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Biomedical subjects

J Rozniecki

Publications and source records attributed to J Rozniecki.

At least 73 records · Page 4Linked to original sources
PubMed1987

Fibrinolysis, blood coagulation, and platelet function during aspirin-induced bronchoconstriction in aspirin-intolerant asthmatics.

Nineteen asthmatic patients, 11 with and eight without aspirin (ASA) intolerance were studied in order to test possible platelet and coagulation system involvement in the pathogenesis of aspirin-induced bronchoconstriction (AIB). Aspirin-intolerant asthmatics were challenged with a previously established ASA threshold dose and, in nine of them, a positive asthmatic reaction occurred (mean fall in FEV1 39.4%). Seven out of nine patients with a positive reaction had a significant decrease in euglobulin lysis time (P less than .01) during AIB. A positive reaction after ASA was accompanied by an increase in the plasma recalcification time in five of these patients. There were no concomitant statistically significant changes in the platelet count, circulating platelet aggregates, and platelet factor 4 activity. In a control group of ASA-tolerant asthmatics, aspirin at a 200-mg dose did not evoke any respiratory reaction and, during two hours after ASA, no significant variation was found in any of the laboratory parameters studied. We conclude that activation of fibrinolysis accompanying AIB results from intrinsic pharmacologic properties of aspirin, and may contribute to the pathogenesis of aspirin intolerance through a more generalized activation of plasma proteolytic activity.

Adult↗
PubMed1986

Studies on lymphokine-mediated demyelination in organotypic rat cerebellum in culture.

Supernatants of peripheral blood lymphocytes (PBL), containing lymphokines, isolated from MS patients and healthy subjects were tested for demyelinating activity in organotypic culture of the rat cerebellum. PBL were isolated on Ficoll-paque gradient and cultures in RPMI 1640 medium for 72 h with or without phytohemagglutinin and Concanavalin A. Both stimulated and unstimulated PBL supernatants from MS patients consistently demyelinated cerebellum cultures. The supernatants of unstimulated PBL from healthy subjects did not produce demyelination, however, slight effect was present in the cultures treated with PBL stimulated supernatants. The results indicate that lymphokines might be involved in demyelination in MS.

Adult↗
PubMed1986

Bacterial antigens stimulate the production of histamine releasing factor (HRF) by lymphocytes from intrinsic asthmatic patients.

Lymphocyte from 12 intrinsic asthmatic patients and 10 healthy controls were studied for their capability to produce histamine releasing factor (HRF) in vitro. Spontaneous HRF production was measured by culturing the lymphocytes alone for 20 h. In another set of experiments lymphocytes were first preincubated separately with phytohaemagglutinin, antigens of Haemophilus influenzae, Streptococcus viridans, Staphylococcus sp. and Neisseria catarrhalis for 4 h then carefully washed three times and cultured alone for an additional 16 h. Cell-free supernatant was assayed for histamine releasing activity using basophils from healthy donors. It was observed that lymphocytes from intrinsic asthmatic patients spontaneously produced HRF. The production of this lymphokine was enhanced following preincubation of lymphocytes with phytohaemagglutinin or bacterial antigens. Results of skin test with bacterial antigens did not correlate with the magnitude of the production of HRF by lymphocytes. At gel chromatography over Sephadex G-75 bacterial antigen-stimulated lymphocyte supernatant revealed two peaks of HRF activity in the molecular weight ranges 35,000-50,000 and 3,000-7,000.

Adult↗
PubMed1986

Clinical efficacy of aspirin in "desensitised" aspirin-sensitive asthmatics.

The effect of daily aspirin (ASA) administration after "desensitisation" was studied in 16 aspirin-sensitive asthmatics. Fourteen patients completed the trial; 12 of them also had perennial rhinitis and eight in addition suffered from chronic headache. During 4 weeks of daily treatment with 600 mg of ASA a marked reduction of the nasal symptoms score was noticed in 8/12 patients and head pain score was significantly decreased in 6/8 patients when compared with the 4-week non-ASA period. Daily aspirin resulted in decreases in both the mean asthma score and in daily beta-agonist usage in 7/14 patients, and 10/13 patients showed a decrease in bronchial responsiveness to inhaled histamine (geometric mean of provocative concentration of histamine 1.8 and 5.8 mg/ml, respectively. In four patients we noticed untoward epigastric symptoms. A decrease in thrombocyte counts was observed during ASA treatment. Our study suggests that daily aspirin administration after "desensitisation" may be helpful in the management of some ASA-sensitive asthmatics.

Adult↗
PubMed1985

A mononuclear cell-derived histamine releasing factor in asthmatic patients. II. Activity in vivo.

In an attempt to study the role of lymphokines in asthma, lymphocytes from asthmatic patients were stimulated in vitro with skin test-positive allergen (dust mite) or with non-specific mitogen-phytohaemagglutinin for 4 h, then washed carefully and cultured alone for 16 h. Cell-free supernatants were subsequently collected and applied in the basophil histamine release test in vitro and in bronchial provocation test and skin prick test in vivo. Supernatant of non-stimulated lymphocytes from asthmatic patients released significant amounts of histamine from basophils. Stimulation of lymphocytes with specific allergen or phytohaemagglutinin augmented the supernatant-induced histamine release. Lymphocyte supernatants from the majority of patients also induced bronchoconstriction and elicited skin wheal and flare reaction in vivo.

Asthma↗
PubMed1985

The effect of aspirin during aspirin "desensitisation" on compound 48/80 and histamine-induced skin responses in aspirin-sensitive asthmatics.

In a group of aspirin-sensitive asthmatics we studied skin weal and flare responses to intradermal injections of compound 48/80 and histamine during oral aspirin (ASA) provocation and after ASA "desensitisation". During provocation (bronchospasm accompanied by naso-ocular symptoms) the mean weal area after compound 48/80 increased to about 42.4% (P less than 0.05). Neither the threshold (provocative) doses of ASA nor 600 mg ASA, when given after ASA-desensitisation, significantly influenced the weal reactions to compound 48/80 (mean changes of area were -1.8% and -16.5% respectively). Aspirin did not change flare reactions to compound 48/80 and weal and flare reactions to histamine on any of the three study occasions. Initial (pre-aspirin) weal reactions to compound 48/80 after desensitisation to the threshold ASA doses were significantly reduced, but after desensitisation to 600 mg ASA were significantly increased as compared with the reactions before. These data suggest that ASA-"desensitisation" may influence the skin reactivity to non-specific mast cell degranulating stimulus in ASA-sensitive asthmatics.

Adult↗
PubMed1985

Bronchial and basophil reaction to polymyxin B in asthmatic patients.

The hypothesis that increased reactivity to polymyxin B in asthmatic patients is not limited to the bronchi but also exists in basophils was investigated in 26 atopic asthmatic subjects. Quantification of basophil degranulation induced by polymyxin B was performed using a flow-cytometric method. Significant degranulation was noted in 17 patients, but in none of 10 healthy controls. There was close relationship between basophil "releasability" to polymyxin B and bronchial reactivity to inhaled polymyxin B. These findings support the hypothesis.

Airway Obstruction↗