Linkage of nicotine dependence and smoking behavior on 10q, 7q and 11p in twins with homogeneous genetic background.

The significant worldwide health burden introduced by tobacco smoking highlights the importance of studying the genetic determinants of smoking behavior and the key factor sustaining compulsive smoking, that is, nicotine dependence (ND). We have here addressed the genetic background of smoking in a special study sample of twins, harmonized for early life events and specifically ascertained for smoking from the nationwide twin cohort of the genetically unique population of Finland. The twins and their families were carefully examined for extensive phenotype profiles and a genome-wide scan was performed to identify loci behind the smoking status, ND and the comorbid phenotype of ND and alcohol use in 505 individuals from 153 families. We replicated previous linkage findings on 10q (max logarithm of the odds (LOD) 3.12) for a smoker phenotype, and on 7q and 11p (max LOD 2.50, and 2.25, respectively) for the ND phenotype. The loci linked for ND also showed evidence for linkage for the comorbid phenotype. Our study provides confirmatory evidence for the involvement of these genome regions in the genetic etiology of smoking behavior and ND and for the first time associates drinking and smoking to a shared locus on 10q.

Breast-feeding and the development of cows' milk protein allergy.

Early feeding with cows' milk (CM) may cause cows' milk allergy (CMA). Breast milk contains many immune factors which compensate for the undeveloped defence mechanisms of the gut of the newborn infant. We studied the effect of supplementary CM feeding at the maternity hospital on the subsequent incidence of CMA, the effects of formula and breast feeding on the subsequent immunologic types of CMA, and the importance of immune factors present in colostrum in the immune responses of infants with CMA. In a cohort of 6209 infants, 824 were exclusively breast-fed and 87% required supplementary milk while in the maternity hospital: 1789 received CM formula, 1859 pasteurized human milk, and 1737 whey hydrolysate formula. The cumulative incidence of CMA, verified by a CM elimination-challenge test, was 2.4% in the CM, 1.7% in the pasteurized human milk and 1.5% in the whey hydrolysate group. Among these infants, exposure to CM at hospital and a positive atopic heredity increased the risk of CMA. Of the exclusively breast-fed infants, 2.1% had CMA. Risk factors for the development of IgE-mediated CMA were: exposure to CM at hospital, breast-feeding during the first 8 weeks at home either exclusively or combined with infrequent exposure to small amounts of CM and long breast-feeding. The content of transforming growth factor-beta1 (TGF-beta1) in colostrum from mothers of infants with IgE-mediated CMA was lower than from mothers of infants with non-IgE-mediated CMA. In infants with CMA, TGF-beta1 in colostrum negatively correlated with the result of skin prick test and the stimulation of peripheral blood mononuclear cells to CM, but positively with infants' IgA and IgG antibodies to CM proteins. Feeding of CM formula at maternity hospital increases the risk of CMA, but exclusive breast-feeding does not eliminate the risk. Prolonged breast-feeding exclusively or combined with infrequent exposure to small amounts of CM during the first 8 weeks induces the development of IgE-mediated CMA. Colostral TGF-beta1 may inhibit IgE- and cell mediated reactions and promote IgG-IgA antibody production to CM in infants prone to developing CMA.

Supplementary feeding in maternity hospitals and the risk of cow's milk allergy: A prospective study of 6209 infants.

BACKGROUND: Early feeding with cow's milk (CM) may increase the risk of cow's milk allergy (CMA). OBJECTIVE: We sought to examine prospectively whether supplementary feeding of CM at the maternity hospital would increase the risk when compared with feeding with pasteurized human milk or hydrolyzed formula. METHODS: We studied 6209 unselected healthy, full-term infants, of whom 5385 (87%) required supplementary milk while in the hospital. The infants were randomly assigned to receive CM formula (1789 infants), pasteurized human milk (1859 infants), or whey hydrolysate formula (1737 infants). The comparison group (824 infants) was composed of infants who were exclusively breast-fed. The infants were followed for 18 to 34 months for symptoms suggestive of CMA. The primary endpoint was a challenge-proven adverse reaction to CM after a successful CM elimination diet. RESULTS: The cumulative incidence of CMA in the infants fed CM was 2.4% compared with 1.7% in the pasteurized human milk group (odds ratio [OR], 0.70; 95% confidence interval [CI], 0. 44-1.12) and 1.5% in the whey hydrolysate group (OR, 0.61; 95% CI, 0. 38-1.00). In the comparison group, CMA developed in 2.1% of the infants. Among the infants who required supplementary feeding at hospital, both exposure to CM while in the hospital (OR, 1.54; 95% CI, 1.04-2.30; P =.03) and obvious parental atopy (OR, 2.32; 95% CI, 1.53-3.52; P <.001) increased the risk of CMA. CONCLUSIONS: Our data indicate that feeding of CM at maternity hospitals increases the risk of CMA when compared with feeding of other supplements, but exclusive breast-feeding does not eliminate the risk.

Bar coding--a functional tool in survey research.

STUDY OBJECTIVE: The aim was to assess the value of bar coding, together with developed microcomputer programs, as a tool to speed up mailing and handling of return responses of a survey where over 4000 adolescents received a mailed questionnaire. DESIGN: Bar codes were used for displaying the identification number of a questionnaire, as well as each response alternative and number of the question. These bar codes were read by a wand, a handhold scanner, connected to a microcomputer and the data were automatically entered into a computer data file. RESULTS AND CONCLUSIONS: Compared with previous similar surveys, the use of bar codes did not seem to affect a manner of responding. Bar coding saved human steps in handling of return responses, reduced an error rate, and helped to control the process of work. Bar coding is recommended as a new technical tool for preparations of future large scale surveys.