***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: Introduction The Centers for Disease Control and Prevention has recommended using a nucleic acid amplification test ( NAAT ) for diagnosing pulmonary tuberculosis ( TB ) but there is a lack of data on NAAT cost-effectiveness . Methods We conducted a prospect i ve cohort study that included all patients with an AFB smear-positive respiratory specimen at Grady Memorial Hospital in Atlanta , GA , USA between January 2002 and June 2008 . We determined the sensitivity , specificity , and positive and negative predictive value of a commercially available and FDA -approved NAAT ( amplified MTD , Gen-Probe ) compared to the gold st and ard of culture . A cost analysis was performed and included costs related to laboratory tests , hospital charges , anti-TB medications , and contact investigations . Average cost per patient was calculated under two conditions : ( 1 ) using a NAAT on all AFB smear-postive respiratory specimens and ( 2 ) not using a NAAT . One-way sensitivity analyses were conducted to determine sensitivity of cost difference to reasonable ranges of model inputs . Results During a 6 1/2 year study period , there were 1,009 patients with an AFB smear-positive respiratory specimen at our public urban hospital . We found the NAAT to be highly sensitive ( 99.6 % ) and specific ( 99.1 % ) on AFB smear-positive specimens compared to culture . Overall , the positive predictive value ( PPV ) of an AFB smear-positive respiratory specimen for culture-confirmed TB was 27 % . The PPV of an AFB smear-positive respiratory specimen for culture-confirmed TB was significantly higher for HIV-uninfected persons compared to those who were HIV-seropositive ( 152/271 [ 56 % ] vs. 85/445 [ 19 % ] ; RR = 2.94 , 95 % CI 2.36–3.65 , p<0.001 ) . The cost savings of using the NAAT was $ 2,003 per AFB smear-positive case . Conclusions Routine use of the NAAT on AFB smear-positive respiratory specimens was highly cost-saving in our setting at a U.S. urban public hospital with a high prevalence of TB and HIV because of the low PPV of an AFB smear for culture-confirmed TB Background To investigate the ability of rESAT6 to identify different mycobacteria-sensitized guinea pigs and its safety in pre clinical and phase I clinical study . Material / Methods Guinea pigs were sensitized with different Mycobacteria . After sensitization , all animals were intradermally injected with rESAT6 and either PPD or PPD-B. At 24 h after the injection , the erythema of the injection sites were measured using a double-blind method . For the pre clinical safety study , different doses of rESAT6 and BSA were given 3 times intramuscularly to guinea pigs . On day 14 after the final immunization , the guinea pigs were intravenously injected with the same reagents in the hind legs and the allergic reactions were observed . A single-center , r and omized , open phase I clinical trial was employed . The skin test was conducted in 32 healthy volunteers aged 19–65 years with 0.1 μg  , 0.5 μg , and 1 μg rESAT6 . Physical examination and laboratory tests were performed before and after the skin test and adverse reactions were monitored . The volunteers ’ local and systemic adverse reactions and adverse events were recorded for 7 days . Results Positive PPD or PPD-B skin tests were observed in all Mycobacteria-sensitized guinea pigs ; the diameters of erythema were all > 10 mm . The rESAT6 protein induced a positive skin test result in the guinea pigs sensitized with MTB , M. bovis , M. africanum and M. kansasii ; the diameters of erythema were 14.7±2.0 , 9.3±3.8 , 18.7±2.4 , and 14.8±4.2 mm , respectively . A negative skin test result was detected in BCG-vaccinated and other NTM-sensitized guinea pigs . The rESAT6 caused no allergic symptoms , but many allergic reactions , such as cough , dyspnea , and even death , were observed in the guinea pigs who were administered BSA . During the phase I clinical trial , no adverse reactions were found in the 0.1 μg rESAT6 group , but in the 0.5 μg rESAT6 group 2 volunteers reported pain and 1 reported itching , and in the 1 μg rESAT6 group there was 1 case of pain , 1 case of itching , and 1 case of blister . No other local or systemic adverse reactions or events were reported . Conclusions The rESAT6 can differentiate effectively among MTB infection , BCG vaccination , and NTM infection and is safe in healthy volunteers Background This study aim ed to determine the efficacy and safety of recombinant Mycobacterium tuberculosis ESAT-6 protein for diagnosis of pulmonary tuberculosis ( TB ) . Material / Methods A phase II trial was performed in 158 patients with pulmonary TB ( 145 initially-treated and 13 re-treated ) and 133 healthy subjects . Skin testing was carried out by injecting purified protein derivative ( PPD ) ( on left forearm ) or recombinant ESAT-6 protein at a dosage of 2 , 5 , or 10 μg/mL ( on the right forearm ) in each subject . Reaction activity and adverse events were monitored at 24 , 48 , and 72 h following the injection . Receiver operating characteristic curves were plotted to determine the areas under the curves ( AUCs ) and the cut-off in duration diameters for the optimal diagnostic performance . Results The reaction activity was significantly increased upon recombinant ESAT-6 injection in pulmonary TB patients compared with healthy subjects . In pulmonary TB patients , the reaction was dose-dependent , and at 48 h , 10 μg/mL recombinant ESAT-6 produced a reaction similar to that produced by PPD . The AUCs for a 10 μg/mL dosage were 0.9823 , 0.9552 , and 0.9266 for 24 h , 48 h , and 72 h , respectively , and the in duration diameters of 4.5–5.5 mm were the optimal trade-off values between true positive rates and false positive rates . No serious adverse events occurred in any subjects . Conclusions Recombinant ESAT-6 protein  is efficacious and safe for diagnosing pulmonary TB . Based on the reaction , performance , safety , and practicability , we recommend that 10 μg/mL at 48 h with an in duration cut-off value of 5.0 mm be used OBJECTIVE The goal of this study was to determine the optimal number of aspirations per lymph node ( LN ) station during endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration ( TBNA ) for maximum diagnostic yield in mediastinal staging of non-small cell lung cancer ( NSCLC ) in the absence of rapid on-site cytopathologic examination . METHODS EBUS-TBNA was performed in potentially operable NSCLC patients with mediastinal LNs accessible by EBUS-TBNA ( 5 to 20 mm ) . Every target LN station was punctured four times . RESULTS We performed EBUS-TBNA in 163 mediastinal LN stations in 102 NSCLC patients . EBUS-TBNA confirmed malignancy in 41 LN stations in 30 patients . Two malignant LN stations were missed in two patients . The sensitivity , specificity , positive predictive value , negative predictive value ( NPV ) , and accuracy of EBUS-TBNA in predicting mediastinal metastasis were 93.8 % , 100 % , 100 % , 96.9 % , and 97.9 % , respectively . Sample adequacy was 90.1 % for one aspiration , and it reached 100 % for three aspirations . The sensitivity for differentiating malignant from benign LN stations was 69.8 % , 83.7 % , 95.3 % , and 95.3 % for one , two , three , and four aspirations , respectively . The NPV was 86.5 % , 92.2 % , 97.6 % , and 97.6 % for one , two , three , and four aspirations , respectively . Maximum diagnostic values were achieved in three aspirations . When at least one tissue core was obtained by the first or second aspiration , the sensitivity and NPV of the first two aspirations were 91.9 % and 96.0 % , respectively . CONCLUSIONS Optimal results can be obtained in three aspirations per LN station in EBUS-TBNA for mediastinal staging of potentially operable NSCLC . When at least one tissue core specimen is obtained by the first or second aspiration , two aspirations per LN station can be acceptable RATIONALE Patients with isolated mediastinal lymphadenopathy ( IML ) are a common presentation to physicians , and mediastinoscopy is traditionally considered the " gold st and ard " investigation when a pathological diagnosis is required . Endobronchial ultrasound-guided transbronchial needle aspiration ( EBUS-TBNA ) is established as an alternative to mediastinoscopy in patients with lung cancer . OBJECTIVE To determine the efficacy and health care costs of EBUS-TBNA as an alternative initial investigation to mediastinoscopy in patients with isolated IML . METHODS Prospect i ve multicenter single-arm clinical trial of 77 consecutive patients with IML from 5 centers between April 2009 and March 2011 . All patients underwent EBUS-TBNA . If EBUS-TBNA did not provide a diagnosis , then participants underwent mediastinoscopy . MEASUREMENTS AND MAIN RESULTS EBUS-TBNA prevented 87 % of mediastinoscopies ( 95 % confidence interval [ CI ] , 77 - 94 % ; P < 0.001 ) but failed to provide a diagnosis in 10 patients ( 13 % ) , all of whom underwent mediastinoscopy . The sensitivity and negative predictive value of EBUS-TBNA in patients with IML were 92 % ( 95 % CI , 83 - 95 % ) and 40 % ( 95 % CI , 12 - 74 % ) , respectively . One patient developed a lower respiratory tract infection after EBUS-TBNA , requiring inpatient admission . The cost of the EBUS-TBNA procedure per patient was £ 1,382 ( $ 2,190 ) . The mean cost of the EBUS-TBNA strategy was £ 1,892 ( $ 2,998 ) per patient , whereas a strategy of mediastinoscopy alone was significantly more costly at £ 3,228 ( $ 5,115 ) per patient ( P < 0.001 ) . The EBUS-TBNA strategy is less costly than mediastinoscopy if the cost per EBUS-TBNA procedure is less than £ 2,718 ( $ 4,307 ) per patient . CONCLUSIONS EBUS-TBNA is a safe , highly sensitive , and cost-saving initial investigation in patients with IML . Clinical trial registered with Clinical Trials.gov ( NCT00932854 ) Background Tuberculin skin test ( TST ) has been used for years as an aid in diagnosing latent tuberculosis infection ( LTBI ) but it suffers from a number of well-documented performance and logistic problems . Quantiferon-TB Gold In Tube test ( QFT-GIT ) has been reported to have better sensitivity and specifity than TST . In this study , it was aim ed to compare the performance of a commercial IFN-γ release assay ( QFT-GIT ) with TST in the diagnosis of HCWs at risk for latent TB infection in BCG vaccinated population . Material / Methods Hundred healthy volunteer health care workers were enrolled . All were subjected to TST and QFT-GIT . Results were compared among Health Care Workers ( HCWs ) groups in terms of profession , workplace , working duration . Results TST is affected by previous BCG vaccinations and number of cases with QFT-GIT positivity is increased in accordance with the TST in duration diameter range . QFT-GIT result was negative in 17 of 32 TST positive ( ≥15 mm ) cases and positive in 4 of 61 cases whose TST diameters are between 6–14 mm , that is attritutable to previous BCG vaccination(s ) . It was negative in all cases with TST diameters between 0–5 mm . HCWs with positive QFT-GIT results were significantly older than the ones with negative results . Furthermore duration of work was significantly longer in QFT-GIT positive than in negative HCWs . Conclusions There was a moderate concordance between QFT-GIT and TST , when TST result was defined as positive with a ≥15 mm diameter of in duration . We suggest that QFT-GIT can be used as an alternative to TST for detection of LTBI , especially in groups with high risk of LTBI and in population with routine BCG vaccination program STUDY OBJECTIVES Although various techniques are available for obtaining pathology specimens from the mediastinal lymph nodes , including conventional bronchoscopic transbronchial needle aspiration ( TBNA ) , transesophageal ultrasonography-guided needle aspiration , and mediastinoscopy , there are limitations to these techniques , which include low yield , poor access , need for general anesthesia , or complications . To overcome these problems 
    Output:
    
EBUS-TBNA appears to be an efficacious and safe procedure and should be used as an initial diagnostic tool for mediastinal TBLA