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J Kreukniet

Publications and source records attributed to J Kreukniet.

At least 19 recordsLinked to original sources
PubMed1991

Modulation and induction of eosinophil chemotaxis by granulocyte-macrophage colony-stimulating factor and interleukin-3.

Eosinophilia and eosinophil function are regulated by cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5. We have investigated the modulatory role of GM-CSF and IL-3 on the platelet-activating factor (PAF)-, neutrophil-activating factor (NAF/IL-8)-, leukotriene B4 (LTB4)-, N-formyl-methionyl-leucyl-phenylalanine (FMLP)-, and human complement factor C5a-induced chemotaxis of eosinophils from normal individuals. These eosinophils show a chemotactic response toward PAF, LTB4, and C5a, but not to NAF/IL-8 and FMLP. Preincubation of the eosinophils with picomolar concentrations of GM-CSF caused a significant increase in the response toward LTB4 and induced a significant chemotactic response toward NAF/IL-8 and FMLP. Preincubation of the eosinophils with picomolar concentrations of IL-3 also induced a chemotactic response toward NAF/IL-8 and FMLP, and enhanced the PAF-induced chemotaxis response toward C5a was not influenced by both cytokines. Nanomolar concentrations of GM-CSF or IL-3 caused a significant inhibition of the C5a-induced chemotaxis. The LTB4-induced chemotaxis was also significantly inhibited in case of GM-CSF. At these concentrations both GM-CSF and IL-3 acted as chemotaxins for eosinophils were washed after pretreatment with GM-CSF and IL-3 the potentiation of the chemotactic response remained, whereas the inhibitory mode of action disappeared. Our data indicate that at picomolar concentrations the cytokines GM-CSF and IL-3 can modulate eosinophil chemotaxis and at nanomolar concentrations these cytokines can act as chemotaxins for eosinophils.

Chemotaxis, Leukocyte↗
PubMed1990

Inhibition of neutrophil and eosinophil induced chemotaxis by nedocromil sodium and sodium cromoglycate.

1. Neutrophils and eosinophils infiltrate the airways in association with the allergen-induced late phase asthmatic reaction. Mobilization of these cells takes place via lipid-like and protein-like chemotactic factors. In this study platelet-activating factor (PAF), leukotriene B4 (LTB4), zymosan-activated serum (ZAS) and N-formyl-methionyl-leucyl-phenylalanine (FMLP) were used as illustrative examples of both groups. Chemotaxis was studied in human neutrophils and eosinophils. The inhibitory effects of nedocromil sodium and sodium cromoglycate were evaluated. 2. All chemotactic factors tested attracted neutrophils with the following rank order of activity: ZAS greater than PAF identical to FMLP identical to LTB4. Eosinophils were only mobilized by PAF, LTB4 and ZAS with the following rank order of activity: ZAS greater than PAF greater than LTB4. 3. Nedocromil sodium and sodium cromoglycate were equally active as the PAF antagonist BN 52021 in inhibiting the PAF-induced chemotaxis of neutrophils (IC50 approximately 10(-8) M). Both drugs were also equally active in inhibiting the chemotaxis of neutrophils induced by ZAS (IC50 approximately 10(-7)-10(-6) M), FMLP (IC50 approximately 10(-7) M) and LTB4 (IC50 approximately 10(-6) M). 4. Nedocromil sodium significantly inhibited the chemotaxis of eosinophils induced by PAF (IC50 approximately 10(-6) M) and LTB4 (IC50 approximately 10(-7) M). The inhibitory potency of BN 52021 was similar to that of nedocromil sodium on the PAF-induced chemotaxis of eosinophils. Sodium cromoglycate was incapable of eliciting significant inhibition of these chemotactic responses. However, sodium cromoglycate significantly inhibited the chemotaxis of eosinophils induced by ZAS (IC50 approximately 10(-7) M), whereas nedocromil sodium was ineffective.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1989

[The probability of survival of patients with bronchial carcinoma].

A study was made of the effect of the discontinuation of population screening for tuberculosis, on January 1, 1982, on the referral pattern and therapeutic results in patients with bronchial carcinoma. In 1981 only a few patients were referred because of lesions detected at the screening. Accordingly, discontinuing the screening had no demonstrable effect. Also, there was no difference between patients referred because of a fortuitous finding and those who consulted because of symptoms. Nevertheless the results, especially the 5-year survival rates, were far better for those whose tumours had favourable TNM classifications. This applied in particular if resection of parts of the lung was feasible and operation revealed no metastases in mediastinal lymph nodes and no infiltrating growth. For this group of patients the 5-year survival rate amounted to 59.4%. With only symptomatic treatment the rate was 16.7% and for patients with small-cell anaplastic carcinomas given chemotherapy, it was 5.6%.

Adult↗
PubMed1989

Nedocromil sodium inhibits the A23187- and opsonized zymosan-induced leukotriene formation by human eosinophils but not by human neutrophils.

1. Inflammatory cells such as eosinophils and neutrophils are thought to contribute actively to the pathogenesis of asthma by the release of bronchoconstrictor mediators including leukotrienes. Previous studies have revealed the almost exclusive synthesis of leukotriene C4 (LTC4) by human eosinophils and of leukotriene B4 (LTB4), 20-OH-LTB4 and the non-enzymatically formed LTB4-isomers by neutrophils when stimulated in vitro with the calcium ionophore A23187 or opsonized zymosan (OZ). In this study we have investigated whether nedocromil sodium, a new anti-asthma drug, was capable of inhibiting A23187- and OZ-induced leukotriene formation by these cells. 2. Nedocromil sodium inhibited A23187- and OZ-induced LTC4 formation by eosinophils in a concentration-dependent manner (mean IC30 for A23187: 5.6 X 10(-5) M; mean IC30 for OZ: 6.3 X 10(-5) M), whereas it did not inhibit A23187- and OZ-induced LTB4 formation by neutrophils. 3. Extension of the preincubation time of the cells with the drug did not alter the observed inhibitory capacity. The optimal preincubation time was 5 min. 4. The in vitro inhibition of LTC4 formation by eosinophils by nedocromil sodium may be a valuable property of this drug in the treatment of asthma.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1989

Inhibitory effects of nedocromil sodium on the in vitro induced migration and leukotriene formation of human granulocytes.

Inflammatory cells, such as neutrophils and eosinophils, are thought to actively contribute to the pathogenesis of asthma since they infiltrate into the lung tissue and may be activated locally to release bronchoconstrictor mediators. In this study we provide evidence that nedocromil sodium is capable of effectively inhibiting the platelet-activating factor (PAF) and zymosan-activated serum (ZAS)-induced chemotaxis of polymorphonuclear granulocytes (PMN) [IC50 approximately 1 nmol/L and 0.1 mumol/L respectively]. The same inhibitory potency was obtained with sodium cromoglycate. Thus, nedocromil sodium may effectively inhibit the mobilisation of inflammatory cells in the lung. Furthermore, nedocromil sodium is capable of inhibiting the formation of the bronchoconstrictor mediator leukotriene-C4 (LTC4) by eosinophils in a concentration-dependent way [IC30 for A23187: 5.6 10(-5) mol/L; IC30 for opsonised zymosan (OZ): 6.3 10(-5) mol/L], whereas this drug is not capable of inhibiting leukotriene-B4 (LTB4) formation by neutrophils. These findings indicate that nedocromil sodium inhibits the release of bronchoconstrictor mediators not only from mast cells but also from eosinophils.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1989

Patients with chronic bronchitis differ in their mast cell subtypes as compared with normal subjects.

Mast cells were isolated by enzymatic digestion from lung tissue obtained from patients with chronic obstructive lung disease and from normal subjects. Two mast cell subtypes could be demonstrated in human lung tissue. Mast cell subtypes were differentiated in formalin-sensitive and formalin-insensitive mast cells. It appeared that compared with normal individuals, patients suffering from chronic bronchitis had increased numbers of mast cells of the formalin-sensitive type, whereas patients with emphysema had reduced numbers, but the same ratio, of both mast cell subtypes.

Aged↗
PubMed1988

Mast cell subtypes from human lung tissue: their identification, separation, and functional characteristics.

The contribution of mast cell subtypes and their different mediators to the pathogenesis of chronic obstructive lung diseases (COLD) has not yet been established. In the present study, enzymatic digestion, centrifugal elutriation and Percoll gradient centrifugation were used to obtain two populations of mast cell subtypes from human lung tissue. Mast cell subtypes were challenged with anti-human IgE, propranolol, compound 48/80, or opsonized zymosan. Both subtypes were able to release histamine, but differed in the amount of the amine release. Only the formalin-sensitive and alcian blue-positive type (FS-AB) released histamine on challenge with opsonized zymosan. The same subtype was able to release leukotriene C4 (LTC4) after challenge with anti-human IgE. The other subtype, the formalin-insensitive and alcian blue-positive type (FI-AB), did not respond to opsonized zymosan and did not release LTC4 after challenge with anti-human IgE. Stimulation with propranolol or compound 48/80 did not release histamine from the FS-AB mast cells while the FI-AB mast cells released only about 10% of their histamine content upon challenge with these secretagogues.

Histamine Release↗
PubMed1988

The isolation of human lung mast cells by affinity chromatography.

A method of isolation has been developed to purify mast cells from human lung tissue. The purification steps are: (1) dispersion of human lung tissue in single-cell suspensions by enzymatic digestion, (2) partial purification by counterflow centrifugal elutriation, (3) Percoll gradient centrifugation, and (4) enrichment of the mast cells by affinity chromatography using anti-human IgE-Sepharose. Enzymatic dispersion yielded 0.6 +/- 0.2 x 10(6) mast cells per gram wet tissue with purities of 3.3 +/- 1.0% (mean +/- SEM n = 3). Elutriation and gradient centrifugation yielded 0.36 +/- 0.05 x 10(6) mast cells per gram lung tissue in fractions with purities of 30.8 +/- 10.7%. Enriched mast cell fractions were combined, and disposed of contaminating cells by affinity chromatography, thereby yielding 0.25 +/- 0.03 x 10(6) mast cells per gram lung tissue, and improving the purity to 75.3 +/- 8.3%. The purified mast cells were intact and vitality exceeded 95%. In this way from 1 g wet lung tissue 0.25 +/- 0.03 x 10(6) mast cells may be isolated with a mean recovery of 41.7 +/- 2.4% and a mean purity of 75.3 +/- 8.3%.

Cell Separation↗
PubMed1987

Combination therapy of theophylline and terbutaline as sustained-release preparations in patients with asthmatic bronchitis.

In a group of ten patients with chronic asthmatic bronchitis, the effect of monotherapy with theophylline and terbutaline and the combination of both drugs, as sustained-release tablets, was compared to placebo, in a double-blind cross-over, triple dummy at random study. Lung function parameters, tremor measurements, c-AMP plasma levels, theophylline- and terbutaline-plasma levels were determinated. Monotherapy with theophylline and terbutaline in a relatively low dosage achieved a good lung function improvement without severe side effects, as compared to placebo. The combination of both drugs in the same dosage achieved a statistically significant enhancement of the lung function improvement, as compared to monotherapy, without an increase of side effects. An additional effect of theophylline and terbutaline on bronchodilation is demonstrated.

Adult↗
PubMed1987

Terbutaline sustained-release treatment during one week 5 mg b.i.d. compared to one week placebo: terbutaline plasma levels, c-AMP plasma levels, lung function and tremor measurement.

In a group of ten patients with chronic asthmatic bronchitis, a good improvement of the lung function was achieved by a sustained-release terbutaline preparation (Bricanyl Retard) in a dosage of 5 mg twice daily. Tremor measurements and c-AMP plasma level showed a statistically significant increase. A good patient compliance was achieved with this dosage of terbutaline two times daily. The sustained-release preparation caused a rather constant and low terbutaline plasma level. We think that this relative low terbutaline plasma level is the most important reason for the lack of side effects.

Adult↗
PubMed1986

Pharmacodynamics (lung function tests, tremor measurements and cAMP determinations) of a single dose of 0.5 mg terbutaline subcutaneously during sustained-release theophylline medication in patients with asthmatic bronchitis.

A group of 10 patients with chronic asthmatic bronchitis was titrated with slow-release theophylline (Theolin Retard) to a steady state plasma theophylline level of 10 mg/l. After one week of this treatment a single s.c. dose of 0.5 mg terbutaline (Bricanyl) at 10:30 a.m was administered. Lung function at 8:15 a.m. on this day was better than on the reference day without any medication, but the differences were not statistically significant. At 11:00 p.m., 30 min after s.c. administration of terbutaline all lung function parameters (VC, FEV1, MMEF and sGaw) were significantly raised compared to the values of 8:15 p.m. cAMP levels and tremor were significantly higher after the combined medication (30, as well as 150 min after s.c. administration of terbutaline) than on the reference day. This observation implies that we have to be careful with the administration of terbutaline s.c. to patients on theophylline treatment in the daily practice of the lung function laboratory.

Adult↗
PubMed1986

Lung function improvement, tremor measurements and c-AMP determinations in a group of ten patients with asthmatic bronchitis after one week sustained release theophylline medication (theophylline plasma level +/- 10 mg/l) compared to one week placebo.

After one week theophylline therapy with a sustained release preparation (TheoDur 200 and 300 mg), a mean theophylline level of 10 mg/l was obtained in a group of ten patients with chronic asthmatic bronchitis with a mean dosage of 760 mg theophylline/24 h. A good improvement of the lung function was achieved, although only statistically significant for the mid maximal expiratory flow rate (MMEF) and the end expiratory specific airway conductance (sGaw) compared to placebo therapy. Tremor measurements and cyclic-AMP determinations showed a slight increase after theophylline therapy compared to placebo, although not statistically significant.

Asthma↗