***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: OBJECTIVE Experimental evidence suggests that neutrophils and their metabolites play an important role in the pathogenesis of pyelonephritis . The aim of this study was to investigate the diagnostic value of polymorphonuclear elastase-a(1)-antitrypsin complex ( E-a(1)-Pi ) for the detection of  acute pyelonephritis in children . METHODS Eighty-three patients , 29 boys and 54 girls , 25 days to 14 years of age , with first-time symptomatic urinary tract infection were prospect ively studied . Fifty-seven healthy children served as controls .  Dimercaptosuccinic acid ( DMSA ) scan and voiding cystourethrography were performed in all patients . Plasma and urinary E-a(1)-Pi , C-reactive protein ( CRP ) , erythrocyte sedimentation rate ( ESR ) , neutrophil count , urinary N-acetyl-beta-glucosaminidase ( NAG ) , N-acetyl-beta-glucosaminidase b ( NAG b ) , and creatinine levels were measured in all patients on admission and 3 days after the introduction of antibiotics . The same markers were also measured in the control subjects . RESULTS Planar DMSA scintigraphy demonstrated changes of acute pyelonephritis in 30 of 83 children ( group A ) . It was normal in the remaining 53 children ( group B ) . The sex and age distributions were not significantly different between the 2 groups , as well as between the patients and the control subjects ( group C ) . Nineteen of the 53 children with a normal DMSA had body temperature > /=38 degrees C , whereas all but 4 children with abnormal DMSA had temperature > /=38 degrees C. Therefore , the temperature was significantly different between these 2 groups . The sensitivity and specificity of fever ( > /=38 degrees C ) as an indicator of renal involvement based on isotopic findings were 86 % and 64 % , respectively . Given the significant number of the febrile children with normal DMSA scintiscans , group B was subdivided into B(1 ) with 19 febrile children ( 14 boys and 5 girls ) and B(2 ) with 34 children whose body temperature was below 38 degrees C ( 8 boys and 26 girls ) . The sex and age distribution was significantly different between groups B(1 ) and B(2 ) . The mean age of group B(1 ) was.78 years ( range : 28 days to 9 years ; median:.25 years ; st and ard deviation : 2.1 ) . All but 1 child in this group were younger than 1 year of age . In contrast , in group B(2 ) , there were only 4 infants , the remaining 30 children were older than 2.5 years ( mean age : 6 years ; median : 7 years ; st and ard deviation : 3.5 ; range : 34 days to 12 years ) . The mean duration of fever before hospital admission was 2.8 days for group A and 1.8 days for group B(1 ) . This difference was not statistically significant . Similarly , body temperature was not significantly different between these 2 groups . The distribution of plasma E-a(1)-Pi values was normal in the control subjects . The sensitivity and specificity of plasma E-a(1)-Pi , as an indicator of renal involvement , were 96 % and 50 % , respectively , taking the 95th percentile of the reference range as a cutoff value . However , considering as a cutoff value the level of 72 microg/dL ( 95th percentile of group B(2 ) ) , its sensitivity and specificity were 74 % and 86 % , respectively . Plasma E-a(1)-Pi levels were significantly elevated in group A compared with group B and in both groups , the plasma E-a(1)-Pi values were significantly higher than in the control subjects . A significant difference also was noticed between group A and each of the subgroups B(1 ) and B(2 ) and also between the subgroups themselves . Plasma E-a(1)-Pi concentrations correlated significantly with neutrophil count in groups A ( r = .3 ) , B ( r = .4 ) , and B(2 ) ( r = .46 ) , but the correlation was not significant in group B(1 . ) ESR levels showed , among the different groups , similar differences with those of E-a(1)-Pi values . Unlike E-a(1)-Pi , CRP levels were comparable between groups A and B(1 ) , which both consisted of febrile children . Neutrophil count was not significantly different between subgroups B(1 ) and B(2 ) . ( ABSTRACT TRUNCATED AIM To compare urinary gram staining and dipstick for the detection of urinary tract infection (UTI)in  febrile infants . METHODS Prospect i ve study of 175 febrile infants aged 124 months . In all infants , a urine specimen was analyzed to detect UTI . The dipstick test was used to detect leukocytes and nitrites and sample s were taken for gram staining and urine culture . Urine was obtained by urethral catheterization . Positive urine results were defined as 50.000 colony forming units per millimeter of urinary tract pathogen . RESULTS The mean age was 9.8 months ( SD : 6.64 ) .  Urine culture was positive in 87 patients ( 49.5 % ) . Diagnosis of UTI was confirmed in 91 patients ( 51.9 % ) , of whom 74 were admitted for clinical ly suspected pyelonephritis ( 81.3 % ) . Gram stain had the highest specificity ( 98.9 % ) and pyuria the highest sensitivity ( 90.8 % ) . Better results were obtained using the combination of dipstick and Gram stain with a sensitivity of 93.1 % , specificity of 98.4 % , positive predictive value of 98.5 % and negative predictive value of 92.5 % . CONCLUSIONS Urinary Gram stain appears to be more reliable than dipstick in detecting UTI in febrile infants but the results of both tests should be interpreted together Background . During the course of our routine renal ultrasound examinations , we noticed that some children who developed dilatation of a renal pelvis following voiding had reflux found on voiding cystourethrography ( VCUG ) . Purpose . To determine if increase in renal pelvic size on post-void ultrasound is an accurate predictor of vesicoureteral reflux . Material s and methods . Fifty-seven children ( 113 kidneys ) underwent renal ultrasound and VCUG on the same day . Anteroposterior dimensions of the renal pelves were prospect ively measured on ultrasound prior to and following patient voiding and correlated with the results of the VCUG . Results . The diameter of the renal pelvis increased in 12 and decreased in 38 kidneys on post-void ultrasound . Vesicoureteral reflux occurred in 19 kidneys and among these kidneys , renal pelvic diameter increased in 2 , decreased in 7 , and was unchanged in 10 following voiding . There was no significant correlation between post-void change in renal pelvic diameter and the presence of vesicoureteral reflux . Conclusion . Increase in renal pelvic size on post-void ultrasound is not a reliable indicator of vesicoureteral reflux The main purpose of the study was to see whether excretory urography ( EU ) can be safely replaced by ultrasound ( US ) in children with urinary tract infection ( UTI ) younger than 6 years . 101 hospitalised children were admitted to the prospect i ve study . They were all diagnosed as having UTI and were treated accordingly . All children had  voiding cystography ( VCU )  , EU and US done . US and EU correlated well in 94 % of the cases . In all 6 cases with discrepancy between EU and US , the VCU was abnormal . Our results confirm the data from other authors , that VCU and US should be sufficient as an initial work-up on children with UTI , while EU should be done only in the cases with abnormal findings on either one or both of the former investigations . However , it should be kept in mind that some cases of parenchymal involvement or mild subpelvic stenosis can be missed using this protocol . If EU is obtained only in the cases with abnormal US and /or VCU , only 55 children ( 54 % ) in our group would have had an EU done Objective . To determine the validity of the Uriscreen , a rapid diagnostic test based on the detection of urine catalase for the early detection of urinary tract infection ( UTI ) in children , compared with st and ard urinalysis and dipstick tests . Study Design . Cross-sectional study . Study Population . Children 1 month to 17 years of age who presented to the emergency department of a pediatric tertiary care center between March and November of 1996 with symptoms suggestive of UTI . Methods . Urine specimens obtained from a r and om sample of 121 patients were evaluated simultaneously for possible UTI by Uriscreen ( catalase test ) , urinalysis ( microscopic pyuria ) , dipstick ( leukocyte esterase and nitrite ) , and quantitative urine culture . All specimens were collected by one of three sterile techniques ( midstream void technique , bladder catheterization , or suprapubic aspiration ) , as appropriate for age , and tested immediately . Using the quantitative urine culture as the gold st and ard ( reference test ) , the sensitivity , specificity , and positive and negative predictive values of all the screening tests were determined and compared . Age , sex , temperature , presenting symptoms , and method of urine collection were recorded for each participant . Results . Of the 121 patients , 35 ( 28.9 % ) had positive culture results : 30 girls ( 85.7 % ) and 5 boys ( 14.3 % ) . Compared with urinalysis and dipstick tests , Uriscreen had the highest sensitivity ( 100 % vs 88.6 % and 97.1 % , respectively ) and the highest negative predictive value ( 100 % vs 95 % and 98.6 % , respectively ) , but the poorest specificity ( 68.6 % vs 88.4 % and 82.5 % , respectively ) and positive predictive value ( 56.4 % vs 75.6 % and 69.4 % , respectively ) . Conclusions . The clinical use of Uriscreen for the presumptive diagnosis of UTI in children is limited and not significantly superior to urinalysis or the dipstick test . However , because of its 100 % sensitivity and negative predictive value and its ease of use , rapidity , and low cost , it is recommended highly for ruling out the diagnosis of UTI . In laboratories , a negative Uriscreen result may prevent the need for performing expensive urine cultures A prospect i ve blind study comparing the findings of ultrasonography , intravenous pyelography , and voiding cystourethrography was conducted on 81 patients to examine the place of ultrasonography in the initial radiologic evaluation of children with urinary tract infection . The patients ' mean age was 4.8 years ; 15 were male . Forty-eight were in patients ( mean age , 3.2 years ) and 33 were out patients ( mean age 7.2 years ) . In 29 patients ( 35.8 % ) abnormality of the urinary system was detected by one or more of the three imaging procedures ; 21 were in patients and eight were out patients . The most frequent finding was vesicoureteral reflux , occurring in 62.1 % of the pathologic cases . The findings at ultrasonography correlated well with those of intravenous pyelography in 73 of the 81 studies ( 90.1 % ) , but they failed to demonstrate double collecting systems and several of the minor changes . However , ultrasonography in combination with cystourethrography identified all patients who had abnormal urinary systems , except for two children with negligible findings . Moreover , ultrasonography and cystourethrography together identified all 11 patients , nine of them in patients , in whom surgical treatment was indicated . It is concluded that ultrasonography can successfully replace intravenous pyelography as a screening imaging procedure for the urinary system , but because of the superiority of intravenous pyelography in the detection of some types of lesions , intravenous pyelography will be required whenever ultrasonography or cystourethrography results are abnormal . ( ABSTRACT TRUNCATED AT 250 WORDS Objectives . To determine the association of clear urine by visual inspection with the absence of significant bacteruria , and to compare it with st and ard urinalysis . Methods . The study was performed in the emergency department of Children 's Hospital Medical Center , Cincinnati , Ohio . It was a prospect i ve , convenience sample of children < 21 years of age who had catheterized or midstream clean-catch urine specimen collected for culture . Clinical findings including the presence or absence of fever , abdominal pain , dysuria , frequency , and urgency were collected for each patient . Urine was visually assessed for clarity by 2 independent observers using a st and ardized technique . St and ard laboratory urinalysis and microscopy were also performed on all specimens . A positive urine culture was defined as ≥104 colony-forming unit (CFU)/mL of a urinary pathogen if obtained by catheterization and ≥105 CFU/mL if obtained by midstream . Results . Sample s were obtained from 159 patients ranging in age from 4 weeks to 19 years . Females comprised 77 % of the patients . One hundred ten of the sample s ( 69 % ) were clear to visual inspection . There were a total of 29 positive cultures ; however , 3 were in children with clear urine . The finding of clear urine on visual inspection had a negative predictive value of 97.3 % . These results were similar to those obtained with st and ard urinalysis . Conclusion . Clear urine on visual inspection can not completely eliminate the possibility that 
    Output:
    
However , as might be expected , the individual items fulfilled differed between the three clinical stages .
Regression analysis found that different items showed a strong association with test performance for the different tests evaluated .
These differences were observed both within and between the three clinical stages assessed by the review .