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Biomedical subjects

H R Anderson

Publications and source records attributed to H R Anderson.

At least 181 records · Page 10Linked to original sources

Regulation of asthma by intestinal parasites. Investigation of possible mechanisms.

The serum IgE levels of asthmatic subjects from Papua, New Guniea (PNG) were similar to those of corresponding control subjects but significantly higher than Caucasian asthmatics from Western Australia (AUS). Notwithstanding these differences in total IgE, the levels of IgE antibodies to D. pteronyssinus (RAST units) were similar in both asthmatic groups. The mite specific IgE antibody levels were independent of those to Ascaris and hookworm, suggesting that antigenic competition is not a factor of importance in sensitization to environmental allergens in the tropics. This study does not support the proposal that the low prevalence of allergic disease in tropical areas where parasitism is endemic is attributed to mast cell blockade through saturation of IgE receptors.

Ancylostomatoidea↗

Respiratory abnormalities and ventilatory capacity in a Papua New Guinea Island community.

On Karkar Island, off the coast of Papua New Guinea, 87 per cent of the 1,026 resident adults of 3 villages were surveyed for respiratory abnormalities. The prevalence of abnormalities suggestive of chronic lung disease was similar for each sex and increased with age. After 35 years of age, the combined rates were: adventitious breath sounds, 29 per cent; positive loose cough sign, 33 per cent; chronic cough, 11 per cent; and shortness of breath on exertion, 12 per cent. All of these abnormalities were associated with an obstructive ventilatory defect. Smoking began in late adolescence and was established in more than 90 per cent of both sexes by 25 years of age. Most persons smoked a home-grown variety of Nicotiana tabacum. The nonsmoking group was too small to allow adequate comparison; but among smokers, inhalation was related to both respiratory abnormalities and reduced lung function. The prevalence of respiratory abnormalities appeared to be at least as high as in some developed western societies, despite the fact that smoking habits resembled those of cigar smokers elsewhere, and that atmospheric and occupational exposures were absent. Among persons more than 35 years of age, 4 per cent had a history of pulmonary tuberculosis, and 5 per cent showed evidence of localized lung disease in a 70-mm chest radiograph. The predominant condition resembled the chronic nonspecific lung disease of developed societies. Unless this population is unusually susceptible to the effect of cigar-type smoking, other etiologic factors must be considered. These might include repeated acute chest infections, the indirect effects of pulmonary tuberculosis, larval migrations of intestinal parasites, or impaired host response as a result of poor nutrition. A wide spectrum of severity coexisted with a uniform environment and smoking pattern, which suggests that individual susceptibility is important.

Adolescent↗

A clinical and lung function study of chronic lung disease and asthma in coastal Papua New Guinea.

A prevalence survey on the island of Karkar had previously shown that chronic lung disease was common in both sexes after the age of 35 years and that, in part, this was related to the smoking of home-grown air-cured tobacco. To investigate the nature of this chronic lung disease, 37 nontuberculous subjects with reduced ventilatory capacity (forced expiratory volume in one second less than 75% predicted) underwent clinical and lung function investigations. Ninety-two per cent had adventitiae, 62% had chronic productive cough and 54% had dyspnoea on exertion. Lung function tests showed an irreversible obstructive defect with a variable, but on average, only moderately reduced transfer factor. The chest radiography showed evidence of hyperinflation in 38% of cases but non had narrowing or loss of pulmonary vessels suggestive of emphysema. "Inflammatory changes" occurred in 35% and were associated with a mild but significant element of restriction. The results suggest that chronic bronchitis and chronic bronchiolitis were the main underlying abnormalities and that emphysema was comparatively unimportant. Asthma appeared to be relatively uncommon, especially in children. The clinical and lung function findings in 16 asthmatics were essentially similar to those observed in asthmatics elsewhere and the atopic status of asthmatics and controls was similar to that observed in developed societies. In common with Highland asthmatics however, the age at onset was in early adult life rather than in childhood.

Adult↗

Asthma in the highlands of New Guinea Total IgE levels and incidence of IgE antibodies to house dust mite and Ascaris lumbricoides.

Serum IgE levels in adults from the Highland area of Papua-New Guinea were considerably elevated above those found for Caucasian residents in Australia and most Western countries. The median IgE value for the asthmatic group in New Guinea was significantly (p less than 0.01) elevated above that of control subjects. Identification of IgE antibodies by the radio-allergosorbent test to house dust mite showed an 85-percent correlation with the results of skin reactions to extracts of the mite. 90% of the asthmatic subjects had IgE antibodies to Dermatophagoides pteronyssinus compared with 23% of patients with chronic obstructive lung disease and 6% of controls (p less than 0.0001). No significant difference was found in the incidence of IgE antibodies to Ascaris lumbricoides in asthmatic versus control subjects but the incidence was elevated (p less than 0.005) in patients with chronic obstructive lung disease. Apparently hypersensitivity to Ascaris is not a factor of importance in the aetiology of asthma in New Guinea.

Absorption↗