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Biomedical subjects

S Bar-Sela

Publications and source records attributed to S Bar-Sela.

At least 19 recordsLinked to original sources

Codeine-induced mast cell degranulation in human skin: effect of calcium channel blockers.

Codeine and other opiates can induce immediate type wheal and flare skin reactions. Calcium channel blockers including nifedipine have been shown to inhibit mast cell degranulation in different systems. The oral administration of nifedipine (10 mg) did not affect the size of codeine-induced skin reactions in ten normal volunteers. Mean wheal over flare sizes were 11.7 mm/29.2 mm before nifedipine and 11.5 mm/31.0 mm at peak nifedipine blood levels. Similar observations were made when codeine was injected locally with or without 20 micrograms nifedipine (12.1/29.2 mm and 13.2/29.2 mm, respectively). These data suggest that codeine-induced mast cell degranulation may be mediated by a calcium-independent mechanism. Alternatively, mast cells in the human skin may differ in their reactions to secretagogues when compared with basophils and mast cells from other human tissues or other species.

Adult

Respiratory disease in animal house workers.

A cross-sectional survey was made to determine the prevalence of respiratory disorders, and the association between symptoms and workplace exposure, in 90 animal-house workers (AHW) and 100 controls (C) without occupational exposure to laboratory animals. Each subject provided a detailed history and serum for radioimmunoassays, and underwent: physical examination, skin testing with common inhalant and animal-derived antigens, and pulmonary function studies. Both groups were comparable with respect to age, sex, smoking habits, and atopy. Rhinitis occurred with similar frequency in each group. However, a more frequent occurrence of asthma (p less than 0.05, non-specific infectious respiratory disease (p less than 0.005), and impaired pulmonary functions (p less than 0.001) was found among AHW. An atopic background was a predisposing factor for the development of laboratory-animal-related respiratory symptoms. These findings imply an increased vulnerability to respiratory disease related to workplace exposure to laboratory animals in atopic individuals.

Adult

Antigen-induced enhancement of bronchial reactivity.

Bronchial hyperreactivity as determined by the airway response to methacholine was evaluated pre- and post-antigen challenge in three patients with specific antigen sensitivity. No significant change in pulmonary function was noticed after inhalation of antigen alone. However, transient but significant increase in methacholine responsiveness followed the antigen challenge. The studies indicate a need for a nonspecific inhalation challenge following a negative antigen challenge when clinically indicated.

Adult

Occupational respiratory disease in veterinarians.

In order to determine the effect of occupational animal exposure on the occurrence of respiratory disease, we studied 257 active veterinarians and 100 control subjects who had not had occupational animal contact. All participants provided a detailed medical history and underwent spirometry, skin tests, and determination of total serum IgE levels. Asthma was significantly more prevalent in veterinarians (16.3%) than in controls (6%), (P less than .05), as was infectious/obstructive respiratory disease, 10.5% in veterinarians, 3% in controls (P less than .025). Only 13 of 257 veterinarians had respiratory symptoms related to animal contact; of these, seven experienced only allergic rhinitis while six reported both asthma and rhinitis. Animal-related allergic rhinitis was found more frequently in laboratory animal veterinarians than among veterinarians in farm, pet, or poultry practice. No symptoms typical of hypersensitivity pneumonitis were reported in veterinarians, nor were precipitins to animal antigens demonstrable.

Humans

Occupational asthma due to poultry mites.

The possible role of the northern fowl mite (NFM) in occupation-related respiratory disease of poultry workers was examined. The study population included 16 poultry workers with workplace-associated asthma and rhinitis, 27 atopic individuals with similar symptoms but no occupational exposure to poultry, and 12 asymptomatic nonatopic poultry-exposed controls. Ten of the 16 atopic poultry workers had immediate wheal-and-flare reactions to NFM, as compared with two of 27 non-poultry-exposed controls (p less than 0.001). In cutaneous testing with five poultry-related antigens, the NFM was the most reactive. On skin tests, four atopic poultry workers were positive for NFM and negative for Dermatophagoides farinae; four workers were negative for NFM and positive for D. farinae. Radioallergosorbent test (RAST) showed specific IgE levels for NFM, with positive RAST scores in 60% of poultry workers having positive skin tests. A provocative bronchial test with NFM extract in a poultry worker having positive NFM skin test and RAST score resulted in an immediate 25% reduction in the FEV1 and a 62% fall in forced expiratory flow volume at 25% of vital capacity. Collectively, the established presence of NFM in the poultry workplace, associated clinical histories, positive cutaneous tests, positive specific-IgE assays, and positive bronchial challenge combine to establish a role for NFM in occupational allergic respiratory disease of poultry farmers.

Adolescent

Occupational asthma in poultry workers.

Sixteen poultry workers with poultry house--related rhinitis and/or asthma underwent clinical and laboratory evaluation that included history and physical examination, skin tests with common inhalant and PAg, total- and specific-IgE levels, and pulmonary-function studies. Sixteen age- and sex-matched atopic subjects who were not occupationally exposed to poultry and 12 asymptomatic veterinarians with occupational exposure to poultry served as controls. Rhinitis and asthma developed only in symptomatic poultry workers after exposure to poultry; only in these individuals could immediate wheal-and-flare reactions to poultry antigens be detected (p less than 0.001). The elapsed time between the initial poultry exposure and the onset of poultry house--related symptoms averaged 10 yr. In the symptomatic poultry workers, immediate skin test reactivity and RAST reactions were most frequently associated with NFM. The association between respiratory symptoms temporally related to poultry house exposure and the demonstrable IgE antibody-mediated reaction suggests a relationship between the two.

Adolescent

Immunoregulation in hypersensitivity pneumonitis: phenotypic and functional studies of bronchoalveolar lavage lymphocytes.

We examined the immunologic phenotype and function of bronchoalveolar lymphocytes isolated from 4 pigeon breeders who developed symptoms of hypersensitivity pneumonitis on exposure to pigeons, and 6 asymptomatic but equally exposed individuals. Similar numbers of bronchoalveolar lymphocytes were found in symptomatic breeders compared with the asymptomatic, and the percent of T11, T4, and T8 bearing cells as well as the T4/T8 ratios were similar in both groups. Despite these similarities, the groups had significantly different functional activity. Bronchoalveolar lymphocytes from symptomatic breeders demonstrated a marked (p less than 0.001) increase in blastogenic activity to both phytohemagglutinin and pigeon serum stimulation when compared with asymptomatic breeders. In addition, enriched bronchoalveolar T-cells suppressed the response of autologous preincubated peripheral blood lymphocytes to both phytohemagglutinin and pigeon serum in the asymptomatic compared with the symptomatic breeders. These studies suggest a discrepancy between the phenotype and function of immunoregulatory T-cell subsets in bronchoalveolar lavage lymphocytes in pigeon breeder's disease, and support a role for functional immunoregulatory imbalances in the pathogenesis of hypersensitivity pneumonitis.

Adult

The relative value of skin tests and radioallergosorbent test in the diagnosis of bee sting hypersensitivity.

The relative diagnostic value of ST and RAST was evaluated in 97 patients with BSH. Eighteen patients had LRs, 79 showed SRs including 18 with urticaria, 26 had bronchospasm, and 35 had anaphylactic shock. ST but not the RAST reactivity was strongly related to the severity of the clinical reaction (p less than or equal to 0.001) and found superior to the RAST in identifying patients with SRs in whom venom therapy was indicated.

Aging

Lead encephalopathy treated by versenate (CA-EDTA).

A patient with generalised epileptic seizures, mental and psychotic signs was diagnosed as suffering from lead encephalopathy. He was a big consumer of home-made arrack, illicit alcohol prepared at home in secrecy, in tools containing copper and lead. Basophilic stippling increased the possibility of lead encephalopathy, which was soon proved. He was successfully treated with low doses of Versenate, a chelating factor, and totally recovered.

Chelating Agents