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Biomedical subjects

J Hofman

Publications and source records attributed to J Hofman.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Effect of fenoterol, ipratropium bromide and their combination--Berodual--on pulmonary ventilation in patients with asthma].

The study aimed at evaluating FVC, FEV1, and FMF25-75% following and inhalation of fenoterol, ipratropium bromide and Berodual in 10 patients with the bronchial asthma. Berodual may be inhaled directly from the metered dose inhaler or with added tube spacer. Spirometry was performed after a single deep inspiration of each drug in the consecutive days, and after 5, 15, 30 and 60 minutes as well as 2, 3, 4, and 5 hours following the inhalation. The differences at each time point were compared with baseline values and expressed as percentage of the increase. The obtained results were analysed statistically. It was shown that bronchodilatory action of Berodual, being both beta 2-agonist and anticholinergic agent, is the most pronounced. The highest values of the measured spirometric parameters followed Berodual inhalation with the aid of tube spacer but the differences compared with Berodual applied with the metered dose inhaler were not statistically significant.

Administration, Inhalation↗
PubMed1989

[Effect of cimetidine and ranitidine on bronchial reactivity in patients with asthma].

The results of studies on the effect of cimetidine and ranitidine on the bronchial reactivity in a group of 10 patients with atopic bronchial asthma are discussed. The patients received 800 mg of cimetidine daily for 6 days and, after a three-day interval, 300 mg of ranitidine daily for a further 6 days. Bronchial reactivity was determined with the histamine test, according to Spector and Farr, before the administration of each drug and on the third and sixth days of each course of the treatment. A comparison of the effect of cimetidine and ranitidine on the bronchial reactivity in the same patients revealed that a 3-day exposure to each of the two drugs, cimetidine enhanced bronchial reactivity to a greater extent than ranitidine; the difference between the action of the two drugs being statistically significant (p less than 0.05). Bronchial reactivity was found to increase significantly after a 6-day treatment with each of the drugs but no statistically significant differences were noted comparing the effect of these drugs.

Asthma↗
PubMed1989

Comparison of the effects of cimetidine and ranitidine in histamine provocation tests in atopic asthma.

The effects of cimetidine and ranitidine on the bronchial reactivity in the group of 10 patients with atopic bronchial asthma are presented. The patients received 800 mg of cimetidine daily for 6 days and, after a three-day interval, 300 mg of ranitidine daily for a further 6 days. Bronchial reactivity to histamine was determined before the administration of each drug and on the third and sixth days of each course of treatment. A comparison of the effect of cimetidine and ranitidine on the bronchial reactivity of the same patients revealed that after 3 days' exposure to each of the two drugs, cimetidine enhanced bronchial reactivity to a statistically (p less than 0.05) greater extent than ranitidine. Bronchial reactivity was found to increase significantly after 6 days of treatment with each of the drugs but no statistically significant differences were noted on comparing the effect of these drugs. The results seem to indicate that H2 receptor antagonists may cause bronchoconstriction in some patients with bronchial asthma. The blocking effect depends on the type of the drug used and is connected with the chemical structure of the compounds.

Asthma↗
PubMed1989

The influence of the calcium channel antagonist verapamil on histamine release from target cells.

The aim of the study was to investigate the influence of verapamil on anti-IgE induced histamine release from basophils isolated from the blood of 10 atopic asthma patients. The results of the investigations showed that verapamil in concentration of 10(-2)M - 10(-6)M significantly inhibits histamine release from basophils of asthmatic patients. The degree of inhibition of histamine secretion depends on the concentration of the drug. Our studies suggest that verapamil may be useful in combination with more conventional drugs in the treatment of asthmatic patients, particularly those with ischemic heart diseases or hypertonia.

Asthma↗
PubMed1988

The role of H2-receptors in bronchial reactivity in atopic asthma.

The aim of the present study was to evaluate lung function and bronchial reactivity during therapy with the H2-blockers, cimetidine and ranitidine, in order to determine the role of H2-receptors in the bronchial response of asthmatic patients. Bronchial reactivity was evaluated by the histamine provocation test before, and 3 or 6 days after administration of cimetidine (800 mg per day) or ranitidine (300 mg per day). It was shown that after 6 days treatment, an increase in bronchial reactivity occurred in 85% of the patients treated with cimetidine and in 64% of the patients treated with ranitidine. These results seem to confirm the presence of H2 receptors in the bronchial tree of asthmatic patients. Blockade of these receptors causes an increase in bronchial reactivity and potential exacerbation of the asthmatic symptoms.

Asthma↗
PubMed1987

The influence of cimetidine and ranitidine on basophil histamine release and bronchial reactivity in asthmatic patients.

Anti-IgE induced histamine release from isolated basophils after Cimetidine and Ranitidine administration was evaluated in 22 patients with atopic bronchial asthma. The histamine provocation test after Ranitidine treatment in 10 patients with atopic bronchial asthma and 10 patients with peptic ulcer was also performed. Investigations in vitro revealed that Cimetidine and Ranitidine in low concentrations had an inhibitory effect whereas in concentrations of over 10(-6) M and 10(-4) M, respectively, they enhanced histamine release. Investigations in vivo after administration of Ranitidine showed that it does not cause marked changes in the bronchial reactivity in patients with bronchial asthma and any change in patients with peptic ulcer. These preliminary studies seem to suggest that in patients with atopic bronchial asthma and concomitant peptic ulcer Ranitidine is preferable to Cimetidine in the treatment of digestive tract disorders.

Antibodies, Anti-Idiotypic↗
PubMed1987

Changes in the arrangement of the microtubule system of murine peritoneal cells after an antigenic stimulation.

We determined two characteristic morphological patterns typical for the organization of microtubule systems of murine peritoneal macrophages and lymphocytes. A small number of both cell types formed uropods with an axial bundle of microtubules. This number remains practically unchanged during 48 h of cultivation in non-antigenic environment but grows rapidly in the presence of an antigen.

Animals↗
PubMed1987

Escape from dexamethasone-induced ACTH and cortisol suppression by corticotrophin-releasing hormone: modulatory effect of basal dexamethasone levels.

The response of ACTH and cortisol to corticotrophin-releasing hormone (CRH) after pretreatment with various doses of dexamethasone was investigated in five healthy subjects. The five subjects participated in six experiments. In each experiment 200 micrograms ovine CRH was administered as an i.v. bolus injection at 0900 h after pretreatment with respectively: (A) 1 mg dexamethasone orally at 2300 h in the evening before CRH injection, (B) 2 mg dexamethasone orally at 2300 h in the evening before CRH injection, (C) 4 mg dexamethasone orally at 2300 h in the evening before CRH injection, (D) 2 mg dexamethasone orally at 2300 h in the evening before CRH injection, followed by 2 mg dexamethasone orally 1 h before CRH, (E) no dexamethasone and (F) 1 mg dexamethasone orally 1 h before CRH injection. In spite of overnight suppression with a single dose of dexamethasone CRH elicited cortisol rises in all individuals (experiments A-C). Dexamethasone pretreatment in experiment D abolished the CRH-induced stimulation of the pituitary-adrenal axis. There was a significant and negative correlation between the basal dexamethasone levels (i.e. the dexamethasone levels immediately before CRH administration) in the experiments A-D and the areas under the individual ACTH (R = -0.62; P less than 0.01 by Spearman's rank correlation test) and cortisol (R = -0.81; P less than 0.001 by Spearman's test) curves, i.e. the lower the basal dexamethasone levels, the greater the rise in ACTH and cortisol levels after CRH administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1986

Immunologic histamine release from isolated human basophils during specific immunotherapy.

Anti-IgE- and antigen-induced histamine release from basophils isolated from 20 atopic patients sensitive to grass pollen allergens was evaluated. The studies were made before and after short-term immunotherapy with Pollinex. It was shown, that after hyposensitization a significant decrease on anti-IgE and specific antigen-induced histamine release from basophils occurs.

Allergens↗
PubMed1986

Bronchial hyper-reactivity in atopic patients during H2-receptor blocker treatment.

Bronchial reactivity after Cimetidine treatment was evaluated by the histamine provocation test in 24 patients with atopic bronchial asthma and 10 patients with peptic ulcer. Anti-IgE induced histamine release from isolated basophils was also investigated. After blockade of H2 receptors, an increase of bronchial reactivity and an exacerbation of clinical symptoms were observed in 4 asthmatic patients [17%]. A moderate increase in bronchial reactivity without exacerbation of asthma symptoms was observed in 16 other patients [66%]. In some of the patients treated with Cimetidine an enhancement of IgE-induced histamine release from isolated basophils was observed.

Asthma↗
PubMed1985

Phenol-water extracts of gram-positive Listeria monocytogenes and gram-negative Salmonella typhimurium. Comparison of biological activities.

Using phenol--water extraction, a lipopeptidopolysaccharide complex (LPPS) was isolated from Listeria monocytogenes. Some biological and immunological properties of LPPS were compared with lipopolysaccharide isolated by the same procedure from Salmonella typhimurium. LPPS possesses low pyrogenicity, but the immunological activity is comparable with LPS: slightly lower adjuvant and polyclonal stimulating effect, almost equal mitogenic effect on mouse spleen cells and higher mitogenic effect on human peripheral blood cells. The results are discussed in connection with the chemical structure of both substances.

Adjuvants, Immunologic↗
PubMed1985

The effect of short-term immunotherapy with Pollinex on anti-IgE and antigen-induced histamine release from sensitive human basophils.

Anti-IgE and antigen-induced histamine release from basophils isolated from 30 atopic patients sensitive to grass pollen allergens was evaluated. The studies were made before and after short-term immunotherapy with glutaraldehyde-pollen-tyrosine adsorbate (Pollinex). It was shown, that after immunotherapy a significant drop in anti-IgE and specific antigen-induced histamine release from isolated basophils occurs. The investigations confirm that the diminution of the target cell sensitivity and releasability may be one of the effects of specific immunotherapy.

Aldehydes↗
PubMed1984

The effect of H1 and H2 receptor blockers on immunological and nonspecific histamine release from isolated target cells.

The investigations were carried out on isolated peritoneal rat mast cells and human basophils. Cell histamine release was induced by a specific antigen, anti-IgE and by compound 48/80. Mepyramine and Diphenhydramine were used as H1 receptor blockers and Cimetidine as H2 receptor blocker. It was shown that effect of H1 and H2 receptor blockers on histamine release depends on concentration of drugs used in experiments, on the presence of exogenous histamine in the medium, on the kind of histamine liberators and also on the type of investigated target cells. The results obtained seem to indicate the presence of H2 receptors not only on basophils but also on mast cells.

Animals↗
PubMed1982

The effect of hydrocortisone and intal on histamine release from isolated target cells.

The effect of hydrocortisone on cell degranulation and histamine release in the presence of specific and non-specific liberators as compared with that of intal was investigated. Experiments were carried out on isolated rat most cells and human basophils. It was found that the stabilizing effect of drugs investigated depends on their concentration, the kind and concentration of histamine liberators and type of the target cells used in experiments.

Animals↗
PubMed1982

Histamine level in the blood and in the lung tissue during anaphylactic reaction in guinea-pigs treated with hydrocortisone and sodium cromoglycate.

The effect of hydrocortisone and disodium cromoglycate (Intal) on histamine release during immediate allergic reaction in experimental animals was studied. Histamine level in the blood and lung tissue was determined before antigen challenge during experimental asthma and after administration of hydrocortisone or Intal. The investigations revealed some differences in the histamine content in the blood and lung tissue depending on the time of the drug administration in relation to the antigen challenge and to the period of treatment.

Anaphylaxis↗