Impact of maternal pre-pregnancy overweight on infant overweight at 1 year of age: associations and sex-specific differences

BACKGROUND

Maternal overweight or obesity (OWOB) is linked to gestational diabetes, fetal macrosomia and higher rates of caesarean delivery.

OBJECTIVES

The study aims to assess whether maternal pre-pregnancy OWOB is associated with infant overweight in a sex-dependent manner, independent of microbiota-altering variables.

METHODS

Weight and length measurements of 955 mother-infant pairs were obtained from the Canadian Healthy Infant Longitudinal Development cohort. Maternal pre-pregnancy weight was defined as follows: normal, overweight (25 ≤ body mass index < 30) and obese (body mass index ≥ 30). Age and sex-adjusted weight-for-length z-scores >97th percentile were classified as infant overweight at age 1 year. Associations between pre-pregnancy and infant overweight were determined by linear and logistic regression, adjusting for covariates.

RESULTS

Maternal pre-pregnancy OWOB were associated with infant weight-for-length and overweight risk at 1 year. Except for pre-pregnancy obesity, these associations were not attenuated appreciably after adjustment for birth mode, exclusivity of breastfeeding, exposure to antibiotics and infant sex. Yet only boys born to mothers with obesity were three times more likely to become overweight at age 1 independent of microbiota-altering variables. Pre-pregnancy obesity was associated with weight-for-length in male and female infants.

CONCLUSIONS

Maternal pre-pregnancy OWOB increases the risk of infant overweight, and this association is more evident in male infants.

Stability of pro- and anti-inflammatory immune biomarkers for human cohort studies

BACKGROUND

Although discovery research has identified the importance of dozens of pro- and anti-inflammatory immune mediators in the pathogenesis, maintenance, exacerbation and resolution of inflammatory diseases, most human cohort studies have incorporated few or no immunological intermediate phenotypes in their analyses. Significant hindrances have been (1) the limited panel of biomarkers known to be readily detected in healthy human populations and (2) the stability, hence utility, of such biomarkers to repeated analysis.

METHODS

The frequency and stability of 14 plasma biomarkers linked to in vivo immune regulation of allergic and autoimmune inflammatory disorders was determined in 140 healthy pediatric and adult participants. The impact of initial and multiple subsequent freeze/thaw cycles on pro-inflammatory (CCL2, CXCL10, IL-18, TNFα, IL-6), anti-inflammatory (IL-10, sTNF-RII, IL-1Ra), acute phase proteins (CRP, PTX3) and other biomarkers (sST2, IL-1RAcP) was subsequently quantified.

RESULTS

Multiple biomarkers capable of providing an innate immune signature of inflammation were readily detected directly ex vivo in healthy individuals. These biomarker levels were unaffected when comparing paired data sets from freshly obtained, never frozen plasma or serum and matched aliquots despite extensive freeze/thaw cycles. Neither age nor sex affected stability. Similarly, no quantitative differences were found following repetitive analysis of inflammatory biomarkers in culture samples obtained following in vitro stimulation with TLR and RLR ligands.

CONCLUSIONS

A broad panel of in vivo and ex vivo cytokine, chemokine and acute phase protein biomarkers that have been linked to human chronic inflammatory disorders are readily detected in vivo and remain stable for analysis despite multiple freeze thaw cycles. These data provide the foundation and confidence for large scale analyses of panels of inflammatory biomarkers to provide better understanding of immunological mechanisms underlying health versus disease.

Impact of maternal intrapartum antibiotics, method of birth and breastfeeding on gut microbiota during the first year of life: a prospective cohort study

OBJECTIVE

Dysbiosis of the infant gut microbiota may have long-term health consequences. This study aimed to determine the impact of maternal intrapartum antibiotic prophylaxis (IAP) on infant gut microbiota, and to explore whether breastfeeding modifies these effects.

DESIGN

Prospective pregnancy cohort of Canadian infants born in 2010-2012: the Canadian Healthy Infant Longitudinal Development (CHILD) Study.

SETTING

General community.

SAMPLE

Representative sub-sample of 198 healthy term infants from the CHILD Study.

METHODS

Maternal IAP exposures and birth method were documented from hospital records and breastfeeding was reported by mothers. Infant gut microbiota was characterised by Illumina 16S rRNA sequencing of faecal samples at 3 and 12 months.

MAIN OUTCOME MEASURES

Infant gut microbiota profiles.

RESULTS

In this cohort, 21% of mothers received IAP for Group B Streptococcus prophylaxis or pre-labour rupture of membranes; another 23% received IAP for elective or emergency caesarean section (CS). Infant gut microbiota community structures at 3 months differed significantly with all IAP exposures, and differences persisted to 12 months for infants delivered by emergency CS. Taxon-specific composition also differed, with the genera Bacteroides and Parabacteroides under-represented, and Enterococcus and Clostridium over-represented at 3 months following maternal IAP. Microbiota differences were especially evident following IAP with emergency CS, with some changes (increased Clostridiales and decreased Bacteroidaceae) persisting to 12 months, particularly among non-breastfed infants.

CONCLUSIONS

Intrapartum antibiotics in caesarean and vaginal delivery are associated with infant gut microbiota dysbiosis, and breastfeeding modifies some of these effects. Further research is warranted to explore the health consequences of these associations.

TWEETABLE ABSTRACT

Maternal #antibiotics during childbirth alter the infant gut #microbiome.

The Canadian healthy infant longitudinal development birth cohort study: biological samples and biobanking

BACKGROUND

It is hypothesised that complex interactions between genetic and environmental factors give rise to allergy and asthma in childhood. The Canadian Healthy Infant Longitudinal Development (CHILD) study was designed to explore these factors.

METHODS

CHILD is a longitudinal, general population birth cohort study following infants from mid-pregnancy to age 5 years. Over this time period, biological samples, questionnaires, clinical measures and environmental data are collected.

RESULTS

A total of 3624 families have been recruited, and many thousands of samples and questionnaires have been collected, annotated, and archived. This report outlines the rationale and methodology for collecting and storing diverse biological samples from parents and children in this study, and the mechanisms for their release for analyses.

CONCLUSIONS

The CHILD sample and data repository is a tremendous current and future resource and will provide a wealth of information not only informing studies of asthma and allergy, but also potentially in many other aspects of health relevant for Canadian infants and children.

Associations between bacterial communities of house dust and infant gut

The human gut is host to a diverse and abundant community of bacteria that influence health and disease susceptibility. This community develops in infancy, and its composition is strongly influenced by environmental factors, notably perinatal anthropogenic exposures such as delivery mode (Cesarean vs. vaginal) and feeding method (breast vs. formula); however, the built environment as a possible source of exposure has not been considered. Here we report on a preliminary investigation of the associations between bacteria in house dust and the nascent fecal microbiota from 20 subjects from the Canadian Healthy Infant Longitudinal Development (CHILD) Study using high-throughput sequence analysis of portions of the 16S rRNA gene. Despite significant differences between the dust and fecal microbiota revealed by Nonmetric Multidimensional Scaling (NMDS) analysis, permutation analysis confirmed that 14 bacterial OTUs representing the classes Actinobacteria (3), Bacilli (3), Clostridia (6) and Gammaproteobacteria (2) co-occurred at a significantly higher frequency in matched dust-stool pairs than in randomly permuted pairs, indicating an association between these dust and stool communities. These associations could indicate a role for the indoor environment in shaping the nascent gut microbiota, but future studies will be needed to confirm that our findings do not solely reflect a reverse pathway. Although pet ownership was strongly associated with the presence of certain genera in the dust for dogs (Agrococcus, Carnobacterium, Exiguobacterium, Herbaspirillum, Leifsonia and Neisseria) and cats (Escherichia), no clear patterns were observed in the NMDS-resolved stool community profiles as a function of pet ownership.

Combined exposure to dog and indoor pollution: incident asthma in a high-risk birth cohort

The impact of single exposures on asthma development is better understood than the effect of multiple exposures. The objective of the present study was to evaluate the effect of combined early exposure to dog allergen (Can-f1) plus indoor nitrogen dioxide (NO₂) or environmental tobacco smoke (ETS) on asthma and bronchial hyperreactivity (BHR) in a high-risk birth cohort. We also aimed to assess atopy's impact on the effects of these exposures. Peri-birth ETS exposure was measured using cord blood cotinine (CCot). During year 1, atopy, NO₂, Can-f1, and urinary cotinine (UCot) were measured. At 7 yrs of age, 380 children were assessed for asthma and BHR. Exposure effects were determined using stepwise multiple linear regression. Co-exposure to elevated Can-f1 and NO₂, or Can-f1 and ETS (CCot), increased risk for asthma, relative to having neither such exposure (OR 4.8 (95% CI 1.1-21.5) and 2.7 (1.1-7.1), respectively); similar risks resulted when substituting dog ownership for allergen. Atopy increased asthma and BHR risk associated with several exposures; notably, atopy with elevated UCot, relative to atopy without such exposure, increased risk of BHR (OR 3.1 (95% CI 1.1-8.6)). In a high-risk birth cohort, early co-exposure to Can-f1 and NO₂ or ETS increased the risk of incident asthma. Atopy increased the risk of asthma and BHR associated with ETS.

A novel study design to investigate the early-life origins of asthma in children (SAGE study)

This is a description of the Study of Asthma, Genes and the Environment (SAGE), a novel birth cohort created from provincial healthcare administrative records. It is a general population-based cohort, composed of children at high and low risk for asthma, living in urban and rural environments in Manitoba, Canada. The SAGE study captures the complete longitudinal healthcare records of children born in 1995 and contains detailed information on early-life exposures, such as antibiotic utilization and immunization, in relationship to the development of asthma. Nested within the birth cohort is a case-control study, which was created to collect information on home environmental exposures from detailed surveys and home dust sampling, to confirm asthma status in children and use this data to validate healthcare database measures of asthma, to determine differences in immune system responsiveness to innate and adaptive immune stimuli in asthma, to genotype children for genes likely associated with the development of asthma and to study the epigenetic regulation of pre-established protective vs allergic immune responses. The SAGE study is a multidisciplinary collaboration of researchers from pediatric allergy, population health, immunology, and genetic and environmental epidemiology. As such, it serves as a fertile, interdisciplinary training ground for graduate students, and postdoctoral and clinician fellows.

Fast food consumption counters the protective effect of breastfeeding on asthma in children?

BACKGROUND

Fast food consumption and childhood asthma have rapidly increased in recent decades. During the same period there has been an increased rate of prolonged breastfeeding.

OBJECTIVE

To evaluate if fast food consumption was associated with asthma in children, and if the proposed protective effect of breastfeeding on asthma was altered by fast food consumption.

METHODS

This case-control study included 246 children with allergist-diagnosed asthma and 477 non-asthmatic controls at age 8-10 years. Information on fast food consumption and exclusive breastfeeding was obtained from questionnaire data. The association between asthma and fast food consumption was evaluated. Asthma in relation to exclusive breastfeeding was also evaluated, taking into account fast food consumption as a modifying factor.

RESULTS

Children with asthma were more likely to consume fast food than children without asthma [crude odds ratio (OR) 1.70, 95% confidence interval (CI) 1.23-2.34]. In comparison to prolonged exclusive breastfeeding (> or =12 weeks), asthma was positively associated with short-term exclusive breastfeeding (<12 weeks) in children who never or occasionally consumed fast food (crude OR 1.84, 95% CI 1.09-3.11), but not in children who frequently consumed fast food (crude OR 1.07, 95% CI 0.72-1.61). The P-value for this interaction (0.109) was borderline. Children with high fast food consumption who were exclusively breastfed <12 weeks as infants, had greater than a twofold risk of asthma compared with infants who had been exclusively breastfed for a longer time period and who did not become high consumers of fast food in later childhood. These findings were not affected after final adjustment of confounders and covariates.

CONCLUSION

Fast food consumption is associated with asthma in children and potentially counteracts the protective effect of prolonged breastfeeding on asthma. This may explain the paradoxical phenomenon of parallel increased rates of prolonged breastfeeding and asthma in children. 556-561.

Infrequent milk consumption plus being overweight may have great risk for asthma in girls

BACKGROUND

Inadequate milk consumption and being overweight are each associated with asthma symptoms in children. Milk consumption has been inversely related to childhood overweight. Thus, being overweight may be a pathway or a confounder in milk-asthma relationship. A combination of both factors may be associated with greater risk of asthma than one factor alone.

METHODS

This study included 246 children with allergist-diagnosed asthma and 477 nonasthmatic controls at the age of 8-10 years. Information on milk consumption during the last 12 months was obtained from questionnaires. Being overweight was defined as body mass index > or =85th percentile. Being overweight as a possible pathway or confounder was formally tested. The odds ratio (OR) for combined infrequent milk consumption and being overweight in asthmatic vs nonasthmatic children was determined in multivariate logistic regression analyses.

RESULTS

There was a significant interaction between milk consumption and sex of the child in relation to asthma. Asthma was significantly associated with infrequent milk consumption in girls (crude OR 2.11, 95% CI 1.05-4.24) but not in boys. The asthma-milk relation in girls was neither mediated by being overweight (p(mediation tests) = 0.27) nor was the relationship confounded by being overweight (a 9% change in coefficient). Asthmatic girls had 3.6 times increased odds of having combination of infrequent milk consumption and being overweight than nonasthmatic girls (adjusted OR 3.64, 95% CI 1.18-11.24). Asthma was not associated with either factor or with absence of the other in girls.

CONCLUSION

Infrequent milk consumption plus being overweight may have great risk for asthma in girls.

Novel cytokine peptide-based vaccines: an interleukin-4 vaccine suppresses airway allergic responses in mice

BACKGROUND

Monoclonal antibodies or soluble receptors have been used to block over-produced endogenous cytokines. However, they have disadvantages of short half-lives, high costs, and possible adverse effects. Using interleukin (IL)-4 as a model target, we sought to develop a novel therapeutic strategy by constructing an IL-4 peptide-based vaccine for blocking IL-4 on a persistent basis, and to evaluate its efficacy in a mouse model of asthma.

METHODS

A peptide was selected by antigenic prediction and structure analysis of IL-4/receptor complex. The vaccine was constructed by employing truncated hepatitis B core antigen as carrier with the peptide inserted using gene engineering methods. It was then expressed, purified and identified. Prior to intraperitoneal sensitization and intranasal challenge with ovalbumin, mice were subcutaneously immunized three times with the vaccine, or the carrier or saline as controls. Serum antibodies, inflammatory cells in bronchoalveolar lavage fluids (BALF), lung histology, and responsiveness to inhaled methacholine were analyzed.

RESULTS

The vaccine presented as virus-like particles and reacted to polyclonal anti-IL-4 in Western blotting. Vaccinated mice produced high titers of IgG to IL-4. Serum ovalbumin-specific IgE, eosinophil accumulation in BALF, goblet cell hyperplasia, tissue inflammation and methacoline-induced respiratory responses were markedly suppressed in vaccinated mice with statistical significance, as compared with those in the control groups.

CONCLUSIONS

Administration of this novel IL-4 vaccine led to an overall decrease in the development of airway allergic inflammatory responses. The results indicate that cytokine peptide-based vaccines hold potential for treatment of asthma and, by extension, other diseases where over-expressed cytokines play a pivotal role in pathogenesis.

Age differences in health effects of stressors and perceived control among urban African American women

A conceptual model of the stress process has been useful in examining relationships among a variety of stressors, health status, and protective factors that modify the health-stress relationship. The model can contribute to an understanding of variations in health among people living in urban environments experiencing high degrees of stress. This study examines social contextual stressors in the neighborhood, health outcomes, and perceived control at multiple levels beyond the individual as a protective factor, among a random sample (N = 679) of predominantly low-income African American women who reside on Detroit's east side. Findings suggest that although stress has a consistently negative impact on health, perceived control may buffer against the deleterious effects of stress. The buffering role of perceived control, however, depends on age, the type of stressor examined, and the context or level at which perceived control is assessed (e.g., organizational, neighborhood, beyond the neighborhood). For young women, perceived control was found to be health protective. Among older women, perceived control in the face of stressors was inversely related to health. These findings suggest the need for health and social service programs and policy change strategies to both increase the actual influence and control of women living in low-income urban communities and to reduce the specific social contextual stressors they experience.

Constant infusion of epinephrine, but not bolus treatment, improves haemodynamic recovery in anaphylactic shock in dogs

OBJECTIVE

Epinephrine (Epi) is the treatment of choice for reversing cardiovascular collapse in anaphylactic shock (AS). In this condition, most treatment guidelines have been anecdotally derived and no randomized clinical trials have been conducted. In the present study, we examined the time course of haemodynamic recovery in a canine model of AS when Epi was administered at the initiation of allergen challenge before fully developed shock had occurred.

METHODS

Randomized, controlled, crossover studies were performed approximately 3-5 weeks apart in ragweed-sensitized dogs while the animals were ventilated and anaesthetized. Epi was administered by bolus intravenous (i.v.), subcutaneous (s.c.), intramuscular (i.m.) routes and by continuous i.v. infusion (CI). The findings obtained in the Epi treatment (T) studies were compared with those found in a no treatment (NT) study. In the bolus studies, Epi was administered at 0.01 mg/kg, while in the CI study, the dose of Epi was titrated to maintain mean arterial pressure (MAP) at 70% of preshock levels. MAP, cardiac output (CO), stroke volume (SV), and pulmonary wedge pressure (Pwp) were determined over a 3 h period.

RESULTS

In the CI study, haemodynamics (CO, MAP, and SV) were significantly higher than those measured in the NT study and the bolus studies over approximately the first hour of the study. In the CI study, the amount of Epi infused was significantly less than in the bolus studies.

CONCLUSION

When administered at the initiation of allergen challenge, bolus treatment of Epi by i.m., i.v., or s.c. routes caused limited haemodynamic improvement in AS. In contrast, constant infusion of Epi at a lower total dose produced significant haemodynamic improvement. Within the limits of this anaesthetized canine model, the results suggest that CI should be the preferred route in the treatment of AS when this treatment option is available.

Genetic variants of the IL13 and IL4 genes and atopic diseases in at-risk children

We studied a cohort containing 368 children at high risk of developing atopy and atopic disorders and 540 parents of those children to investigate whether the IL13 Arg130Gln and C-1112 T polymorphisms were associated with these outcomes. We also investigated whether haplotypes consisting of any two polymorphisms of IL13 Arg130Gln, IL13 C-1112 T and IL4 C-589 T were associated with these phenotypes. In 288 white children, the IL13 130Gln allele was associated with atopy (RR=1.9, P=0.047), and with atopic dermatitis (RR=2.5, P=0.014). The associations were confirmed using a family-based test of association (P=0.027 and 0.030, respectively) in all subjects. In white subjects there were associations of haplotypes consisting of IL13 Arg130Gln and IL4 C-589 T with atopic dermatitis (P=0.006) and with atopy (P=0.009). Our data suggest that the IL13 Arg130Gln polymorphism and haplotypes consisting of IL13 Arg130Gln and IL4 C-589 T were associated with the development of atopy and atopic dermatitis at 24 months of age.

Gradual dose taper following chronic buprenorphine

This paper describes the time course of withdrawal and relapse in opioid-dependent volunteers (n = 8) who completed a gradual outpatient buprenorphine dose taper (28 days). Compliance with treatment was very high, as evidenced by clinic attendance (96-100%). Urinalysis showed that 6 of the 8 volunteers had relapsed to opiates by the end of the dose taper, even though reports of withdrawal were generally low. Relapse may have been triggered by a desire to re-experience the drug's positive subjective effects, craving, or low motivation to remain drug-free. A longer taper combined with an expanded range of treatments may improve prognosis.

Effects of jet engine noise and performance feedback on perceived workload in a monitoring task

This study examined the effects of exposure to intermittent jet aircraft noise (70 dBA or 95 dBA maximum intensity) and knowledge of results concerning signal detections (hit-KR) on performance efficiency and perceived workload in a 40-min visual vigilance task. The noise featured a Doppler-like quality in which planes seemed to approach from the monitor's left and recede to the right. Perceptual sensitivity (d') was poorer in the context of noise than in quiet but only in the presence of hit-KR. The lack of noise-related performance differences in the absence of hit-KR most likely reflected a "floor effect" rather than some special relation between noise and feedback. When compared to subjects performing in quiet, those who operated in noise were less able to profit from hit-KR, a result that may reflect the effects of noise on information processing. In addition to its negative effects on signal detectability, noise elevated the perceived workload, as measured by the NASA-TLX. This effect was robust; it was independent of the presence of hit-KR, even though hit-KR generally lowered the overall level of perceived workload. The results provide the initial experimental demonstration that perceived workload is a sensitive measure of the effects of aircraft noise in monitoring tasks.

The association between respiratory viruses and symptoms in 2-week-old infants at high risk for asthma and allergy

OBJECTIVES

The role of viral respiratory tract infections in the onset of childhood asthma and allergy is controversial, partly because of limited understanding about postnatal viral exposures. We investigated the prevalence of 3 common respiratory viruses and associated respiratory symptoms in 2-week-old infants at high risk for having asthma and allergy.

STUDY DESIGN

Frozen nasal specimens from 2-week-old children at high risk (n = 495) underwent reverse transcription-polymerase chain reaction (RT-PCR) for picornavirus-, parainfluenza-, and respiratory syncytial virus-specific nucleic acid. RT-PCR findings were related to respiratory symptoms (cold, cough, and wheeze) and to characteristics implicated with increased risk for asthma and allergy.

RESULTS

Viral RT-PCR was positive in 199 (40.2%) of 495 specimens examined, with picornavirus and parainfluenza significantly associated with respiratory symptoms. Viral prevalence was significantly higher in children born during the winter and summer months.

CONCLUSIONS

A high percentage (40.2%) of infants at high risk for asthma and allergy had been exposed to common respiratory viruses at 2 weeks of age. RT-PCR is a powerful diagnostic method that can be used in epidemiologic studies examining the role of viral respiratory tract infections in the pathogenesis of pediatric asthma and allergy.

Outcomes in pediatric asthma: What are the important issues?

Historic characteristics related to children and their parents remain the primary focus for diagnosis of asthma in the preschool-aged child. Important questions remain unanswered. Physicians must be better able to assess whether asthma is present. They also need to better understand the genetics of asthma and allergy and to have access to simple, quantitative measurements of those environmental exposures that enhance the risk of allergy and asthma. Physicians must also balance benefits and risks from any intervention, which is difficult because existing guidelines do not offer much information on the preschool-aged child. Although we are unable to prevent the development of asthma and allergy, it is possible to help children and their families control asthma.

Community-based participatory research: policy recommendations for promoting a partnership approach in health research

Community-based participatory research in public health focuses on social, structural, and physical environmental inequities through active involvement of community members, organizational representatives, and researchers in all aspects of the research process. Partners contribute their expertise to enhance understanding of a given phenomenon and integrate the knowledge gained with action to benefit the community involved. This article presents key principles of community-based participatory research (CBPR), discusses the rationale for its use, and provides a number of policy recommendations at the organizational, community and national levels aimed at advancing the application of CBPR. While the issues addressed here draw primarily upon experiences in the United States, the emphasis throughout this article on the establishment of policies to enhance equity that would serve both to increase the engagement of communities as partners in health research, and to reduce health disparities, has relevant applications in a global context.

Is primary prevention of asthma possible?

The increased prevalence of asthma over the past quarter century has become a major public health problem for the industrialized world. Asthma is a disease process which has a strong heritable component which is impacted by multiple environmental factors. Given the rapid increase in asthma prevalence, it is difficult to ascribe the change to a genetic alteration. Therefore, the focus for understanding the changing prevalence of asthma must be on environmental factors. This article reviews factors which may contribute, in whole or in part, to the development of the disease process. In questioning whether it is possible to prevent development of a disease (primary prevention), it is critical to understand these factors. The environment may even have an impact on the fetus during intrauterine life. There does appear to be a "window of opportunity" in early life where a variety of factors, including food and inhalant allergen exposure, exposure to pollutants, and infection with both viral and bacterial agents, may be important in initiating the development of asthma and allergy. Potential approaches to primary prevention of asthma and allergy must consider each of these important factors. Given that asthma is a multifactorial disease with both complex genetic and environmental components, it is unlikely that any single intervention will significantly decrease the prevalence of asthma.

Polymorphisms of the IL-4, TNF-alpha, and Fcepsilon RIbeta genes and the risk of allergic disorders in at-risk infants

Polymorphisms in the TNF-alpha (A-308G), IL-4 (C-589T), and Fcalpha RIbeta (E237G) genes have been associated with asthma and related phenotypes. To determine the predictive value of these polymorphisms we have assessed their relative risk (RR) for the development of atopy, asthma, and rhinitis in a high-risk infant population that is being followed longitudinally from birth. DNA was extracted and genotyped for 373 infants and 572 parents for each polymorphism. Phenotypic data were collected for atopy and allergic diseases in the infants at 12 mo of age. The prevalence of these phenotypes in the 281 white infants was compared in each genotypic group. There were no differences in the prevalence of any phenotype between genotypes of the TNF-alpha and Fcalpha RIbeta polymorphisms. However, we found that the IL4-589*T allele was associated with "probable" asthma (RR = 4.1) and that homozygotes for the IL4-589*T allele had an increased risk for the development of rhinitis (RR = 2.4). Using the transmission disequilibrium test, an association of IL4-589*T with atopy was found. We conclude that IL-4-589*T, but not TNF-alpha-308*2 or Fcalpha RIbeta*G, is a risk factor for the development of atopy, asthma, and rhinitis by 12 mo of age.

Breast-feeding and environmental tobacco smoke exposure

BACKGROUND

Exposure to environmental tobacco smoke is associated with adverse effects in infants and children.

OBJECTIVE

To explore whether an increase in urinary cotinine fumarate level is caused by ingested nicotine and cotinine in breast-feeding infants.

METHODS

We studied newborns at risk for developing asthma and allergies based on a strong family history. We measured urinary cotinine levels in the infants as a measure of environmental tobacco smoke exposure and cotinine levels in the breast milk of breast-feeding mothers.

RESULTS

Of 507 infants, urinary cotinine levels during the first 2 weeks of life were significantly increased in infants whose mothers smoked. Breast-fed infants had higher cotinine levels than non-breast-fed infants, but this was statistically significant (P<.05) only if mothers smoked. Urinary cotinine levels were 5 times higher in breast-fed infants whose mothers smoked than in those whose mothers smoked but did not breast-feed.

CONCLUSIONS

Mothers should be encouraged to not smoke, and parents must be advised of the potential respiratory and systemic risks of environmental tobacco smoke exposure to their child, including the potential for future addiction to smoking.

Is primary prevention of asthma possible?

Two major factors are critical to the development of asthma: the individual's genetic background and the environment. The gene for asthma has not yet been identified. Thus, environmental factors appear to be the critical factors that can be controlled. Exposure to specific allergens is important. Ingestants may be the earliest initiating trigger for 'turn on' of allergy. Subsequently, sensitization to indoor inhalants becomes important in asthma. Among pollutants, environmental tobacco smoke (ETS) is most important. Finally, infections play a role in the development of asthma. Approaches to primary prevention include potential novel techniques such as vaccines or immunization. Dietary intervention appears to be important for atopic dermatitis but less so for asthma. Nevertheless, breastfeeding is successful in decreasing respiratory illness and should be encouraged. In terms of allergen avoidance, avoidance of indoor allergens, particularly house dust mite, cat and cockroach, have the greatest potential for benefit. Exposure to ETS in early life must be avoided. Asthma is a multifactorial disease, and complex interventions are likely to be required to decrease prevalence of this increasingly common disease.

Review of community-based research: assessing partnership approaches to improve public health

Community-based research in public health focuses on social, structural, and physical environmental inequities through active involvement of community members, organizational representatives, and researchers in all aspects of the research process. Partners contribute their expertise to enhance understanding of a given phenomenon and to integrate the knowledge gained with action to benefit the community involved. This review provides a synthesis of key principles of community-based research, examines its place within the context of different scientific paradigms, discusses rationales for its use, and explores major challenges and facilitating factors and their implications for conducting effective community-based research aimed at improving the public's health.

Conducting a participatory community-based survey for a community health intervention on Detroit's east side

This article describes a participatory action research process that brought together community members, representatives from community-based organizations and service providers, and academic researchers to collect, interpret, and apply community information to address issues related to the health of women and children in a geographically defined urban area. It describes the development and administration of a community-based survey designed to inform an intervention research project; discusses the establishment of a community/research partnership and issues that the partnership confronted in the process of developing and administering the survey; and examines the contributions of participants, and implications for research and collective action.

Respiratory symptoms in a susceptible population due to burning of agricultural residue

STUDY OBJECTIVES

To identify characteristics associated with respiratory symptoms due to an episode of air pollution.

DESIGN

Mail survey.

SETTING

In October 1992, the population of the city of Winnipeg was exposed to elevated levels of particulate matter (total and <10 microm size), carbon monoxide, nitrogen dioxide, and volatile organic compounds due to smoke from adjacent fields where farmers were burning agricultural residue (straw and stubble).

PARTICIPANTS

We surveyed 428 participants in the ongoing Lung Health Study (35 to 64 years old, both sexes) with mild to moderate airways obstruction (mean FEV1 percent predicted 73+/-12%), and a high level of airways hyperreactivity (23% of men and 37% of women).

RESULTS

While 37% of subjects were not bothered by smoke at all, 42% reported that symptoms (cough, wheezing, chest tightness, shortness of breath) developed or became worse due to the air pollution episode and 20% reported that they had breathing trouble. Those with symptoms were more likely to be female than male and were more likely to be ex-smokers than smokers. Subjects with asthma and chronic bronchitis were also more likely affected. The degree of airways obstruction and the level of bronchial hyperresponsiveness were not associated with increased susceptibility.

CONCLUSIONS

Gender, smoking habit, and respiratory symptoms but not bronchial hyperresponsiveness or the degree of airways obstruction are factors influencing susceptibility to symptoms due to air pollution in adult smokers and former smokers.

Review of community-based research: assessing partnership approaches to improve public health

Community-based research in public health focuses on social, structural, and physical environmental inequities through active involvement of community members, organizational representatives, and researchers in all aspects of the research process. Partners contribute their expertise to enhance understanding of a given phenomenon and to integrate the knowledge gained with action to benefit the community involved. This review provides a synthesis of key principles of community-based research, examines its place within the context of different scientific paradigms, discusses rationales for its use, and explores major challenges and facilitating factors and their implications for conducting effective community-based research aimed at improving the public's health.

"It's a 24-hour thing ... a living-for-each-other concept": identity, networks, and community in an urban village health worker project

Social networks are webs of relationships between individuals, and they play an important role in the complex social processes through which individuals seek information, obtain social support, and mobilize for collective action to modify social, economic, and environmental conditions associated with health and illness. Studies have described and evaluated lay health advisor (LHA) programs that use social networks to improve individual and community health. The experience and perceptions of community members involved with LHA programs have been explored less often and offer essential information to health educators about the design, implementation, evaluation, and support of such programs. This article examines the perspective of LHAs in Detroit, Michigan. Their understanding and experience of their work, the relationships between their activities and a sense of self and community, and personal and programmatic rewards and challenges are examined. The authors discuss implications for health educators related to LHAs' roles, relationship to supporting organizations, recruitment, training, and ongoing support.

Heterogeneity of polyclonal IgE characterized by differential charge, affinity to protein A, and antigenicity

Functional and physical heterogeneity of polyclonal IgE has been reported. Extremely low serum concentrations of IgE have limited the study of these important differences. We have purified polyclonal dog IgE and developed polyclonal and monoclonal (mAb C2) anti-dog IgE antibodies. In this study chromatofocusing of dog IgE revealed two biologically active IgE fractions: IgE1 eluted at pH 5.0, and IgE2 eluted at pH 4.7. The two IgE subforms (IgEs) exhibited typical IgE characteristics: positive in the 48-hour passive cutaneous anaphylaxis response, heat-labile, identical molecular weight, and reactive to polyclonal anti-dog IgE. However, the two IgEs were found to be significantly heterogeneous. IgE1 bound to protein A and did not react with mAb C2 in ELISA and isoelectric focusing-immunoblotting, whereas IgE2 did not bind to protein A and reacted with mAb C2. Further, in sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunoblotting, IgE2, but not IgE1, reacted with seven well-defined mAb anti-human IgE antibodies and an mAb anti-mouse IgE antibody, even though both IgE1 and IgE2 reacted with polyclonal anti-human and anti-mouse IgE. Neuraminidase or endoglycosidase treatment did not abolish the differential antigenicity and charge of IgE1 and IgE2, although the antigenicity of IgE2 was significantly reduced after incubation with endoglycosidase. These data suggest that carbohydrate moieties are not involved in the observed differences in antigenicity and charge and that the two IgE molecules represent distinct isotypes. In studies with seven purified IgE fractions obtained from different ragweed-allergic dogs, the distribution of ragweed IgE2 varied 200-fold, whereas ragweed total IgE levels varied only fourfold. This raises the possibility of a relationship between different IgEs and the allergic response.

Potential therapeutic efficacy of allergen-monomethoxypolyethylene glycol conjugates for in vivo inactivation of sensitized mast cells responsible for common allergies and asthma

Skin sites of rats, which had been systemically sensitized to ovalbumin (OVA) were injected intradermally with murine anti-DNP IgE mAbs or with murine polyspecific IgE to recombinant Bet v 1. Injection of OVA(mPEG)10-11 conjugates into these skin sites inhibited passive cutaneous anaphylaxis (PCA) on subsequent intravenous challenge with DNP44-BSA and rBet v 1; by contrast, neither OVA nor an unrelated mPEG conjugate affected the PCA reactions. In dogs sensitized to both OVA and ragweed pollen extract (RAG), inhalation of either allergen (AL) caused a dramatic increase in airway resistance (Rrs). By contrast, administration of an aerosol of OVA(mPEG) caused no change in Rrs. Moreover, thereafter, (1) in spite of repeated challenges with aerosolized OVA over many months, the increase in Rrs on inhalation of OVA was blocked and (2) insufflation of RAG resulted in increase in Rrs of only about 50% in relation to that prior to inhalation of the conjugate; this dog's anti-RAG hyperreactivity remained blunted over many months. It is concluded that AL-mPEG conjugates of optimal composition inactivate sensitized mast cells and basophils, as manifested by a significant decrease of cutaneous or airway responses on subsequent challenge with the respective AL(s).

Hospital-acquired infections among surgical patients in a Brazilian hospital

A historical cohort study was conducted among surgical patients in a large general hospital in Porto Alegre, Brazil between March 1992 and May 1993. Data were collected by means of a retrospective chart review, which followed a standardized method based on the systematic review of all clinical and laboratory information available in the hospital records. The criteria for diagnosis of all hospital-acquired infections (HAIs) were based on those from the Centers for Disease Control, Atlanta. In total, 890 HAIs were detected among the 4199 patients included in the cohort. The incidence rate of HAIs for all sites combined was 21.20%. Incidence rates ranged from 2.95% for bloodstream infections to 8.65% for surgical wound infections. The overall incidence density was 16.32 HAIs per 1000 patient-days. Incidence densities ranged from 2.03 for bloodstream infections to 7.46 per 1000 patient-days for surgical wound infections. The median incubation period for surgical wound infections was seven days, and 29.4% of these infections were detected at post-discharge. Gram-negative bacteria were the most common organisms implicated in HAIs.

Cross-reactivity and molecular mass of the epsilon chains of the IgE antibodies in dogs, humans, rats, and mice

We report the cross-reactivities and comparative molecular masses of the IgE epsilon chains in humans, rats, mice, and dogs. Monoclonal human, rat, and mouse IgE, and our purified polyclonal dog IgE were used in the study. IgE of the 4 species, separated by SDS-PAGE, were analyzed by immunoblotting with polyclonal and monoclonal antihuman IgE, polyclonal and monoclonal antimouse IgE, monoclonal antirat IgE, and polyclonal antidog IgE antibodies. The polyclonal antihuman and polyclonal antimouse IgE cross-reacted with the IgE of the other 3 species, while their monoclonal forms cross-reacted with dog IgE only. Polyclonal antidog IgE cross-reacted with human and mouse IgE, while the monoclonal antirat IgE did not cross-react with any other species. "Reverse' passive cutaneous anaphylaxis in ragweed-sensitized dogs revealed that polyclonal antihuman and polyclonal antimouse IgE were able to elicit positive skin responses, and monoclonal antihuman, antirat, and antimouse IgE antibodies were not. The molecular masses of the epsilon chains were 77 kDa for mice, 75 kDa for rats and dogs, and 70 kDa for humans.

Increased response to antigen and histamine release in smaller sensitized canine bronchi

We studied the Schultz-Dale response in vitro in large and small size branches from 3rd to 6th generation bronchi from ragweed-sensitized dogs. The response to electric field stimulation (EFS) increased after antigen from 65.56 +/- 8.11 to 78.6 +/- 9.0 mN/mm2 of smooth muscle (P < 0.01), but no topographical difference was observed. The response to ragweed (% of the response to EFS) was 158.3 +/- 12 and 67.1 +/- 11.7 in strips from small and large branches respectively (P < 0.01), while no difference was observed between generations; when clustering bronchi according to dimension, it was 129.9 +/- 13.4 in small and 71.9 +/- 19.8 in large bronchi (P < 0.01). Histamine released from small and large branches was 2.90 +/- 1.01 and 0.76 +/- 0.20 (ng/mg of tissue) respectively (P < 0.05); no difference was found between generations. In conclusion, in sensitized dogs a greater response to antigen, which involves a higher histamine release, occurs in small compared to large bronchi. We suggest that control of distribution of ventilation occurs mainly at small bronchi level, which becomes the elective tissue to study the Schultz-Dale response. Finally, the classification of bronchi into generations is inadequate to study allergic bronchospasm.

Identification of a dog IgD-like molecule by a monoclonal antibody

IgD has not been identified in dogs. We produced a monoclonal antibody (mAb) designated 9B during the production of hybridomas to dog IgE. Using Western blot analysis under non-reducing conditions, the mAb (9B) recognized a predominant protein band of 185 kDa which was also recognized by anti-dog IgG F(ab')2, suggesting that this 185 kDa protein is an immunoglobulin (Ig) containing light chains. Under reducing conditions, the mAb (9B) recognized only one protein band of 55 kDa which presented a distinct molecular weight (MW) and immunoreactivity from the dog tau, mu, alpha, and epsilon chains. The 55 kDa band did not react with anti-dog IgE, IgM, IgA, and IgG, but did react with the mAb (9B). The MW was 75 kDa for the epsilon chain, 77.5 kDa for the mu chain, 58 kDa for the alpha chain, and 52 kDa for the tau chain. Further, by immunofluorescent staining, this Ig recognized by the mAb (9B) was found on the surface of dog lymphocytes. Studies of this dog Ig with the mAb revealed that this Ig bound to protein A and protein G-Sepharose, and that its enzyme-linked immunosorbent assay (ELISA) activity as measured by the mAb (9B) did not change after heating at 56 degrees C for 2 h. Ragweed-specific IgG, IgE, and this newly defined Ig significantly increased when dogs were immunized with ragweed extract. These data suggest that this Ig is a previously unrecognized IgD-like molecule in dogs.

Effects of rhIL-11 on normal dogs and after sublethal radiation

The effects of recombinant human interleukin-11 (rhIL-11) were studied in normal dogs and dogs given otherwise sublethal total-body irradiation (TBI) without marrow transplantation. Ten normal dogs were given rhIL-11 subcutaneously, twice daily for 14 days at varying doses, two dogs at 30 micrograms/kg/day, four dogs at 60 micrograms/kg/day, two dogs at 120 micrograms/kg/day, and two dogs at 240 micrograms/kg/day. Peripheral blood platelet counts increased in all dogs. The increase in platelet counts ranged from 1.4 to 3.1 times the pre-treatment level. The greater increases of platelets were associated with higher doses (p = 0.01). No change in platelet size was evident except at the dose of 240 micrograms/kg/day. There were no changes in the total white blood cell (WBC) count or differential. A higher proportion of megakaryocytes with a DNA content of 32N/64N was observed in dogs treated with rhIL-11 at day 7 (n = 6) than for control dogs that did not receive rhIL-11 (n = 7; p = 0.01). In both peripheral blood and marrow, significantly increased hematopoietic progenitors (i.e, colony-forming unit granulocyte/macrophage [CFU-GM]) were present 7 and 14 days after the start of treatment. Concentrations of serum fibrinogen increased by a median of 155 mg/dL at day 7 of rhIL-11 (p < 0.01). Cholesterol also increased by a median of 52 mg/dL at day 14 (p < 0.01). There was a single death of a non-irradiated dog from pneumonitis on day 15 after the start of rhIL-11 administration at a dose of 120 micrograms/kg/day. All other non-irradiated dogs tolerated rhIL-11 without any significant adverse effects. Five dogs were given 200 cGy TBI without marrow grafting, followed by 240 micrograms/kg/day rhIL-11 subcutaneously in two divided doses for 28 days starting within 2 hours of TBI. The results in this group were compared with 10 dogs that had previously or concurrently been given 200 cGy without marrow grafting or hematopoietic growth factors. Two of the five treatment dogs died of pneumonitis on day 13 compared to one death among 10 control dogs on day 24. Among dogs that survived to hematologic recovery, the rhIL-11 dogs had decreased platelet counts (< 150,000) for a median of 24 days (range = 24 to 41) compared to a median of 28 days (range = 21-40) for the control group. Treatment with rhIL-11 increased platelet counts, platelet size, ploidy number of megakaryocytes, and marrow and peripheral blood CFU-GM in normal dogs.(ABSTRACT TRUNCATED AT 400 WORDS)

Nasal patency in children with allergic rhinitis: correlation of objective and subjective assessments

BACKGROUND

Children with allergic rhinitis may have difficulty with self-assessment of nasal symptoms.

OBJECTIVE

To correlate objective and subjective assessments of nasal stuffiness in children with seasonal allergic rhinitis.

METHODS

Children, aged 6 to 12 years, with seasonal allergic rhinitis recorded their degree of nasal obstruction on two separate occasions using a nasal stuffiness score and a visual analogue scale. Physicians also assessed the degree of nasal obstruction using a visual analogue scale. Anterior rhinometry was performed and saccharin transient time was also measured. Correlations between subjective scores and objective measurements were calculated using Spearman correlation coefficients.

RESULTS

Patient's nasal stuffiness scores correlated with their visual analogue assessment (r = .45, P = .0001). Patients visual analogue assessments did not correlate with anterior nasal airflow (r = -.12, P > .05). Physicians' visual analogue assessment correlated better with nasal airflow than childrens' assessment (r = -.41, P = .0001). Saccharin transit time was not helpful in assessment of degree of nasal obstruction.

CONCLUSION

Children appear to have difficulty in self-assessment of nasal symptoms, and to be poor judges of the presence or severity of nasal obstruction. In studies of allergic rhinitis in children, objective measurements should be performed, if possible, to facilitate more accurate interpretation of data.