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Biomedical subjects

R A Simon

Publications and source records attributed to R A Simon.

At least 19 recordsLinked to original sources
PubMed1991

Safety and possible efficacy of fiberoptic bronchoscopy with lavage in the management of refractory asthma with mucous impaction.

Mucous impaction may be suspected in asthmatic exacerbation when, despite aggressive medical management, patients continue to produce sputum containing mucous plugs and exhibit prominent rhonchi and/or wheezes on chest auscultation. Spirometric measurements in this setting corroborate lack of improvement and reveal significant impairment in indices that may reflect small airways function (FEF25-75). We hypothesized that clearance of inspissated secretions by fiberoptic bronchoscopy with lavage (FOBwL) may promote or hasten the clinical improvement of such patients. Fifty-one therapeutic FOBwL were accomplished in 19 patients during 20 episodes of stabilized yet refractory asthma with mucous impaction. No significant complications were encountered. After FOBwL, spirometric measurements of FEV1, FEF25-75, and FVC increased significantly (P less than .01, paired t test), and correlated with relief of dyspnea and mobilization of secretions with cough. FOBwL can be safely performed in stabilized, refractory asthma, and with apparent efficacy. Further investigation is needed to document the therapeutic utility of FOBwL in refractory asthma.

Adult↗
PubMed1990

Long-term effects of aspirin desensitization--treatment for aspirin-sensitive rhinosinusitis-asthma.

One hundred seven known aspirin (ASA)-sensitive patients with rhinosinusitis-asthma were studied from 1975 to 1988. Forty-two of the patients avoided ASA and served as the control group. Thirty-five patients were desensitized to ASA and treated with daily ASA treatment (Rx) for as long as 8 years (mean, 3.75 years) to May 1988 and were designated the continuous group. Thirty patients, initially desensitized to ASA and treated with daily ASA, who stopped Rx permanently after a mean duration of 2 years, were designated the discontinued group. Retrospective analyses of baselines revealed that both continuous and discontinued groups during ASA Rx demonstrated statistically significant reduction in number of hospitalizations per year, emergency room visits per year, outpatient visits per year, upper respiratory infections-sinusitis-antibiotics per year, need for nasal polypectomies and additional sinus operations, and improvement in sense of smell compared to the control group. Simultaneously, the ASA-Rx groups were able to significantly reduce systemic corticosteroid dosage, corticosteroid bursts per year, and, in the continuous group only, significantly reduce inhaled corticosteroids. All three groups maintained control of respiratory symptoms. ASA desensitization followed by long-term daily ASA Rx appears to improve ASA-sensitive rhinosinusitis-asthma and concomitantly allows reduction of systemic corticosteroids.

Adrenal Cortex Hormones↗
PubMed1989

Sulfite-treated lettuce challenges in sulfite-sensitive subjects with asthma.

This study was designed to determine whether lettuce treated with a commercially available sulfite-containing freshener prepared according to manufacturer's directions could provoke reactions in sulfite-sensitive subjects with asthma (SSAs). Five adult SSAs with stable asthma who had multiple prior reactions to double-blind, placebo-controlled, sulfite-capsule challenges were studied. Each patient ingested, in a double-blind, placebo-controlled fashion, four portions of lettuce (3 oz) pretreated with one of two commercially available, nearly identical vegetable fresheners. One freshener contained sodium bisulfite and was used on one portion of lettuce. The other freshener contained no sulfite and was used on three portions of lettuce. The fresheners were prepared and the lettuce was treated according to label instructions. After baseline spirometry, the SSAs consumed the lettuce samples with the same dressing of their choice, serial spirometry was performed, and a positive reaction was defined as a greater than 20% drop in FEV1 decreased 0% to 7%; mean, 3%. Two of the subjects experienced severe reactions to the sulfite-treated lettuce. One of these reactions was life threatening; the other reaction occurred despite placing only 30% of the usual sulfite dose on the lettuce. This study has demonstrated that sulfite-treated lettuce is capable of provoking bronchospasm in SSAs and suggests that such food is one cause of restaurant-provoked asthma in these individuals.

Adult↗
PubMed1987

Heparin-like anticoagulants in asthma.

In a previous study, and in the present study, we have found that the baseline plasma samples of patients with asthma contain average levels of an endogenous heparin-like material (EHM) that is significantly higher than that noted in non-allergic, non-asthmatic controls. This material appears to have properties of both heparin and heparan sulfate. Three out of six patients responding to inhalational antigen challenge displayed an acute increment in EHM concentration that coincided with a fall in FEV values. The relation of EHM concentration to provoked asthma, or to asthma in general, remains to be determined.

Adult↗
PubMed1987

Alpha 2-macroglobulin-kallikrein potentiates contact system activity: possible effect in asthma.

Bradykinin release, an end product of contact system activation, is thought to play a significant role in the pathophysiology of asthma. We have found an increased level of native alpha 2-macroglobulin-kallikrein (alpha 2M-KK) in asthma plasmas, and have demonstrated increased levels of contact system activity in these plasmas under certain laboratory conditions. We investigated the possible role of alpha 2M-KK as a modulator of the contact system activity. Alpha 2M-KK potentiated the factor XII activation on kaolin and the kallikrein production in a dextran-sulfate-mediated assay. This potentiation presumably involves a proteolytic effect of alpha 2M-KK on high molecular weight kininogen.

Asthma↗
PubMed1985

Precipitating factors in asthma. Aspirin, sulfites, and other drugs and chemicals.

Several types of reactions to drugs and chemicals may precipitate or perpetuate asthmatic relapse. This review focuses on reactions to aspirin and sulfites. Approximately 40 percent of patients with rhinosinusitis, nasal polyps, and asthma and 5 to 10 percent of all asthmatic patients are sensitive to aspirin and aspirin-like nonsteroidal anti-inflammatory drugs at some time in their course. A prudent recommendation to all asthmatics is to substitute acetaminophen for aspirin. When aspirin/aspirin-like drug is essential for treatment of cardiovascular or musculoskeletal disorder, desensitization by cautious oral challenges with graded doses of aspirin can be accomplished. Treatment of the respiratory disorder per se by desensitization followed by daily therapeutic aspirin remains investigational. Sulfur dioxide and sulfites, commonly used as sanitizers and preservatives of foods and pharmaceuticals, may precipitate acute asthma in 5 percent or more of asthmatic patients. When the history suggests sulfite sensitivity, challenges can be used to confirm sensitivity and the patient counseled in avoidance of these chemicals.

Adult↗
PubMed1979

Lymphocytes with immunoglobulin E Fc receptors in patients with atopic disorders.

Lymphocytes from normal nonallergic donors and patients with atopic disorders were analyzed for subpopulations bearing Fc receptors for immunoglobulin (Ig)E (Fc(epsilon)) and IgG (Fc(gamma)), surface IgM (sIgM) and IgD (sIgD), and for T cells forming spontaneous rosettes with sheep erythrocytes (E). The patients were divided into three groups according to serum IgE concentrations and systemic corticosteroid treatment. Group I consisted of 12 atopic patients with either normal or moderately increased IgE levels up to 4,000 U/ml. Four patients of group II and three of group III had 10,500-31,000 U/ml and severe atopic dermatitis. Patients of group III, but not I and II, were receiving corticosteroids systemically. The percentage (mean +/-SD) and total number of Fc(epsilon) (+) lymphocytes were 1.2+/-0.5%, 41+/-24/mm(3) in 12 normals; 1.6+/-0.9%, 59+/-43/mm(3) in patients of group I: 7.0+/-2.0%, 187+/-67/mm(3) in group II; and 0.3+/-0.1%, 13+/-5/mm(3) in patients of group III. The increase in group II and decrease in group III of Fc(epsilon) (+) cells were statistically significantly different from the normal persons and patients of group I. In contrast, the patients did not differ significantly from the donors in sIgM(+), sIgD(+), Fc(gamma) (+), and E(+) cell populations. As shown by depletion of sIg(+) cells in four patients with atopic disorders, the great majority of the Fc(epsilon) (+) lymphocytes were B cells. However, two patients with elevated Fc(epsilon) (+) cell numbers had small numbers of mixed E- and Fc(epsilon)-rosetting cells, presumably T cells. Two patients of group II were examined during an acute herpes simplex infection. Both showed an congruent with80% decrease of Fc(epsilon) (+) cells at that time. No apparent correlation between numbers of Fc(epsilon) (+) cells and IgE level existed in patients of group I. Injection of an IgE myeloma protein into two monkeys did not significantly change their percentages of Fc(epsilon) (+) lymphocytes. The data indicate that Fc(epsilon) (+) lymphocytes are increased in patients with markedly elevated serum IgE and severe atopic disease, suggesting that these cells may be involved in the regulation and(or) synthesis of IgE antibody formation.

Adrenal Cortex Hormones↗
PubMed1978

Increased in vitro histamine release by radiographic contrast media in patients with history of incompatibility.

This study was designed to compare in vitro leucocyte histamine release in patients with a history of previous radiographic contrast media (RCM) reactions and normal controls. Peripheral leucocytes of ten patients with a positive history of RCM imcompatibility and nineteen normal volunteers were stimulated in vitro with different RCM in different concentrations and the amount of histamine released was measured in the supernatant. There was a significant increase in histamine release induced by RCM in low doses (0.02-0.1 M) in the patients as compared to the normals. At the high doses (0.2-0.3 M), no significant differences were found. Leucocytes from four of the patients were stimulated preferentially by the dye responsible for the incompatibility. Six patients showed no such preference. The increased "releasability" of the patients' leucocytes could not be transferred by serum. Normal leucocytes, when incubated with serum from "high releasing" patients did not show increased histamine release after stimulation with the respective dye. It is suggested that an excessive non-immunological response of basophil leucocytes to RCM stimulation might, in part, account for the adverse clinical reactions observed. Furthermore, leucocyte histamine release might be a useful diagnostic tool for detecting patients with a high risk of developing contrast media reactions.

Adult↗