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Biomedical subjects

D J Hendrick

Publications and source records attributed to D J Hendrick.

At least 109 records · Page 6Linked to original sources
PubMed1981

Protective value of dust respirators in extrinsic allergic alveolitis: clinical assessment using inhalation provocation tests.

Six subjects with budgerigar fancier's lung, pigeon breeder's lung, or mushroom worker's lung underwent identical paired inhalation provocation tests of 20 minutes to five hours duration (mean 2.3 hours) using a natural method of antigen exposure. For one test of each pair, the subjects were protected by the use of industrial dust respirators that incorporate electrostatically charged, resin-impregnated merino wool filters. The unprotected challenges provoked late responses of mild to moderate severity, that were characteristic of extrinsic allergic alveolitis. These were monitored by methods described previously, using four subjective and six objective monitoring tests. A score of 1 was allowed for each monitoring test showing a significant change. A combined monitoring score of 32/57 was associated with the unprotected challenges-that is, 56% of the maximum score possible. The respirators successfully protected four of the subjects from any suspicion of a positive response. The remaining two subjects reported symptoms of minimal severity, but there was no independent confirmatory evidence of positive reactions. The combined monitoring score associated with all six protected challenges was 2/60 (3%), while that associated with corresponding control challenges was 3/73 (4%). We conclude that respirators of this type can offer substantial, and in most cases complete, protection against single exposures to environmental dusts that may provoke extrinsic allergic alveolitis.

Adult↗
PubMed1980

Positive "alveolar" responses to antigen inhalation provocation tests: their validity and recognition.

The validity of inhalation tests in the investigation of extrinsic allergic alveolitis was assessed from the results of 144 antigen and control tests in 31 subjects. A definitive pattern of positive late responses was observed. Reactions to nebulised bird serum and droppings in subjects with bird fancier's lung were identical to reactions after "natural" exposures in aviaries or lofts, and to reactions after "occupational" challenges in subjects with farmer's lung and mushroom worker's lung. In general, positive tests were easily recognised subjectively from symptoms and signs appropriate to an influenza-like illness and undue respiratory effort on exercise. They were associated with significant changes in six readily available objective monitoring measurements--exercise minute ventilation (greater than or equal to +15%), body temperature (> 37.2 degrees C), circulating neutrophils (greater than or equal to +2500/mm3), exercise respiratory frequency (greater than or equal to +25%), circulating lymphocytes (greater than ore equal to -500/mm3 with lymphopenia), and forced vital capacity (greater than or equal to -15%). These confirmatory monitoring tests had specificities of approximately 95% and sensitivities of 85-48%. Measurement of diffusing capacity, lung volume subdivisions, or resting minute ventilation/respiratory frequency proved to be too insensitive to be useful, as did auscultation and chest radiography. We conclude that responses that do provoke significant changes in these less sensitive tests are unnecessarily distressing and, presumable, unnecessarily hazardous.

Alveolitis, Extrinsic Allergic↗
PubMed1978

Budgerigar-fancier's lung: the commonest variety of allergic alveolitis in Britain.

A questionnaire survey of 1005 consecutive attenders at four outpatient clinics yielded 117 (12%) budgerigar fanciers (exposed to budgerigars- known in North America as parakeets-for at least three months) and 296 (29%) former fanciers. Twnety had precipitins to budgerigar serum or droppings or both, and 10 of these together with 39 precipitin-negative patients reported undue breathlessness on exertion during exposure to buderigars. These 59 patients were investigated further, seven completing a series of inhalation provocation tests with budgerigar antigens designed to confirm or exclude budgerigar-fancier's lung (BrFL). Typical positive responses were obtained from four current and one former fancier. The prevalence of confirmed BrFL among the 11n current budgerigar fanciers was 3.4% (four cases). This was biased, however, by the inclusion of one patient whose attendance at the surveyed clinic was attributable to the disease. With the exclusion of this patient, confidence limits suggested that the true prevalence of BrFL among current budgerigar fanciers in the general population lies between 0.5% and 7.5%, which is similar to the prevalence of farmer's lung in farm workers. In view of the enormous population at risk, however, this implies that BrFL rather than farmer's lung is by far the commonest type of allergic alveolitis in Britain.

Adolescent↗
PubMed1978

Precipitins to different avaian serum antigens in bird fancier's lung and coeliac disease.

Precipitins to avian serum antigens have been found in the sera of bird fanciers and, until now, they have been considered strong supporting evidence for a clinical diagnosis of bird fancier's lung (BFL). We now report that 35% of patients with coeliac disease, none of whom had recently kept a bird, had precipitins against an avian serum antigen common to all the avian species tested, but which was distinct from the antigens usually associated with BFL. This antigen was a component of hen egg yolk but not of bird droppings. In patients with BFL the antibody response results from inhaled antigens in the bird droppings, whereas the antibody response in patients with coeliac disease probably results from eating uncooked or soft-boiled eggs.

Adult↗
PubMed1978

Is bird fancier's lung associated with coeliac disease?

Precipitin responses to different avian serum antigens occur in bird fancier's lung (BFL) and coeliac disease. Failure to distinguish between them could encourage an erroneous diagnosis of BFL in patients with coeliac disease, and the recent suggestion that these two disorders are strongly associated may be questioned, partly for this reason. In the present study small bowel biopsy specimens were obtained from 12 of a series of 14 patients proved to have BFL by inhalation provocation tests. None was suggestive of coeliac disease. Of a further 61 patients with biopsy-proved coeliac disease, seven were found to be exposed currently and 33 formerly to birds. As a result of clinical evaluation, BFL was considered a possible cause of undue breathlessness reported by three of the current bird fanciers only, and all underwent inhalation provocation tests. One alone gave positive results. We conclude that if a real association does exist between these two disorders, its clinical importance has been greatly exaggerated.

Alveolitis, Extrinsic Allergic↗
PubMed1977

Occupational formalin asthma.

Hypersensitivity to formalin used to sterilise artificial kidney machines was shown by inhalation provocation tests to be responsible for attacks of wheezing accompanied by productive cough in two members of the nursing staff of a haemodialysis unit. Three further members of the staff of 28 who were continually exposed to this substance occupationally had developed similar recurrent but less frequent episodes since joining the unit. Two underwent inhalation provocation tests with formalin which did not reproduce these symptoms. Single episodes of these symptoms had been noted by three additional staff members so that altogether eight (29%) had experienced attacks described as bronchitic since becoming exposed to formalin. We suggest that, while exposure to formalin did not seem to be directly responsible in all cases, it might have increased susceptibility to other provoking agents or induced a hyper-reactive responsiveness of the airways. The responses observed in the two nurses after inhalation provocation tests with fromalin were predominantly of airways obstruction. Wheezing began between two and three hours after exposure, and peak expiratory flow rates fell maximally by approximately 50%. Reactions persisted for 10 hours to 10 days depending on the exposure dose. A productive cough was a prominent feature. The sputum appeared to be mucopurulent, but culture produced a scanty growth of Haemophilus influenzae only, together with upper respiratory tract commensals. The cellular content was not homogeneous, neutrophil leucocytes and eosinophil leucocoytes variably dominating. Variable responses of neutrophil and eosinophil leucocytes were also seen in the peripheral blood.

Adult↗
PubMed1976

Chest pain in the presentation of sarcoidosis.

The cases of six patients are reported illustrating that chest pain may be a prominent feature of sarcoidosis. It may be severe and be the chief presenting symptom. In the cases described it was mostly retrosternal and had few consistent aggravating factors. In each case there was bilateral hilar lymph node enlargement and it is suggested that htis was chiefly responsible for this relatively uncommon symptom of sarcoidosis. It is also suggested that undue persisting pain may respond to corticosteroid administration.

Adrenal Cortex Hormones↗
PubMed1976

Bakers' asthma.

Bronchial provocation tests by "occupational" exposure to flour provoked dual asthmatic reactions accompanied by rhinitis in two atopic bakers engaged in the manufacture of bread and pies. Ingestion tests with uncooked flour produced no reactions. Skin prick tests with aqueous extracts of flour produced positive immediate reactions in both bakers, and negative reactions in nine of ten atopic asthmatic control subjects with no occupational exposure to flour. Intracutaneous tests, performed in one precipitin negative baker, gave dual responses. Precipitating antibodies to an aqueous extract of flour were found in the unconcentrated serum of the other baker, and not in ten control subjects.

Adult↗
PubMed1975

An analysis of skin prick test reactions in 656 asthmatic patients.

Of 656 asthmatic patients referred specifically for allergy assessments, 544 (84 percent) gave positive immediate skin prick tests to at least one of 22 common allergens used routinely. Comparison of these skin test positive patients with the 102 (16 percent) who were skin test negative showed a number of significant differences. The majority of the skin test positive patients (52 percent) were less than 10 years old at the time of onset of the asthma, whereas, of the skin test negative patients, 56 percent were aged over 30 years at the time of onset. Seventy per cent report rhinitis compared with 48 per cent of the skin test negative patients, and 29 per cent reported infantile eczema compared with 9 per cent. Symptoms attributed to house dust, pollens, and animals were noted two to three times more frequently by the skin test positive patients, while corticosteroid drugs had been used more commonly by the skin test negative patients (45 percent compared with 35 percent). No significant differences were observed with the other factors studied, namely, history of urticaria or angio-oedema, family history of "allergic" disease, and awareness of sensitivity to foods, aspirin or penicillin. Prick test reactions in the skin test positive patients were most commonly seen to house dust or the acarine mite, Dermatophagoides farinae (82 percent), followed by pollens (66 percent), animal danders (38 percent), foods (16 percent), Aspergillus fumigatus (16 percent), and other moulds (21 percent). There was a highly significant association of positive history with positive prick test for all allergens studied.

Adrenal Cortex Hormones↗