***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: OBJECTIVES This large , prospect i ve cohort study of private applicators , commercial applicators , and spouses of farmer applicators was undertaken to ascertain the etiology of cancers elevated in agriculture . METHODS The participants were matched to cancer registry files in Iowa and North Carolina . Incident cases were identified from enrollment through 31 December 2002 . St and ardized incidence ratios ( SIR ) were used to compare the cancer incidence of the participants with that of the total population in the two states . RESULTS The overall cancer incidence among farmers [ SIR 0.88 , 95 % confidence interval ( 95 % CI ) 0.84 - 0.91 ] and their spouses ( SIR 0.84 , 95 % CI 0.80 - 0.90 ) were significantly lower than expected , particularly for respiratory and urinary cancers .  Commercial pesticide applicators had an overall cancer incidence comparable with the expected ( SIR 1.01 , 95 % CI 0.84 - 1.20 ) . Smoking prevalence was significantly lower than the national average . Prostate cancer was elevated among private applicators ( SIR 1.24 , 95 % CI 1.18 - 1.33 ) and commercial applicators ( SIR 1.37 , 0.98 - 1.86 ) . Excess ovarian cancer was observed for female applicators ( SIR 2.97 , 95 % CI 1.28 - 5.85 ) , but not for female spouses ( SIR 0.55 , 95 % CI 0.38 - 0.78 ) . Female spouses had a significant excess of melanoma ( SIR 1.64 , 95 % CI 1.24 - 2.09 ) , which was not observed among pesticide applicators . CONCLUSIONS Low overall cancer incidence rates seem to be a result of low overall smoking prevalence and other lifestyle factors , while excess cancer of the prostate and ovaries among applicators may be occupationally related . The excess risk of melanoma observed among spouses was unexpected We report the immunological and clinical results of a phase II trial with intravenously administered highly purified endotoxin ( Salmonella abortus equi ) in patients with advanced cancer . 15 patients with non-small cell lung cancer and 27 with colorectal cancer were entered into the study . 37 evaluable patients received at least four injections of endotoxin  ( 4 ng/kg body weight ) and 1600 mg ibuprofen orally in 2-week intervals . Transient renal ( WHO grade 0 - 1 ) and hepatic ( WHO grade 0 - 4 ) toxicities occurred in several patients . Constitutional side-effects such as fever , chills and hypotension could not be prevented completely by pretreatment with ibuprofen . 3 patients in the colorectal cancer group demonstrated objective responses ( 1 complete remission ( CR ) , 2 partial remission ( PR ) ) . The complete remission has been maintained for more than 3 years , while the partial remissions were stable for 7 and 8 months , respectively . Only marginal antitumour effects were seen in the lung cancer group . Tolerance of the macrophage system to the stimulatory effect of endotoxin , as measured by human necrosis factor alpha ( TNF-alpha ) release into serum , built up after the first administration and remained at a steady-state level after each subsequent injection . In constrast , rising CD4:CD8 ratio and release of tumour necrosis factor beta ( TNF-beta ) indicated the continuing activation of the lymphocyte system by repetitive injections of endotoxin Objective : A prospect i ve study of newly exposed cotton workers was performed to investigate the natural history of respiratory symptoms and lung function changes . Methods : A total of 157 workers naive to cotton dust exposure  were investigated by question naire , spirometry , and skin tests . They were examined before employment ( baseline ) and at the end of the first week , and the first , third , sixth , and 12th month after starting work . Acute airway response was defined as either a cross-first-shift or a cross-week fall in forced expiratory volume in one second ( FEV1 ) . The longitudinal change of lung function over the year was also calculated . Five hundred seventy-two personal dust sampling and 191 endotoxin measurements were performed to assess the exposure . Results : Forty percent of workers reported work-related symptoms in the first week of the study . Smoking , endotoxin , and dust concentrations were risk factors for all work-related symptoms . Acute airway responses were witnessed after immediate exposure . Female status was the only factor found to be predictive of acute airway response . The mean longitudinal fall in FEV1 at 1 year was 65.5 mL ( st and ard error = 37.2 ) . Age , early respiratory symptoms , and early fall in cross-week FEV1 were found to predict the 12-month fall in FEV1 . Cross-first-shift and cross-week falls in FEV1 reduced in magnitude during the course of the study . Conclusions : This study of workers naive to cotton dust exposure has demonstrated that respiratory symptoms and acute airway responses develop early following first exposure , and a tolerance effect develops in those workers with the continued exposure . Current smoking and increasing exposure predicts the development of work-related lower respiratory tract symptoms , while early symptoms and acute airway changes across the working week predict the longitudinal loss of lung function at 1 year Objectives Preventive workplace regulations are so far not based on an ubiquitously accepted threshold for airborne endotoxin in the bioaerosol . Methods In a cross-sectional study , 150 employees of a cotton spinning mill underwent lung function testing . Furthermore , in a r and om subset of 75 textile workers cross-shift lung function test and methacholine challenges were performed . Airborne current endotoxin exposure was classified as “ low ” , “ medium ” , and “ high ” ( ≤100 , > 100–≤450 , and > 450 Endotoxin Units (EU)/m3 , respectively ) based on endotoxin activity . Results The exposure – response relationship between current endotoxin exposure and prevalence of an obstructive ventilation pattern was significant ( test for linear trend : P = 0.019 ) ; the adjusted odds ratio for high endotoxin exposure was 11.22 ( 95 % confidence interval 1.03–121.17 ) . Within individuals , FEV1/FVC% was significantly reduced after the shift ( paired t test : P = 0.009 ) but not related to current endotoxin exposure . Twelve workers showed bronchial hyperresponsiveness ( 8.1 % before and 12.2 % after the work shift ; Fisher ’s exact test : P = 0.021 ) . Conclusion The study among German cotton textile workers suggests an exposure-dependent effect of current endotoxin exposure on lung function impairment with significant effects above 450 EU/m3 In order to evaluate chronic effects of long-term exposure to cotton dust on respiratory health , and the role of dust and endotoxin , longitudinal changes in lung function and respiratory symptoms were observed prospect ively from 1981 to 2001 in 447 cotton textile workers , along with 472 silk textile controls . The results from five surveys conducted over the 20-yr period are reported , including st and ardised question naires , pre- and post-shift spirometric measurements , work-area inhalable dust sample collection s and airborne Gram-bacterial endotoxin analysis . Cotton workers had more persistent respiratory symptoms and greater annual declines in forced expiratory volume in one second ( FEV1 ) and forced vital capacity as compared with silk workers . After exposure cessation , in the final 5-yr period , the rate of FEV1 decline tended to slow in nonsmoking males , but not in nonsmoking females . Workers who reported byssinotic symptoms more persistently suffered greater declines in FEV1 . Chronic loss in lung function was more strongly associated with exposure to endotoxin than to dust . In conclusion , the current study suggests that long-term exposure to cotton dust , in which airborne endotoxin appears to play an important role , results in substantial adverse chronic respiratory effects This case-referent study evaluated cancer risks among farmers in central Italy . Cancer cases ( N = 1674 , 17 sites ) were selected from all deceased men aged 35 - 80 years ; a r and om sample of 480 decedents formed the reference series . Farmers had a decreased risk of lung and bladder cancer and melanoma and nonsignificant excess risks for stomach , rectal , kidney , and nonmelanoma skin cancer . Stomach and kidney cancer were significantly increased among the farmers with > 10 years ' experience , and stomach , rectal , and pancreatic cancer were increased among licensed pesticide users with > 10 years ' experience . Possible relationships emerged between specific crops and cancer : fruit and colon and bladder cancer , wheat and prostate cancer , olives and kidney cancer , and potato and kidney cancer . The results regarding stomach , pancreatic , lung , bladder , and prostate cancer and melanoma congrue with earlier results . The kidney cancer excess , the association of colon and bladder cancer with orchard farming , and the excess of rectal cancer among licensed farmers are new and unexpected findings BACKGROUND Cancer incidence in women textile workers has not been adequately studied . The aim of this study was to examine site-specific cancer incidence patterns in a cohort of 267,400 women textile workers in Shanghai , China . METHODS Women employed by the Shanghai Textile Industry Bureau ( STIB ) were followed for cancer incidence from 1989 to 1998 . Age-adjusted st and ardized incidence ratios ( SIRs ) and 95 % confidence intervals ( CI ) were computed based on Shanghai Cancer Registry ( SCR ) rates . RESULTS There was a decrease in cancer incidence for the cohort compared with urban Shanghai women ( SIR = 0.91 , 95 % CI = 0.89 - 0.93 ) . There were small increased risks of other endocrine tumors ( SIR = 1.31 , 95 % CI = 1.02 - 1.65 ) . There were decreased risks for esophageal ( SIR = 0.54 , 95 % CI = 0.44 - 0.66 ) , stomach ( SIR = 0.79 , 95 % CI = 0.73 - 0.85 ) , rectal ( SIR = 0.88 , 95 % CI = 0.78 - 0.98 ) , lung ( SIR = 0.80 , 95 % CI = 0.74 - 0.86 ) , cervical ( SIR = 0.37 , 95 % CI = 0.28 - 0.50 ) , ovarian ( SIR = 0.85 , 95 % CI = 0.75 - 0.96 ) , and bladder cancers ( SIR = 0.63 , 95 % CI = 0.46 - 0.85 ) . CONCLUSIONS Women employed in the textile industry had a lower than expected cancer experience compared with urban Shanghai women . Further research on this cohort will examine associations between site-specific cancers and occupational exposures to dusts and chemicals 
    Output:
    
Conclusion Despite several limitations , this meta- analysis based on high- quality studies adds weight to the hypothesis that occupational exposure to endotoxin in cotton textile production and agriculture is protective against lung cancer