Bronchial hyperresponsiveness in two populations of Australian schoolchildren. II. Relative importance of associated factors

In a cross-sectional study of 2363 schoolchildren living in two rural areas of New South Wales, we used a questionnaire to collect details of sex, area of residence, social class, early respiratory illness (ERI), parental history of asthma and recent upper respiratory tract infection (URTI), and we used skin-prick tests to measure atopic status. The relative importance of these factors on the likelihood of children having bronchial hyperresponsiveness (BHR) was assessed using a linear modelling analysis. The extent to which these factors affected the severity of BHR was also examined. We found that social class or recent URTI had no association with BHR, that sex and area of residence (inland or coastal) had a small association and that a history of early respiratory illness, a history of asthma in either parent, and atopic status had an important association with BHR. Atopic status was the most important factor. The proportion of children with atopy, with ERI or with parental asthma increased as the severity of BHR increased. The odds ratio for moderate or severe BHR doubled if either ERI or parental asthma was present in addition to atopy and there was a six-fold increase if all three factors were present together. The identification of these risk factors makes it possible to predict which children in the community are most likely to have BHR, and which children are at high risk for having more severe levels of BHR.     

Bronchial hyperresponsiveness in two populations of Australian schoolchildren. I. Relation to respiratory symptoms and diagnosed asthma

In order to explore the relationship between bronchial hyperresponsiveness (BHR) to inhaled histamine, respiratory symptoms and diagnosed asthma in children, we undertook a cross-sectional study of 2363 Australian schoolchildren aged 8-11 years. The methods used included a self-administered questionnaire to parents, which was shown to have a high degree of repeatability, and a histamine inhalation test to measure bronchial responsiveness (BR). The study showed that 17.9% of children had BHR, defined as a 20% fall in FEV1 at a provoking dose of histamine (PD20 FEV1) of less than 7.8 mumol. The distribution of PD20 FEV1 appeared to be continuous. Most children with PD20 FEV1 values less than 1.0 mumol had symptoms of asthma. However, 6.7% of children had BHR without symptoms or a previous diagnosis of asthma and 5.6% had had a diagnosis of asthma but had no BHR. Although there was a good association between BHR and respiratory symptoms, questionnaire data of wheeze and diagnosed asthma do not reflect accurately the level of BHR in the community. We conclude that cross-sectional studies of BR to identify children with BHR probably do not reflect the prevalence of asthma in populations of children. However, the strong association between BHR and symptoms, particularly in children with severe and moderate BHR, suggests that measurements of BR in populations are useful for defining a group of children whose airways behave differently from those of the majority. Prospective studies are needed to define the level of BHR that is associated with important sequelae.     

Markers of exposure to spotted fever rickettsiae in patients with chronic illness, including fatigue, in two Australian populations

Background: Some investigators believe that a proportion ofchronically unwell patients, many with fatigue, have an underlyingrickettsial disease. Aim: To investigate the prevalence of markers of rickettsialinfection in patients with chronic illnesses. Design: Observational study. Methods: A 526 patient cohort with chronic illnesses from Melbourne,Australia and 400 control patients from Newcastle, Australiawere assessed using serology, culture and PCR for the detectionof rickettsiae. Rickettsial serology was performed on anothercohort of 581 chronically unwell patients (and 34 non-fatiguedpatients from the same practice) from Adelaide, Australia. Results: Of the Melbourne patient cohort, 14/526 (3%) were real-timePCR positive for rickettsial DNA compared to none of the 400control patients (P < 0.001). Of these 14 patients, Rickettsiahonei strain ‘marmionii’ was detected in 5 and isolatedfrom 2. Rickettsaemia was seasonal, with more in winter (8/145;P < 0.03) and less in spring (0/143; P < 0.03). Positiverickettsial serology titres of 1:256 were seen in 206 (39%)patients. Of the Adelaide patient cohort, 238/581 (41%) hadpositive rickettsial antibodies titres. Of the 34 control sera,5 (15%) were serologically positive (P < 0.002). Both Melbourneand Adelaide patient cohorts had significantly higher seropositivitythan the Newcastle control cohort (3/399; P < 0.0001). Conclusions: In patients with chronic illness, rickettsial DNAin peripheral blood and/or rickettsial seropositivity may representexposure to rickettsiae or underlying rickettsial diseases.It is not known whether the presence of rickettsiae is causallyrelated to the patients’ chronic illnesses, or reactivationof a latent rickettsial infection.     

Bronchial histamine reactivity: its relationship to the reactivity of the bronchi to allergens.

The aim of this study was to examine the proposal that the magnitude of the response of the bronchi to an immediate allergic reaction depends not only on the degree of sensitization of the bronchi by allergen specific IgE antibody but also on the reactivity of the bronchi to the vasoactive mediators which are released during immediate allergic reactions. This was done by determining the bronchial reactivity to Dermatophagoides pteronyssinus and to histamine of both symptomatic and asymptomatic groups of atopic subjects who had comparable serum levels of D. pteronyssinus specific IgE. Positive bronchial responses to the D. pteronyssinus extract were recorded with both the symptomatic and asymptomatic subjects, the mean bronchial threshold dose of allergen being significantly higher in the asymptomatic than in the asthmatic patients. There was a highly significant correlation between the serum level of allergen specific IgE and the bronchial threshold dose of allergen extract and also between the bronchial threshold dose of allergen extract and of histamine in all groups of subjects. The ability to predict bronchial reactivity to the allergen from the serum level of allergen specific IgE within each group was significantly better if the bronchial reactivity to histamine was included in the correlation analysis. This supports the hypothesis that whether a particular subject who is producing specific IgE antibody will develop symptoms on the inhalation of that allergen depends not only on the amount of allergen which he inhales and on the degree of sensitization of his bronchi but also on the reactivity of his bronchi to the vasoactive mediators which are released by allergen-IgE interaction.     

Influence of topical exposure to chemical allergens on murine Langerhans cells. Comparison of 2,4-dinitrochlorobenzene with trimellitic anhydride.

Chemical allergens differ with respect to the type of hypersensitivity reactions they preferentially elicit. Some chemicals, such as trimellitic anhydride (TMA), have the potential to induce both contact and respiratory hypersensitivity. Other chemicals cause only contact allergy. For example, 2,4-dinitrochlorobenzene (DNCB), a potent contact allergen, appears not to induce respiratory sensitization. In previous studies we have shown that topical exposure of mice to TMA and DNCB, under conditions of equivalent immunogenicity with respect to draining lymph node activation and contact sensitization, caused qualitatively different antibody responses. While the chemicals provoked IgG anti-hapten antibody responses of equivalent magnitude, only TMA induced an IgE response, and DNCB caused a significantly stronger IgG2a response. These data are consistent with the preferential activation by DNCB and TMA of Th1 and Th2 cells respectively. The purpose of the present study was to examine whether the qualitative differences in immune responses stimulated by these chemicals is reflected by variable affects on Langerhans cells (LC) in situ. Mice were exposed to concentrations of DNCB (1%) and TMA (50%) which caused equivalent levels of contact sensitization. Under these conditions topical exposure to DNCB, but not to TMA, or to vehicle alone, resulted in increased expression by LC of Ia antigen. Similar treatment with an irritant concentration (20%) of sodium dodecyl sulphate failed to influence Ia expression by LC. These data indicate that, at concentrations which induce similar levels of skin sensitization, not all contact allergens cause rapid changes in LC Ia expression, and that the qualitative differences in immune responses elicited by chemical allergens DNCB and TMA is associated with variable effects on LC.     

Bibliotherapy: using fiction to help children in two populations discuss feelings.

PURPOSE: To identify whether bibliotherapy will help children with short stature and diabetes discuss their feelings and to explore themes that may help children cope with short stature and diabetes. METHOD: Twenty-seven children, referred to a pediatric endocrinologist, aged 7-16 years, participated in interviews after reading a work of fiction. A semi-structured interview guide was used in both groups to elicit feelings about the work of fiction, feelings of self-esteem, and attitudes toward the condition. FINDINGS: Children freely discussed their feelings about school experiences and condition-related issues. Several themes emerged from data analysis including the child's development of compensatory attributes, responses to teasing, and management of diabetes. CONCLUSION: This study confirmed that bibliotherapy is an effective nursing intervention in children with short stature and diabetes. Bibliotherapy can be used by nurses to facilitate open discussion between nurses, children, and families.     

Epicutaneous sensitization with protein antigen induces localized allergic dermatitis and hyperresponsiveness to methacholine after single exposure to aerosolized antigen in mice.

Our understanding of the pathogenesis of atopic dermatitis (AD) and its relationship to asthma remains incomplete. Herein, we describe a murine model of epicutaneous (EC) sensitization to the protein allergen, chicken egg albumin, ovalbumin (OVA), which results in a rise in total and OVA-specific serum IgE and leads to the development of a dermatitis characterized by infiltration of CD3(+) T cells, eosinophils, and neutrophils and by local expression of mRNA for the cytokines IL-4, IL-5, and interferon-gamma. A single exposure of the EC sensitized mice to aerosolized OVA induced eosinophilia in the bronchoalveolar lavage fluid and airway hyperresponsiveness to intravenous methacholine as assessed by measurement of pulmonary dynamic compliance (Cdyn). These results suggest a possible role for EC exposure to antigen in atopic dermatitis and in the development of allergic asthma.     

Potentiation of IgE production to common environmental allergens by storage house dust mite Dermatophagoides farinae

Total serum IgE and IgE antibodies against ten common antigens, including Dermatophagoides farinae (D.f.), moth, ragweed, orchard grass, cryptomeria, alternaria, aspergillus, dog dander, cat dander and tetanus toxoid, were determined using the PRIST and the Sepharose-RAST, respectively, in 100 clinically non-allergic Japanese subjects and interrelations of IgE responses to these antigens were investigated. We obtained following results. The number of positive RAST antigens, to which the subjects responded, increased in parallel to their total serum IgE levels. Among ten antigens, D.f. and moth antigens contributed a great deal to the elevation of total serum IgE level as compared with other antigens. When the relationship between IgE response to D.f. and similar responses to the other nine antigens was investigated, positive RAST responses to various antigens occurred selectively in the subjects with positive RAST for D.f., and the number of positive RAST antigens to which the subjects responded increased depending upon their D.f. specific RAST levels. Such an association was not found between IgE response to moth and the other nine antigens. These findings suggest that non-specific activation of IgE-producing B cells occurs as a result of continuing stimulation by D.f.     

Alterations in Cyclic AMP Metabolism in Human Bronchial Asthma. III. LEUKOCYTE AND LYMPHOCYTE RESPONSES TO STEROIDS

On the basis of serial studies the responsiveness of leukocytes and lymphocytes from asthmatic donors to catecholamines was increased during high dose corticosteroid therapy. Similar changes were observed in the cells of normal control subjects given 200 mg of hydrocortisone intravenously. The increase in responsiveness did not appear to be due to changes in lymphocyte subpopulations although this may be a contributing factor. In an effort to elucidate the basis for the improved response, in vitro effects of glucocorticoids on lymphocyte cyclic AMP concentrations were investigated. Glucocorticoids (prednisolone succinate, hydrocortisone, hydrocortisone phosphate, and hydrocortisone succinate) stimulated cyclic AMP accumulation in asthma and normal control lymphocytes, increases occurring within the first 2 min of incubation. In the absence of theophylline, responses were regularly obtained at 10 muM hydrocortisone and usually at 1 muM hydrocortisone but not at submicromolar steroid concentrations. Theophylline potentiated the cyclic AMP response to glucocorticoids and also increased the percentage of positive responses in the 0.01-1.0 muM corticosteroid range. Combinations of 1 muM hydrocortisone and 1 muM epinephrine were sometimes additive or synergistic but in many instances higher glucocorticoid concentrations were needed to obtain augmentation of the catecholamine response. The in vitro glucocorticoid effects may not fully explain their potentiating action in vivo.     

The management of lead exposure in pediatric populations

Chronically elevated lead levels are a common problem affecting children. Although this problem occurs most frequently in the inner city, no community is safe from excessive pediatric lead exposure. Screening by erythrocyte protoporphyrin is a sensitive early indicator of rising lead levels. A Centers for Disease Control report recommends that all children be screened starting at 9 to 12 months. A classification system of various lead levels helps determine proper treatment. Health care practitioners need to be well-informed about lead exposure and how it occurs in order to educate parents.     

Effect of prostaglandin E in multiple experimental models. III. Effect on response to septic challenge

Severe thermal injuries result in significant physiologic alterations. These alterations have been attributed in part to the elevated prostaglandin E levels that follow traumatic injuries. We evaluated the physiologic sequelae of elevated prostaglandin E levels by administering a long-acting prostaglandin E2 derivative, 16,16-dimethyl-prostaglandin E2 (dPGE), to rats with septic burns. The dPGE was found to increase gut translocation of bacteria. Administration of dPGE had no significant effect on resting metabolic rate. In rats with nonseptic burns the administration of dPGE resulted in increased serum levels of acute-phase proteins. In conclusion prostaglandin E may have both detrimental and beneficial effects on traumatized persons.     

Addressing environmental health Implications of mold exposure after major flooding.

Extensive water damage resulting from major flooding is often associated with mold growth if materials are not quickly and thoroughly dried. Exposure to fungal contamination can lead to several infectious and noninfectious health effects impacting the respiratory system, skin, and eyes. Adverse health effects can be categorized as infections, allergic or hypersensitivity reactions, or toxic-irritant reactions. Workers and building occupants can minimize their exposure to mold by avoiding areas with excessive mold growth, using personal protective equipment, and implementing environmental controls. Occupational health professionals should encourage workers to seek health care if they experience any symptoms that may be linked to mold exposure.     

Application of Neuman's framework: infant exposure to environmental tobacco smoke

The purpose of this article is to demonstrate how Neuman's systems model can be applied to nursing practice and research through the examination of the problem of infant exposure to environmental tobacco smoke. By operationalizing Neuman's framework, it was possible to develop a research-based theory investigating the interaction between the infant's physiological variable and the environment. A nursing process tool and theoretical model developed from Neuman's framework are utilized to examine the problem. Further theory development could identify relationships among Neuman's other variables and create a theoretical basis for providing holistic nursing care to infants exposed to environmental tobacco smoke.     

Breast cancer incidence and exposure to environmental chemicals in 82 counties in Mississippi

OBJECTIVE: Breast cancer is a major public health problem in the United States and in most industrialized countries. Environmental exposure to several chemicals has been implicated in the cause of breast cancer. However, data are not consistent about the role of the environment in breast cancer incidence. To assess environmental risks for breast cancer, patterns of breast cancer incidence in relation to environmental chemicals in Mississippi counties were mapped. METHODS: This article presents an analysis of age-adjusted incidence rates of female breast cancer and environmental chemical emissions by county in the state of Mississippi. The incidence data were obtained from the State Department of Health, and emissions data sources included the U.S. Environmental Protection Agency's Air-Data and Toxics Release Inventory Program. RESULTS: Counties having a significantly higher incidence of breast cancer compared with the state's rate were identified. Also identified were counties with higher levels of chemical emissions. The incidence of breast cancer in 1998 was significantly associated with the amount of ammonia (r = 0.268, P = 0.015), minimum emissions (r = 0.233, P = 0.035), and maximum emissions (r = 0.237, P = 0.032) of the facilities in the county. A linear dose-response relationship was observed between increased amounts of chemical emissions and breast cancer incidence. CONCLUSIONS: This study found a significant link between breast cancer incidence and maximum emissions of environmental chemicals. However, further research using individual-level data is needed.     

Bronchial responses to enalapril in asthmatic, hypertensive patients.

The subjects, six asthmatic patients with mild essential hypertension, were aged 48 to 63 years and each was being treated with theophylline. Five patients received 10 mg of enalapril daily for two weeks and one received 5 mg for four weeks. Their bronchial responses to inhaled methacholine were measured with a modification of the 3-Hz oscillation method before and after the enalapril treatment. The patients' mean blood pressures decreased significantly from 180.7/100.3 to 152.0/93.3 mmHg after treatment. No treatment-associated changes in the frequency of coughing, the number of asthmatic attacks, or use of antiasthmatic drugs were noted. The results of the bronchial provocation tests revealed no changes in bronchial sensitivity or reactivity during treatment. Serum substance P levels were 61.3 pg/ml before treatment and 60.2 pg/ml after treatment. It is concluded that therapeutic doses of enalapril did not exacerbate asthmatic attacks or increase bronchial hypersensitivity in these asthmatic, hypertensive patients.     

Bronchial hypersensitivity to methacholine in monkeys with beta-adrenergic blockade.

In monkeys with beta-adrenergic blockade caused by administration of propranolol, we found that the conductance of the total respiratory system markedly decreased following intravenous administration of methacholine. The presence of beta-adrenergic blockade was judged from inotropic effect on the heart, levels of blood glucose and lactic acid, and the reaction of eosinophils after adrenalin injection.     

Coping and Quality of Life in relation to headache in Dutch schoolchildren.

The aim of this study was to describe the Quality of Life and pain coping strategies of school children in relation to headache severity. We conducted a cross-sectional study in 2815 children between the age of 9 and 17 years, who filled out Waters' Headache Questionnaire (WHQ), the Paediatric Pain Assessment Tool (PPAT), the Quality of Life Headache in Youth (QLH-Y) questionnaire and the Pain Coping Questionnaire (PCQ) in the class-room setting.Weekly headaches were reported by 22% of the sample. Low, medium, and high headache severity groups were constructed, based on headache frequency, duration and intensity criteria. Results show that children with the highest headache severity report the lowest Quality of Life in general and the lowest Quality of Health, as well as the most problems with regard to physical functioning, impact of headache on daily and leisure activities, physical symptoms other than headache, and social functioning at home. With regard to using pain coping strategies, children with the most severe headaches seek more social support, they internalize and externalize more, they use less behavioural and cognitive distraction techniques, and seek information less.