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Biomedical subjects

D J Pearson

Publications and source records attributed to D J Pearson.

At least 37 records · Page 2Linked to original sources
PubMed1984

A psychiatric study of patients with supposed food allergy.

Twenty-three patients who believed they suffered from food allergy were studied at the time of their presentation to an allergy clinic. The presence of organic food hypersensitivity could not be confirmed in 19 who attributed common neurotic symptoms to allergy; this group was almost identical, in terms of psychiatric symptomatology and general characteristics, with a group of new psychiatric out-patient referrals. There was no evidence of psychiatric disorder of food-related psychological symptoms in four patients with proven food-related atopic symptoms. The study failed to find evidence that psychological symptoms might be the result of organic reactions to foods.

Adult↗
PubMed1983

Clinical immunology.

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Allergy and Immunology↗
PubMed1983

Food hypersensitivity in irritable bowel syndrome.

Food hypersensitivity as a cause of abdominal symptoms was investigated by means of exclusion diets and double-blind food provocation in patients with irritable bowel syndrome. Twenty-seven patients entered the study; nineteen complied with dietary manipulation. Food hypersensitivity as a cause of their presenting symptoms was confirmed by double-blind food provocation in only three patients, who also had evidence of associated atopic disease and positive skin tests to common inhalant allergens. Evidence of minor psychiatric disorder was found in twelve of fourteen patients examined by an independent psychiatrist.

Adolescent↗
PubMed1983

Food allergy.

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Double-Blind Method↗
PubMed1983

Food allergy: how much in the mind? A clinical and psychiatric study of suspected food hypersensitivity.

Objective evidence of food hypersensitivity was sought by the use of exclusion diets and provocation tests in 23 patients who attributed a wide variety of symptoms to food allergy. Hypersensitivity to ingested substances was confirmed in 4, each of whom presented with typical atopic symptoms. None of these had psychological symptoms, but a high incidence of psychiatric disorder was found in patients whose belief that they had a food allergy could not be confirmed.

Adult↗
PubMed1983

Polyuria and inappropriate secretion of arginine vasopressin in hypothalamic sarcoidosis.

Inappropriate arginine vasopressin release and polyuria with excessive thirst were found in a patient with hypothalamic sarcoidosis subsequently confirmed at autopsy. He became intensely thirsty during a 5% saline infusion at a plasma osmolality of 274 mosmol/liter. The normal thirst threshold under these conditions is 294 +/- 3 mosmol/liter (+/- SD). An increase in radioimmunoassayable arginine vasopressin was detected at an inappropriately low plasma osmolality, and free water clearance was negative despite a plasma osmolality of 265 +/- 5 mosmol/liter with ad libitum fluid intake. The syndrome of inappropriate antidiuresis has not been described previously in combination with hypothalamic sarcoidosis. Demeclocycline therapy was associated with an exacerbation of the patient's polyuria. Propranolol administration, however, was associated with a reduction of urine output and an increase in plasma osmolality to 279 mosmol/liter on one and 299 mosmol/liter on another occasion.

Adult↗
PubMed1981

Soluble and particulate activators of complement and granulomatous pulmonary reactions.

In order to test the hypothesis that the histological changes of extrinsic allergic alveolitis result from non-specific activation of the complement cascade we studied pulmonary reactions to equivalent doses of soluble and particulate activators of complement in rats. A single intratracheal instillation of zymosan, a particulate activator of the complement system, produced a florid granulomatous pneumonitis which was maximal at 5 days. This granulomatous reaction did not appear to be associated with the development of hypersensitivity to zymosan. Complement depletion by cobra venom factor did not suppress the granulomatous reaction. Equivalent doses of soluble activators of complement failed to produce any inflammatory changes in the lung. Large doses of immune complex produced an acute, complement dependent, haemorrhagic alveolitis which was maximal at 8 hr and which resolved completely by 48 hr. We conclude that the late granulomatous pulmonary reaction to intra-tracheally administered zymosan is not due to an immune response, or a consequence of direct activation of the alternative pathway of complement, but is of 'foreign body' type. We urge caution in drawing conclusions regarding the pathogenesis of the allergic alveolitides on histological appearances alone.

Alveolitis, Extrinsic Allergic↗
PubMed1981

Serologic changes in pneumoconiosis and progressive massive fibrosis of coal workers.

Serum from 109 coal workers with simple pneumoconiosis, 114 with progressive massive fibrosis, and 130 with normal chest radiographics as control subjects was examined for rheumatoid and antinuclear factors, and antibodies against both native human IgG and Mycobacterium tuberculosis. A significantly greater prevalence of autoantibodies was observed in subjects with pneumoconiosis than in control subjects; however, a rheumatoid factor prevalence of 16% with observed inthe control subjects. No serologic differences were observed between subjects with simple pneumoconiosis and those with progressive massive fibrosis.

Adult↗
PubMed1981

HLA-B8 in sarcoidosis.

One hundred and seventy-four unrelated white patients with biopsied and clinically diagnosed sarcoidosis and a reference population of 97 were tested for HLA antigens. Selected comparisons showed a statistically significant association of HLA-B8 with the sarcoidosis group (28.9%) when compared to the reference group (15.5%).

Chromosome Mapping↗
PubMed1981

Immunology of clinically inactive sarcoidosis: serum factors.

Sera from 84 white patients with inactive sarcoidosis were analyzed for immunoglobulins, complement, autoantibodies, alpha 1-antitrypsin and lysozyme. The levels of serum factors were compared with levels in serum from a reference population which was matched for age, sex, ethnic background and geographic location. IgG, IgA, IgD, and C3 levels were similar for both groups, as were frequencies of rheumatoid factor, antinuclear antibody and anti-DNA antibody. Lysozyme levels were significantly lower in the inactive sarcoidosis group but the acute phase reactants alpha 1-antitrypsin, IgM as well as complement consumption were increased. The data suggest that the underlying etiological events of sarcoidosis continue, albeit at a subclinical level.

Adult↗
PubMed1978

The effect of phenobarbitone on cytoplasmic NADP-linked dehydrogenase activities in rat liver.

Phenobarbitone administered in drinking water (0.5 g/l) or by daily intraperitoneal injection (100 mg/kg body weight) consistently caused an elevation of hepatic NADP-linked malic enzyme in rats maintained on a pellet diet. Three to four days appeared to be required for maximum response. The effect was also observed in animals maintained on a protein rich diet, in which the basic hepatic malic enzyme activity was low, but not in animals maintained on a sucrose rich diet, in which the basic enzyme activity was almost twice normal. Methyl cholanthrene, administered by daily intraperitoneal injection (40 mg/kg body weight), resulted in elevated hepatic levels not only of malic enzyme but also of the pentose phosphate pathway dehydrogenases. The timing of the "starve-refeed" response of the hepatic NADP-linked dehydrogenases in phenobarbitone-treated rats was similar to that in controls, and similar maximum enzyme activities were reached. The role of cytoplasmic NADP-linked dehydrogenases in the provision of reducing equivalent is discussed, particularly in relation to hepatic microsomal drug metabolism.

Animals↗
PubMed1978

Activation of the alternative pathway of complement by grain. I. C3PA conversion and quantification of complement consumption by rye.

Ground whole rye and airborne rye dust of comparable size distribution were tested for their ability to activate the complement cascade via the alternative pathway. Precipitin-negative pooled normal human serum was incubated with increasing amounts of the two rye dusts. Electrophoresis of the resultant supernatant fluids demonstrated the conversion of the proactivator of the third component of complement to the gamma-migrating activator of the third component. This activation was completely prevented by pre-treating the serum with the chelator EDTA, while pre-treatment with EGTA allowed suboptimal arc conversion, strongly implying that complement was activated via the alternative pathway. Quantification of the supernanant fluids showed dose-dependent complement consumption as defined by both CH100 immunodiffusion and CH50 tube haemolytic techniques. Airborne rye dust showed a greater quantitative potential than ground whole rye for activating the alternative pathway. These results indicate the possibility of the direct action of airborne organic dusts on the induction of inflammatory sequelae in the lungs of both sensitized and unsensitized individuals.

Air Pollutants↗
PubMed1977

Respiratory allergy and month of birth.

A total of 476 patients with respiratory allergy were interviewed to establish whether the season of birth influenced the type of allergy experienced. Patients with perennial symptoms did not differ from the general population of the U.K. in the distribution of their months of birth. Patients with summer seasonal symptoms attributable to grass pollen sensitivity were more likely to have been born in December to February than in August to November. This trend was most significant in female patients who did not have associated perennial symptoms and who developed symptoms early in life. Other significant differences were also noted between groups of patients complaining of the same symptoms. More males than females had summer seasonal symptoms whereas more females than males had perennial symptoms. Patients who had both perennial symptoms and summer seasonal exacerbations had a higher incidence of a positive family history of atopy and developed symptoms earlier in life than those patients who had summer seasonal or perennial symptoms only.

Adolescent↗
PubMed1977

The influence of IgE-mediated reactions on the expression of delayed hypersensitivity in the rat.

The effect of IgE-mediated reactions on the expression of delayed hypersensitivity skin reactions was examined in the rat. It was found that the elicitation of an IgE-mediated reaction at the time of skin test could either potentiate or inhibit the development of delayed reactions. At a fixed level of IgE sensitivity, large delayed reactions were potentiated and small delayed reactions suppressed. These interactions were not dependent on the two types of sensitivity being direct against the same antigen but were dependent on the reaction of IgE with its appropriate antigen.

Animals↗