Experimental studies of sensitization to beryllium, zirconium, and aluminum compounds in the rabbit

In a study designed to assess the potential sensitizing and granulomagenic capacities of selected metallic salts, rabbits were inoculated intradermally with zirconium aluminum glycinate (ZAG), sodium zirconium lactate (NZL), aluminum chlorhydrate (ACH), BeSO₄, and ovalbumin (OVA) by single and multiple injections. Animals immunized with BeSO₄ and with OVA developed delayed skin reactivity as well as antigen-specific alveolar macrophage migration inhibition. Neither single nor multiple injections of ZAG or ACH resulted in clear-cut positive skin reactivity, macrophage migration inhibitory factor (MIF) production, or lymphocyte stimulation. Rabbits inoculated with multiple injections of NZL (500 μg) showed some marginally positive macrophage migration inhibition and skin reactivity. Histologically, ZAG and ACH were found to induce well-organized foreign-body granulomas after intradermal injection in both normal and inoculated rabbits. NZL and BeSO₄ also induced skin granulomas, but these were less organized and distinct. Cell viability and ultrastructural studies indicated that BeSO₄ was highly toxic for isolated alveolar macrophages in vitro at concentrations above 10 μg/ml, but NZL and ZAG did not exert such an effect at these dose levels. BeSO₄ also depressed lymphocyte stimulation in sensitized animals which demonstrated delayed skin reactivity and macrophage migration inhibition.     

Allergenicity and immunogenicity of Basidiomycetes.

Species selected from six families of the class Basidiomycetes were evaluated for allergenicity in atopic and nonatopic individuals and for immunogenicity and antigenic cross-reactivity in experimental animals. Between 42% and 68% of atopic asthmatics demonstrated positive Type 1 wheal-and-flare skin reactivity to basidiomycete metabolic and somatic antigens. Sixty-four percent of skin test-positive atopic asthmatics exhibited positive RAST to as basidiomycete metabolic antigen and 50% were positive to somatic antigen. Negative RAST results were obtained in all nonatopic control sera. Only an occasional individual demonstrated positive serum antibasidiomycete precipitins by counterimmunoelectrophoresis. All basidiomycete species studied were highly immunogenic in the rabbit and most appeared to contain an electrophoretically heterogenous group of antigens with predominant anodal mobility. Ouchterlony double-diffusion analysis employing hyperimmune rabbit antisera indicated the presence of shared antigens among all basidiomycete species with the exception of Pleurotus. Rabbit antibasidiomycete sera did not cross-react with antigens of several common species of the Fungi imperfecti. Results indicate that many atopic asthmatics of the Gulf South area demonstrate IgE-medicated hypersensitivity to basidiomycete antigens as evidenced by positive wheal-and-flare skin reactivity and/or RAST. Basidiomycetes are also immunogenic in the rabbit and possess antigens that do not cross-react with those of certain Fungi imperfecti.     

Passive transfer of experimental hypersensitivity pneumonitis with lymphoid cells in the rabbit

Although precipitating antibody is associated with human hypersensitivity pneumonitis, there is evidence that cell-mediated hypersensitivity may be involved in disease pathogenesis. In this study, alveolar, interstitial, and peribronchial lesions were produced by respiratory challenge of rabbits passively sensitized with ovalbumin-sensitive lymph node cells. Ovalbumin sensitivity of donor rabbits and lymph node cells was demonstrated by skin testing, migration inhibition factor (MIF) production using alveolar wash cells as migrating cells, and lymphocyte stimulation. Passive cell transfer was accomplished by intraperitoneal injection with all lymph node cells obtained from one donor transferred to one recipient. Recipients were challenged by aerosol or intratracheal injection of antigen immediately or 24 hr after passive sensitization and were killed 48 hr after challenge. Lesions in rabbits passively sensitized by lymph node cells and challenged with antigen by intratracheal inoculation consisted of focal pneumonitis with intra-alveolar edema and infiltrates of mononuclear cells in alveoli and alveoli septa. Aerosol challenge of passively sensitised animals produced similar changes, but peribronchial lymphoid tissue containing macrophages and germinal centers was prominent in this group. Antiovalbumin serum recipients challenged by intratracheal injection demonstrated only mild peribronchial mononuclear cell infiltrates, without pneumonitis. Control animals receiving lymph node cells only or challenge only demonstrated no changes in lung histology.     

Experimental production of granulomatous pneumonitis: Comparison of immunological and morphological sequelae with particulate and soluble antigens administered via the respiratory route

Rabbits were sensitized with either a soluble protein antigen (BSA) or a particulate thermophilic actinomycete antigen (Micropolyspora faeni) via the respiratory route, followed by monitoring of sequential morphologic changes and the humoral plus cellular immunologic response. Primary respiratory tract sensitization with BSA resulted in a humoral anti-BSA response, Arthus and delayed skin reactivity, and in some cases specific antigen-induced alveolar macrophage migration inhibition, all in the absence of pulmonary lesions. Lesions characterized by mild multifocal perivascular mononuclear cell infiltrates in the lungs developed only after secondary BSA aerosol challenge. In contrast to these findings, “primary” respiratory tract sensitization with M. Faeni particulate antigen in saline solution resulted in the gradual development of extensive and progressive pulmonary interstitial and alveolar mononuclear cell infiltrates. These lesions were uniformly associated with specific serum precipitating antibody and delayed skin reactivity. Alveolar macrophage migration was significantly inhibited by Micropolyspora faeni in virtually of these animals. These results, while not excluding a primary irritant effect or Type II or III allergic tissue injury, suggest a role for delayed (cell-mediated) hypersensitivity in the pathogenesis of particulate actinomycete-induced pulmonary lesions. They also indicate that primary immunization with soluble purified protein antigens via the respiratory route can lead to systemic humoral and cell-mediated immunity without production of pulmonary lesions.     

Myoid hamartomas of the breast

Tumors containing smooth muscle are rare in the breast. A myoepithelial origin for the myoid component of such lesions was postulated in previous reports. Myoepithelial hyperplasia has long been recognized as a common component of some breast lesions, including sclerosing adenosis, papillomas, and fibroadenomas. Three breast tumors composed of variable admixtures of adipose tissue, fibrous tissue, and smooth muscle are described. The authors postulate that the myoid component of two of the three lesions may have arisen in a milieu of myoepithelial hyperplasia. The origin of the myoid component in the third case is not clearly defined.     

Occupational asthma caused by low molecular weight chemical agents.

The increasing mortality in acute asthma noted during the sixties has been ascribed to resistance of the beta₂ receptors of the bronchi due to treatment with beta-stimulating drugs. This study questions that theory. Eight patients with reversible airways obstruction were studied. Treatment with oral terbutaline 5 mg 3 times a day was given for 1 yr. Thereafter, terbutaline as metered aerosol was added in the dose of 2 puffs (0.5 mg) 4 times a day for 4 days and 6 puffs (1.5 mg) 4 times a day for further 4 days. The responsiveness of the receptors of bronchi, heart, skeletal muscles, and peripheral vessels was tested before and after 1, 2, 3, 6, 9, and 12 mo of treatment with oral terbutaline and after the two 4-day periods with inhaled terbutaline. The receptors were tested by infusion of increasing doses of isoprenaline, so that dose-response curves for isoprenaline were recorded. No signs of resistance of the beta₂ receptors of the bronchi developed during the terbutaline treatment period. Thus not even spray in moderate overdose caused resistance. Within 1 mo of treatment with oral terbutaline, resistance developed to the tremorogenic effect of terbutaline. Six of the 8 patients showed no signs of development of resistance to the chronotropic effect of isoprenaline. No signs were found of resistance of the beta₂ receptors of peripheral blood vessels.     

Salivary, nasal wash, and sputum IgA concentrations in atopic and nonatopic individuals

IgA and IgG levels were quantitated in parotid and nasal secretions of atopic and nonatopic children and young adults by single radial diffusion and electroimmunodifsion on the hypothesis that exocrine IgA deficiencies in atopic individuals might facilitate absorption of common “natural” inhalant allergens across respiratory tract mucosal tissues. Mean salivary and nasal wash IgA and nasal wash IgG levels were similar in both groups when expressed as per cent total protein or as IgA/ albumin ratios. Salivary IgA levels varied in individual subjects on repeated weekly, daily, or hourly analysis, but a relationship between IgA and albumin was noted in repeated samples from the same individual. Nasal wash IgA and IgG levels varied markedly among all subjects irrespective of atopic status, whether expressed in absolute values, per cent total protein, or per cent albumin. These findings suggest that a theoretical heightened mucosal absorption of inhalant allergens by atopic individuals cannot be accounted for on the basis of a local “protective” exocrine IgA deficiency per se.     

Effect of treadmill exercise on asthmatic children.

Measurement of peak expiratory flow rate before and after treadmill walking repeated at hourly intervals in asthmatic children disclosed progressive decreases in exercise-induced asthma. Treadmill running was followed by more extreme excercise-induced bronchospasm than treadmill walking. Exercise-induced asthma occurred in some children whose heart rates did not reach 160 during treadmill exercise, and heart rate during exercise was not correlated with the extent of exercise-induced bronchospasm.     

Involvement of band 3p14 in t(3;8) hereditary renal carcinoma

High resolution prometaphase G-banding analysis was applied to three translocation carriers from the t(3;8) hereditary renal cell carcinoma family. It was clearly illustrated that the chromosomal rearrangement is reciprocal with breakpoints occurring at the subbands 3p14.2 (instead of 3p21) and 8q24.1.     

Home humidifier thermophilic actinomycete isolates.

Twenty-seven thermophilic actinomycete isolates obtained from humidification systems or living-bedroom areas of individuals with suspected but unproved home environment-related respiratory disease were characterized morphologically and biochemically. All isolates were demonstrated to be members of the Thermoactinomyces genus. Two previously misidentified isolates were reclassified as a Thermoacetinomyces sp. Thus, all of our thermophilic actinomycete humidifier isolates studied to date have been identified as either Thermoactinomyces vulgaris or Thermoactinomyces sp. Large numbers of unidentified thermotolerant bacteria have also been isolated from virtually all residual humidifier water samples and their possible role in production of "humidifier-associated" respiratory disease is unknown.     

Evidence for histamine-mediated inhibition of monocyte chemotaxis in atopic dermatitis

Leukocyte chemotaxis was studied in 11 patients with severe childhood onset atopic dermatitis at a time when their disease was relatively quiescent. Pyoderma had been an important complication of the dermatitis in these patients. The chemotactic responsiveness of patient neutrophils and monocytes was on the average not significantly different from that of healthy control subjects, although three patients were identified who had significantly impaired responses. No correlation between IgE levels and leukocyte chemotaxis was observed. Because excessive amounts of histamine have been recovered from the skin of patients with atopic dermatitis, we evaluated the effects of histamine on the chemotactic responsiveness of leukocytes from these patients. Histamine caused a small dose-related increase in chemotaxis of neutrophils from both patients and control subjects (10^?7M to 10^?5M histamine). In contrast, histamine had no effect on the chemotaxis of monocytes from control subjects but inhibited the chemotactic responsiveness of monocytes from atopic dermatitis patients. These findings suggest that an abnormal sensitivity of monocytes to histamine is an intrinsic feature of atopic dermatitis that may be detectable when the disease is quiescent. Furthermore, this abnormality may contribute to the impairment of monocyte chemotaxis that has been previously observed in patients with active atopic dermatitis.     

Comparison of subcutaneous terbutaline with epinephrine in the treatment of asthma in children.

Comparison of the bronchodilator and cardiovascular effects of subcutaneous terbutaline and epinephrine in the treatment of acute asthmatic attacks in children disclosed that bronchodilation occurred with 5 min after subcutaneous injection of either drug (0.01 mg/kg, maximum 0.25 mg). Bronchodilation was maintained for 4 hr after administration of either drug. Small increases in pulse rate followed administration of terbutaline but not epinephrine. No clinically significant side effects were noted with either drug.     

The in vitro effect of toluene diisocyanate on lymphocyte cyclic adenosine monophosphate production by isoproterenol, prostaglandin, and histamine: a possible mode of action.

Toluene diisocyanate (TDI) significantly inhibits the rise in intracellular cyclic 3',5'-adenosine monophosphate (cAMP) that follows in vitro incubation of human lymphocytes with 6.7 x 10(-3) M isoproterenol and 1 x 10(-6) M prostagladin E1 (p less than 0.05). TDI has no significant effect on th production of lymphocyte cAMP following incubation with histamine (1 x 10(-3) M). The inhibitory action of TDI is greatest at a concentration of 3.3 x 10(-4) M and diminishes as the TDI concentration is increased or decreased. TDI also caused four- to fivefold stimulation of lymphocyte cAMP, an effect that is maximal at 1 x 10(-3) M, a concentration which has no significant inhibitory effect on stimulation of cAMP by isoproterenol or prostagladin E1. Conversely, 3.3 x 10(-4) M TDI, which inhibits cAMP production by isoproterenol and prostaglandin, has little stimulatory effect itself on cAMP production. This evidence suggests that TDI might induce obstructive airways disease through pharmacologic mechanisms and that TDI may be acting as a partial agonist.     

A comparison of the beta-blocking activities of practolol, sotalol, and propranolol in human and guinea pig tracheal smooth muscle

Beta adrenergic blockade was studied in vitro with hitman tracheal muscle strips and guinea pig tracheal chains. It was shown in isolated smooth muscle from both man and guinea pig that the order of potency for the three beta-blocking agents studied was: propranolol > sotalol > practolol. Under the conditions of this study, propranolol was about 30,000 times and sotalol about 30 times as potent as practolol. The order of potency suggests that the nature of adrenergic blockade induced by practolol on tracheal smooth muscle is only weakly beta₂-relative to the blocking effects of propranolol and sotalol. Beta adrenergic blockade by propranolol, sotalol, and practolol produced different degrees of increased histamine lethality in mice. Whereas both propranolol at 0.01 mg/kg and sotalol at 1.0 mg/kg resulted in 100% histamine-induced lethality, practolol at 50 mg/kg resulted in only 50% histamine-induced lethality. These data, when added to those from our previous studies, suggest that the mechanisms responsible for resistance to the effects of histamine in untreated mice are at least partially mediated by the beta₂-adrenergic system. Thus, in three different tissues, the blocking activity of practolol was shown to be less than that of sotalol or propranolol.     

Activation of the alternative complement pathway and generation of chemotactic factors by asbestos.

Five types of asbestos plus silica and glass wool fibers were tested for their ability to activate the alternative complement pathway and to generate chemotactic factor activity from fresh normal human serum (NHS). Two assays were used to detect alternative pathway activation by the fibers. The first method was a hemolytic assay that utilized glutathione-sensitized human erythrocytes (GSHE) to detect the C5b-C9 complexes generated by activation of fresh NHS with the various fibers. The second method was an immunoelectrophoretic assay to detect split products of activation of factor B after the fibers were incubated with NHS. Both assays were performed under conditions that have been shown to block the initial steps of classical pathway activation but permit activation of the alternative complement pathway. All five asbestos fibers tested, amosite, anthophyllite, crocidolite, and chrysotiles A and B activated the alternative pathway when tested by both methods. In addition, it was demonstrated that chemotactic factor activity was generated when asbestos fibers were incubated with fresh NHS. In contrast, silica and glass wool fibers did not activate the alternative complement pathway and did not generate chemotactic factor activity. These observations suggest that the complement system may mediate the initial inflammatory response observed upon exposure to certain types of asbestos fibers.     

Characterization of thermophilic actinomycetes isolated from residential heating and humidification systems

Seven thermophilic actinomycete isolates from heating-humidification systems of individuals with definite or suspected “environment-associated” hypersensitivity chest disease were characterized. Five of the isolates were Thermoactinomyces sp., 4 exhibiting characteristics identical to those of Thermoactinomyces vulgaris. One isolate was a Micromonospora sp. on the basis of biochemical cell wall composition, and another morphologically resembled Promicromonospora. Two additional thermophilic actinomycete isolates, Micropolyspora faeni, strain A-94, known to be an important source of “farmer's lung” antigen, and a newly described species, Thermoactinomyces sacchari, the most important source of “moldy bagasse” antigen, were also characterized. These 2 isolates were completely different from the home heater-humidifier isolates in gross and microscopic characteristics. Results of “metabolic” and “cellular” antigenic analyses, using specific hyperimmune rabbit antisera, revealed shared “cellular” and “metabolic” antigens among all home humidifier isolates, but not between these isolates and M faeni. Thus, the testing of human sera against any single heating-humidifier Thermoactinomyces sp. would likely detect the presence of precipitins against many closely related strains, but not against M. faeni.