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Biomedical subjects

K de Vries

Publications and source records attributed to K de Vries.

At least 73 records · Page 4Linked to original sources
PubMed1983

Ovarian pregnancy in association with an intrauterine device.

Within a 1-year period, two cases of primary ovarian pregnancy associated with an intrauterine device (IUD) occurred in our institution. The clinical signs and symptoms were similar to those in any other ectopic pregnancy. Both cases satisfied the criteria of Spiegelberg. The final diagnosis was based on the histopathological findings. A review of the literature is presented summarizing the 53 cases reported until now. The association between IUD, ectopic pregnancy in general, and ovarian pregnancy in particular is discussed.

Adult↗
PubMed1983

Comparison of antibody measurements against Aspergillus fumigatus by means of double-diffusion and enzyme-linked immunosorbent assay (ELISA).

IgG antibody titers against Aspergillus fumigatus from different sera were measured by means of a standardized ELISA and compared with precipitates measured by double diffusion (D.D.). There was a significant correlation between the number of precipitates and the ELISA IgG titers in the 758 sera examined. However, in several individual sera within this group, large deviations between these two immunologic parameters were found. Further analysis indicated that ELISA detects antibodies against nonprecipitating antigenic components in addition to the antibodies detected by D.D. Furthermore, not all precipitating antigenic components appear to play a role in the detection of antibodies against A. fumigatus by ELISA. Patients with aspergillosis largely show increased titers of IgG antibody by ELISA even when the results of D.D. are negative, except those of patients with Aspergillus-provoked asthma which fall within a normal range.

Alveolitis, Extrinsic Allergic↗
PubMed1983

Plasma histamine concentrations and complement activation during house dust mite-provoked bronchial obstructive reactions.

Lung function and histamine levels in peripheral venous plasma samples were followed after challenge with house dust mite allergen. In eight patients the mean maximal histamine concentration showed a significant rise during the early obstructive reaction when compared with the concentrations at similar time intervals after inhalation of a control solution. In nine other patients treatment with disodium cromoglycate (DSCG) caused a significant fall in plasma histamine concentrations indicating that histamine liberation plays a role during the early obstructive reaction and was released from the lung compartment. Histamine during early obstructive reactions compared with the pre-inhalation values did show a rise in mean maximal histamine concentration (1.5-4.1 ng/ml) but this was statistically not significant. During the late reaction neither significant increase in histamine nor inhibition by DSCG was found. Measurement of complement degradation products did not support the role of complement activation during either early or late bronchial obstructive reactions.

Adolescent↗
PubMed1982

[Treatment of CARA].

Explore the source record for details and available documents.

Adrenal Cortex Hormones↗
PubMed1982

The beta-adrenergic system and allergic bronchial asthma: changes in lymphocyte beta-adrenergic receptor number and adenylate cyclase activity after an allergen-induced asthmatic attack.

Beta-adrenergic receptor characteristics and adenylate cyclase responses to different stimuli were measured in lymphocyte membrane preparations of six normal control subjects and five allergic asthmatic patients with mild airways disease and increased bronchial reactivity to histamine and acetylcholine. The determinations were performed just before and 24 hr after inhalation challenge with house-dust mite antigen to investigate the influence of an allergen-induced asthmatic attack on the beta-adrenergic receptor system. Before the house-dust mite challenge, the lymphocyte membranes of the patients showed a normal receptor density, dissociation constant for (-)3H-dihydroalprenolol, and adenylate cyclase response to isoproterenol, guanyl-5'-yl-imidodiphosphate, (GppNHp) and NaF. After the allergen-induced asthmatic reaction, however, the beta-adrenergic receptor number in the patients was significantly reduced by 21%, while the basal adenylate cyclase activity and isoproterenol-, GppNHp-, and NaF-induced cyclic AMP responses were simultaneously reduced by about 40%. The allergen challenge had no significant effect on the lymphocyte membranes of the control subjects. These results suggest (1) that a reduced beta-adrenergic function is not an intrinsic component of allergic bronchial asthma but is rather the consequence of an active disease state, and (2) that next to changes in beta-adrenergic receptor number, alterations distal to the receptor may play an important role in the observed decrease in beta-adrenergic responsiveness.

Adenylyl Cyclases↗
PubMed1982

Bronchial obstructive reactions after inhalation with endotoxin and precipitinogens of Haemophilus influenzae in patients with chronic non-specific lung disease.

Bronchial obstructive reactions occur after inhalation of Haemophilus influenzae in the absence of proteolytic activity in patients with CNLSD and a lowered histamine threshold in whom specific precipitins are demonstrated. It may be presumed, that the direct bronchial reaction is caused by its content of endotoxin, whereas the late bronchial reaction is the result of a toxic action and a type III allergic reaction. When proteolytic activity is present it lowers the histamine threshold and may influence the endotoxin effect in this way.

Administration, Intranasal↗
PubMed1982

Protective effect of disodium cromoglycate on propranolol challenge.

The protective activity of cromoglycate in histamine and propranolol bronchial provocation tests was studied in seven asthmatic patients by inhalation of increasing doses 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.

Adult↗
PubMed1982

Some aspects of the regulation of the bronchial tree in obstructive lung disease: an introduction.

Hyperreactivity of the bronchial tree is a common characteristic in chronic obstructive lung disease. The mechanism underlying this phenomenon may be a disturbed equilibrium between contracting and relaxing forces acting upon the effector organ, the bronchial smooth muscle. The most important bronchial obstructive forces result from an increased vagal activity and from mediator release from the mast cell. The adrenergic system may be considered as a counter-regulating force inducing a bronchodilatation. This system was studied by challenge tests with histamine, acetylcholine, and propranolol. Special attention will be paid to the relationship between the propranolol response and allergic characteristics in asthmatic patients.

Acetylcholine↗
PubMed1982

The role of the adrenergic system in allergy and bronchial hyperreactivity.

The adrenergic system may have an influence on the severity and activity of bronchial asthma. It has been suggested that there might be a relationship between the allergic process and the adrenergic system. Therefore this system was studied before and after an allergen challenge. Two parameters were measured: in vivo: propranolol threshold measurement to assess adrenergic involvement; in vitro: the beta-adrenergic response of peripheral lymphocytes as parameter for beta-receptor function. Seven allergic asthmatics who were not treated with beta-stimulants or corticosteroids and seven normals inhaled house dust mite extract. On the days before and after the challenge, propranolol threshold measurements were performed. Six patients had a dual reaction after a house dust mite inhalation; one patient had an early response. The propranolol threshold changed from 1.32% (SEM 0.16) on the day before challenge to 0.86% (SEM 0.19) on the day after (0.02 less than P less than 0.025). In the same patients the maximal cAMP response of lymphocytes in the presence of 10(-6) mM isoproterenol changed from 339% (SEM 18.9) above basal level before the allergen challenge to 194% (SEM 24.6) after the challenge (0.001 less than P less than 0.005). The pre-challenge beta-response of lymphocytes of the asthmatic patients was comparable with that of normal lymphocytes (298% SEM 59.8). The results suggest that an allergen-induced asthmatic attack may lead to an impaired beta-adrenergic function.

Adolescent↗
PubMed1981

Correlation of serum and saliva theophylline concentration after administration of a sustained release preparation.

The 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.

Absorption↗
PubMed1981

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

The 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.

Administration, Oral↗
PubMed1981

Pharmacokinetics of sustained release theophylline in low and high multidose regimens.

1 The in vitro characteristics (dissolution rate) of a sustained release theophylline preparation (Theo-Dur were first measured in acid medium (pH = 1) for 2 h and after that in a phosphate buffer (pH = 6.8) for 6 h. 2 The tablets released more than 95% of the active ingredient within 5 h at a rate of approximately 11% of the dose per hour at pH = 1 and about 18% at pH = 6.8. 3 Dose dependency of the pharmacokinetics of theophylline was tested in seven healthy volunteers by giving them either 300 mg Theo-Dur or 900 mg Theo-Dur in two doses a day for 5 days in a cross over design. After the last tablet on day 6 the fall-off curve was followed in order to calculate the pharmacokinetic parameters. 4 Theophylline (300 mg) resulted on day 6 in a mean serum concentration of 4.4 +/- 0.8 microgram ml-1. The dose of 900 mg resulted in a proportional increase in the serum concentration. The result was 13.3 +/- 2.2 micrograms ml-1. 5 The T1/2 (300 mg) was 9.3 +/- 1.4 h and the T1/2 (900 mg) was 8.5 +/- 2.0 h. These values do not significantly differ (0.10 less than P less than 0.20). 6 It was concluded that theophylline exhibits the rules of linear pharmacokinetics when serum concentrations are in the therapeutic range.

Adult↗