , there were no differences in clinical outcome measures , including radiographic ( Brasfield score , 23.4 vs 23.2 ) or anthropometric scores or pulmonary function . CONCLUSIONS Although long-term prophylaxis with cephalexin successfully delayed the acquisition of S aureus , it enhanced colonization with P aeruginosa and did not lead to clinical ly significant improvement in major health outcomes . These data do not support routine antistaphylococcal prophylaxisin otherwise healthy infants and young children with CF [ N PATIENTS with cystic fibrosis , the progression of pulmonary disease following Staphylococcus aureus colonization and the improvement after its 
    Output:
    
Prophylaxis:1 .
There was no significant difference between groups in infant or conventional lung function ( moderate quality evidence ) .
We found no significant effect on nutrition ( low quality evidence ) , hospital admissions , additional courses of antibiotics ( low quality evidence ) or adverse effects ( moderate quality evidence ) .
There was no significant difference in the number of isolates of Pseudomonas aeruginosa between groups ( low quality evidence ) , though there was a trend towards a lower cumulative isolation rate of Pseudomonas aeruginosa in the prophylaxis group at two and three years and towards a higher rate from four to six years .
As the studies review ed lasted six years or less , conclusions can not be drawn about the long-term effects of prophylaxis .
Anti-staphylococcal antibiotic prophylaxis leads to fewer children having isolates of Staphylococcus aureus , when commenced early in infancy and continued up to six years of age .