***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*** 
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    Input: Data collected prospect ively on over 3800 cadaveric renal transplants performed between June 1977 and July 1982 by the 41 member institutions of the South-Eastern Organ Procurement Foundation were analyzed to determine the influence of  delayed graft function ( DGF ) on patient and graft outcome . Approximately 35 % of first graft recipients and 47 % of regrafted patients were found to have DGF , as determined by the necessity for dialysis at one week posttransplant . First-graft recipients with DGF tended to include more black recipients , patients with higher peak levels of panel reactive antibody ( PRA ) , less use of antilymphocyte serum ( ALS ) posttransplant , slightly longer organ preservation times and the more frequent use of organs preserved by ice alone . Multivariate ( Cox ) regression analysis considering DGF simultaneously with ten other potentially confounding variables showed a highly significant association between DGF and overall graft loss from all causes ( P<10−5 ) , irreversible graft rejection ( P<0.001 ) as well as patient death ( P=0.012 ) . The differences in graft survival between first graft recipients with DGF ( n=961 ) versus those without DGF ( n=1769 ) at one and four years posttransplant were 46%±2 vs. 60%±1 and 28%±3 vs. 40%±2 , respectively . The detrimental effect of DGF was highly significant irrespective of the source of donor organs or the type of preservation used . For first transplant recipients who recovered good graft function by one month following DGF ( n=564 ) , there was a significant decrease in eventual graft survival , as compared with patients who had graft function at one month but no prior history of DGF ( n=1407 ; P=0.008 ) . However , patients with history of DGF who had good graft function at six months ( n=361 ) showed no significant difference in longer-term graft survival when compared with similar patients with good graft function at six months but no history of DGF ( n=912 ) . Interestingly , first transplant recipients with DGF were found to have significantly better graft survival if they had received bilateral native nephrectomy at least one month prior to transplantation . These results indicate that delayed graft function following cadaver donor renal transplantation provides a significant risk for eventual graft and patient survival that is principally manifested during the first six months posttransplant . In addition , patients who recover graft function following DGF appear to also remain at higher risk for early graft loss , while pretransplant bilateral native nephrectomy may afford some protection against the detrimental effects of DGF The aim of this study was to identify early clinical and pathologic variates that independently predict diminished renal allograft function  at  24 mo posttransplant . A clinical pathologic data base was prospect ively derived from 71 patients in whom protocol renal biopsies were performed at 1 , 2 , 3 , 6 , and 12 mo posttransplant . The major end point was the 24-mo serum creatinine . Variates correlating independently ( r2 = 0.67 ) with the 24-mo serum creatinine were the chronic biopsy scores ( months 3 and 6 ) , late rejections ( months 4 to 6 ) , cyclosporin A ( CsA ) levels ( months 1 to 2 ) , and delayed graft function . The adjusted odds ratio ( OR ) and 95 % confidence interval ( CI ) for having a serum creatinine > or = 130 mumol/L at 24 mo increased for every year the donor age increased ( OR = 1.07 ; 95 % CI , 1.02 to 1.13 ; range , 9 to 55 ) or for each late rejection episode ( OR = 5.9 ; 95 % CI , 1.7 to 20.1 ) , whereas a mean CsA level > 300 micrograms/L from months 1 to 3 was protective ( OR = 0.07 ; 95 % CI , 0.01 to 0.43 ) . Variates correlating independently ( r2 = 0.53 ) with the change in serum creatinine from 6 to 24 mo ( delta Cr6 - 24 ) were the chronic biopsy scores at months 3 and 6 . The adjusted OR of the delta Cr6 - 24 rising > or = + 20 mumol/L increased for every year the donor age increased ( OR = 1.09 ; 95 % CI , 1.02 to 1.16 ; range 9 to 56 ) or when the 6-mo chronic biopsy score was > or = 2 ( OR = 6.6 ; 95 % CI , 1.2 to 36.4 ) . An estimate of the relative risk for diminished renal function at 2 yr can be assigned within 6 mo of transplant based on chronic pathology , late acute rejections , CsA levels , and donor age BACKGROUND Unlike simple cold storage ( CS ) , pulsatile machine preservation ( MP ) of kidneys for transplantation permits pharmacologic manipulation of the perfusate and aids in the pretransplant assessment of the kidney graft . These characteristics of MP may have importance in the era of increasing use of extended criteria donor kidneys . The overall aim of this article is to critically assess practice s at our preservation unit with respect to graft function . Specific aims are to ( 1 ) compare the influence of MP versus CS on graft function , ( 2 ) determine which pretransplant variables have significance in pretransplant assessment , and ( 3 ) determine whether pharmacologic manipulation during MP is advantageous . METHODS There were 650 consecutive kidneys preserved in our laboratory between January 1 , 1993 and March 1 , 999 , by either MP or CS .  All MP kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer-MPS or Belzer II solution . Perfusion parameters and electrolytes were measured serially during pulsatile perfusion . All CS kidneys were stored in University of Wisconsin solution . All kidneys obtained from donors exhibiting extended criteria features underwent pretransplant frozen section biopsies . Transmission electron microscopy ( EM ) was performed on a subset of kidneys undergoing pharmacologic manipulation . Four agents were assessed prospect ively for their ability to influence MP characteristics when added to perfusate : PGE1 , trifluoperazine , verapamil , and papaverine . RESULTS MP was associated with improved immediate , 1- , and 2-year graft function and reduced length of initial hospital stay when compared with CS grafts . Changes in the machine perfusion variables flow and resistance , and the [ Ca++ ] in perfusate , were significantly associated with delayed graft function ( DGF ) after the transplant . Biopsy information was not predictive of DGF . The addition of PGE1 to perfusate improved MP characteristics , reduced the release of [ Ca++ ] into perfusate , and ameliorated mitochondrial ischemic injury in transmission EM images . Early graft function was improved in the presence of PGE1+MP , compared with function in the presence of other pharmacologic agents or CS alone . CONCLUSIONS MP is associated with improved early and long term renal function . Moreover , PGE1 augments MP in improving graft function . The combination of MP+PGE1 may be important in optimizing the ability to use extended donor criteria kidneys and , thereby , improve the overall efficiency of cadaveric renal transplantation BACKGROUND The aim of the present study was to investigate the effect of delayed graft function ( DGF ) in graft outcome when adjusted by the presence of acute rejection in the first month after transplantation . METHODS A total of 437 cadaveric renal transplant patients on cyclosporine and steroids  were included in the study . Variables related to donor , recipient , and graft were prospect ively collected . RESULTS The incidence of DGF was 44.4 % . When patients dying with a functioning graft were censored , graft survival rates at 1 and 6 years were similar in patients with immediate function to those with DGF , when rejection was not present ( 96 % and 81 % vs. 95 % and 83 % , respectively ) . Rejection negatively influenced graft survival rates at 1 and 6 years , both in patients with immediate graft function ( 80 % and 73 % , P<0.05 vs. no DGF/no rejection ) and more deeply in those with associated DGF ( 77 % and 62 % , P<0.001 vs. no DGF/no rejection ) . Rejection was more frequently diagnosed in patients with DGF than in those with immediate graft function ( 50 % vs. 39.9 % , P<0.05 ) . Length of hospitalization was longer and the number of needle core biopsies was higher in patients with DGF or rejection . The presence of both complications had an additive effect . CONCLUSIONS This study showed that DGF did not adversely affect kidney graft survival in patients without rejection . However , it increased the length of hospitalization and the number of graft biopsies , thus increasing the cost of transplantation . Moreover , rejection was more frequent in patients with DGF , and it had a negative impact on graft outcome . Because the association of DGF and rejection gave the poorest outcome , an effort should be made to prevent both complications RATIONALE AND OBJECTIVES The authors differentiate acute tubular necrosis from transplant rejection in patients with delayed kidney graft function using gadolinium (Gd)-DTPA enhanced magnetic resonance ( MR ) imaging . METHODS Twenty-four patients after renal transplantation ( 10 with normal graft function , 14 with delayed graft function ) underwent conventional and Doppler sonography and MR imaging examination after bolus application of Gd-DTPA . Within a time period of 512 seconds , 39 single-slice MR images were obtained . Measurements of signal intensity in three regions of interests ( cortex , medulla , renal pelvis ) result ed in a graphic description of the dynamics of the contrast enhancement . The time between the start of the scan and the peaks of the curves was measured . RESULTS In patients with normal graft function the curves reached the peaks between 39 and 55 seconds ( cortex ) , 44 and 61 seconds ( medulla ) , and between 161 and 318 seconds ( renal pelvis ) . Six patients with acute tubular necrosis showed normal values for the curves 1 and 2 but markedly prolonged time for curve 3 ( between 420 and 512 seconds ) . In all patients with histologically proven transplant rejection , the peaks of all curves were not reached before the ends of the scans . CONCLUSION The authors ' preliminary results suggest that MR imaging seems to be a sensitive , noninvasive diagnostic tool to differentiate acute tubular necrosis from transplant rejection in the critical early postoperative period BACKGROUND The quality of a damaged kidney , the complexity of the surgery , and the events in the first weeks after transplantation , such as delayed graft function ( DGF ) and acute rejection , may influence its histological appearance and long-term survival . The aim of this study was to evaluate the importance of these factors in predicting renal allograft histology at 3 months . METHODS Prospect i ve , protocol kidney biopsy specimens ( n=112 ) , obtained 3 months after transplantation , were scored for chronic damage by the Banff schema and evaluated by multivariate analysis against donor factors , implantation histology , prior recipient sensitization , ischemia , perioperative factors , and subsequent clinical events , such as DGF and acute rejection . RESULTS Adequate sample s were obtained in 102 of 112 biopsies and classified as chronic Banff grade 0 ( n=22 ) , grade I ( n=56 ) , grade II ( n=23 ) , or grade III ( n=1 ) . Acute Banff scores were minimal . DGF occurred in 49 % and was the strongest predictor of tubulointerstitial damage at 3 months . DGF correlated with acute tubular necrosis on the implantation biopsy specimen and with the number of acute rejection episodes ; DGF also correlated with the Banff grade s of chronic glomerulitis , chronic interstitial fibrosis , and tubular atrophy scores ( P<0.05 - 0.001 ) in the 3-month biopsy specimen . By multivariate analysis , chronic tubular atrophy was independently predicted by the presence of vascular disease in the donor biopsy specimen , DGF , and vascular rejection occurring within the first 3 months ( P<0.05 - 0.001 ) . Chronic interstitial fibrosis was unrelated to fibrosis in the donor biopsy specimen but was independently predicted by DGF , donor age , and vascular rejection ( P<0.05 - 0.001 ) . Vascular disease in the donor biopsy specimen correlated with chronic intimal thickening ( r=0.36 , P<0.01 ) and arteriolar hyalinosis score ( r=0.54 , P<0.001 ) on the 3-month biopsy specimen . Banff chronic intimal vascular thickening was independently predicted by donor biopsy specimen vascular grade , prior vascular rejection episodes , and renal cold ischemia time ( P<0.05 - 0.01 ) . There were no correlates with the mean cyclosporine ( CsA ) dose , blood levels , diagnosis of CsA toxicity , or cellular rejection within the first 3 months . CONCLUSIONS This study has demonstrated that the quality of the donor organ at implantation was strongly predictive of subsequent renal histology in grafts functioning at 3 months . Vascular rejection and DGF had a significant long-term effect on graft 
    Output:
    
The utilization of heterogeneous clinical criteria to define DGF has certain limitations .