***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: BACKGROUND Children with asthma who live in the inner city are exposed to multiple indoor allergens and environmental tobacco smoke in their homes . Reductions in these triggers of asthma have been difficult to achieve and have seldom been associated with decreased morbidity from asthma . The objective of this study was to determine whether an environmental intervention tailored to each child 's allergic sensitization and environmental risk factors could improve asthma-related outcomes . METHODS We enrolled 937 children with atopic asthma ( age , 5 to 11 years ) in seven major U.S. cities in a r and omized , controlled trial of an environmental intervention that lasted one year ( intervention year ) and included education and remediation for exposure to both allergens and environmental tobacco smoke . Home environmental exposures were assessed every six months , and asthma-related complications were assessed every two months during the intervention and for one year after the intervention . RESULTS For every 2-week period , the intervention group had fewer days with symptoms than did the control group both during the intervention year ( 3.39 vs. 4.20 days , P<0.001 ) and the year afterward ( 2.62 vs. 3.21 days , P<0.001 ) , as well as greater declines in the levels of allergens at home , such as Dermatophagoides farinae ( Der f1 ) allergen in the bed ( P<0.001 ) and on the bedroom floor ( P=0.004 ) , D. pteronyssinus in the bed ( P=0.007 ) , and cockroach allergen on the bedroom floor ( P<0.001 ) . Reductions in the levels of cockroach allergen and dust-mite allergen ( Der f1 ) on the bedroom floor were significantly correlated with reduced complications of asthma ( P<0.001 ) . CONCLUSIONS Among inner-city children with atopic asthma , an individualized , home-based , comprehensive environmental intervention decreases exposure to indoor allergens , including cockroach and dust-mite allergens , result ing in reduced asthma-associated morbidity Background : It is not clear whether associations between respiratory symptoms and indoor mould are causal . A r and omised controlled trial was conducted to see whether asthma improves when indoor mould is removed . Methods : Houses of patients with asthma were r and omly allocated into two groups . In one group , indoor mould was removed , fungicide was applied and a fan was installed in the loft . In the control group , intervention was delayed for 12 months . Question naires were administered and peak expiratory flow rate was measured at baseline , 6 months and 12 months . Results : Eighty-one houses were allocated to the intervention group and 83 to the control group ; 95 participants in 68 intervention houses and 87 in 63 control houses supplied follow-up information . Peak expiratory flow rate variability declined in both groups , with no significant differences between them . At 6 months , significantly more of the intervention group showed a net improvement in wheeze affecting activities ( difference between groups 25 % , 95 % CI 3 % to 47 % ; p = 0.028 ) , perceived improvement of breathing ( 52 % , 95 % CI 30 % to 74 % ; p<0.0001 ) and perceived reduction in medication ( 59 % , 95 % CI 35 % to 81 % ; p<0.0001 ) . By 12 months the intervention group showed significantly greater reductions than the controls in preventer and reliever use , and more improvement in rhinitis ( 24 % , 95 % CI 9 % to 39 % ; p = 0.001 ) and rhinoconjunctivitis ( 20 % , 95 % CI 5 % to 36 % ; p = 0.009 ) . Conclusions : Although there was no objective evidence of benefit , symptoms of asthma and rhinitis improved and medication use declined following removal of indoor mould . It is unlikely that this was entirely a placebo effect Objective Home dampness and the presence of mold and allergens have been associated with  asthma morbidity . We examined changes in  asthma morbidity in children as a result of home remediation aim ed at moisture sources . Design In this prospect i ve , r and omized controlled trial , symptomatic , asthmatic children ( n = 62 ) , 2–17 years of age , living in a home with indoor mold , received an asthma intervention including an action plan , education , and individualized problem solving . The remediation group also received household repairs , including reduction of water infiltration , removal of water-damaged building material s , and heating/ventilation/air-conditioning alterations . The control group received only home cleaning information . We measured children ’s total and allergen-specific serum immuno-globulin E , peripheral blood eosinophil counts , and urinary cotinine . Environmental dust sample s were analyzed for dust mite , cockroach , rodent urinary protein , endotoxin , and fungi . The follow-up period was 1 year . Results Children in both groups showed improvement in asthma symptomatic days during the preremediation portion of the study . The remediation group had a significant decrease in symptom days ( p = 0.003 , as r and omized ; p = 0.004 , intent to treat ) after remodeling , whereas these parameters in the control group did not significantly change . In the postremediation period , the remediation group had a lower rate of exacerbations compared with control asthmatics ( as treated : 1 of 29 vs. 11 of 33 , respectively , p = 0 . 003 ; intent to treat : 28.1 % and 10.0 % , respectively , p = 0.11 ) . Conclusion Construction remediation aim ed at the root cause of moisture sources and combined with a medical/behavioral intervention significantly reduces symptom days and health care use for asthmatic children who live in homes with a documented mold problem Exposure to house‐dust mites ( Dermatophagoides spp . ) was investigated in 30 asthmatic patients before and after moving to homes with mechanical ventilation systems .  Median house‐dust mite concentration was 110 mites per gram of mattress dust at the initial investigation and 20 mites per gram at the first follow‐up after a mean of 4.7 months in the new homes . This was lower ( P < 0.05 ) than counts in a control group of 23 asthmatic patients that had unchanged counts . At a second follow‐up , after 15.0 months , mite counts in the study group were further reduced ( P < 0.01 ) from initial values . Among 16 patients , with initial mite counts above the recommended threshold limit value ( TLV ) of 100 mites per gram of dust , the mite counts fell , in most cases , below this TLV . Air‐exchange rates increased ( P < 0.001 ) from a median value of 0.40 air changes per hour ( ach ) to 1.52 ach at the second follow‐up investigation . Furthermore , a reduction ( P < 0.01 ) was found in indoor absolute air humidity , with a median value of 5.6 g of water/kg . No such changes were found in the control group . The present study indicates that reduction of air humidity through an increased supply of fresh air may significantly diminish and , in some cases , even eliminate house‐dust mites in homes To evaluate the effect of a room high-efficiency particulate air ( HEPA ) cleaner on cat-induced asthma and rhinitis , 35 cat-allergic subjects who were living with one or more cats were studied in a double-blind , placebo controlled trial . After a 1 mo baseline period , subjects ' bedrooms were equipped with an active or placebo air cleaner for the following 3 mo . Evaluations included monthly measurement of cat-allergen levels , daily morning , afternoon , and nighttime nasal- and chest-symptom scores , twice-daily measurement of peak-flow rates , daily medication scores , monthly spirometry , and methacholine ( MCh ) challenge testing before and after the study . Airborne allergen levels were reduced in the active-filter group as compared with the placebo group ( p = 0.045 ) . However , no differences were detected in settled-dust allergen levels ( p = 0.485 ) , morning , afternoon , or nighttime nasal-symptom scores ( p = 0.769 , 0.534 , and 0.138 ) , chest-symptom scores ( p = 0.388 , 0.179 , and 0.215 ) , sleep disturbance ( p = 0.101 ) , morning or afternoon peak-flow rates ( p = 0 . 424 and 0.679 ) , or rescue medication use ( nasal , p = 0.164 , chest , p = 0.650 ) , respectively . Although the combination of a HEPA room air cleaner , mattress and pillow covers , and cat exclusion from the bedroom did reduce airborne cat-allergen levels , no effect on disease activity was detected for any parameter studied This study looked at the influence of inspired air water content on exercise-induced bronchospasm ( EIB ) . On separate days , 12 mild asthmatics ( 4 M , 8F ) , aged 18 - 39 yrs ( mean : 27 yrs ) , performed four six minute steady-state exercises on ergometer at 80 % of their maximum workload . Exercises were r and omized to the following inspired air conditions : dry air ( 0 % relative humidity ( RH ] during exercise followed by dry ( DD ) or humid air ( 100 % RH ) ( DH ) after exercise , humid air during exercise followed by dry ( HD ) or humid air ( HH ) . Room temperature was kept constant ( 22 + /- 1 degree C ) at all visits . Forced expiratory volume in one second ( FEV1 ) was measured before and every 5 min for 25 min after exercise . Ventilation ( VE ) was not significantly different whether the exercise was done under dry or humid air . There was a residual bronchodilatation at the end of exercises performed in humid air , while at this time FEV1 was already lower than baseline when exercise was done in dry air conditions . The maximal fall in FEV1(% ) following exercise was significantly greater after those performed in dry air : DD ( 29 + /- 5.6 % ) and DH ( 30 + /- 5.8 % ) than in humid air : HD ( 12 + /- 4.9 % ) and HH ( 20 + /- 4.9 % ) ( p less than 0.05 ) . The time-course of recovery from bronchoconstriction was significantly improved when inhaling dry air after exercise . However , the difference found in the maximal % fall in FEV1 after exercise when recovery was in dry compared to humid air did not achieve statistical significance . In conclusion , EIB is influenced by the changes in water content during and after exercise . Bronchoconstriction following exercise is minimal if exercise is done in humid air and recovery in dry air , and maximal if the exercise is performed in dry air and recovery in humid air We have examined the effect of reducing relative humidity ( RH ) , with inbuilt mechanical ventilation and heat‐exchange ( MVHE ) units , on house‐dust‐ mite ( HDM ) counts and allergen levels , in a pilot study of 10 Wellington dwellings . Recent international prevalence studies in adults and children have confirmed a high prevalence of asthma in New Zeal and , Sensitivity to HDM is common among the general population , and HDM is the major allergen associated with asthma . Recent studies of allergen levels have confirmed high concentrations of Der p 1 in the domestic environment . While humidity was significantly reduced in those dwellings fitted with ventilation units , no systematic effect on mites or Der p 1 was observed during the study period . When the reductions in humidity were examined in the context of the time spent below the critical equilibrium humidity ( CEH ) , the intervention led to RH values below the CEH for only 39 % of the total of 24‐h periods for which measurements were made . Reducing RH by means of MVHE in New Zeal and domestic dwellings does not lower humidity sufficiently , or long enough , to have any measurable effect on HDM population To evaluate the effect of preventive measures 46 patients , all allergic to house‐dust mites ( Dermatophagoides spp . ) , were r and omly allocated to a study and a control group . According to the patients ' subjective recordings of symptom score and use of medicine , compared with the control group , the study group had improved . There was , however , no improvement when comparing the objective recordings of morning and evening peak flow and use of medicine , and it is concluded that the preventive measures in this programme are not very effective for patients allergic to house‐dust mites . The reduction in indoor humidity in the study group was limited and , as a high indoor humidity is the cause of huge population s of house‐dust mites in homes , it is emphasized that future programmes of preventive measures should focus more on damp problems , particularly those related to bad housing construction BACKGROUND The relationship between exposure to house dust mite ( HDM ) allergens and prevalence of sensitization to these allergens in patients with asthma has been confirmed in many studies . Mite population growth is regulated by humidity . Reducing humidity and removing allergen by efficient vacuuming should control mite allergen and reduce symptoms . OBJECTIVE We sought to investigate the effect of mechanical ventilation and high-efficiency vacuuming on HDM numbers and Der p 1 concentrations in the homes of mite-sensitive asthmatic subjects and to evaluate the effect of any reductions on symptoms . METHODS The homes of 40 HDM-sensitive asthmatic subjects were r and omized to receive ( 1 ) mechanical ventilation and a high-efficiency vacuum cleaner ( HEVC ) ; ( 2 ) mechanical ventilation alone ; ( 3 ) an HEVC alone ; and ( 4 ) 
    Output:
    
There was no significant difference in quality of life , rescue medication , requirement for oral corticosteroids , visits to the GP , emergency department ( ED ) or hospitalisations for asthma .
There was no significant difference in the house dust mite count and the antigen levels in the new trial , in contrast to the previous trial .
Evidence on clinical benefits of dehumidification using mechanical ventilation with dehumidifiers remains scanty , and the addition of a new double blind trial to this review does not indicate significant benefit in most measure of control of asthma from such environmental interventions