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Biomedical subjects

C W Clarke

Publications and source records attributed to C W Clarke.

28 records · Page 2Linked to original sources

A comparison of the efficacy of ketotifen (HC 20-511) with sodium cromoglycate (SCG) in skin test positive asthma.

1 Ketotifen (HC 20-511 Sandoz) 1 mg twice daily for 12 weeks was found to be equivalent to sodium cromoglycate (SCG) 20 mg four times daily for 12 weeks in 35 skin test positive asthmatic patients in a randomised double-blind cross-over study. 2 No statistically significant difference between the two drugs in mean values for daily peak flow rates, diary card scores and spirometry at monthly visits was demonstrated. 3 Treatment failures as judged by severe asthma requiring withdrawal from the trial or addition of short courses of prednisone occurred in three patients on each drug. 4 Sedation was noted by 10 patients onHC 20-511 and 5 on SCG. 5 Weight loss was noted in those patients on SCG, but not those on HC 20-511.

Adolescent↗

The nature of asthma in Brisbane.

Clinical details and skin prick test reactions are described for 183 asthmatic patients who attended an asthma clinic at the Royal Brisbane Hospital in 1976. These features were compared with similar studies reported from London, Sydney, Tristan da Cunha and New Guinea. Asthma in Brisbane was shown to be similar in many ways to asthma in those centres; however, a higher frequency of positive immediate skin test reactions to antigens of A. fumigatus, a larger percentage of skin test-negative patients developing symptoms before the age of 10 years, and a lack of association between the age of onset of symptoms and number of positive skin tests was noted. A difference in mean weal diameter (in mm) on skin testing with house dust mite antigens was not found between patients giving a history of sensitivity to these antigens and those that did not. A seasonal increase in symptoms was only described by 27% of patients.

Adolescent↗

Relationship of bacterial and viral infections to exacerbations of asthma.

Fifty-one asthmatic patients were followed for up to 18 months. During this time 111 exacerbations of wheeze were recorded. Involvement by pathogenic respiratory bacteria and viruses was looked for directly by culture and indirectly by antibody studies. Proof of infection was found in only 12 (10.8%) of the 111 exacerbations. Only eight patients provided sputum samples. Potential bacterial pathogens were found in four. Viruses were isolated in four of 27 exacerbation specimens; significant rises in specific viral antibody titres occurred in three. Six patients developed precipitating antibody to respiratory bacteria over the study but only one in relation to an exacerbation. The study therefore indicated that the great majority of exacerbations of asthma in these patients were not due to respiratory tract infection.

Adult↗

In vivo and in vitro reactions to antigens of Haemophilus influenzae in bronchial obstruction.

The frequency of precipitating antibody to heat-labile (H(1--2) and heat-stable (HCW and HCF) antigens of Haemophilus influenzae was determined in patients with asthma, chronic bronchitis, cystic fibrosis and bronchiectasis and compared with that in a control group. This showed that the immune response of asthmatic patients to heat-stable antigens was different from that to the heat-labile antigens. Exposure to antigens of H. influenzae is common in all the disease groups. Skin test reactions having the time course and macroscopic appearance of Type I (immediate) and Type III (late) were obtained after prick and intracutaneous skin testing with HCW antigen in varying concentrations in a group of patients with asthma, chronic bronchitis or cystic fibrosis and in a control group. It is suggested that IgE and short-term sensitizing IgG antibodies may be responsible for the immediate reactions while activation of the alternative pathway of complement by endotoxin contained in HCW could be responsible for the late reactions. HCW antigens were shown to release histamine from non-sensitized human leucocytes; HCW and HCF antigens were shown to release histamine from non-sensitized human lung. None of the antigens tested had an effect on beta-receptors in tracheal preparations. It is proposed that these reactions may contribute to the pathogenicity of H. influenzae in the lower respiratory tract.

Antigen-Antibody Reactions↗

Terbutaline sulphate nebulizer solution: a dose-response study.

A dose-response study of terbutaline nebulizer solution has been performed in nine convalescent asthmatic patients. Both 5-mg and 10-mg doses administered as a wet aerosol resulted in effective bronchodilatation, but the higher dose caused a mild tachycardia.

Asthma↗

Antigens of Haemophilus influenzae.

Three antigenic preparations were obtained from a non-capsulated strain of Haemophilus influenzae by ultrasonic disintegration, hot phenol extraction and from a fluid culture. They were designated H. influenzae cytoplasmic antigen (H(1-5); H. influenzae cell wall antigen (HCW); and H. influenzae culture filtrate antigen (HCF). Studies showed that H(1-5) antigen contained heat stable and heat labile components. The heat stable fraction stained positively for polysaccharide, had a positive limulus lysate test and there was immunological cross-reactivity between this and heat stable fractions of HCW and HCF. Limulus lysate assay indicated the presence of endotoxin in HCW and HCF preparations. Heat stable as well as heat labile antigens of H. influenzae should be given consideration in future studies regarding the pathogenicity of this organism in the lower respiratory tree. The specificity of the heat stable antigen of H. influenzae needs to be determined.

Antibodies, Bacterial↗

Precipitating antibody to antigens of Pseudomonas aeruginosa in chronic obstructive lung disease.

Two antigens designated Pseudomonas aeruginosa cytoplasmic antigen (P(1-5)) and P. aeruginosa cell wal antigen (PCW) were prepared by ultrasonic disintegration and hot phenol extraction of a smooth polyagglutinable strain of P. aeruginosa isolated from the respiratory tract. It was shown that P(1-5) and PCW are immunologically distinct, that P(1-5) is heat-labile while PCW contains a heat-stable component which stains positively for polysaccharide, is positive for endotoxin and cross-reacts with a cell wall antigen of Haemophilus influenzae prepared by hot phenol extraction. Both antigens were able to activate the alternate pathway for complement. A statistically significant number of patients with cystic fibrosis and bronchiectasis have precipitating antibody to that fraction of cytoplasmic antigen specific for P. aeruginosa (P(1-2)) and PCW compared to controls, whereas patients with asthma and chronic bronchitis do not. The use of both antigens increases the number of patients with antibody to P. aeruginosa. Radioactive immunodiffusion studies indicate that 80.8% of controls have precipitating antibody to PCW antigen and that antibody to it is IgG, IgA and IgM. These studies indicate that consideration should be given to PCW as well as P(1-5) in any consideration of the pathogenesis of P. aeruginosa in these conditions.

Absorption↗

Aspects of serum and sputum antibody in chronic airways obstruction.

Immunoglobulin levels and precipitating antibody against a range of microbial antigens were measured in simultaneously collected serum and sputum samples from patients with chronic bronchitis (11), cystic fibrosis (9), bronchiectasis (9), and asthma (4). Sputum was prepared by dialysis and high-speed centrifugation methods. Results showed that it was possible to detect precipitating antibody in the sputum, and the rate was increased when both methods were used. A discrepancy was noted between the detection rate in the sputum and serum. This, combined with the lack of correlation between sputum and serum immunoglobulins, lack of relationship between bronchial inflammation and sputum immunoglobulins, and the lack of IgM in the sputum suggested that the antibody and immunoglobulin were locally produced. Sputum IgA (7S) in patients with chronic bronchitis was significantly lower (P less than 0-05) than that found in patients with cystic fibrosis and bronchiectasis. Significant differences (P less than 0-05) were also noted in serum IgG levels between patients with chronic bronchitis, bronchiectasis, and cystic fibrosis while serum IgM levels in patients with chronic bronchitis were significantly lower (P less than 0-05) when compared to serum levels in patients with cystic fibrosis. The presence of precipitating antibody in the sputum raises the possibility that type III reactions may be important in the pathogenesis of these conditions.

Airway Obstruction↗

Hepatitis B antigen, alpha1 fetoprotein and liver disease in the eastern highlands of Papua New Guinea.

The sera from 89 patients from the Eastern Higlands of Papua New Guinea, all with histologically diagnosed liver disease, were tested for Hepatitis B Antigen (HB Ag) and Hepatitis B antibody (HB Ab) and alpha1 fetoprotein (AFP) by a variety of techniques which included radioimmunoassay. In the three main forms of liver disease, viral hepatitis, cirrhosis and hepatoma, HB Ag was found with a higher frequency than in patients with non specific liver disease. The frequency of HB Ab was decreased in cirrhosis and hepatoma. AFP was detected in all hepatoma patients by radioimmunoassay, levels being very high in most subjects. In hepatitis, cirrhosis and non specific liver disease, elevated levels of AFP were again frequently present, but at generally lower levels. It is conlcuded that HB Ag and AFP frequency and levels in liver disease are similar to those reported from other tropical countries. Further study is required to elicit the cellular immunological changes in liver disease.

Antibodies, Viral↗