human
***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: We have prospect ively evaluated for the past 8 years 29 children who were hospitalized during infancy with acute lower respiratory tract illness caused by respiratory syncytial virus ( RSV ) . No differences in the prevalence of a family history of atopy or breast-feeding in these infants compared with controls were noted . However , a history of parental smoking was significantly associated with hospital admission for RSV lower respiratory tract disease . Evidence of atopy , as defined by serum IgE levels and radioallergosorbent testing , have developed in only three ( 10 % ) of 29 children . Six children ( 21 % ) continue to have recurrent lower respiratory tract disease . Fifty-five percent of these children had abnormally low oxyhemoglobin levels ( SaO2 ) measured by ear oximetry for the first 3 to 4 years after the acute illness . Twenty-one percent have persistently low SaO2 levels during the eighth year of follow-up . Spirometric values indicate evidence of peripheral airway obstruction . These studies suggest that an association between RSV lower respiratory tract infections and chronic abnormalities of pulmonary function may be detected sequentially through the first 8 years of life . These abnormalities are not limited to those children developing an atopic state during that same time period A prospect i ve study of 1,144 infants and their families was performed . Smoking and family histories were evaluated with respect to the incidence of lower respiratory disease during the first year of life . It was found that ( 1 ) tracheitis and bronchitis occurred significantly more frequently in infants exposed to cigarette smoke in the home , ( 2 ) maternal smoking imposed greater risks upon the infant than paternal smoking , ( 3 ) occurrence of neither tracheitis nor bronchitis showed a consistent relationship to the number of cigarettes smoked , ( 4 ) a family history that was positive for respiratory illness ( chronic cough or bronchitis ) significantly influenced the incidence of bronchitis , ( 5 ) too few cases of laryngitis and pneumonia were seen to warrant any opinions regarding the adverse influence of either smoking or a family history that was positive for respiratory illness , and ( 6 ) occurrence of bronchiolitis was not affected by the presence of a smoker nor influenced by a family history that was positive for respiratory illness . It is concluded that passive smoking is dangerous to the health of infants and that infants born to families with a history that is positive for respiratory illness ( chronic cough or bronchitis ) are at risk of developing bronchitis BACKGROUND Many young children wheeze during viral respiratory infections , but the pathogenesis of these episodes and their relation to the development of asthma later in life are not well understood . METHODS In a prospect i ve study , we investigated the factors affecting wheezing before the age of three years and their relation to wheezing at six years of age . Of 1246 newborns in the Tucson , Arizona , area enrolled between May 1980 and October 1984 , follow-up data at both three and six years of age was available for 826 . For these children , assessment s in infancy included measurement of cord-serum IgE levels  ( measured in 750 children ) , pulmonary-function testing before any lower respiratory illness had occurred ( 125 ) , measurement of serum IgE levels at nine months of age ( 672 ) , and question naires completed by the children 's parents when the children were one year old ( 800 ) . Assessment s at six years of age included measurement of serum IgE levels  ( in 460 ) ,  pulmonary-function testing  ( 526 ) , and  skin allergy testing  ( 629 ) . RESULTS At the age of six years , 425 children ( 51.5 percent ) had never wheezed , 164 ( 19.9 percent ) had had at least one lower respiratory illness with wheezing during the first three years of life but had no  wheezing at six years of age , 124 ( 15.0 percent ) had no  wheezing  before the age of three years but had wheezing at the age of six years , and 113 ( 13.7 percent ) had wheezing both before three years of age and at six years of age . The children who had wheezing before three years of age but not at the age of six had diminished airway function ( length-adjusted maximal expiratory flow at functional residual capacity [ Vmax FRC ] ) both before the age of one year and at the age of six years , were more likely than the other children to have mothers who smoked but not mothers with asthma , and did not have elevated serum IgE levels or skin-test reactivity . Children who started wheezing in early life and continued to wheeze at the age of six were more likely than the children who never wheezed to have mothers with a history of asthma ( P < 0.001 ) , to have elevated serum IgE levels ( P < 0.01 ) , to have normal lung function in the first year of life , and to have elevated serum IgE levels ( P < 0.001 ) and diminished values for VmaxFRC ( P < 0.01 ) at six years of age . CONCLUSIONS The majority of infants with wheezing have transient conditions associated with diminished airway function at birth and do not have increased risks of asthma or allergies later in life . In a substantial minority of infants , however , wheezing episodes are probably related to a predisposition to asthma Respiratory symptoms are common in infancy . Nevertheless , few prospect i ve birth cohort studies have studied the epidemiology of respiratory symptoms in normal infants . The aim of this study was to prospect ively obtain reliable data on incidence , severity , and determinants of common respiratory symptoms ( including cough and wheeze ) in normal infants and to determine factors associated with these symptoms . In a prospect i ve population -based birth cohort , we assessed respiratory symptoms during the first year of life by weekly phone calls to the mothers . Poisson regression was used to examine the association between symptoms and various risk factors . In the first year of life , respiratory symptoms occurred in 181/195 infants ( 93 % ) , more severe symptoms in 89 ( 46 % ) . The average infant had respiratory symptoms for 4 weeks and 90 % had symptoms for less than 12 weeks ( range 0 to 23 ) . Male sex , higher birth weight , maternal asthma , having older siblings and nursery care were associated with more , maternal hay fever with fewer respiratory symptoms . The association with prenatal maternal smoking decreased with time since birth . This study provides reliable data on the frequency of cough and wheeze during the first year of life in healthy infants ; this may help in the interpretation of published hospital and community-based studies . The apparently reduced risk in children of mothers with hayfever but no asthma , and the decreasing effect of prenatal smoke exposure over time illustrate the complexity of respiratory pathology in the first year of life BACKGROUND Acute respiratory infections ( ARI ) are one of the major problems of childhood in developing countries . The objective of the study was to obtain the incidence of ARI and its risk factors in Antalya , Turkey . METHODS We carried out a prospect i ve cohort study on 204 infants who were born between 1 November and 31 December 1997 , in the area of two primary health-care units in the Antalya city center . The research group was followed periodically every 2 months by home visits and the infants were investigated to determine their symptoms of ARI . The weight and length of children were measured in every home visit . Additional questions about socioeconomic status , some environmental characteristics , and nutrition practice were asked . Data were entered into the computer and the Z-scores were calculated by the Epi Info 5 package program . The incidence rates , relative risks and confidence intervals were calculated by Microsoft Excel version 5.0 program . RESULTS The incidence of ARI was 6.53 episodes per child per year among the children in the research group . The factors that influenced the incidence of ARI were lack of mother 's and father 's education , heating by wood stove , being a low-birthweight infant , not being completely breast-fed in the first 4 months of life and being stunted . There were no associations between the number of persons per room or smoking status of family members with ARI incidence . CONCLUSION Our results demonstrated that ARI were also associated with some socioeconomic , environmental and nutritional status characteristics such as paternal education , house ownership , breast-feeding , stunting , prematurity and burning of biomass fuels in Turkey The Indoor Air and Children 's Health Study is a prospect i ve cohort study of the relation between indoor air pollution  and lower respiratory illness ( LRI ) during the first 2 years of life . Information on family and household characteristics was obtained from a health maintenance organization for 1,424 infants enrolled at birth . Data on LRI were abstract ed from medical records . The incidence of all LRI was 48.4 per 100 child-years . Wheezing-associated respiratory illness (WARI)/ asthma was the most common specific LRI , with an incidence of 11.5 per 100 child-years . Total LRI incidence was lowest during the first 6 months of life . Girls had lower incidence than boys [ rate ratio ( RR ) = 0.8 ; 95 % confidence interval ( CI ) = 0.7–0.8 ) ] . With the exception of croup , all LRI were most common during February and March . These results are comparable with those of other prospect i ve studies . Consistent with other studies , self-reported maternal smoking demonstrated an RR of 1.5 ( 95 % CI = 1.2–1.8 ) for total LRI , but the association varied for specific LRIs from 2.3 ( 95 % CI = 1.5–3.0 ) for WARI/asthma to 1.0 ( 95 % CI = 0.7–1.6 ) for bronchitis Studies of the effects of passive smoking on  lower respiratory illness ( LRI ) have relied on question naires to measure exposure . We studied the association between two measures of passive smoking and the incidence of acute LRI in infants . We analyzed data from a community-based cohort study of respiratory illness during the first year of life in North Carolina . The incidence of LRI was determined by telephone calls at 2-week intervals . Environmental , demographic , and psychosocial risk factors for LRI were measured during home interviews . Tobacco smoke exposure was measured as the mean number of cigarettes smoked per day in the infant 's presence . Smoke absorption by the infants was measured by the urinary cotinine/ creatinine ratio . Of the 485 infants in the study , 325 ( 67 % ) had telephone follow-up and at least two home interviews . In bivariate analyses , reported tobacco smoke exposure and urinary cotinine were associated with LRI . Only the association between reported exposure and LRI remained significant after adjusting for confounders , [ adjusted incidence of LRI ( episodes/child-year ) non-exposed : 0.6 ; < or = 10 cigarettes/day : 0.9 ( RR 1.5 , 95 % CI : 1.1 , 2.0 ) ; > 10 cigarettes/day : 1.3 ( RR 2.2 , 95 % CI : 1.3 , 3.8 ) ] . We conclude that infants reportedly exposed to tobacco smoke have an increased incidence of LRI . There are differences between question naire and biochemical measures of passive smoking . Urinary cotinine will not necessarily improve the validity of studies of the relationship of passive smoking to LRI in infants AIMS : To document the prevalence of , and identify risk factors for ,  recurrent wheezing treated with bronchodilators in the first year of life . METHODS : Parental history and neonatal data were collected prospect ively in a regional cohort of very preterm infants ( < 33 weeks ) .  Data on maternal smoking , siblings at home , breast feeding , respiratory symptoms , and hospital re-admissions were documented at 12 months . RESULTS : Outcome data were available for 525/560 ( 95 % ) of survivors . The incidence of recurrent wheeze was 76/525 ( 14.5 % ) in very preterm infants and 20/657 ( 3 % ) in a cohort of term newborns . Significant risk factors for recurrent wheeze in very preterm infants were parental history of asthma , maternal smoking , siblings at home , neonatal oxygen supplementation at 28 days , 36 , and 40 weeks of gestation . CONCLUSIONS : Wheezing respiratory illnesses are common in very preterm infants . The factors involved are similar to those in more mature infants , with the addition of immaturity and neonatal lung injury STUDY OBJECTIVE --The aim was to investigate the relation between  passive smoking and childhood acute respiratory illness .  DESIGN --The study involved an initial postal survey on a r and om sample of children followed by a case-control study based on the survey . A respiratory illness score was calculated from maternal reports of episodes of illness in the previous 12 months . SETTING --The study was a population survey based on Adelaide metropolitan area in South Australia . PARTICIPANTS --The reference population ( n = 13,996 ) was all live born children registered in South Australia in 1983 whose parents lived in Adelaide metropolitan area . Of these , 4985 families were contacted by post and from 2125 respondents , 1218 ( 58 % ) gave consent for home interview .  " Cases " were children with respiratory illness scores in the top 20 % , controlling for age and time of year ( n = 258 ) ; " controls " were taken in the bottom 20 % ( n = 231 ) . MEASUREMENTS AND MAIN RESULTS --Mat 
    Output:
    
agent
***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: We have prospect ively evaluated for the past 8 years 29 children who were hospitalized during infancy with acute lower respiratory tract illness caused by respiratory syncytial virus ( RSV ) . No differences in the prevalence of a family history of atopy or breast-feeding in these infants compared with controls were noted . However , a history of parental smoking was significantly associated with hospital admission for RSV lower respiratory tract disease . Evidence of atopy , as defined by serum IgE levels and radioallergosorbent testing , have developed in only three ( 10 % ) of 29 children . Six children ( 21 % ) continue to have recurrent lower respiratory tract disease . Fifty-five percent of these children had abnormally low oxyhemoglobin levels ( SaO2 ) measured by ear oximetry for the first 3 to 4 years after the acute illness . Twenty-one percent have persistently low SaO2 levels during the eighth year of follow-up . Spirometric values indicate evidence of peripheral airway obstruction . These studies suggest that an association between RSV lower respiratory tract infections and chronic abnormalities of pulmonary function may be detected sequentially through the first 8 years of life . These abnormalities are not limited to those children developing an atopic state during that same time period A prospect i ve study of 1,144 infants and their families was performed . Smoking and family histories were evaluated with respect to the incidence of lower respiratory disease during the first year of life . It was found that ( 1 ) tracheitis and bronchitis occurred significantly more frequently in infants exposed to cigarette smoke in the home , ( 2 ) maternal smoking imposed greater risks upon the infant than paternal smoking , ( 3 ) occurrence of neither tracheitis nor bronchitis showed a consistent relationship to the number of cigarettes smoked , ( 4 ) a family history that was positive for respiratory illness ( chronic cough or bronchitis ) significantly influenced the incidence of bronchitis , ( 5 ) too few cases of laryngitis and pneumonia were seen to warrant any opinions regarding the adverse influence of either smoking or a family history that was positive for respiratory illness , and ( 6 ) occurrence of bronchiolitis was not affected by the presence of a smoker nor influenced by a family history that was positive for respiratory illness . It is concluded that passive smoking is dangerous to the health of infants and that infants born to families with a history that is positive for respiratory illness ( chronic cough or bronchitis ) are at risk of developing bronchitis BACKGROUND Many young children wheeze during viral respiratory infections , but the pathogenesis of these episodes and their relation to the development of asthma later in life are not well understood . METHODS In a prospect i ve study , we investigated the factors affecting wheezing before the age of three years and their relation to wheezing at six years of age . Of 1246 newborns in the Tucson , Arizona , area enrolled between May 1980 and October 1984 , follow-up data at both three and six years of age was available for 826 . For these children , assessment s in infancy included measurement of cord-serum IgE levels  ( measured in 750 children ) , pulmonary-function testing before any lower respiratory illness had occurred ( 125 ) , measurement of serum IgE levels at nine months of age ( 672 ) , and question naires completed by the children 's parents when the children were one year old ( 800 ) . Assessment s at six years of age included measurement of serum IgE levels  ( in 460 ) ,  pulmonary-function testing  ( 526 ) , and  skin allergy testing  ( 629 ) . RESULTS At the age of six years , 425 children ( 51.5 percent ) had never wheezed , 164 ( 19.9 percent ) had had at least one lower respiratory illness with wheezing during the first three years of life but had no  wheezing at six years of age , 124 ( 15.0 percent ) had no  wheezing  before the age of three years but had wheezing at the age of six years , and 113 ( 13.7 percent ) had wheezing both before three years of age and at six years of age . The children who had wheezing before three years of age but not at the age of six had diminished airway function ( length-adjusted maximal expiratory flow at functional residual capacity [ Vmax FRC ] ) both before the age of one year and at the age of six years , were more likely than the other children to have mothers who smoked but not mothers with asthma , and did not have elevated serum IgE levels or skin-test reactivity . Children who started wheezing in early life and continued to wheeze at the age of six were more likely than the children who never wheezed to have mothers with a history of asthma ( P < 0.001 ) , to have elevated serum IgE levels ( P < 0.01 ) , to have normal lung function in the first year of life , and to have elevated serum IgE levels ( P < 0.001 ) and diminished values for VmaxFRC ( P < 0.01 ) at six years of age . CONCLUSIONS The majority of infants with wheezing have transient conditions associated with diminished airway function at birth and do not have increased risks of asthma or allergies later in life . In a substantial minority of infants , however , wheezing episodes are probably related to a predisposition to asthma Respiratory symptoms are common in infancy . Nevertheless , few prospect i ve birth cohort studies have studied the epidemiology of respiratory symptoms in normal infants . The aim of this study was to prospect ively obtain reliable data on incidence , severity , and determinants of common respiratory symptoms ( including cough and wheeze ) in normal infants and to determine factors associated with these symptoms . In a prospect i ve population -based birth cohort , we assessed respiratory symptoms during the first year of life by weekly phone calls to the mothers . Poisson regression was used to examine the association between symptoms and various risk factors . In the first year of life , respiratory symptoms occurred in 181/195 infants ( 93 % ) , more severe symptoms in 89 ( 46 % ) . The average infant had respiratory symptoms for 4 weeks and 90 % had symptoms for less than 12 weeks ( range 0 to 23 ) . Male sex , higher birth weight , maternal asthma , having older siblings and nursery care were associated with more , maternal hay fever with fewer respiratory symptoms . The association with prenatal maternal smoking decreased with time since birth . This study provides reliable data on the frequency of cough and wheeze during the first year of life in healthy infants ; this may help in the interpretation of published hospital and community-based studies . The apparently reduced risk in children of mothers with hayfever but no asthma , and the decreasing effect of prenatal smoke exposure over time illustrate the complexity of respiratory pathology in the first year of life BACKGROUND Acute respiratory infections ( ARI ) are one of the major problems of childhood in developing countries . The objective of the study was to obtain the incidence of ARI and its risk factors in Antalya , Turkey . METHODS We carried out a prospect i ve cohort study on 204 infants who were born between 1 November and 31 December 1997 , in the area of two primary health-care units in the Antalya city center . The research group was followed periodically every 2 months by home visits and the infants were investigated to determine their symptoms of ARI . The weight and length of children were measured in every home visit . Additional questions about socioeconomic status , some environmental characteristics , and nutrition practice were asked . Data were entered into the computer and the Z-scores were calculated by the Epi Info 5 package program . The incidence rates , relative risks and confidence intervals were calculated by Microsoft Excel version 5.0 program . RESULTS The incidence of ARI was 6.53 episodes per child per year among the children in the research group . The factors that influenced the incidence of ARI were lack of mother 's and father 's education , heating by wood stove , being a low-birthweight infant , not being completely breast-fed in the first 4 months of life and being stunted . There were no associations between the number of persons per room or smoking status of family members with ARI incidence . CONCLUSION Our results demonstrated that ARI were also associated with some socioeconomic , environmental and nutritional status characteristics such as paternal education , house ownership , breast-feeding , stunting , prematurity and burning of biomass fuels in Turkey The Indoor Air and Children 's Health Study is a prospect i ve cohort study of the relation between indoor air pollution  and lower respiratory illness ( LRI ) during the first 2 years of life . Information on family and household characteristics was obtained from a health maintenance organization for 1,424 infants enrolled at birth . Data on LRI were abstract ed from medical records . The incidence of all LRI was 48.4 per 100 child-years . Wheezing-associated respiratory illness (WARI)/ asthma was the most common specific LRI , with an incidence of 11.5 per 100 child-years . Total LRI incidence was lowest during the first 6 months of life . Girls had lower incidence than boys [ rate ratio ( RR ) = 0.8 ; 95 % confidence interval ( CI ) = 0.7–0.8 ) ] . With the exception of croup , all LRI were most common during February and March . These results are comparable with those of other prospect i ve studies . Consistent with other studies , self-reported maternal smoking demonstrated an RR of 1.5 ( 95 % CI = 1.2–1.8 ) for total LRI , but the association varied for specific LRIs from 2.3 ( 95 % CI = 1.5–3.0 ) for WARI/asthma to 1.0 ( 95 % CI = 0.7–1.6 ) for bronchitis Studies of the effects of passive smoking on  lower respiratory illness ( LRI ) have relied on question naires to measure exposure . We studied the association between two measures of passive smoking and the incidence of acute LRI in infants . We analyzed data from a community-based cohort study of respiratory illness during the first year of life in North Carolina . The incidence of LRI was determined by telephone calls at 2-week intervals . Environmental , demographic , and psychosocial risk factors for LRI were measured during home interviews . Tobacco smoke exposure was measured as the mean number of cigarettes smoked per day in the infant 's presence . Smoke absorption by the infants was measured by the urinary cotinine/ creatinine ratio . Of the 485 infants in the study , 325 ( 67 % ) had telephone follow-up and at least two home interviews . In bivariate analyses , reported tobacco smoke exposure and urinary cotinine were associated with LRI . Only the association between reported exposure and LRI remained significant after adjusting for confounders , [ adjusted incidence of LRI ( episodes/child-year ) non-exposed : 0.6 ; < or = 10 cigarettes/day : 0.9 ( RR 1.5 , 95 % CI : 1.1 , 2.0 ) ; > 10 cigarettes/day : 1.3 ( RR 2.2 , 95 % CI : 1.3 , 3.8 ) ] . We conclude that infants reportedly exposed to tobacco smoke have an increased incidence of LRI . There are differences between question naire and biochemical measures of passive smoking . Urinary cotinine will not necessarily improve the validity of studies of the relationship of passive smoking to LRI in infants AIMS : To document the prevalence of , and identify risk factors for ,  recurrent wheezing treated with bronchodilators in the first year of life . METHODS : Parental history and neonatal data were collected prospect ively in a regional cohort of very preterm infants ( < 33 weeks ) .  Data on maternal smoking , siblings at home , breast feeding , respiratory symptoms , and hospital re-admissions were documented at 12 months . RESULTS : Outcome data were available for 525/560 ( 95 % ) of survivors . The incidence of recurrent wheeze was 76/525 ( 14.5 % ) in very preterm infants and 20/657 ( 3 % ) in a cohort of term newborns . Significant risk factors for recurrent wheeze in very preterm infants were parental history of asthma , maternal smoking , siblings at home , neonatal oxygen supplementation at 28 days , 36 , and 40 weeks of gestation . CONCLUSIONS : Wheezing respiratory illnesses are common in very preterm infants . The factors involved are similar to those in more mature infants , with the addition of immaturity and neonatal lung injury STUDY OBJECTIVE --The aim was to investigate the relation between  passive smoking and childhood acute respiratory illness .  DESIGN --The study involved an initial postal survey on a r and om sample of children followed by a case-control study based on the survey . A respiratory illness score was calculated from maternal reports of episodes of illness in the previous 12 months . SETTING --The study was a population survey based on Adelaide metropolitan area in South Australia . PARTICIPANTS --The reference population ( n = 13,996 ) was all live born children registered in South Australia in 1983 whose parents lived in Adelaide metropolitan area . Of these , 4985 families were contacted by post and from 2125 respondents , 1218 ( 58 % ) gave consent for home interview .  " Cases " were children with respiratory illness scores in the top 20 % , controlling for age and time of year ( n = 258 ) ; " controls " were taken in the bottom 20 % ( n = 231 ) . MEASUREMENTS AND MAIN RESULTS --Mat 
    Output:
    