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Biomedical subjects

K de Vries

Publications and source records attributed to K de Vries.

At least 19 recordsLinked to original sources
PubMed1995

Subendometrial myometrial contractions associated with transcervical chorionic villous sampling.

Thirty-two consecutive patients, referred for prenatal diagnosis by chorionic villous sampling, were examined by transvaginal ultrasound for the presence of myometrial contractions before and after the procedure. Increased myometrial activity was observed in 78% of patients. The mean frequency increased by 3.5 times and the amplitude increased by 4.2 times compared to the preprocedure condition. Cramping was associated with the increased amplitude and/or frequency of contractions. No significant correlation was found between the direction of propagation of the contraction wave and its frequency or amplitude. The sensitivity of ultrasonographically detected myometrial contractions in predicting cramping is 70%, but only 31% in predicting vaginal bleeding or spotting. Further studies are required to elucidate the prognostic significance of this uterine activity.

Adult↗
PubMed1994

Seasonal variation in airway hyperresponsiveness and natural exposure to house dust mite allergens in patients with asthma.

Nonspecific airway hyperresponsiveness is a fundamental characteristic of patients with asthma and can be influenced by several stimuli. In nine patients with asthma and an isolated allergy to house dust mite, the variation of natural exposure to the house dust mite allergen Der p I and the corresponding changes in nonspecific airway hyperresponsiveness were followed up for 1 year. The concentration of Der p I in floor dust from living rooms and bedrooms (as a measure of exposure) reached maximum levels in late summer and the beginning of autumn (August to October), whereas the lowest levels were found during the months of March to May (delta Der p I = +2.31 micrograms/gm and -1.33 micrograms/gm respectively, both compared with the year average). Airway hyperresponsiveness (as measured by the provocative concentration of histamine causing a 20% fall in forced expiratory volume in 1 second [PC20] threshold) also showed a seasonal variation, with most severe hyperresponsiveness during the months of August to November, almost the same period in which the exposure to house dust mite allergens reached maximal levels (delta PC20 histamine = -1.47 mg/ml in November vs +1.79 mg/ml in March, both compared with the year average). Our results support the view that seasonal changes of exposure to environmental allergens such as house dust mite allergens will have an effect on the level of airway hyperresponsiveness in patients with allergic asthma.

Adult↗
PubMed1993

Facial palsy after sagittal split osteotomies. A survey of 1747 sagittal split osteotomies.

Facial nerve palsy following a sagittal split osteotomy is a rare but serious complication. The incidence of facial nerve injury in a group of 1747 patients who had undergone a bilateral sagittal split osteotomy (3494 sagittal splits) was determined and proved to be 0.26% (9 cases). The case histories of 2 patients are presented, and the etiology, diagnosis, treatment and prevention of this complication are discussed.

Adult↗
PubMed1991

The Dutch hypothesis (chronic non-specific lung disease) revisited.

In 1961 the hypothesis (later referred to as the Dutch Hypothesis (DH)) was put forward that asthma, chronic bronchitis and emphysema should be considered as different expressions of one disease entity, in which both endogenous (host) and exogenous (environmental) factors play a role in the pathogenesis. A hereditary predisposition to develop allergy and bronchial hyperreactivity were considered to be important denominators of disease susceptibility. Complications and complicating diseases would also contribute to the ultimate phenotype of the patient. In the present paper we discuss the relevance of this hypothesis in 1990. Until now it has not been refuted; circumstantial evidence in its favour has accumulated, but formal proof is still lacking. Further research should pay more attention to the genetic aspects of the disease. Arguments are presented against the use of the terms asthma, chronic bronchitis, and emphysema as indicators of disease entities, and in favour of the use of an umbrella-term, e.g. chronic non-specific lung disease (CNSLD), provided that, in addition, every patient is characterized using so-called defining criteria.

Asthma↗
PubMed1990

Contractions of the inner third of the myometrium.

Forty-six consecutive endovaginal ultrasound examinations were screened for the presence of myometrial contractions. The study group contained pregnant women up to 10 weeks' menstrual age, nonpregnant, and postmenopausal women. Rhythmic myometrial contractions of the inner myometrial third not previously reported were seen in 35 studies in pregnant, nonpregnant, and postmenopausal women. The contractions involved the inner third of the myometrium in all but two cases. In these two cases, all three muscular layers were involved. The majority of women showed retrograde contractions, with the contraction wave moving from the cervix to the fundus. In menstruating women and one case of abortion, the contractions were antegrade. It is our speculation that these retrograde contractions of the inner myometrial third may be important in sperm transport and for the conservation of early pregnancies within the uterine cavity.

Adult↗
PubMed1989

Precipitating antibodies and positive skin tests in workers exposed to airborne antigens from a contaminated humidification system.

Precipitating antibodies and positive skin tests to antigens from a contaminated humidification system in a synthetic carpet yarn plant were tested in a group of exposed (n = 66) and non-exposed (n = 45) workers. The first investigation was carried out in 1979 shortly before hygienic actions to reduce exposure had been taken. In 1981 and 1985 they were repeated. The significant difference between the positive skin reactions and of positive serology (4 or more lines), observed in 1979 between the exposed and non-exposed population, was not found in 1981 and 1985. In 1979 the differences were the most pronounced in the non-smoking individuals. However, even in that category the significant difference disappeared in 1981 and 1985. A positive skin test in 1979 did not increase the chance of having a positive skin test during repeat investigations. In serology this was only the case when the positive criterion was lowered to three or more lines. This study demonstrates that, in the absence of a quantitative analysis of airborne antigens, skin tests and serology may be helpful in obtaining an estimation of antigenic contamination of the air and subsequent sensitization on a group level. However, these tests are less appropriate when used in an individual health surveillance program at this type of nonspecific antigen exposure.

Adult↗
PubMed1989

Cellular and humoral observations in a patient with allergic bronchopulmonary aspergillosis during a nonasthmatic exacerbation.

A patient is described with an asymptomatic exacerbation of allergic bronchopulmonary aspergillosis (ABPA), clinically characterized by pulmonary infiltrates, with absence of obstructive reactions and a short period of hemoptysis 2 weeks before hospitalization. Cell counts and antibody concentrations were measured in serum, and bronchoalveolar fluid (BAF) samples and values were compared with data from previous periods of symptomatic exacerbations. During the asymptomatic exacerbation, concentrations of antibody to Aspergillus fumigatus, total IgE, and precipitating antibodies were elevated in peripheral blood. No quantitative differences in specific antibody concentrations (IgE, IgG, IgA, and IgM) against A. fumigatus were found between sera from symptomatic and asymptomatic periods of ABPA. In contrast to observations in the serum, protein concentrations in BAL fluid were normal during the asymptomatic period, whereas high concentrations were found during the symptomatic phases. Local antibody concentrations (in BAF) were characterized by high levels of IgA antibodies against A. fumigatus. During asymptomatic and symptomatic phases, eosinophils were elevated in peripheral blood, in sputum, in BAF, and highly elevated in tissue biopsy specimens. Activated eosinophils were found, as indicated by the presence of light-density cells in the circulation and monoclonal antieosinophil cationic protein binding to bronchoalveolar lavage eosinophils. In contrast to the symptomatic phase of ABPA in 1980, demonstrating aspecific airway reactivity to several pharmacologically active substances, no such hyperreactivity was found during the asymptomatic phase of ABPA in 1986. It is proposed that the asymptomatic infiltrative phase of ABPA is an intermediate stage that can develop into a symptomatic phase after prolonged and intensified infiltration of eosinophils. Mediators from the inflammatory cells may be involved in the induction of bronchial hyperresponsiveness. After induction of this hyperreactive stage of the airways, additional liberation of mediators from either eosinophils and/or mast cells will lead to a symptomatic (obstructive) phase of ABPA.

Adult↗
PubMed1989

The distribution of bronchial responsiveness to histamine in symptomatic and in asymptomatic subjects. A population-based analysis of various indices of responsiveness.

The distribution of bronchial responsiveness (BR) and the place of symptomatic subjects in this distribution was investigated in a random population sample of 339 subjects who participated in the 1984 survey of the Vlagtwedde/Vlaardingen Study. BR was assessed by a histamine provocation test. The following indices of BR were used: (1) a histamine threshold both at 10 and at 20% decreases in FEV1 (PC10 and PC20); (2) the concentration causing a 10 or a 20% decrease estimated by linear interpolation (IPC10 and IPC20), and by linear regression of all data points (PD10 and PD20); (3) the slope of the linear regression line through all data points (SAP) and the slope of the line through the origin and the last data point (SOL). Disease was defined as the self-reported presence of respiratory symptoms from a respiratory symptom questionnaire. Bronchial challenge was considered as a test to predict symptom prevalence. Receiver-operator characteristic curves were applied to define optimal cutoff points for each of the indices used to define a positive and a negative test. For each index, sensitivity, specificity, predictive value of a positive and negative test, and efficiency rate of the test were calculated. The overall distribution of BR in this population appeared to be log normal for the different continuous indices. Subjects with symptoms were on the more responsive tail of the distribution. After adjusting for age, sex, smoking habit, and level of pulmonary function, the mean log-transformed values of PD10, PD20, SAP, and SOL for the various symptom groups differed significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Regulation of the beta-receptor-adenylate cyclase system in lymphocytes of allergic patients with asthma: possible role for protein kinase C in allergen-induced nonspecific refractoriness of adenylate cyclase.

Allergen challenge of allergic patients with asthma caused various changes in the beta-receptor-adenylate cyclase system of lymphocyte membranes from these patients. These changes included uncoupling and down regulation of beta-adrenergic receptors and nonspecific refractoriness of adenylate cyclase, as demonstrated by reduced responses to isoproterenol (beta 2), histamine (H2), 5'-guanylylimidodiphosphate, and sodium fluoride. Since these changes could be due to desensitization by enhanced plasma levels of catecholamines and/or histamine during the allergic response, we explored the effects of these agonists on the beta-receptor-adenylate cyclase system in vitro with normal lymphocytes. In addition, we assessed the effect of the tumor-promoting phorbol ester, phorbol 12-myristate 13-acetate (PMA), on this system, since phorbol esters have been demonstrated to modulate several receptor systems, presumably via activation of protein kinase C. That both the agonists and PMA may cause refractoriness of lymphocyte adenylate cyclase was demonstrated, but, however, by apparently different mechanisms. The agonists isoproterenol and histamine induced only a specific desensitization of the homologous responses, whereas PMA-induced refractoriness was nonspecific in nature. Radioligand-binding studies demonstrated that both uncoupling and down regulation contributed to the isoproterenol-induced beta-adrenergic hyporesponsiveness, whereas beta-adrenergic receptor uncoupling but not beta-adrenergic receptor down regulation was involved in PMA-induced desensitization. Histamine had no effect on the beta-adrenergic system at all. The data suggest that the agonist-induced changes in the adenylate cyclase system are specifically located at the receptors, whereas PMA-induced refractoriness can be explained by alterations distal to the receptors, presumably at the stimulatory guanine nucleotide regulatory protein. Thus, enhanced levels of catecholamines or histamine could be involved in the development of receptor-specific changes in the lymphocyte adenylate cyclase system of allergic patients with asthma. However, they are unlikely to cause the nonspecific changes distal to the receptors. The latter changes could be induced by physiologic activation of protein kinase C during the allergic response by a still unknown stimulus, possibly via the receptor-mediated turnover of phosphatidylinositol 4,5-diphosphate.

ADP-Ribosylation Factors↗
PubMed1987

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.

Cell Count↗
PubMed1987

Botrytis cinerea: a study of the immunological properties during growth. Incidence of antibodies against B. cinerea in a group of patients with aspergillosis.

When growing Botrytis cinerea in Sabouraud medium, different phases of growth could be recognized using pH, mycelium yield, and culture filtrate antigens as parameters of growth. Immunological characteristics of the different phases (early, intermediate, and late) of growth were measured using IgE and IgG binding by enzyme allergosorbent test and enzyme-linked immunosorbent assay, respectively, and quantities of precipitating components (double immunodiffusion and rocket immunoelectrophoresis). The number of precipitating components was maximal in culture filtrate extracts during late phase (III) of growth. In contrast, both IgE and IgG binding were already maximal in the early phase of growth (9 days of cultivation). In a group of patients with elevated IgE antibodies against Aspergillus fumigatus, about half of them also showed elevated IgE antibodies against B. cinerea. This indicates that multiple exposition is a cause of multiple sensitization; however, cross-reactivity in some of these sera cannot be excluded.

Antibodies, Fungal↗
PubMed1987

The beta-adrenergic system of non-allergic patients with chronic airflow obstruction and early morning dyspnoea.

Lymphocyte beta-adrenergic receptor function and urinary excretion of catecholamines were measured in eight non-allergic patients with partially reversible chronic airflow obstruction (CAO) and early morning dyspnoea (EMD), and in eight matched healthy control subjects. In order to establish a possible relationship between the early morning dyspnoea and a reduced beta-adrenergic activity, these parameters were measured during the "morning dip" in FEV1 and in the afternoon, when lung function is maximal. No differences were observed for lymphocyte beta-adrenergic receptor characteristics (beta-receptor number, Kd, for 3H-dihydroalprenolol, and cAMP response to isoproterenol) between patients and controls, when determined at 8 AM or at 4 PM. Nor was there a significant circadian variation in these parameters present in both groups. By contrast, the patients showed a significantly reduced urinary excretion of epinephrine and norepinephrine, as measured in four-hourly urine portions collected between 8 and 12 AM and between 4 and 8 PM, respectively. In addition, the urinary excretion of epinephrine showed a significant circadian variation in the patients, which was correlated with the FEV1 (% predicted). Such a relationship was not found for norepinephrine. The results suggest that a (generalized) dysfunction of the beta-adrenergic receptor is not involved in the pathogenesis of CAO or EMD. However, reduced beta-adrenergic receptor stimulation due to decreased levels of catecholamines may contribute to the observed (variation in) airflow obstruction of the patients.

Adult↗
PubMed1986

Phorbol 12-myristate 13-acetate induces beta-adrenergic receptor uncoupling and non-specific desensitization of adenylate cyclase in human mononuclear leukocytes.

Tumour-promoting phorbol esters such as phorbol 12-myristate 13-acetate (PMA) have been reported to modulate beta-adrenergic receptor responses in various cell types, presumably by the activation of protein kinase C. In the present investigation we assessed the effect of PMA on the beta-adrenergic receptor-adenylate cyclase system of human mononuclear leukocytes (MNL). It was found that incubation of MNL with PMA resulted in a time- and concentration-dependent desensitization of isoproterenol-induced adenylate cyclase activity. However, the effect of PMA was not restricted to the beta-adrenergic receptor system, since basal adenylate cyclase activity and histamine-, prostaglandin E1-, 5'-guanylylimidodiphosphate (GppNHp)-, and NaF-stimulated values were also reduced. By contrast, no effect was found on the forskolin-induced adenylate cyclase activity. The inactive phorbol ester, 4 alpha-phorbol 12,13-didecanoate had no effect on adenylate cyclase at all, suggesting that the observed PMA effect was specifically mediated by activation of protein kinase C. The reduced beta-adrenergic response induced by PMA was not associated with a reduced beta-adrenergic receptor number, indicating uncoupling of this receptor from adenylate cyclase. Isoproterenol competition curves for 3H-dihydroalprenolol binding to membranes from untreated and PMA-treated cells demonstrated that the uncoupling was due to a reduced ability of the agonist to promote formation of the guanine nucleotide-sensitive high affinity state of the receptor. The results indicate that PMA may cause desensitization of catecholamine-responsive adenylate cyclase in MNL, and that the major locus of alteration is the guanine nucleotide regulatory protein.

Adenylyl Cyclases↗