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Biomedical subjects

S Pedersen

Publications and source records attributed to S Pedersen.

At least 19 recordsLinked to original sources
PubMed1992

Protective effect and duration of action of inhaled formoterol and salbutamol on exercise-induced asthma in children.

The magnitude and duration of protection against exercise-induced asthma (EIA) afforded by salbutamol and the new, long-acting beta 2-agonist, formoterol, were compared in a double-blind, placebo-controlled crossover study. Twelve children with asthma and EIA (greater than 25% fall from baseline at a pretrial exercise test) were studied on 3 different days receiving, in random order, either formoterol, 12 micrograms, salbutamol, 200 micrograms, or placebo by inhalation. The effect on EIA was evaluated by standardized treadmill-exercise tests repeated at the following times after medication: 1/2 hour (test 1), 3 hours (test 2), and, if the trial drug still demonstrated an effect, 5 1/2 hours (test 3) and 8 hours (test 4). The mean (SD) maximum percent fall in FEV1 at the pretrial test was 45% (14%). Placebo treatment had no effect on EIA. The mean (SD) maximum percent fall in FEV1 was 44% (14%) (test 1) and 39% (13%) (test 2) (not significant). Salbutamol offered good protection against EIA after 1/2 hour (percent fall in FEV1, 18% [18%]; p less than 0.02) but was not significantly different from that of placebo after 3 hours, 39% (13%) fall in FEV1. Formoterol blocked EIA in all the children and demonstrated a significant effect in most children for at least 8 hours. The percent fall in FEV1 after the various tests were 8% (16%) (test 1), 10% (9%) (test 2), 18% (15%) (test 3), and 18% (7%) (test 4; N = 9) (all tests, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1992

Decreasing transcription elongation rate in Escherichia coli exposed to amino acid starvation.

The time required for transcription of the lacZ gene in Escherichia coli was determined during exponential growth and under conditions, when the bacterium was exposed to partial isoleucine starvation. To do this, RNA was extracted from the cells at 10 s intervals following induction and quantified by Northern hybridization with probes complementary to either the beginning or the end of the lacZ mRNA. The time lag between inducer addition and the appearance of a hybridization signal at the 'late' probe represents the transit time for RNA polymerase on the lacZ gene, and this parameter and the known length of the transcribed sequence were used to calculate the lacZ mRNA chain growth-rate. The transcription elongation rate was c. 43 nucleotides s-1 during exponential growth and decreased abruptly to c. 20 nucleotides s-1 in a relA+ strain after the onset of isoleucine starvation, when massive concentrations of guanosine tetraphosphate (ppGpp) accumulated in the cells. The starvation condition did not affect initiation of transcription at the lac-promoter, but a substantial fraction of the initiated lacZ mRNA chains was never completed. For the rel+ strain the polarity was moderate, since c. 25% of the initiated lacZ mRNA' chains were continued into full-length mRNAs, but for the relA strain the polarity was so strong that no completed lacZ mRNA could be detected. The protein chain elongation rates decreased from 13 amino acids (aa) s-1 in the unperturbed growth phase to approximately 6 as s-1, when the cells starved for isoleucine. In combination, these results suggest that ppGpp plays a major role in maintaining the coupling between transcription and translation during the downshift by inhibiting mRNA chain elongation. The implications of this result for the control of stable RNA synthesis during the stringent response are discussed.

Amino Acids↗
PubMed1992

A double-blind, placebo-controlled study of the effect of intranasal budesonide in the treatment of children with seasonal rhinitis.

The effectiveness of the intranasal glucocorticosteroid budesonide was investigated in children with grass pollen-induced rhinitis during a pollen season. The trial was of a randomized, double-blind, placebo-controlled, parallel-group design with a one-week run-in period and a three-week treatment period. Twenty-four children received treatment with budesonide 200 micrograms bid and 27 children with placebo, administered by a nasal aerosol. Concomitant terfenadine, as required, was allowed in both groups. Recordings of nasal symptom severity, use of terfenadine and adverse effects were made in diaries. Nasal symptoms were significantly less severe in patients treated with budesonide as compared with placebo-treated patients. An overall assessment of treatment effect made by the children was significantly in favour of budesonide, and the consumption of terfenadine was significantly larger in the placebo than in the budesonide group. These results provide good evidence that intranasal budesonide is effective in seasonal rhinitis in children.

Administration, Intranasal↗
PubMed1992

Fast one-step procedure for the detection of nucleic acids in situ by primer-induced sequence-specific labeling with fluorescein-12-dUTP.

We provide fast, simple, one-step procedures for sequence-specific detection of nucleic acids in situ. Tandem repeat sequences in DNA are stained within 30 min, and mRNA is stained within 2 h. The procedures are based on the incorporation of the newly available fluorescein-labeled dUTP into DNA synthesized in situ by primed in situ labeling, with denatured fragments of cloned DNA or oligonucleotides as primers. The extreme speed and simplicity of the reaction make it attractive for automatization in routine laboratory procedures and opens up new diagnostic possibilities.

DNA↗
PubMed1992

Knemometry in the assessment of short-term linear growth in a population of healthy school children.

Short-term lower leg length increments were monitored with weekly knemometry measurements during 3 months in 27 healthy school children aged 8-12 years. One year after the first visit the children were measured once again. The mean short term velocity of lower leg growth was 0.40 mm/week (SD 0.12 mm/week). The mean short-term and annual ratios between height velocity and lower leg growth velocity were identical (2.8). The relative variation between two observers was 0.08%. Knemometry is a suitable method for monitoring short-term linear growth in populations of children. Two trained observers may substitute for each other in group studies.

Anthropometry↗
PubMed1992

Controlled study of linear growth in asthmatic children during treatment with inhaled glucocorticosteroids.

Linear growth was investigated with weekly knemometry in a population of 43 schoolchildren with mild asthma treated with inhaled budesonide. The design was a randomized, double-blind, parallel group study with three dose groups of 200, 400, and 800 micrograms of budesonide per day. Each dose group received budesonide for 8 consecutive weeks. Placebo was given for either 4 weeks before or after budesonide treatment. Twelve children in the 200-micrograms group, 14 in the 400-micrograms group, and 12 in the 800-micrograms group completed the 12-week study period. There was no significant difference in mean growth velocity among the three dose groups during placebo treatment. Compared with placebo (growth velocity: 0.39 mm/wk), mean lower leg growth velocity was reduced with 0.26 mm/wk (P less than .001, t = 5.0, df = 11; 95% confidence interval 0.14 to 0.37 mm/wk) in children treated with 800 micrograms of budesonide. There was no statistically significant difference in growth velocity between 200- or 400-micrograms budesonide treatments and placebo. These data indicate that inhaled budesonide can be safely used in doses up to 400 micrograms/d in schoolchildren with asthma.

Administration, Topical↗
PubMed1991

Absolute in vivo translation rates of individual codons in Escherichia coli. The two glutamic acid codons GAA and GAG are translated with a threefold difference in rate.

We have determined the absolute translation rates for four individual codons in Escherichia coli. We used our previously described system for direct measurements of in vivo translation rates using small, in-frame inserts in the lacZ gene. The inserts consisted of multiple synthetic 30 base-pair DNA oligomers with high densities of the four individual codons, GAA (Glu), GAG (Glu), CCG (Pro) and CGA (Arg). Our method is independent of expression level, of mRNA half-life and of transcription rate. Codon GAA was found to be translated with a rate of 21.6 codons/second whereas codon GAG was translated 3.4-fold slower (6.4 codons/s). These two codons are read by the same tRNA species. Codon CCG and CGA are both read by abundant tRNA species but nevertheless we found them to be translated slowly with rates of 5.8 and 4.2 codons/second, respectively. The context of these codons were varied, but we found no significant influence of context on their translation rates and we suggest a mechanism for why context may not affect translation rates. One insert with a low translation rate gave results that most readily can be explained by assuming queue formation of ribosomes on the insert. Such a queue was found to reduce the expression level by approximately 35%. Our experiments allowed us to estimate the average distance between ribosomes and thereby the translation initiation frequency on the wild-type lacZ mRNA. This was found to be one per three seconds.

Base Sequence↗
PubMed1991

[Allergy to insect stings].

Components in the insect venom and probably also in their saliva may have direct toxic effects or may cause sensitization and may result in allergic reactions to subsequent stings. In Denmark, only the stings of honey bees and wasps (yellow jackets) are of clinical significance and it is important to be aware that these insects contain separate allergenic components. Clinical manifestations following stings are observed from all of the organ systems on the whole. The commonest are itching of the skin, urticaria, possibly angioedema and slight generalized symptoms with vertigo, headache and fatigue. Life-threatening reactions may also occur and one or two fatal cases are registered annually in Denmark. It may be difficult to decide whether an allergic or a toxic reaction is involved on the basis of the symptoms. Possible IgE-sensitization must therefore be assessed by means of a prick test and measurement of specific IgE. The main treatment in cases of acute systemic reactions is adrenaline which may possibly be supplemented with antihistamine and corticosteroid. In cases of massive local reactions and urticaria, antihistamines will, as a rule, prove sufficient. Hyposensitization with insect venom preparations eliminates the future risk for systemic insect sting reactions practically entirely and this must be recommended for patients with demonstrated IgE-sensitizing and generalized reactions. At present, treatment should be continued for three to five years and protection lasts for a series of years after cessation of treatment.

Humans↗
PubMed1991

Growth of asthmatic children during treatment with budesonide: a double blind trial.

OBJECTIVE: To determine whether the inhaled glucocorticosteroid budesonide has any adverse effect on short term linear growth in children with mild asthma. SETTING: Outpatient clinic in secondary referral centre. PATIENTS: 15 children aged 6-13 years with normal statural growth velocity during the previous year, no signs of puberty, and no use of systemic or topical steroids in the two months before the study. DESIGN OF INTERVENTIONS: Double blind, randomised crossover trial with two active periods in which budesonide was given in divided daily doses of 200 micrograms and 800 micrograms. During run in and two washout periods placebo was given. After the second washout period the children received open treatment with 400 micrograms budesonide daily. All periods were of 18 days' duration. MAIN OUTCOME MEASURE: Growth of the lower leg as measured twice a week by knemometry. RESULTS: Mean growth velocity of the lower leg was 0.63 mm/week during run in and during washout 0.64 mm/week. Budesonide treatment was associated with a significant dose related reduction of growth velocity: the mean reduction in growth velocity during treatment was 0.11 (95% confidence interval -0.15 0.36 (0.13 to 0.59) mm/week with 800 micrograms budesonide (p less than 0.05; Page's test). During treatment with 400 micrograms budesonide a reduction of 0.17 (-0.10 to 0.45) mm/week was found. CONCLUSIONS: Treatment with inhaled budesonide is associated with a dose related suppression of short term linear growth in children with mild asthma.

Adolescent↗
PubMed1991

Assignment of structures to oligosaccharides produced by enzymic degradation of a beta-D-glucan from barley by 1H- and 13C-n.m.r. spectroscopy.

The structures of one tri-(1), two tetra-(2 and 3), and one hexa-saccharide (4) produced by treatment of barley flour, after removal of the starch components, with a fungal beta-D-glucanase (Finizyme) have been assigned on the basis of 1H- and 13C-n.m.r. data as follows: beta-D-Glcp-(1----3)-beta-D-Glcp-(1----4)-D-Glcp (1), beta-D-Glcp-(1----4)-beta-D-Glcp-(1----3)-beta-D-Glcp-(1----4)-D-Glcp (2), beta-D-Glcp-(1----3)-beta-D-Glcp-(1----4)-beta-D-Glcp-(1----4)-D-Glcp (3), and beta-D-Xylp-(1----4)-[alpha-L-Araf-(1----3)]-[alpha-L-Ara f-(1----2)-beta-D-Xylp-(1----4)-beta-D-Xylp- (1----4)-D-Xylp (4).

Carbohydrate Sequence↗
PubMed1991

Bacterial contamination of air and surgical wounds during joint replacement operations. Comparison of two different types of staff clothing.

Compared with conventional surgical clothing, polypropylene coveralls reduced the bacterial contamination of the air of a conventionally ventilated operating room by 62%. The contamination of surgical wounds during joint replacement was also reduced, but not to a significant degree. Sixteen percent of the bacteria sampled from the wounds were resistant to the prophylactic antibiotic and the importance of a clean air system for performing joint replacement operations is stressed. The use of commercially available non-woven swabs for sampling bacteria from the surgical wound compared favourably with the use of specially prepared velvet pads.

Air Microbiology↗
PubMed1991

Adrenal function in asthmatic children treated with inhaled budesonide.

The effect of the inhaled topical steroid budesonide on adrenal function was evaluated in 33 children (aged 7-15 years) with moderate bronchial asthma. The trial was designed as a prospective single-blind study of the effect of budesonide in daily doses of 200 microgram through 400 microgram to 800 micrograms in three randomized consecutive periods of 8 weeks. The unstimulated diurnal production of cortisol was assessed by measurement of free cortisol in 24-hour urine samples at the end of each period. No significant dose-related suppression was found. The cortisol production did not differ significantly during treatment with 800 microgram budesonide as compared to treatment with 200 microgram budesonide (95% confidence interval: 74%-112%). It is concluded, that budesonide is a topical steroid with a favourable ratio between topical and systemic effects in asthmatic children.

Administration, Inhalation↗
PubMed1991

ClpB is the Escherichia coli heat shock protein F84.1.

ClpB is thought to be involved in proteolysis because of its sequence similarity to the ClpA subunit of the ClpA-ClpP protease. It has recently been shown that ClpP is a heat shock protein. Here we show that ClpB is the Escherichia coli heat shock protein F84.1. The F84.1 protein was overproduced in strains containing the clpB gene on a plasmid and was absent from two-dimensional gels from a clpB null mutation. Besides possessing a slower growth rate at 44 degrees C, the null mutant strain had a higher rate of death at 50 degrees C. We used reverse transcription of in vivo mRNA to show that the clpB gene was expressed from a sigma 32-specific promoter consensus sequence at both 37 and 42 degrees C. We noted that the clpB+ gene also caused the appearance of a second protein spot, F68.5, on two-dimensional gels. This spot was approximately 147 amino acids smaller than F84.1 and most probably is the result of a second translational start on the clpB mRNA. F68.5 can be observed on many published two-dimensional gels of heat-induced E. coli proteins, but the original catalog of 17 heat shock proteins did not include this spot.

Base Sequence↗
PubMed1991

An unusual correlation between ppGpp pool size and rate of ribosome synthesis during partial pyrimidine starvation of Escherichia coli.

Escherichia coli was exposed to partial pyrimidine starvation by feeding a pyrBI strain orotate as the only pyrimidine source. Subsequently, differential rates of synthesis of rRNA and of a few ribosome-associated proteins as well as the pool sizes of nucleoside triphosphates and ppGpp were measured. As the orotate concentration in the medium was reduced, the growth rate decreased and the pools of pyrimidine nucleotides, particularly UTP, declined. We did not observe the normal inverse relation between concentration of ppGpp and growth rate; rather, we observed that the ppGpp pool was low at slow growth rates. Upshifts in growth rate were made by adding uracil to a culture growing slowly on orotate. Downshifts could be provoked by adding aspartate plus glutamate to a culture growing at a high concentration of orotate. Following the upshift, both the rates of synthesis of the ribosomal components and the pool of ppGpp increased rapidly, while they all decreased after the downshift. These results are discussed in relation to the role of ppGpp in the growth rate control and the stringent response.

Escherichia coli↗
PubMed1990

Ribosomal protein S1 of Escherichia coli is the effector for the regulation of its own synthesis.

To facilitate the study of the regulation of the rpsA gene, a translational fusion between the rpsA gene and the lacZ gene was constructed. Synthesis of the fusion protein was repressed about 10-fold when rpsA was supplied in trans on a multicopy plasmid. This repression is similar to the post-transcriptional regulation previously found for the wild type rpsA gene. Addition of purified protein S1 to a coupled in vitro transcription-translation system caused a specific reduction in the synthesis of the rpsA-lacZ fusion protein. Addition of various subdomain fragments of protein S1 to the coupled in vitro system showed that the N-terminal fragment, possessing the ribosome binding domain of protein S1, was able to repress the synthesis of the rpsA-lacZ fusion protein. In contrast, fragments from the C-terminal region, containing the nucleic acid binding domain of protein S1, were inactive in this repression. Induction of truncated rpsA genes, coding for either the N-terminal 101 or 329 amino acids caused a reduction in the synthesis of the chromosomally encoded protein S1, thus confirming in vivo that the N-terminal part of protein S1 represses rpsA expression.

Amino Acid Sequence↗