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Biomedical subjects

S Pedersen

Publications and source records attributed to S Pedersen.

At least 19 recordsLinked to original sources
PubMed2002

Impact of protein energy malnutrition on Trichuris suis infection in pigs concomitantly infected with Ascaris suum.

The objective of this experiment was to investigate a possible interaction between protein and energy malnutrition (PEM) and intestinal nematode infections. We report on a 3 x 2 factorial study in which pigs were fed either a low protein energy (LPE), low protein (LP) or a normal protein energy (NPE) diet, and 6 weeks later inoculated with Trichuris suis (4000 infective eggs). Secondarily, in order to obtain a polyparasitic status, pigs were concomitantly inoculated with Ascaris suum (600 infective eggs). The number of T. suis-infected pigs was higher in LP pigs compared with NPE pigs (100 versus 58%; P = 0.037), although the differences in median T. suis worm burdens between groups at necropsy 10 weeks post-infection (p.i.) (LPE: 795; LP: 835; NPE: 48 worms; P = 0.33) were not significant. Interestingly, only T. suis in NPE were highly aggregated (k = 0.44), in contrast to a more uniform distribution among pigs in LPE (k = 1.43) and LP (k = 1.55) i.e. the majority of pigs harboured moderate worm burdens in LPE and LP, while most pigs had few or no worms in NPE. Further, T. suis worms in the LPE and LP groups were decreased in length (mean: LPE: 23.5 mm; LP: 24.3 mm; NPE: 29.4 mm; P = 0.004). The pre-patency period of T. suis was also extended in the LPE and LP groups, as reflected by lower faecal egg output at week 6 (P = 0.048) and/or 7 p.i. (P = 0.007). More A. suum worms were recovered from LP compared with the NPE group (mean: 5.4 versus 0.6; P = 0.040); this was accompanied by a higher faecal egg output in the former (P = 0.004). The low protein diets resulted in lower pig body weight gains, serum albumin, haemoglobin and packed cell volume (PCV) levels as well as diminished peripheral eosinophil counts. Infection significantly altered these parameters in the low protein groups, i.e. the pathophysiological consequences of infection were more severe in the PEM pigs. These results demonstrate that reduced protein in the diet leads to malnourishment of both the host pigs and T. suis, and compromises the pig's ability to resist infection by T. suis and A. suum.

Animals↗
PubMed2002

Long-term outcomes in paediatric asthma.

Over the years the aims of asthma management have changed markedly from effective prednisolone treatment of symptoms and exacerbations towards more use of continuous prophylactic treatment. With our new understanding of the disease and its management definition of the aims of treatment and assessment of optimal asthma control have become much more complex. Even in times of evidence-based medicine our asthma management is based upon findings of effects on various outcomes in somewhat short-term (<1 year) controlled studies. However, assumptions about long-term effects upon the basis of findings in such studies should be made with great caution. Good examples of this are studies which assess the risk of systemic effects and clinical adverse effects of inhaled corticosteroids. From such studies it has become clear that systemic effects detected in short-term trials may have no predictive value of long-term adverse effects. Thus steroid-induced changes in lower leg growth rates assessed by knemometry do not predict long-term statural growth. Moreover, steroid-induced changes in statural growth over 1 year are not predictive of effects upon attained adult height. In contrast, reduced growth caused by uncontrolled asthma disease also seems to affect attained adult height adversely. These findings suggest that long-term outcomes should play a larger role when future asthma management strategies are decided. Some important long-term outcomes of asthma management in children include cure or remission of the disease, prevention of complications of the disease (airway remodelling, adverse effects upon growth/adult height, peak bone mineral density, physical impairment and psychosocial development) or its pharmacological management (adverse effects upon adult height, peak bone mineral density). More controlled long-term studies (several years) are needed to provide a better understanding of how these outcomes are best achieved.

Adrenal Cortex Hormones↗
PubMed2002

Host age influence on the intensity of experimental Trichuris suis infection in pigs.

The impact of age-related resistance on the regulation of population dynamics of adult Trichuris suis was investigated in an experimental pig model. Helminth-naïve pigs varying in age from five weeks to four years were infected with T. suis to determine susceptibility to infection. Sows had a significantly lower establishment of adult T. suis worms compared with weaner pigs. Adult worm populations were highly overdispersed in both sows and grower pigs contrasted by a more even distribution among weaner pigs. Sows had significantly lower worm fecundities compared to weaner and grower pigs; T. suis from grower pigs, in turn, had reduced fecundity compared to worms in weaner pigs. In conclusion, we provide the first controlled experimental evidence that age-related resistance to T. suis occurs in pigs.

Age Factors↗
PubMed2002

Frequent musculoskeletal symptoms and reduced health-related quality of life among industrial workers.

The high percentage of musculoskeletal symptoms (MSS) found in studies of general populations and various occupational groups underlines the need to distinguish between severely and mildly affected individuals. To investigate associations between MSS and quality of life, we examined the frequency of MSS on a five-point scale, health-related quality of life (SF-36) and sickness absence among 5654 workers in the aluminium industry. High frequencies of MSS from all body parts were related to lower scores on the SF-36 and increased sickness absence. This relationship was strongest for MSS from the lower back. Workers who reported low back MSS 'very often' had a mean role--physical score equivalent to that of the 15th percentile of the general population. These results show that workers who reported MSS often or very often were severely affected, and this scale can therefore be used to distinguish individuals at high risk for reduced health-related quality of life and sickness absence.

Absenteeism↗
PubMed2001

Reduction and alkylation of proteins in preparation of two-dimensional map analysis: why, when, and how?

The standard procedure adopted up to the present in proteome analysis calls for just reduction prior to the isoelectric focusing/immobilized pH gradient (IEF/IPG) step, followed by a second reduction/alkylation step in between the first and second dimension, in preparation for the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) step. This protocol is far from being optimal. It is here demonstrated, by matrix assisted laser desorption/ionization-time of flight (MALDI-TOF)-mass spectrometry, that failure to reduce and alkylate proteins prior to any electrophoretic step (including the first dimension) results in a large number of spurious spots in the alkaline pH region, due to "scrambled" disulfide bridges among like and unlike chains. This series of artefactual spots comprises not only dimers, but an impressive series of oligomers (up to nonamers) in the case of simple polypeptides such as the human alpha- and beta-globin chains, which possess only one (alpha-) or two (beta-) -SH groups. As a result, misplaced spots are to be found in the resulting two-dimensional (2-D) map, if performed with the wrong protocol. The number of such artefactual spots can be impressively large. In the case of analysis of complex samples, such as human plasma, it is additionally shown that failure to alkylate proteins results in a substantial loss of spots in the alkaline gel region, possibly due to the fact that these proteins, at their pI, regenerate their disulfide bridges with concomitant formation of macroaggregates which become entangled with and trapped within the polyacrylamide gel fibers. This strongly quenches their transfer in the subsequent SDS-PAGE step.

Alkylation↗
PubMed2001

The inhaled Steroid Treatment as Regular Therapy in early asthma (START) study: rationale and design.

Although the beneficial effects of treatment with inhaled steroids in asthma are widely accepted, the role of early intervention in patients with mild asthma remains unsettled. Conventional efficacy trials are often of short duration and involve highly selected patient populations that exclude many patients typical of those encountered in routine clinical practice. Hence, a large "real-world" effectiveness study is needed to evaluate the benefits of early intervention with inhaled steroids in patients with mild, persistent asthma. In the START (inhaled Steroid Treatment As Regular Therapy in early asthma) study, patients ages 6-60 years, from 31 countries and districts worldwide with mild persistent asthma, have been randomized to once-daily treatment with budesonide, 200 microg (for patients < 11 years) or 400 microg (for patients > or = 11 years), or placebo via Turbuhaler for 3 years. The double-blind treatment period will be followed by a 2-year period of open budesonide treatment. Throughout the study, other asthma medication including glucocorticosteroids can be given as judged appropriate by the investigator. Lung function will be measured by spirometry using standardized techniques at 3-month intervals throughout the study, and bronchodilator reversibility will be measured annually. The primary outcome measures are the time to the first severe asthma-related event during the first 3 years of the study and the change in postbronchodilator forced expiratory volume in 1 second (FEV(1)) from baseline during the entire 5-year study period. These measures have been chosen to reflect the progression of mild asthma toward more severe asthma and the extent of irreversible airflow limitation, which should reflect the degree of airway remodeling.

Acute Disease↗
PubMed2001

Effect of iron deficiency on Trichuris suis and Ascaris suum infections in pigs.

The objective of this experiment was to detect a possible interaction between iron deficiency and intestinal nematode infections. We report on a 2 x 2 study where thirty-one 10-week-old pigs fed a low or a normal iron diet were infected with both Trichuris suis (4500 eggs) and Ascaris suum (1200 eggs). No significant difference was detected between diet groups with respect to parasitological parameters for A. suum or the total number of adult T. suis recovered at necropsy 10 weeks p.i. However, in the low iron group T. suis were located more proximally and the worms were increased in length. A higher proportion of pigs with initial faecal egg excretion at 6 weeks p.i. was observed in the low iron group, indicating a shortened pre-patency period. Worm fecundity and total faecal egg excretion were also highest in the low iron group. A significant correlation was found between female worm length and fecundity. The peripheral eosinophil counts were diminished in the low iron host groups. The infected low iron group experienced more severe pathophysiological changes in terms of hypoalbuminaemia and decreases in erythrocyte volumes. A significant inverse correlation existed between iron content in the bone-marrow and liver (body) store. In conclusion, iron deficiency increased the severity of T. suis infection in pigs.

Anemia, Iron-Deficiency↗
PubMed2001

Acquired immunity to Trichuris suis infection in pigs.

Strong resistance to reinfection developed in pigs as a result of trickle inoculations with Trichuris suis (250 infective eggs twice weekly for 4 weeks). At challenge (4000 eggs) 8 weeks after the last trickle inoculation, we observed a 96% reduction in the mean number of established challenge worms in immunized (TRI/CHA) compared with non-immunized controls (CON/CHA) (74 v. 1753; P = 0.004). Moreover, the total faecal egg excretion was significantly lower in immunized pigs compared with controls (P = 0.0003). The trickle inoculations depressed pig weight gains over the 8-week course of immunization (P = 0.042). It was observed that a small number of pigs developed a weaker level of resistance, reflecting the importance of genetic determinants. The relevance of these data to the population biology of porcine and human whipworm infections is discussed.

Animals↗
PubMed2001

Assessing the effect of intranasal steroids on growth.

Several studies have evaluated the effects of childhood use of corticosteroids on growth. In short-term studies, the budesonide (BUD) metered dose inhaler and methylprednisolone (injection) had significant effects on lower-leg growth, whereas terfenadine did not. When two doses of BUD (nasal inhaler, 200 or 400 microg once daily) were compared with placebo, only the 400-microg dose had a significant effect on short-term growth. Intranasal mometasone furoate (MF) (100 and 200 microg) had no significant effect on short-term lower-leg growth. In intermediate studies of 1-year duration, intranasal beclomethasone dipropionate (84 microg twice daily) significantly affected growth rate, whereas in a separate study, 100 microg intranasal MF once daily did not. Long-term growth data come from retrospective studies of children with asthma. In these studies, no significant effect on growth has been demonstrated in children taking inhaled beclomethasone dipropionate or BUD. The reason for the discrepancy between intermediate and long-term studies is unclear and warrants further study. Variables in childhood growth including seasonal variations may make growth difficult to assess. However, because growth suppression has been reported in children receiving inhaled or intranasal corticosteroids, the lowest effective dose of drug with a low systemic absorption ratio should always be used. Overall, there appears to be no growth suppression with 100 microg intranasal MF used once daily in children.

Administration, Intranasal↗
PubMed2001

Release of heat, moisture and carbon dioxide in an aviary system for laying hens.

1. Production of total heat, divided into sensible and latent heat, together with carbon dioxide and animal activity were determined at different ambient temperatures under full-scale conditions in an aviary system with loose-housed laying hens. 2. Sensible heat production decreased approximately linearly with increasing ambient temperature and was lower during the day than at night. One explanation may be that some sensible heat produced by the hens was converted to latent heat by evaporation of moisture due to increased activity of the hens during the day (scratching in the bedding and drinking/waste water). 3. Latent heat production increased with increasing ambient temperature and was higher during the day than at night. This confirms that the hens, by agitating the bedding during the day and by spilling drinking water, transferred some sensible heat to latent heat by evaporation. 4. Total heat production decreased with increasing temperature because the hens by thermoregulation decreased their metabolism in order to maintain a constant body temperature. The difference between day and night values of total heat production was less pronounced than in the case of sensible and latent heat. In comparison with current guidelines the measurements showed a higher total heat production (22% higher at 20 degrees C). 5. There was a large diurnal variation in carbon dioxide production, closely correlated to measured animal activity; on average carbon dioxide production during the 12-h dark period was only 66% of the production during the day.

Animals↗
PubMed2001

Exposure assessment and lung function in pig and poultry farmers.

OBJECTIVES: To describe the relation between spirometric findings and farming characteristics and variables of exposure to organic dust measured during work in animal buildings. Farmers have traditionally been described as having one of the most dangerous occupations, so a large scale study on European farmers was carried out. This is the report of the second part of that study. METHODS: 40 pig farmers in Denmark and 36 poultry farmers in Switzerland were chosen randomly and were assessed over 1 working day. RESULTS: Mean (SD) baseline spirometric results in pig farmers were higher than in poultry farmers (forced expiratory volume in 1 second (FEV(1)) (% of reference value) 108.3 (16.7) v 100.2 (14.2); p=0.04). Baseline lung function results were significantly associated with ventilation of the animal houses. Furthermore, temperature was related to spirometric findings in pig farmers. CONCLUSIONS: Ventilation of the animal house and temperature might influence respiratory morbidity in farmers.

Adult↗
PubMed2000

Effect of long-term treatment with inhaled budesonide on adult height in children with asthma.

BACKGROUND: Short-term studies have shown that inhaled corticosteroids may reduce the growth of children with asthma. However, the effect of long-term treatment on adult height is uncertain. METHODS: We conducted a prospective study in children with asthma to examine the effect of long-term treatment with inhaled budesonide on adult height. We report on 211 children who have attained adult height: 142 budesonide-treated children with asthma, 18 control patients with asthma who have never received inhaled corticosteroids, and 51 healthy siblings of patients in the budesonide group, who also served as controls. RESULTS: The children in the budesonide group attained adult height after a mean of 9.2 years of budesonide treatment (range, 3 to 13) at a mean daily dose of 412 microg (range, 110 to 877). The mean cumulative dose of budesonide was 1.35 g (range, 0.41 to 3.99). The mean differences between the measured and target adult heights were +0.3 cm (95 percent confidence interval, -0.6 to + 1.2) for the budesonide-treated children, -0.2 cm (95 percent confidence interval, -2.4 to +2.1) for the control children with asthma, and +0.9 cm (95 percent confidence interval, -0.4 to +2.2) for the healthy siblings. The adult height depended significantly (P<0.001) on the child's height before budesonide treatment. Although growth rates were significantly reduced during the first years of budesonide treatment, these changes in growth rate were not significantly associated with adult height. CONCLUSIONS: Children with asthma who have received long-term treatment with budesonide attain normal adult height.

Administration, Inhalation↗
PubMed2000

[Will the use of still image electronic referrals save costs?].

BACKGROUND: The use of still images in an electronic referral makes it possible for patients with uncomplicated skin disorders to receive treatment at their local health clinic by their own physician. The aim of this study was to analyse whether investing in technology to forward still images via telemedicine is cost-effective and to assess how many municipalities in the counties of Troms and Finnmark that have a sufficient workload to reach this requirement. MATERIAL AND METHODS: The additional costs of using still images were compared to patient travel costs to the University Hospital of Tromsø. RESULTS: The results showed that whether the use of still image telemedicine is cost-effective or not, depends on distance and annual workload. Given the assumption in this study, 18 out of 44 municipalities have a sufficient number of patients with a dermatological problem to make telemedicine cost-effective. INTERPRETATION: Less than half of the municipalities in the two northernmost counties have an efficiency potential in using still images. However, telemedicine may be justified because it save time for patients and it increases equal access to care.

Cold Climate↗
PubMed2000

Thermodynamics of heat-shock response.

Production of heat-shock proteins is induced when a living cell is exposed to a rise in temperature. The heat-shock response of protein DnaK synthesis in E.coli for temperature shifts T-->T+DeltaT and T-->T-DeltaT is measured as a function of the initial temperature T. We observe a reversed heat shock at low T. The magnitude of the shock increases when one increases the distance to the temperature T0 approximately 23 degrees C, thereby mimicking the nonmonotonous stability of proteins at low temperature. This suggests that stability related to hot as well as cold unfolding of proteins is directly implemented in the biological control of protein folding.

Escherichia coli↗