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Biomedical subjects

F C Lowell

Publications and source records attributed to F C Lowell.

At least 19 recordsLinked to original sources

Myths, morbidity, and mortality in asthma.

Persistence of outmoded concepts or "myths" concerning the diagnosis and treatment of asthma probably is responsible for large economic losses, overutilization of hospital beds, and many preventable deaths. There have been many worthwhile studies refuting these myths, leading to the following conclusions: Asthma consists of much more than wheezing and in many cases must be treated long after wheezing stops. There is no convincing evidence relating the chronic pulmonary changes of asthma to the psyche. Modern methods of prescribing theophylline have not made it universally effective and safe. Intermittent postive-pressure breathing is rarely justified in asthma. Respiratory acidosis may be corrected only by improving alveolar ventilation. Corticosteroids are usually essential for control of severe asthma and may be used safely. Severe asthmatics need careful monitoring because sudden respiratory failure may occur.

Acidosis, Respiratory

Immunotherapy in cat-induced asthma. Double-blind trial with evaluation of bronchial responses to cat allergen and histamine.

Ten asymptomatic patients with normal pulmonary function were selected for a double-blind trial of immunotherapy in cat-induced asthma. Each patient had a positive prick test to cat pelt extract and also a positive bronchial challenge response to the same extract. Patients were randomly assigned to active treatment or placebo groups and received weekly or biweekly injections over a 3 to 4-month period. The 5 patients who received the active treatment received a cumulative dose of cat pelt extract that ranged from 16.4 to 44.8 mg of total solid containing 1.7 to 4.7 mg of cat allergen 1. Apparent systemic reactions were observed in 3 patients who received the placebo and 3 patients who received the active treatment. The 5 patients who received the active treatment showed a reduction in skin reactivity to cat pelt extract as well as a significant mean reduction in bronchial sensitivity to the same extract. The 5 patients who received the placebo showed no significant changes in skin reactivity or bronchial sensitivity to cat pelt extract. Bronchial response to histamine did not change significantly in either the active treatment of the placebo group.

Allergens

Insulin antibodies in the pathogenesis of insulin allergy and resistance.

Insulin allergy developed in a patient treated with beef/pork insulin. Desensitization therapy led to cessation of the allergy, but it was associated with the development of diabetic ketoacidosis with apparent insulin resistance which was successfully treated with fish insulin. The patient's initial serum contained a high titer of anti-insulin immunoglobulin E (IgE) antibody directed primarily against beef insulin. Desensitization therapy with pork insulin was associated with the production of anti-insulin immunoglobulin G (IgG) antibody with highest immunologic reactivity to pork insulin. This IgG antibody may have blocked the interaction of insulin with tissue-fixed IgE antibody but, in addition, led to significant increases in total serum insulin-binding capacity and transient insulin resistance. The favorable clinical response to fish insulin was likely due to the negligible immunologic reactivity of this patient's anti-insulin antibodies with fish insulin. This report suggests that desensitization therapy for insulin allergy can lead to insulin resistance of the immune type.

Animals

Allergens of mammalian origin. IV. Evidence for common allergens in cat and dog serum.

IgE antibodies present in serum from 3 patients clinically sensitive to cat and dog were shown to combine with whole cat and dog sera linked to cellulose particles. Employing a modified radioallergosorbent technique (RAST), it was shown that cat and dog sera inhibited the binding of IgE antibodies to insolubilized cat serum and to insolubilized dog serum. These findings suggest that cat and dog sera have common allergens. Other mammalian sera were also tested and found to have little inhibitory activity. Cat and dog sera did not inhibit the binding of IgE antiragweed antibodies to an insolubilized ragweed fraction. Following separation of cat serum by gel filtration on Sephadex G-200 or electrophoresis in acrylamide gel, several fractions were found to inhibit the binding of IgE antibodies to insolubilized cat and dog sera. Whether the heterogeneity observed reflects the presence of single allergens with diverse size and charge properties or multiple allergens remains to be determined.

Allergens

Allergens of mammalian origin V. Properties of extracts derived from the domestic cat.

Eight commercial cat dander extracts and two pelt extracts derived from mongrel and Siamese cats were compared. Cat allergn 1 and cat albumin were measured by radial immunodiffusion. Allergenic activity was evaluated by prick test and a modified radioallergosorbent test. In the latter, the dilution of each extract that produced 50% inhibition of binding of IgE antibodies to insolubilized cat allergen 1 (RAST 1) and insolubilized cat serum (RAST 2) was determind. The total non-dialysable solid content of the extracts did not correlate with any other parameter. Cat allergen 1 content determined by radial immunodiffusion correlated with average prick test results in ten cat-sensitive subjects and with RAST 1 activity. Cat albumin content correlated weakly with RAST 2 activity but not with any other measure of allergenic activity. Absorption of each extract with the gamma-globulin fraction of rabbit antiserum to cat allergen 1 significantly reduced prick test reactivity and RAST 1 activity, but not RAST 2 activity. These results indicate that cat allergen 1 is an important allergen in cat dander extracts and its measurement may be used to standardize the allergenic activity of such extracts.

Albumins

Allergens of mammalian origin. II. Characterization of allergens extracted from rat, mouse, guinea pig, and rabbit pelts.

Aqueous extracts prepared from lyophilized, defatted rat, mouse, guinea pig, and rabbit pelts elicited intense wheal-and-flare responses in the skin of a high proportion of patients who were clinically sensitive to these animals. The major allergens in each extract were nondialyzable. Skin test reactions to rat, mouse, and guinea pig serum were common in patients allergic to these animals. The fractions of rat, mouse, and rabbit pelt extract showing maximum allergenic activity contained proteins with the electrophoretic mobility of serum albumin. Fractions of guinea pig pelt extract with maximum allergenic activity were of prealbumin mobility and contained little stainable protein. On Sephadex G-100 gel filtration, most allergen from rat, mouse, and guinea pig pelt extracts was recovered in fractions containing proteins with a molecular weight range of 10,000 to 25,000 daltons. Allergen in rabbit pelt extract had a slightly higher molecular weight range of 18,000 to 38,000 daltons.

Allergens