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Biomedical subjects

S Kuiper

Publications and source records attributed to S Kuiper.

13 recordsLinked to original sources
PubMed2006

Association between first-degree familial predisposition of asthma and atopy (total IgE) in newborns.

BACKGROUND: It is generally thought that infants with a first-degree familial predisposition of asthma are at higher risk of developing asthma than infants without predisposition. OBJECTIVE: To investigate whether there is an association between being at high risk for developing asthma and increased level of total IgE in newborns and whether total IgE is influenced by gender, family size, birth season, maternal smoking, birth weight, gestational age, and maternal diet. METHODS: Two hundred and twenty-one high risk and 308 low-risk infants were prenatally selected in a 5-year-period. Three to 5 days after birth, the total IgE was measured in capillary heel blood. RESULTS: Data on total IgE and first-degree familial predisposition were available for 170 high-risk and 300 low-risk infants. There was a statistically significant relationship between being at high-risk (maternal asthma) and increased levels of total IgE in newborns (total IgE cut-off levels: 0.6-0.9 IU/mL (odds ratio (OR)=2.1, 95% confidence interval (CI): 1.2-3.7 to 3.0, 95% CI: 1.5-5.9)), between being born in autumn and increased levels of total IgE in newborns [total IgE cut-off levels: 0.5-0.6 IU/mL (OR=2.5, 95% CI: 1.2-5.1 to 2.5, 95% CI: 1.2-5.4)] and between maternal vitamin supplements intake and decreased levels of total IgE in newborns (total IgE cut-off level: 0.9 IU/mL (OR=0.5, 95% CI:0.3-1.0)). There was no interaction between the effects of maternal asthma and birth season on total IgE, as well as between the effects of maternal asthma and maternal vitamin supplements intake. Gender, family size, maternal smoking, birth weight, and gestational age did not influence the associations. CONCLUSION; Being at high-risk of asthma (maternal asthma) and birth season are positively associated with the presence of increased levels of total IgE at birth, whereas maternal vitamin supplements intake is negatively associated with the presence of total IgE at birth.

Adult↗
PubMed2005

Prenatal exposure to mite and pet allergens and total serum IgE at birth in high-risk children.

To examine the relationship between prenatal exposure to mite, cat and dog allergens and total serum IgE at birth in newborns at high risk of asthma. In the homes of 221 newborns with at least one first-degree relative with asthma, concentrations (ng/g dust) of allergens of house dust mite (mite), cat and dog were measured at the fourth to sixth month of pregnancy in dust samples from the maternal mattress and living room. At day 3-5 after birth, total IgE was measured in capillary heel blood. A total number of 174 blood samples were available (11 mothers refused newborn's blood sampling, and in 36 cases the blood sample was too small for analysis). In 24% of the newborns, total IgE was elevated (cut-off value 0.5 IU/ml). A significant dose response relationship was found between increasing mite allergen levels [divided in quartiles ng/g dust (qrt)] and the percentage of elevated IgE: first qrt (0-85 ng/g) 13%; second qrt (86-381) 19%; third qrt (382-2371) 26%; fourth qrt (> or =2372) 42%, respectively, p=0.01. This relationship remained significant after adjusting for passive smoking, maternal and paternal mite allergy, socio-demographic factors, birth characteristics and (breast) feeding practice in the first week of life. In high-risk newborns, prenatal exposure to mite allergens, but not to cat and dog allergens from dust of the living room and of the maternal mattress was associated with total serum IgE at birth.

Allergens↗
PubMed2001

Assessment of short-term physical loading of the back: is serum keratin sulfate an appropriate biomarker?

STUDY DESIGN: A prospective experimental study. OBJECTIVES: To investigate the potential of serum keratan sulfate (KS) as an indicator of biochemical changes in intervertebral discs induced by physical loading of the back. BACKGROUND: By providing objective information on exposure and effects at the tissue level, biomarkers may enable us to improve our understanding of the intermediate steps between exposure to physical loading and the occurrence of back disorders. Serum KS has been proposed as a potential biomarker of the molecular changes in intervertebral discs that occur because of physical loading and are a potential cause of back disorders. METHODS AND MEASURES: Thirty-two nonimpaired men volunteers with a mean age of 22.5+/-2.3 years participated in the experimental condition, a manual lifting task, as well as in the control condition, lying on the back. Serum KS levels were measured immediately before and after both conditions, as well as 24 hours and 1 week later. RESULTS: No significant changes in serum KS levels were found after exposure to physical loading (mean SD serum KS before, 287.4+/-83.9 ng/mL; immediately after, 279.5+/-65.5 ng/mL; 24 hours after, 266.6+/-71.9 ng/mL; and 1 week after, 268.9+/-79.3 ng/mL), and no significant changes were found after lying on the back for 8 hours (mean+/-SD serum KS before, 273.0+/-94.3 ng/mL; immediately after, 261.6+/-68.9 ng/mL; 24 hours after, 277.3+/-68.9 ng/mL; and 1 week after, 274.5+/-68.5 ng/mL). CONCLUSIONS: These results indicate that the serum KS level is not suitable as a biomarker of the effects of short-term physical loading of the back induced by a manual lifting task.

Adult↗
PubMed2001

Influence of sex, age, and menopausal state on the course of early rheumatoid arthritis.

OBJECTIVE: To investigate the influences of the menopausal state, sex, and age on the course and outcome of rheumatoid arthritis (RA). METHODS: A cohort of patients with early RA (209 female, 123 male) was studied. Sex, age, and menopausal state at baseline, and disease activity, radiographic joint destruction, and physical disability during 6 years of followup were assessed. RESULTS: The Disease Activity Score (DAS) was significantly higher in female compared to male patients at any time point except at the time of inclusion. This was mainly due to postmenopausal patients. Radiographic joint destruction (RJD) was significantly worse in female patients compared to males at the time of inclusion. Postmenopausal patients had significantly higher RJD than premenopausal patients at the time of inclusion and 3 years thereafter. Older male patients showed worse RJD than younger male patients at all time points measured. Physical disability was significantly worse in female compared to male patients, as well as in postmenopausal compared to premenopausal patients, and older male compared to younger male patients. Stepwise regression analysis revealed that at 3 years higher age and female sex were the best predictors for a worse DAS. Higher age and the interaction term between menopausal state and age best predicted higher RJD. Higher age and the interaction term between menopausal state and age best predicted Health Assessment Questionnaire (HAQ) score. CONCLUSION: Higher age at presentation of RA leads to a more severe disease course in terms of DAS, RJD, and HAQ. Although female sex has a deteriorating effect on the DAS, the menopausal state is responsible for the major part of the differences in outcome between men and women. Postmenopausal state in early RA influences future disability and damage, especially in older patients.

Adolescent↗
PubMed1998

Different roles of tumour necrosis factor alpha and interleukin 1 in murine streptococcal cell wall arthritis.

In this study two different aspects of tumour necrosis factor alpha (TNF-alpha) and interleukin 1 (IL-1) in locally induced murine streptococcal cell wall arthritis (SCW) were investigated. First, the kinetics and interdependence of TNF-alpha and IL-1 release; and second; their involvement in inflammation and cartilage destruction. Kinetic studies showed that the TNF-alpha peak level preceded the IL-1 peak level. However, in vivo neutralization of TNF-alpha did not result in decreased IL-1 bioactivity or immunoreactivity, suggesting that there is no dominant TNF-alpha-dependent IL-1 release in this model. Inflammation was studied by measuring knee joint swelling and inflammatory cell influx. Impact on cartilage was studied by measuring chondrocyte proteoglycan synthesis and cartilage proteoglycan depletion. The role of TNF-alpha in these phenomena was investigated using anti-TNF-alpha antibodies and tumour necrosis factor binding protein (TNFbp). Similarly, the role of IL-1 was studied using anti-IL-1 antibodies or IL-1 receptor antagonist (IL-1Ra). Anti-TNF-alpha treatment significantly reduced joint swelling, whereas this effect was not found by using anti-IL-1 or IL-1Ra. In contrast, neutralization of IL-1, but not TNF-alpha, resulted in a significant decrease of chondrocyte proteoglycan synthesis inhibition. Moreover, histology revealed that anti-IL-1 treatment reduced cartilage proteoglycan depletion and inflammatory cell influx. Combined anti-TNF-alpha/anti-IL-1 treatment significantly suppressed both inflammation and cartilage damage. However, the impact on these separate parameters did not exceed the effects of either anti-TNF-alpha or anti-TNF-1. It can be concluded that both TNF-alpha and IL-1 exert specific activities in SCW arthritis. The involvement of TNF-alpha in this model is limited to joint swelling, whereas IL-1 plays a dominant role in cartilage destruction and inflammatory cell influx.

Animals↗
PubMed1997

Coating in vitro of erythrocytes with Tamm Horsfall-protein.

A method is described to coat isolated peripheral blood erythrocytes in vitro with Tamm-Horsfall Protein (THP, uromodulin). Coating of erythrocytes with THP was accomplished by incubation of the cells in the presence of THP, made monomeric by incubation in a high urea concentration. THP-coating of erythrocytes was dependent on the THP-concentration, maximal coating being obtained at a protein concentration > or = 250 mg/ml. The best coating results were obtained if, during the co-incubation of erythrocytes with THP, urea was removed while the sodium chloride concentration was increased up to a physiologic concentration by means of dialysis. This alteration in chemical conditions promotes THP-polymerisation. Erythrocytes coated in this way could be preserved for at least 5 weeks in preserving solution, making them an interesting source of testing and control material. Coating of erythrocytes with THP could also be accomplished under conditions in which THP was preserved in a monomeric form, which suggests that peripheral blood erythrocytes having binding-sites for THP.

Adjuvants, Immunologic↗
PubMed1997

Interleukin-6 reduces cartilage destruction during experimental arthritis. A study in interleukin-6-deficient mice.

Using interleukin (IL)-6-deficient (IL-6(0/0) mice or wild-type mice, we investigated the controversial role of IL-6 in joint inflammation and cartilage pathology during zymosan-induced arthritis (ZIA). Monoarticular arthritis was elicited by injection of zymosan into the right knee joint cavity. Production of IL-1, tumor necrosis factor (TNF), IL-6, and nitric oxide by the inflamed knee was assessed in washouts of joint capsule specimens. Plasma corticosterone was measured using a radioimmunoassay. Proteoglycan synthesis was assessed using [35S]sulfate incorporation into patellas ex vivo. Joint swelling was quantified by joint uptake of circulating 99mTechnetium pertechnetate. Histology was taken to evaluate cellular infiltration and cartilage damage. Zymosan caused a rapid increase in articular IL-1, IL-6, TNF, and NO levels. Except for IL-6, the released amounts and time course of these mediators were comparable in the IL-6-deficient mice and the wild-type mice. Elevated plasma corticosterone levels were measured during the first day of arthritis in both strains. At day 2 of ZIA, joint inflammation (joint swelling and cell exudate) in IL-6-deficient mice was comparable with that in the wild-type mice. The marked suppression of chondrocyte proteoglycan synthesis and proteoglycan degradation were on the average higher in the IL-6-deficient mice. Together this resulted in a more pronounced proteoglycan depletion in the IL-6-deficient mice as compared with the wild-type mice during the first week of arthritis. Injection of recombinant IL-6 into the joint cavity corrected the IL-6 deficiency and significantly reduced cartilage destruction. Inflammation was more chronic in the wild-type mice, and these mice also showed a higher prevalence for osteophyte formation. In ZIA, IL-6 plays a dual role in connective tissue pathology, reducing proteoglycan loss in the acute phase and enhancing osteophyte formation in the chronic phase. The latter could be related to the more severe joint inflammation as seen in the normal (IL-6-producing) animals during the chronic phase of arthritis.

Animals↗
PubMed1995

Lorry drivers' work stress evaluated by catecholamines excreted in urine.

OBJECTIVES: To evaluate lorry drivers' work stress by measurement of adrenaline and noradrenaline excreted in the urine, and to find out which factors in their working situation are related to the excretion rates of these catecholamines. METHODS: The urinary excretion of adrenaline and noradrenaline of 32 lorry drivers, who also had loading and unloading activities to perform, was studied for one working day and one rest day. Each driver was asked to provide six urine samples on both days. RESULTS: For all samples, except the first (overnight) sample, the excretion rates of both catecholamines on the working day were higher than those on the rest day. Hierarchical multiple regression analyses were carried out to find out which factors in the drivers' working situation were related to the excretion rate of the working day. The excretion rate of adrenaline on the rest day, age, and psychosomatic complaints were positively related to the excretion rate on the working day (all P < 0.05). Body mass index and physical workload during loading and unloading were positively related to noradrenaline excretion rate (both P < 0.01). Psychosocial job strain did not significantly contribute to the proportion of variance explained in the excretion rates of both catecholamines. CONCLUSIONS: The excretion rates of adrenaline and, especially, noradrenaline on the working day were higher than those found in earlier studies among professional drivers and insufficient recovery took place after the work was ended. The only association between excretion rate on the working day and work stressors was found for noradrenaline and physical workload. The drivers' sympathoadrenal medullary reactivity to everyday work demands shows the characteristics of sustained activation.

Adult↗
PubMed1993

The use of lower tourniquet inflation pressures in extremity surgery facilitated by curved and wide tourniquets and an integrated cuff inflation system.

Use of the lowest possible cuff inflation pressure should minimize the pathogenic effects of compression beneath the pneumatic tourniquet. Curved tourniquets (designed to fit conically shaped limbs) and wider tourniquets were associated with significantly lower arterial occlusion pressure (AOP) than standard, straight tourniquets on the arms and legs of 26 normal volunteers. These tourniquets were used with an integrated tourniquet inflation system in 29 upper-extremity and 31 lower-extremity surgeries. Mean tourniquet inflation pressures of 183.7 mm Hg and 208 mm Hg were used during various surgical procedures of the arm and leg, respectively. Incomplete hemostasis was associated with elevated systolic blood pressure in several cases, but acceptable surgical hemostasis was achieved by incremental increase of the cuff inflation pressure. Curved cuffs, wide cuffs, and an integrated cuff inflation system should facilitate the use of lower tourniquet inflation pressures in extremity surgery.

Adolescent↗
PubMed1988

Improvements in the simultaneous determination of calcidiol and calcitriol in human serum or plasma.

Technical improvements have been applied to reduce the time required for the determination of calcidiol and calcitriol in serum or plasma. The modifications include the use of Sep-Pak C18 cartridges for the extraction of calciol metabolites from serum instead of a classical liquid/liquid extraction, a considerable shortening of the HPLC purification time compared with our previously described method, and the application of HPLC with UV detection at 254 nm of calcidiol as an alternative to the usual competitive protein binding methods. In none of the 199 samples where calcidiol was determined by HPLC did we observe a detectable peak of ercalcidiol. Quantitation of calcidiol by HPLC and competitive protein binding was compared in 5 series of assays. The correlation between the two methods was 0.99. The average slope of the linear regression line when the HPLC values were plotted versus the competitive protein binding values was 1.14. The average intercept was 0.19 nmol/l. The mean within-run coefficient of variation for calcidiol in these series was 5% for the competitive protein binding method, and 4% for HPLC method. Between-run coefficients of variation were 6% and 12% for the competitive protein binding and for the HPLC method, respectively. Within-run and between-run coefficients of variation for calcitriol were 6% and 15%, respectively.

Calcifediol↗
PubMed1984

An international comparison of vitamin D metabolite measurements.

An international 19-laboratory survey was organized to compare assays for 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, and 1,25-dihydroxyvitamin D in plasma. Each participant received two ethanolic standard solutions of each metabolite and eight plasma samples. Each laboratory used its usual procedures. Mean interlaboratory coefficients of variation (CVs) for the eight plasma samples were 35%, 43%, and 52% for 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, and 1,25-dihydroxyvitamin D, respectively. Average CVs for the standard solutions were 27%, 23%, and 25%, respectively. Of the eight plasma samples, five had the same concentration for one of the metabolites. One sample was diluted to 0.6 times its original concentration and three samples were fortified with one or more of the metabolites under investigation. Fourteen of 18 laboratories (78%) could distinguish between the five unchanged samples and the modified ones with their 25-hydroxyvitamin D assay. Nine of 12 (75%) could distinguish the modified samples from the other samples with the 24,25-dihydroxyvitamin D assay. Only eight of 15 (53%) could do this their 1,25-dihydroxyvitamin D assay. Values from different laboratories evidently cannot be intercompared without making an actual comparison of the assay procedures. Furthermore, in case of clinical applications of these assays, each laboratory should establish its own reference values and should continually use an internal reference sample to assess the precision of the procedures.

24,25-Dihydroxyvitamin D 3↗
PubMedDate not supplied

Patients with ankylosing spondylitis and healthy relatives do not show increased small intestinal permeability with the lactulose-mannitol test.

Small intestinal permeability was measured in 71 subjects: 26 (24 B27+) patients with ankylosing spondylitis (AS); 20 healthy first degree relatives (13 B27+); 6 patients with active Crohn's disease and 19 healthy controls. We determined the urinary excretion ratio of two ingested sugar probes, lactulose (10 g) and mannitol (0.5 g) by gas-liquid chromatography. The median lactulose/mannitol excretion ratio in AS patients (0.0099) and relatives (0.0090) was not significantly different from the median ratio in healthy controls (0.0095). HLA status or use of NSAIDs did not significantly influence the results. In patients with Crohn's disease, on the other hand, the median lactulose/mannitol ratio (0.021) was significantly increased in comparison to healthy controls (0.0095). Our results confirm that the lactulose-mannitol test can be used to demonstrate increased intestinal permeability in Crohn's disease. For patients with AS and their relatives the lactulose-mannitol test may not be sufficiently sensitive. Alternatively, significantly increased permeability may not occur in most patients with AS.

Adult↗