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Biomedical subjects

B Kang

Publications and source records attributed to B Kang.

61 records · Page 4Linked to original sources

Cockroach cause of allergic asthma. Its specificity and immunologic profile.

To assess the etiologic role of cockroach antigen in bronchial asthma, 46 asthmatic subjects were studied using in vitro assays for total and cockroach-specific IgE antibodies (IgEcr) and the responsiveness of the skin and bronchial tree to the antigen challenge in vivo. Asthmatic subjects were divided into skin test-positive (PCR) and skin test-negative (NCR) groups according to immediate skin response to cockroach antigen. The 28 in the PCR group showed high total IgE (1,901 ng/ml) and a high cockroach-specific IgE antibody level (329%) in the serum compared to the 10 in the NCR group (IgE: 915 ng/ml, IgEcr:84%) (p less than 0.001). Bronchial challenge with the antigen revealed immediate asthmatic reaction (30/33) and late asthmatic reaction (16/33) in the PCR asthmatics, whereas the NCR asthmatics showed neither immediate asthmatic reaction (2/13 showed questionable decrease in FEV1) nor late asthmatic reaction (p less than 0.001). A marked increase in peripheral eosinophils (758% vs 121%) was noted following antigen inhalation in the skin test-positive asthmatics (p less than 0.025). The results indicate that cockroach antigen causes antigen-specific IgE-mediated bronchial asthma and peripheral eosinophilia in specifically sensitized asthmatic subjects.

Adult↗

A comparative study of prevalence of skin hypersensitivity to cockroach and house dust antigens.

Allergy skin tests with cockroach antigen along with various common inhalant allergens were performed on 222 atopic and on 63 non-atopic subjects. The most prevalent allergen producing a positive skin test was house dust antigen with a positive response of 72%, 78% and 57% in atopic adults, atopic children and non-atopic children, respectively. The next prevalent positive skin test was to cockroach antigen with 50%, 60% and 27%, respectively, of the three groups tested. The differences between positive cockroach hypersensitivity and house dust hypersensitivity in all three groups tested were statistically significant. Next in order of prevalence of positive skin test to common inhalants were western weeds, ragweeds and cats. Incidence of cockroach hypersensitivity was 58% among asthmatic adults and 69% among asthmatic children. The results indicate that cockroach hypersensitivity is highly prevalent and that cockroach antigen is an independent agent from house dust as a cause of immediate hypersensitivity reaction.

Adolescent↗

Cromolyn therapy in patients with bronchial asthma. Effect on inhalation challenge with allergen, histamine, and methacholine.

The action mechanism of cromolyn sodium and its effect on bronchial sensitivity to allergen, methacholine chloride, and histamine inhalations were studied in 17 asthmatic subjects. Cromolyn capsules or placebo was administered by an inhaler (Spinhaler) randomly on alternate days 30 minutes before aerosol challenge. Cromolyn and placebo did not differ in their effect on bronchial response to histamine or methacholine. However, the degree of decrease in forced vital capacity and forced expiratory volume in one second after allergen challenge was significantly reduced by cromolyn in 15 of 17 subjects. Immediate and delayed reactions of itching, tightness, or wheezing developed in 14 subjects after allergen challenges following placebo intake and were prevented or substantially inhibited by cromolyn.

Adolescent↗

Bronchial reactivity to histamine before and after sodium cromoglycate in bronchial asthma.

Out of 19 patients with extrinsic bronchial asthma challenged with 123 mug histamine acid phosphate by intravenous infusion only 13 responded with a fall in FEV1 of over 10% (mean 16%). Seventeen of these patients were given histamine 2 mg/ml by aerosol, and all responded with a mean decrease in FEV1 of 37.8%. When challenged with allergen extract by aerosol the mean decrease in FEV1 was 37.5%. After 40 mg sodium cromoglycate 15 of the 17 patients showed significant protection against allergen challenge with a mean decrease in FEV1 of only 23.6%. Inhalation of 40 mg sodium cromoglycate, however, failed to protect against histamine given by either the intravenous or aerosol route. Histamine given intravenously to asthmatic patients produces less of a bronchial response than when given by aerosol, even though the intravenous route produces many more systemic symptoms, such as flushing and throbbing headache. The protection of sodium cromoglycate against an allergen inhalation challenge is not due to histamine antagonsim.

Adolescent↗

Study on cockroach antigen as a probable causative agent in bronchial asthma.

Bronchial provocative test (BPT) with cockroach (CR) antigen was performed in 22 asthmatic subjects. Sixteen had positive reaction (CR-positive) and 6 had negative reaction (CR-negative) to CR antigen by skin test. Immediate bronchoconstrictive response was noted following the antigen inhalation in 14 of 16 CR-positive asthmatics, while none of 6 CR-negative asthmatics showed bronchospasm. Late asthmatic responses also were noted in 13 of 16 CR-positive asthmatic individuals following BPT with CR antigen. The dual asthmatic reactions in CR-positive individuals were mostly inhibited by the prior administration of cromolyn sodium. Three-fold increases in peripheral eosinophil counts were noted 24 hr following BPT with CR antigen. Results indicate that CR-induced asthmatic responses are allergen-specific and CR plays a causative role in allergic asthma in the population studied.

Adolescent↗

Bronchial sensitivity to methacholine in current and former asthmatic and allergic rhinitis patients and control subjects.

Ninety-eight subjects underwent methacholine (Mecholyl) aerosol challenge at a concentration of 5 mg/ml. All atopic groups differed significantly in their bronchial response to Mecholyl compared to nonatopic control subjects. Nineteen normal subjects had a mean decrease of 11.4% in forced expiratory volume in one second (FEV1) with 128 Mecholyl inhalations and 2 decreased by greater than 20%. Fifteen of 27 allergic rhinitis patients had a positive response to Mecholyl as defined by a decrease in FEV1 greater than 20%. Four of these responders developed greater diminution in FEV1 response with additional Mecholyl inhalations in a manner similar to that seen in the asthmatic patients. Eighteen current asthmatics showed the greatest bronchial sensitivity to Mecholyl with a mean 33% decrease in FEV1 at 4.5 inhalations. One hundred per cent of current asthmatics and 82% (28 of 34) of former asthmatics (free of asthma symptoms for 1 to 20 yr) showed positive response to Mecholyl. A 20% decrease in FEV1 with a total of 20 inhalations or less is consistent with a diagnosis of "current asthma," and even 20 of 34 former asthmatics responded in this manner. The Mecholyl aerosol test can be used to diagnose previous and current asthma and may be of value in predicting asthma in hay fever patients.

Asthma↗

Abolition of anaphylactic shock by Solanum lyratum Thunb.

We investigated the effects of the aqueous extract of Solanum lyratum THUNB. (Solanaceae) (SLAE) on the anaphylactic reactions. SLAE inhibited compound 48/80-induced anaphylactic shock 100% with a dose of 1.0 mg/g body weight (BW). When SLAE was pretreated at concentration ranging from 0.0001-1.0 mg/g BW, the serum histamine levels were reduced in a dose-dependent manner. Passive cutaneous anaphylaxis also inhibited to 69.3% by oral administration of SLAE (0.05 mg/g BW). Moreover, SLAE dose-dependently inhibited the histamine release from the rat peritoneal mast cells (RPMC) by compound 48/80. The level of cAMP in RPMC, when SLAE was added, significantly increased compared with that of normal control. These results indicate that SLAE possess strong antianaphylactic activity.

Anaphylaxis↗