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Biomedical subjects

S Pedersen

Publications and source records attributed to S Pedersen.

At least 73 records · Page 4Linked to original sources
PubMed1998

[Dust reduction in pig houses].

Airborne dust in pig houses causes health problems for humans with full-time employment in pig houses. Many attempts have been made to reduce the dust burdens, but often without sufficient results. At Research Centre Bygholm ten different possibilities for dust reduction have been tested in the test section, and the results are evaluated on the basis of results obtained simultaneously in an identical control section. Until now, the two most efficient methods are addition of fat to the pigs' diet and spraying a thin layer of rape seed oil in the animal house. By adding 4% of fat to the diet, a reduction of 50% can be seen, and by spraying 5 g of rape seed oil daily per pig place, the aerial dust concentration can be reduced to about 75%. The costs are about 1 DM/pig at a price of rape seed oil of 2 DM/l.

Animal Husbandry↗
PubMed1998

Pharmacological interventions. Childhood asthma.

Airway inflammation is present in early asthma. Chronic inflammation seems to be associated with airway remodelling and reduced growth of lung function. An inverse relationship between lung function and duration of asthma or an increase in bronchial reactivity with asthma duration has been reported in many studies. Several trials have found that late use of inhaled corticosteroids is associated with a smaller effect on bronchial hyperreactivity and lung function compared with early use. Furthermore, it has been suggested that early anti-inflammatory treatment may also influence long-term outcome. These findings have elicited the hope that it might be possible to cause disease resolution or modify the natural course of the disease. It has been hypothesized that there may be a window of opportunity in relation to the treatment of asthma after which remodelling and changes in lung function occur which cannot be reversed. However, just when this window of opportunity presents in the progression of the disease, or at what stage early intervention should be initiated, has not been clearly defined. Early pharmacological intervention in children <3 yrs of age is complicated by the fact that treatment will be given to a large number of children who will never develop persistent asthma. This must be considered when designing the studies addressing the various research questions about early pharmacological intervention. Studies in young children should probably be conducted in both high- and low-risk patients. Older patients with apparently mild disease are the main candidates for placebo-controlled trials. Patients with a greater disease severity are more suitable for studies comparing intervention with different drugs or different doses of drug.

Administration, Inhalation↗
PubMed1997

Distinct repression of translation by wortmannin and rapamycin.

The role of phosphatidylinositol 3-kinase and FK506-binding protein rapamycin-associated protein (FRAP) in translational control has been examined by treating RD-rhabdomyosarcoma cells with wortmannin and rapamycin and studying the effects on cell-growth, translation initiation, and protein synthesis. Whereas wortmannin and rapamycin exhibit subtle effects on global translation, examination of individual mRNAs in sucrose gradients and of individual proteins in two-dimensional polyacrylamide gels reveals that wortmannin and rapamycin exhibit distinct effects on the translation of individual mRNAs. Wortmannin represses the synthesis of a third of cellular proteins, whereas rapamycin affects a subset of these proteins. Since ribosomal protein S6 was rapidly dephosphorylated following wortmannin and rapamycin treatment, and the phosphorylation status of the eukaryotic initiation factor 4E was unchanged, our data imply that the p70 signalling pathway has at least one branch-point upstream of FRAP leading to an additional route of translational control.

Androstadienes↗
PubMed1997

[Counting of axillary lymph nodes during surgery of breast cancer. A comparison between radiographic examination and pathological assessment].

Proper breast cancer surgery should include removal of at least ten axillary lymph nodes according to recommendations given by DBCG (The Danish Breast Cancer Group). The present study evaluated the results of counting the lymph nodes peroperatively on radiographs of the axillary tissue compared to the final pathological examination, the latter being considered the "gold standard". Since agreement between the two methods was found in only 66 out of 90 patients (Kappa value 0.279), we consider the peroperative radiological examination of the axillary fat to be of no practical value.

Axilla↗
PubMed1997

Leukotriene D4-induced Ca2+ mobilization in Ehrlich ascites tumor cells.

Stimulation of Ehrlich ascites tumor cells with leukotriene D4 (LTD4) within the concentration range 1-100 nm leads to a concentration-dependent, transient increase in the intracellular, free Ca2+ concentration, [Ca2+]i. The Ca2+ peak time, i.e., the time between addition of LTD4 and the highest measured [Ca2+]i value, is in the range 0.20 to 0.21 min in ten out of fourteen independent experiments. After addition of a saturating concentration of LTD4 (100 nm), the highest measured increase in [Ca2+]i in Ehrlich cells suspended in Ca2+-containing medium is 260 +/- 14 nm and the EC50 value for LTD4-induced Ca2+ mobilization is estimated at 10 nM. Neither the peptido-leukotrienes LTC4 and LTE4 nor LTB4 are able to mimic or block the LTD4-induced Ca2+ mobilization, hence the receptor is specific for LTD4. Removal of Ca2+ from the experimental buffer significantly reduces the size of the LTD4-induced increase in [Ca2+]i. Furthermore, depletion of the intracellular Ins(1,4,5)P3-sensitive Ca2+ stores by addition of the ER-Ca2+-ATPase inhibitor thapsigargin also reduces the size of the LTD4-induced increase in [Ca2+]i in Ehrlich cells suspended in Ca2+-containing medium, and completely abolishes the LTD4-induced increase in [Ca2+]i in Ehrlich cells suspended in Ca2+-free medium containing EGTA. Thus, the LTD4-induced increase in [Ca2+]i in Ehrlich cells involves an influx of Ca2+ from the extracellular compartment as well as a release of Ca2+ from intracellular Ins(1,4,5)P3-sensitive stores. The Ca2+ peak times for the LTD4-induced Ca2+ influx and for the LTD4-induced Ca2+ release are recorded in the time range 0.20 to 0.21 min in four out of five experiments and in the time range 0.34 to 0.35 min in six out of eight experiments, respectively. Stimulation with LTD4 also induces a transient increase in Ins(1,4, 5)P3 generation in the Ehrlich cells, and the Ins(1,4,5)P3 peak time is recorded in the time range 0.27 to 0.30 min. Thus, the Ins(1,4, 5)P3 content seems to increase before the LTD4-induced Ca2+ release from the intracellular stores but after the LTD4-induced Ca2+ influx. Inhibition of phospholipase C by preincubation with U73122 abolishes the LTD4-induced increase in Ins(1,4,5)P3 as well as the LTD4-induced increase in [Ca2+]i, indicating that a U73122-sensitivity phospholipase C is involved in the LTD4-induced Ca2+ mobilization in Ehrlich cells. The LTD4-induced Ca2+ influx is insensitive to verapamil, gadolinium and SK&F 96365, suggesting that the LTD4-activated Ca2+ channel in Ehrlich cells is neither voltage gated nor stretch activated and most probably not receptor operated. In conclusion, LTD4 acts in the Ehrlich cells via a specific receptor for LTD4, which upon stimulation initiates an influx of Ca2+, through yet unidentified Ca2+ channels, and an activation of a U73122-sensitive phospholipase C, Ins(1,4,5)P3 formation and finally release of Ca2+ from the intracellular Ins(1,4,5)P3-sensitive stores.

Animals↗
PubMed1997

Dose titration of nebulized budesonide in young children.

We compared the clinical effect of the glucocorticoid budesonide delivered from two nebulizers Aiolos and Pari LL in 38 children less than 4 years of age (mean age, 20.2 months) with chronic wheeze. The design was a controlled, single-blind, randomized, cross-over, dose titration study. After a 1-week run-in, patients were randomized to treatment with 1 mg budesonide b.i.d. for 2 weeks from either an Aiolos or a Pari LL nebulizer. This was followed by a gradual dose reduction period during which the budesonide dose was reduced at 2-week intervals until unacceptable asthma symptoms appeared or the placebo level was reached. The patient was then switched to budesonide 1 mg b.i.d. from the other nebulizer for 2 weeks, after which the dose was reduced at 2-week intervals as described for the first period. Patients who completed the study on placebo for 2 weeks without deterioration of their asthma were not included in the statistical analysis. During Period #1 the minimum effective dose of budesonide was 2 mg/day in 9 patients, 1 mg/day in 10 patients, and 0.5 mg/day in 13 patients. In Period #2 the corresponding figures were 14, 5, and 13 patients. Six patients were excluded after the first period because their asthma control did not deteriorate during dose reduction and when finishing on placebo for 2 weeks. For both nebulizers the reduction in budesonide dose was associated with a small increase in symptoms and use of rescue terbutaline. The mean dose of budesonide delivered to the patient by the Aiolos was twice as large as that delivered by the Pari LL: 26% vs. 13% of the nominal dose assessed by the filter method. Nevertheless, no statistically significant difference in clinical effect or mean minimal effective dose (1.1 mg for Aiolos and 1.2 mg for Pari LL) could be detected between the two nebulizers. No serious adverse events were observed. We conclude that the minimal effective dose of nebulized budesonide varies from 0.5 to 2.0 mg/day in young children with asthma. A higher drug delivery, as assessed by the filter method, does not necessarily result in better clinical control or lower minimal effective dose. Further studies are needed to assess whether this is due to insufficient sensitivity of the study design in detecting a difference in clinical effect, or whether measurements of drug delivery by the filter method do not reflect lung deposition or clinical effect in young children with wheezing.

Asthma↗
PubMed1997

The effects of ethylene oxide containing lipopolymers and tri-block copolymers on lipid bilayers of dipalmitoylphosphatidylcholine.

A comparative study is conducted on the influence of two types of polymeric compounds on the phase behavior of 1,2-dihexadecanoyl-s,n-glycero-3-phosphotidylcholine (DC16PC) lipid bilayers. The first polymeric compound is a lipopolymer, with two different lengths of a hydrophilic polyethylene oxide moity, anchored to the bilayer by a 1,2-dioctadecanoyl-s,n-glycero-3-phosphoethanolamine (DC18PE) lipid. The second type, which is a novel type of membrane-spanning object, is an amphiphilic tri-block copolymer composed of two hydrophilic stretches of polyethylene oxide separated by a hydrophobic stretch of polystyrene. Hence the tri-block copolymer may act as a membrane-spanning macromolecule mimicking an amphiphilic protein or polypeptide. Differential scanning calorimetry is used to determine a partial phase diagram for the lipopolymer systems and to assess the amount of lipopolymer that can be loaded into DC16PC lipid bilayers before micellization takes place. Unilamellar and micellar phase structures are investigated by fluorescence quenching using bilayer permeating dithionite. The chain length-dependent critical lipopolymer concentration, denoting the lamellar-to-micellar phase transition, compares favorably with a theoretical prediction based on free-energy considerations involving bilayer cohesion and lateral pressure exerted by the polymer chains.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1997

A randomized, double-blind dose reduction study to compare the minimal effective dose of budesonide Turbuhaler and fluticasone propionate Diskhaler.

BACKGROUND: New inhaled glucocorticosteroids and inhalers are being developed. Their clinical equipotency is difficult to assess and is often discussed. OBJECTIVE: This study was carried out to compare the effect of budesonide Turbuhaler and fluticasone propionate (FP) Diskhaler in a dose reduction study in children (ages 5 to 16 years) with asthma. METHODS: Children treated with budesonide administered through a pressurized metered-dose inhaler with a large volume spacer had their budesonide dose gradually reduced to define the minimal effective dose with this delivery system. After this period, 217 children were randomly allocated to treatment with half the dose of either budesonide Turbukaler or FP Diskhaler for 5 weeks in a double-blind trial. If no deterioration in asthma control was seen, the dose was further reduced by 50% at 5-week intervals until deterioration in asthma control was seen. Throughout the study, morning and evening peak expiratory flow, symptoms, and use of rescue beta 2-agonist were recorded in diaries. Lung function tests and a standardized exercise test were performed at the clinic at the end of each treatment period. Urine cortisol excretion (24 hours) was measured before and after the first 5-week treatment period. Standardized criteria for deterioration in asthma control, based on diary card variables and exercise testing, were used to determine the minimal effective dose for each patient; and from this, the number of dose reduction steps was calculated. RESULTS: No statistically significant difference was seen in number of dose reduction steps from baseline or in minimal effective dose between the two treatments; mean reduction was 1.59 dose steps for budesonide Turbuhaler and 1.65 dose steps for FP Diskhaler (p = 0.52), and minimal effective dose was 188 micrograms for budesonide Turbuhaler and 180 micrograms for FP Diskhaler. After these dose reductions, the same level of asthma control was observed in the budesonide Turbuhaler and FP Diskhaler groups. Furthermore, no statistically significant differences between the two inhaler-drug combinations were seen in daytime or nighttime symptoms, morning and evening peak expiratory flow, use of rescue beta 2-agonist, lung functions at the clinic, exercise-induced fall in lung function, or 24-hour urinary cortisol excretion during the first 5-week period. CONCLUSION: Microgram for microgram, budesonide Turbuhaler and FP Diskhaler are equally effective in treatment of children with moderate asthma.

Administration, Inhalation↗
PubMed1997

ECG changes in epilepsy patients.

OBJECTIVES: To investigate the frequency of ECG abnormalities suggestive of myocardial ischaemia in patients with severe drug resistant epilepsy and without any indication of previous cardiac disease, assuming that these changes may be of significance for the group of epileptic patients with sudden unexpected death. MATERIAL AND METHODS: Twelve patients with medically intractable epilepsy were investigated with simultaneous long ECG and EEG recordings while attending either epilepsy surgery investigational procedures or the investigational programme for diagnostic purposes, and one while having an episode of status epilepticus. RESULTS: The ECG recording failed in 1 patient. This patient had chest pain and minor yet morphologically conspicuous changes in the ECG, suggestive of myocardial infarction. He died in heart arrest. Eight epilepsy patients had episodes of ST segment depression in the ECG, many of which coincided with video- and EEG documented epileptic seizures. Two patients experiencing simple partial seizures and 1 patient experiencing absence seizures had no ST segment depressions in the ECG. One patient had an episode of status epilepticus secondary to brain damage and no ST segment deviation was seen during the ECG recording which continued until 3 h before the patient died. CONCLUSION: Patients with severe drug resistant epilepsy have episodes of ST segment changes, some of which are closely related to epileptic seizures. Further studies are needed to confirm the present results and to investigate the nature of these changes and document the effect of prophylactic treatment with cardioactive drugs to reduce the risk of sudden death.

Adolescent↗
PubMed1997

The Child and Adolescent Trial for Cardiovascular Health (CATCH): intervention, implementation, and feasibility for elementary schools in the United States.

The Child and Adolescent Trial for Cardiovascular Health (CATCH) was the largest school-based field trial ever sponsored by the National Institutes of Health. The trial demonstrated positive changes in the school food service and physical education program, as well as in students' cardiovascular health behaviors. Because the CATCH intervention programs were implemented in 56 schools (in four states) that were typical of schools throughout the United States, their reception by schools and degree of implementation provide evidence about their feasibility for schools nationally. Extensive process evaluation data were collected from students, teachers, school food service personnel, and physical education specialists throughout the three school years of the CATCH intervention. Four of the CATCH programs--school food service, physical education, classroom curricula, and home programs--were assessed over the three school years. The process data provide information on participation, dose, fidelity, and compatibility of the CATCH programs in the intervention schools for these programs. High levels of participation, dose, fidelity, and compatibility were observed for the four programs during the 3 school years. CATCH emerges as a model of a feasible multilevel health promotion program to improve eating and exercise behaviors for elementary schools in the United States.

Adolescent↗
PubMed1997

Short-term knemometry and urine cortisol excretion in children treated with fluticasone propionate and budesonide: a dose response study.

Few thorough comparisons of the systemic effects of inhaled corticosteroids in children are available. The aim of this study was to compare the effect of budesonide and fluticasone propionate on short-term lower leg growth. Fluticasone propionate, budesonide and placebo were administered for 2 weeks in a randomized, double-blind, double-dummy, cross-over design. Twenty four children aged 6-12 yrs received 200 microg x day(-1) of each drug, or placebo. Another 24 children aged 6-12 years received 400 microg x day(-1) of each drug, or placebo. Dry powder inhalers were used. Lower leg length was measured by knemometry twice a week during all three treatment periods, and 24 h cortisol excretion in the urine was measured at the end of each period. In the low-dose group, lower leg growth rate was the same during treatment with placebo (0.35 mm x week(-1)), fluticasone propionate (0.38 mm x week(-1)) or budesonide (0.26 mm x week(-1)). No significant difference (p=0.39) in lower leg growth rate was found between treatment with 400 microg x day(-1) budesonide (0.30 mm x week(-1)) and 400 microg fluticasone propionate treatment (0.37 mm x week(-1)). Growth rate during treatment with budesonide, 400 microg x day(-1), was significantly lower than during placebo treatment (0.52 mm x week(-1)). Cortisol excretion in the urine during treatment with 200 microg x day(-1) fluticasone propionate was significantly reduced as compared with placebo (p=0.006), but not when compared with 200 microg x day(-1) budesonide (p=0.07). Budesonide 200 microg x day(-1) was not significantly different from placebo. Fluticasone propionate and budesonide, both at 400 microg x day(-1), resulted in a significant reduction in cortisol excretion in the urine as compared with placebo (p=0.001). It is concluded that, dose-for-dose, budesonide Turbuhaler and fluticasone propionate Diskhaler have similar systemic effects.

Administration, Inhalation↗