K Devries

Leukotriene C4 production by normal-density and low-density eosinophils of atopic individuals and other patients with eosinophilia

With the use of a percoll gradient separation procedure, eosinophils of individuals with asthma and with allergy could be separated into normal- and low-density cell fractions. The presence of low-density eosinophils possibly reflects an ongoing process of activation of these cells induced by the allergic reaction. Ca-ionophore-induced leukotriene (LT) C4 production, in the absence of added substrates, demonstrated a decreased potency for LT generation by low-density eosinophils compared with the LT generation of normal-density cells (57 +/- 33 ng and 103 +/- 44 ng per 10(6) cells, respectively). In contrast with the Ca-ionophore-induced LT formation, incubations with serum-treated zymosan in the presence of glutathione demonstrated higher productions of LTC4 with the low-density eosinophilic subpopulation compared with normal-density cells. This is compatible with a possibly higher expression of complement C3b receptors on the low-density eosinophils. Total arylsulfatase contents demonstrated that low-density eosinophils are not degranulated with respect to their small granules. Although release of the large granules by low-density eosinophils cannot be excluded, electron-microscopy studies indicated that degranulation is not the only (or major) factor that determines the density of the various eosinophilic subpopulations.

The allergenic and antigenic properties of spore extracts of Aspergillus fumigatus: A comparative study of spore extracts with mycelium and culture filtrate extracts

The antigenic properties of conidial preparations of Aspergillus fumigatus were compared with mycelial and culture filtrate extracts by use of sera of patients with aspergillosis and hyperimmune rabbit serum. Biologic activities were tested by intracutaneous tests. The immunologic parameters used were: precipitating properties in double-diffusion, IgG binding by ELISA, IgE binding by enzyme inhibition assay, and by enzyme allergosorbent test. It has been demonstrated that the components that are released after disintegration of spores have positive titers in all immunologic assays. The immunologic properties of these spore plasma extracts are comparable with mycelial and/or culture filtrate extracts that are in accordance with the corresponding skin reactivities. Components that are released spontaneously from spores are only weakly positive or negative in the immunologic assays and demonstrate a very low biologic activity.

VOLUMETRIC AEROBIOLOGICAL SURVEY OF CONIDIAL FUNGI IN THE NORTHEAST NETHERLANDS .1. SEASONAL PATTERNS AND THE INFLUENCE OF METEOROLOGICAL VARIABLES

In order to obtain actual data about the qualitative and quantitative occurrence of airborne fungi in The Netherlands, a viable‐volumetric sample survey with the Andersen sampler was undertaken. From April 1981 to the end of June 1983, one day a week samples were taken on the unobstructed rooftop of a hospital in the N‐E Netherlands. An average of 268 Colony Forming Units (CFU), per sample, per cubic metre of air were found. Almost three‐quarters of the total catch consisted of seven genera, Cladosporium predominating. Botrytis showed in surprisingly high numbers when compared with other surveys, while Alternaria occurred in very low concentrations. Most atmospheric airborne spora were found between May and September. Aspergillus and Penicillium prevailed in the autumn and winter months, although were present the year‐round. Momentary weather conditions seemed less important for the overall spore picture than the average meteorological characteristics for a whole season. The obtained aero‐mycological information may be useful in determining clinical strategies for skin testing and serological investigations in patients with suspected mould allergies.

Determination of N tau-methylhistamine in urine by gas chromatography using nitrogen-phosphorus detection.

The determination of N tau-methylhistamine in urine, using gas chromatography with nitrogen-phosphorus detection and the homologue N tau-ethylhistamine as internal standard, is described. A comparison between the present method and a previously described stable isotope dilution mass fragmentographic method resulted in a regression line of Y = 0.023 + 0.944X mumol/l with a correlation coefficient of 0.996. The 24-h excretions of 35 normal adults on a free diet ranged from 0.4 to 1.8 mumol. Patients with mastocytosis, chronic myelocytic leukemia, anaphylactic reactions and a patient after bronchial provocation showed above normal values.

HISTAMINE IN LATE ASTHMATIC REACTIONS FOLLOWING HOUSE-DUST MITE INHALATION

In order to investigate the role of histamine in the late asthmatic reaction (LAR) following house-dust mite (HDM) inhalation, we studied, with hourly intervals, urinaryNτ-methylhistamine (an important metabolite of histamine) in 14 allergic asthmatic patients before and after broncho provocation with HDM.Four patients showed an early asthmatic reaction (EAR), while 10 patients developed a LAR as well. In the hour following the EAR a significant increase in urinaryNτ-methylhistamine was observed as compared to the control day (0.01<p<0.05). During the LAR no increase of this metabolite was detected in the urine of the patients. Additionally, histamine was measured in broncho alveolar lavage fluid (BAF) obtained from 6 patients during the HDM-provoked LAR and compared to histamine levels in BAF from patients without a LAR, following broncho provocation.In the LAR group higher histamine levels were found than in the other patient and control groups. For the whole patient group no correlation was found between the degree of bronchial obstruction during the LAR and the BAF histamine values. No difference was found inNτ-methylhistamine in BAF between patients with LAR and controls. Thus histamine metabolite studies in the urine failed to provide evidence of involvement of histamine in the LAR, while further data are needed to interpret the results of local sampling in the lung.

ENVIRONMENTAL AEROBIOLOGICAL STUDIES IN ALLERGIC BRONCHOPULMONARY ASPERGILLOSIS

An aerobiological pilot study was undertaken to measure airborne concentrations of Aspergillus spores in and around the dwellings of two patients with allergic broncho‐pulmonary aspergillosis (ABPA). The aim of the investigation was 1) to find a specific source of Aspergillus antigen, and 2) to find out whether disease activity, or exacerbation, paralleled Aspergillus spore prevalence. In the environment of the first patient heavy spore contaminated air was found in a cow‐shed, and the adjacent hayloft and scullery. The patient experienced no typical exacerbation during the study period, probably because she now scrupulously avoided this source. The environment of the second patient contained lower spore concentrations in and around the house, and the patient had no typical exacerbation, possibly due to low‐intensity exposure. Both patients, however, had increased bronchial obstruction during periods with high Aspergillus spore content in the outside air. The results suggest that avoidance of Aspergillus spore sources and low overall exposure may play a major role in preventing exacerbation of the disease.

Cultivation of fungi in synthetic and semi-synthetic liquid medium. II. Immunochemical properties of the antigenic and allergenic extracts.

Four allergologically important fungi, viz. Aspergillus Fumigatus, Penicillium notatum, Alternaria alternata, and Cladosporium herbarum were cultured in a liquid synthetic medium, with or without addition of 0.1 % yeast extract (YE). After 10 and 28 days of cultivation, immunochemical properties of the fungal extracts, characterised by precipitation pattern and IgG– and IgE‐binding capacity, were studied. In pure synthetic medium no large differences were observed in number of precipitates, as measured by DID, among the four antigenic fractions of each fungus (metabolic and mycelial antigens of both early and late phase cultures). Addition of YE to the growth medium hardly changed the number of precipitates and generally caused a decrease in IgG‐binding capacity of the extracts. In contrast to these observations were the findings with the IgE–binding capacities of the fungal extracts as measured by RAST. Most allergenic fractions demonstrated an increase (sometimes strong) in IgE–binding capacity after YE was added to the growth medium. It is concluded that the time of cultivation influences the immunochemical characteristics of fungal extracts and that mycelial as well as metabolic antigens of both early and late phase cultures should be used in order to obtain a wide spectrum of allergens in extracts used for diagnostic purposes.

CORRELATION OF SERUM AND SALIVA THEOPHYLLINE CONCENTRATIONS AFTER ADMINISTRATION OF A SUSTAINED-RELEASE PREPARATION

SummaryThe correlation between serum and saliva levels of theophylline was investigated in seven healthy volunteers after multiple dose administration of a low dose (300 mg/day) and a high dose (900 mg/day) of a sustained release theophylline preparation (Theo-Dur®). Tablets were taken for five days, at 8 a.m. and 8 p.m. and a last dose was taken on Day 6 at 8 a. m. Fourteen serum and saliva samples were collected simultaneously during the dosing period and for up to 32 h after the last dose. On the 300 mg/day regimen the level in saliva was 55.3% of the serum level, with an overall variability of 6.7% and an intrasubject variability of 10.5%. After 900 mg/day, the saliva concentration was 55.5% of the serum concentration, with an overall variability of 7.6% and an intrasubject variability of 12.7%. A good correlation was found between both determinations (r=0.99), which suggests that saliva levels could be used to monitor theophylline after administration of a sustained release tablet.

Protective Effect of Disodium Cromoglycate on Propranolol Challenge

The protective activity of cromoglycate in histamine and propranolol bronchial provocation test, was studied in seven asthmatic patients by inhalation of increasing does of histamine and propranolol in the absence and presence of inhaled cromoglycate. Cromoglycate showed a significant protective effect on the propranolol challenge, whereas no protection against histamine challenge could be observed.

Disposition and clinical pharmacokinetics of theophylline after administration of a new sustained release tablet.

SummaryThe systemic disposition of theophylline after taking a new, sustained release tablet (Theolair Retard® 250 mg, Theolair S. R.®, Riker Laboratories) has been studied in 8 hospitalized patients. Absolute bioavailability was determined from the ratios of the areas under the serum concentration-time curves after intake of the tablet and after intravenous infusion of aminophylline in the same patient. The absolute bioavailability of Theolair Retard® 250 mg was 110.9±20.8% (mean ± SD). Maximal serum concentrations were reached after 7.3±3.5 h, the large intersubject variation being due to differences in gastric emptying time. The tablets appear to release theophylline slowly in acid conditions, but more rapidly in an alkaline medium. Invasion was found to be either monophasic with a rate constant of about 0.8 h−1 (intestine), or biphasic with rate constants of 0.2 h−1 (stomach) and 0.8 h−1 (intestine). The peak levels accounted for 7.9±2.2 mg · 1−1. The profiles of the serum concentration-time curves were such that the concentrations remained above 80% of cmax for 6.5±3.3 h. The relevant pharmacokinetic parameters (half-life of elimination, total body clearance and volume of distribution) were determined and were used to calculate the individual dosage regimens required to obtain therapeutic serum concentrations. The optimal dosing interval to obtain an average steady state serum concentration of 12.5 mg · l−1 was 9.8±3.1 h.