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Biomedical subjects

A Nilsson

Publications and source records attributed to A Nilsson.

At least 73 records · Page 4Linked to original sources
PubMed2001

Physical activity in relation to aerobic fitness and body fat in 14- to 15-year-old boys and girls.

The purpose of this study was to examine the strength of the relationship between different variables of physical activity and aerobic fitness and body fat in adolescent boys and girls. Activity energy expenditure (AEE), time spent in a sedentary state, and time spent engaged in moderate and vigorous physical activity (MVPA, > or = 50% peak oxygen uptake, VO2peak) were assessed by the minute-by-minute heart rate monitoring method in 82 randomly selected 14- to 15-year olds (42 boys, 40 girls). Body fat was determined by measuring skinfold thicknesses. VO2peak was measured by indirect calorimetry. Somatic maturity level was determined by percentages of adult (i.e. 18 years) height attained at examination. AEE was related to aerobic fitness for both genders (boys, r = 0.30, P = 0.056; girls, r = 0.45, P = 0.003). For boys, there was a significant relationship between maturity level and VO2peak (r = 0.48, P < 0.001). For both genders, body fat was significantly and negatively related to VO2peak (r = -0.48 and r = -0.43, P < 0.01). Body fat and maturity explained 47% of the variation in VO2peak in boys, whereas AEE and body fat explained 22% of the variation in VO2peak in girls. No significant associations between physical activity variables and the data on body fat were observed. The total amount of physical activity (AEE) was related to VO2peak, at least in adolescent girls. Although VO2peak seems to be influenced by the maturity level in adolescent boys, the data support the promotion of a daily active lifestyle among young people.

Adipose Tissue↗
PubMed2001

Evidence for specific ceramidase present in the intestinal contents of rats and humans.

A neutral ceramidase activity stimulated by bile salt was previously identified in the intestinal content. Recently, bile salt stimulated lipase (BSSL) was found to have ceramidase activity. It is unknown whether the ceramidase activity previously found is attributable to BSSL. To address this question, we compared the behaviors of high quaternary aminoethyl (HQ) anion exchange chromatography, the distributions, the stability, and the responses to lipase inhibitor between ceramidase and pancreatic BSSL. The proteins from whole small intestinal contents of humans and rats were precipitated by acetone and dissolved in 20 mM Tris buffer pH 8.2. These proteins had neutral ceramidase activity but not BSSL activity against p-nitrophenyl acetate. When the proteins were subject to HQ chromatography, two peaks of ceramidase activity were identified, which had acid and neutral pH optima, respectively. Neither of them had BSSL activity against p-nitrophenyl acetate. Western blot using BSSL antiserum failed to identify BSSL protein in the fractions with high neutral ceramidase activity. In rat intestinal tract, pancreatic BSSL activity was high in the duodenum and declined rapidly in the small intestine, whereas neutral ceramidase activity was low in the duodenum and maintained a high level until the distal part of the small intestine. In addition, orlistat, the inhibitor of lipase, abolished human BSSL activity against p-nitrophenyl acetate and slightly reduced its activity against ceramide but had no inhibitory effect on ceramidase activity isolated by HQ chromatography. In conclusion, we provide the evidence for a specific ceramidase other than pancreatic BSSL present in the intestinal content. The enzyme may play important roles in digestion of dietary sphingolipids.

Amidohydrolases↗
PubMed2001

Distribution and properties of neutral ceramidase activity in rat intestinal tract.

Ceramide plays an important role in regulating cell proliferation and apoptosis. Recent studies indicate that generation of ceramide in the intestine from sphingomyelin hydrolysis may be implicated in colon cancer development. The enzymes that catalyze the further hydrolysis of ceramide in the intestine have, however, not been well investigated. Our data reveal the existence of a ceramidase (EC 3.5.1.23) in rat intestinal mucosa with an optimal pH of 7.0. One milligram of mucosal protein is able to hydrolyze 44.0+/-9.6 nmol of ceramide in 1 hr. The activity is low in the proximal duodenum and increases to a plateau in the proximal jejunum. The activity is then similar throughout the small intestine, until it declines in the distal part of ileum. Some activity is also detectable in the colon. The activity increases slightly in the presence of monomeric bile salt concentrations and sharply at the critical micellar concentration. Similar patterns were observed for both primary (taurocholate) and secondary (taurodeoxycholate) bile salts. The addition of Triton X-100 enhances the ceramidase activity at optimal bile salt concentration. The reaction is linear with time for the first 20 min and the hydrolytic rate declines slowly thereafter. Finally, the activity shows a considerable resistance against tryptic degradation, as 71% of the ceramidase activity remained when the homogenates were preincubated with high concentrations of trypsin. Intestinal mucosa also has a ceramide synthesis activity, with a distribution pattern generally paralleling ceramide hydrolysis activity. In conclusion, intestinal neutral ceramidase has a distinct distribution pattern and bile salt dependence, which enables it to collaborate with intestinal sphingomyelinase in hydrolysis of sphingomyelin.

Amidohydrolases↗
PubMed2001

Prediction of silent celiac disease at diagnosis of childhood type 1 diabetes by tissue transglutaminase autoantibodies and HLA.

AIMS: The aims were to estimate the diagnostic sensitivity and specificity of autoantibodies to tissue transglutaminase (IgA- and IgG-tTG), gliadin (AGA) and endomysium (EMA) in relation to human leukocyte antigen (HLA)-DQB1 alleles to identify silent celiac disease at diagnosis of type 1 diabetes. METHODS: IgA- and IgG-tTG were measured in radioligand binding assays in 165 type 1 diabetic patients. Data on HLA-DQB1 were available for 148 patients and on both AGA and EMA for 164 patients. For patients considered positive for AGA or EMA, or both, an intestinal biopsy was suggested. HLA-DQB1 typing was carried out by polymerase chain reaction and hybridization with allele specific probes. RESULTS: Three patients, left out from further study of antibodies, but not from HLA-DQB1 analysis, had treated celiac disease at diagnosis. Out of the other 162 type 1 diabetic patients tested, nine had IgA-tTG, six IgG-tTG, eight EMA, and 11 AGA. Biopsy was suggested for nine patients, of whom six showed villous atrophy, one did not and two refused to participate. Thus, silent celiac disease was probable in 8/162 and biopsy-verified in 6/162, where five patients were AGA-positive and six either EMA-, IgA-tTG- or IgG-tTG-positive. Of the 11 patients with celiac disease (three with treated and eight with silent celiac disease), 10 were HLA-DQB1-typed, of whom 65% (13/20) had the DQB1*02 allele, compared with 36% (100/276; p = 0.011) of those without celiac disease. IgA-tTG levels were higher in patients having either *02 or *0302 (0.6; -1.3-112.4 RU) compared with those not having these alleles (0.4; -0.7-3.4 RU; p = 0.023). CONCLUSION: IgA-tTG are HLA-DQB1*02-associated autoantibodies with high sensitivity and specificity for silent celiac disease at diagnosis of type 1 diabetes.

Journal Article↗
PubMed2001

PET with 11C-deuterium-deprenyl and 18F-FDG in focal epilepsy.

OBJECTIVES: This study compares positron emission tomography (PET) using 11C-deuterium-deprenyl (DED) with PET using 18F-fluorodeoxyglucose(18F-FDG) for examining epileptogenic regions in patients with focal epilepsy. MATERIAL AND METHODS: Twenty-three patients undergoing evaluation for epilepsy surgery were subjected to PET with DED. Fourteen patients had mesial temporal lobe epilepsy (TLE) and 9 patients had seizures of neocortical origin. In addition, 6 healthy control subjects were examined. Pixel-by-pixel analysis was used to generate graphical images of tracer distribution volume (intercept) and the accumulation rate (slope). Asymmetries with respect to relative intercept and slope were compared in patients with temporal lobe epilepsy (TLE), in patients with extra-temporal lobe epilepsy (exTLE), and in the control subjects. The results were compared with 18F-FDG-PET. RESULTS: Among the patients with TLE, significant differences between the epileptogenic and the contralateral lobe were found with DED intercept and FDG-uptake. No significant differences were found with DED slope. The exTLE and the control groups showed no significant differences between sides or lobes. CONCLUSIONS: This study indicates that PET with 11C-deuterium-deprenyl is a useful method for identifying TLE and is equivalent to PET with 18F-FDG in this sense. The method has little localizing value in seizures originating from neocortical structures.

Adolescent↗
PubMed2001

Long-term glycaemic improvement after addition of metformin to insulin in insulin-treated obese type 2 diabetes patients.

AIM: To assess the adjunct effect of metformin to insulin in type 2 diabetes. METHODS: Obese and overweight type 2 diabetes patients treated with insulin for at least 1 year, and with poor glycaemic control (HbA1c > upper reference level + 2%), were included in a randomised, double-blind, placebo-controlled study. Patients were treated for 12 months with either metformin (850 mg b.i.d.) or placebo added to their usual insulin, which was stabilized during a 3-month placebo run-in period, but thereafter attempted to be unchanged. RESULTS: Thirty-seven patients were included. Two patients dropped out during run-in. There were no differences between the metformin (n = 16) and placebo (n = 19) group at baseline. Most patients received multiple insulin injections. Metabolic control was improved by addition of metformin. Mean change in HbA1c from baseline showed highly significant difference between groups at 3, 6, 9 and 12 months. Mean change (percentage units +/- s.d.) at 12 months was -1.1 +/- 0.7% vs. + 0.3 +/- 0.8% (p < 0.001) for HbA1c and -1.4 +/- 2.1 mmol/l vs. + 0.6 +/- 2.2 mmol/l (p = 0.025) for fasting blood glucose. Mean low density lipoprotein (LDL) cholesterol change differed slightly at 6 months, but not at 12 months. There were no changes in insulin dose, blood pressure, body weight, triglycerides, total- and high density lipoprotein (HDL) cholesterol, fibrinogen, C-peptide and laboratory safety variables, including serum B12. Combination therapy was well-tolerated with the same adverse event rate as insulin alone, but more patients with diarrhoea. CONCLUSION: Addition of metformin to insulin induced and maintained clinically significant and consistent long-term reduction of hyperglycaemia in obese, insulin-treated type 2 diabetes patients.

Blood Glucose↗
PubMed2001

Evaluation of a randomized preventive behavioural medicine work site intervention for public health workers at risk for developing chronic pain.

Because of the substantial increase of sick listing, reports of work disabilities and early retirement due to the musculoskeletal chronic pain, prevention studies at the work site are greatly needed. The purpose of the present study was to investigate the effects of a cognitive behavioural work site intervention on a group of public health workers judged to be at risk for developing chronic pain. Following baseline measurements, a group of 29 practical nurses with daily pain symptoms working at services for the elderly were randomized into two conditions: an active treatment based on cognitive behaviour therapy and a passive treatment based on traditional symptom alleviation. The two treatment conditions, provided by a registered nurse and a physical therapist, took place 30 min a week each once a week, on an individual basis for 4 weeks at the work site during work time. Results at 4 and 8 weeks and at 6, 12 and 24 month follow-ups showed improvements for those individuals receiving the active treatment with regard to the reduction of use of pain-killers, perception of one's self as being sick and the fear-avoidance response to work-related activities. A preliminary conclusion was that this short-term work site programme for the prevention of chronic pain for individuals at risk may be a promising development in the treatment of pain.

Attitude to Health↗
PubMed2001

HPV-related cancer susceptibility and p53 codon 72 polymorphism.

Conflicting results regarding the association of a polymorphism at codon 72 of the p53 tumour suppressor gene and susceptibility to develop human papilloma virus (HPV)-associated cervical cancer have been published over the last year, implicating differences in ethnic background, sample origin, sample size and/or detection assay. The material for this study was collected in the identical geographical region as for 2 previous reports with contradictory results regarding the association of codon 72 genotype with squamous cell cancer (SCC). We have used an alternative detection assay, based on pyrosequencing technology, that interrogates the variable position by the accuracy of DNA polymerase. In addition to cervical clinical specimens from SCC, HPV16- and HPV18-infected adenocarcinoma cases as well as cervical intraepithelial neoplasia (CIN) were investigated. No significant association was found between p53 codon 72 genotype and the risk to develop adenocarcinoma, SCC or CIN in the Swedish population.

Adenocarcinoma↗
PubMed2001

Transrectal catheter drainage of deep abdominal and pelvic abscesses using combined ultrasonography and fluoroscopy.

OBJECTIVE: To describe our experience with transrectal drainage of deep abdominal or pelvic abscesses guided by ultrasonography and fluoroscopy. DESIGN: Open study. SETTING: Teaching hospital, Sweden. SUBJECTS: Eight seriously ill patients with deep abdominal or pelvic abscesses. INTERVENTION: Ultrasonographic and fluoroscopic transrectal drainage. MAIN OUTCOME MEASURES: Clinical follow-up. RESULTS: Eight patients (2 septic, 2 with high fever, and 2 with moderate fever) were effectively and safely drained without general anaesthesia. Their condition improved considerably within hours after drainage. Three patients had recurrent abscesses as a result of the underlying disease. The drainage overcame the sepsis in two patients and allowed a later elective operation. CONCLUSIONS: Transrectal ultrasonographic and fluoroscopic drainage is an effective and safe method for treatment of deep abdominal or pelvic abscesses in seriously ill patients.

Abdominal Abscess↗
PubMed2001

Physical activity assessed by activity monitor and doubly labeled water in children.

PURPOSE: To validate the Computer Science and Application's (CSA) activity monitor for assessment of the total amount of physical activity during two school-weeks in 9-yr-old children and to develop equations to predict total energy expenditure (TEE) and activity energy expenditure (AEE) from activity counts and anthropometric variables. METHODS: A total of 26 children (15 boys and 11 girls, mean age 9.1 +/- 0.3 yr) were monitored for 14 consecutive days. TEE was simultaneously measured by the doubly labeled water method. Averaged activity counts (counts.min(-1)) were compared with data on: 1) TEE, 2) AEE = TEE minus basal metabolic rate (BMR; estimated from predictive equations), and 3) daily physical activity level (PAL = TEE/BMR). RESULTS: Physical activity determined by activity counts was significantly related to the data on energy expenditures: TEE (r = 0.39; P < 0.05), AEE (r = 0.54; P < 0.01), and PAL (r = 0.58; P < 0.01). Multiple stepwise regression analysis showed that TEE was significantly influenced by gender, body composition (body weight or fat free mass), and activity counts (R(2) = 0.54--0.60). AEE was significantly influenced by activity counts and gender (R(2) = 0.45). There were no significant differences between activity counts and PAL in discriminating among activity levels with "low" (PAL < 1.56), "moderate" (1.57 < or = PAL > or = 1.81), and "high" (PAL > 1.81) intensity. CONCLUSION: Activity counts from the CSA activity monitor seems to be a useful measure of the total amount of physical activity in 9-yr-old children. Activity counts contributed significantly to the explained variation in TEE and was the best predictor of AEE.

Activities of Daily Living↗
PubMed2001

Experimental study of structure-borne sound transmission loss of mechanical joints.

A mechanical joint is one of the most effective ways to reduce the transmission of structure-borne sound. In order to increase the transmission loss, heavily damped joints are often used, which, in many cases, will reduce the structure integrity and hence can only be used in limited cases. In this study attention is focused on a type of resonant joint, i.e., a joint which will increase the transmission loss but will not reduce the structure integrity. The study is based on experiments in a one-dimensional structure. It is found that by adjusting the overlap of the joint, the transmission loss of 30 dB can be obtained at a certain frequency range without adding any dissipative materials. The mechanism of this high transmission loss is the cantilever-type resonance. The resonant frequency can be predicted precisely. The influence of extra dissipative material is investigated. The performance of the same joint in a finite structure is also examined by using the concept of vibrational insertion loss. When there is a certain damping in a finite system, a rather high insertion loss can still be achieved by using the above-mentioned joint, but the resonant frequency is shifted to higher end. It seems that the effective length of the cantilever is shortened by the finiteness.

Journal Article↗
PubMed2001

Characterization of the annexin I gene and evaluation of its role in type 2 diabetes.

In a previous study, we identified suggestive linkage between type 2 diabetes and a locus on chromosome 9p13-q21. This region contains the gene annexin I (ANXA1), encoding a protein suggested to be involved in both insulin secretion and insulin action. In this study, we sequenced the exon/intron boundaries of the human ANXA1 gene and performed mutation screening in 41 individuals from the initial linkage study. We identified five single nucleotide polymorphisms A58G, A401G, intronic variance sequence (IVS)8-28A/G, IVS11 +31A/G, and IVS12-11T/G, which were further tested for association to diabetes in 197 parent/offspring trios using the transmission disequilibrium test. No significant association with type 2 diabetes was observed, although the common A allele of the +58A/G variant gave a 22:12 transmission distortion (P = 0.12). This variant was further genotyped in 481 case and control subjects, but no difference in allele, genotype, or haplotype frequencies were observed between the groups. Further, a novel polymorphic (CA)(15-25) repeat in intron 11 was genotyped in the subjects included in the initial linkage study. No improvement of the original finding was observed. We therefore concluded that the ANXA1 gene is unlikely to harbor variants that contribute to risk of type 2 diabetes.

Alleles↗
PubMed2001

Sources of eicosanoid precursor fatty acid pools in tissues.

Tissue arachidonic acid (AA) pools originate from the diet, and from hepatic and extrahepatic desaturation-elongation of dietary linoleic acid (LA). This review summarizes the roles of absorption, transport, and formation of AA in the buildup of tissue AA pools. In humans who ingest 0.2-0.3 g of AA and 10-20 g of LA per day on a Western diet, the formation of AA from LA exceeds the dietary supply of AA. A number of factors favor the partitioning of AA to tissue phospholipids rather than adipose tissue and plasma triglycerides. The characteristics of AA transport with lipoproteins are discussed with focus on the role of lipoprotein lipase, lecithin:cholesterol acyltransferase, hepatic lipase, and the scavenger receptor BI and LDL receptors in tissue uptake of AA. Liver-derived 2-acyl-lysophosphatidylcholine and plasma free AA are two important sources of AA for extrahepatic tissues which exhibit a low rate of uptake of lipoprotein AA. Desaturation-elongation of LA to produce AA occurs both in liver and in extrahepatic tissues, plasma free LA being an important substrate particularly during fasting. The AA preference of the reacylation and transacylation reactions is crucial for the selective retention of AA in phospholipids.

Acylation↗
PubMed2000

[Cytostatic therapy reduces the immune defense. Children treated for leukemia have impaired immunity against measles and rubella].

A study is summarized analyzing the levels of serum antibodies against vaccination antigens in 43 children treated for acute lymphoblastic leukemia. Two different therapeutical regimens were used. All children had been immunized against measles and rubella before being diagnosed with leukemia. Eight of the 24 children treated 1986-1991 lacked protective levels of antibodies against measles; four of the 24 children lacked antibodies against rubella. In the second cohort of children (n = 16) treated from 1992 and onwards, nine lacked protective levels of antibodies against measles, eight lacked antibodies against rubella.

Antibodies, Viral↗
PubMed2000

How carbon monoxide adsorbs in different sites.

The interplay between the electronic and the geometric structure of adsorbates is of fundamental importance for the understanding of many surface phenomena. Using x-ray emission spectroscopy and ab initio cluster calculations, this issue has been investigated in unprecedented detail for CO adsorption in different adsorption sites. The investigation establishes pi bonding and sigma repulsion, both increasing with the number of coordinated metal atoms. The two contributions partly compensate each other, leading to only small differences in adsorption energies for the different adsorption sites despite very large variations in the electronic structure.

Journal Article↗
PubMed2000

Partitioning of peptides and recombinant protein-peptide fusions in thermoseparating aqueous two-phase systems: effect of peptide primary structure.

Genetic engineering has been used for fusion of peptides, with different length and composition, on a protein to study the effect on partitioning in an aqueous two-phase system. The system was composed of dextran and the thermoseparating ethylene oxide-propylene oxide random copolymer, EO30P070. Peptides containing tryptophan, proline, arginine or aspartate residues were fused at the C-terminus of the recombinant protein ZZ-cutinase. The aim was to find effective tags for the lipolytic enzyme cutinase for large-scale extraction. The target protein and peptide tags were partitioned separately and then together in the fusion proteins in order to gain increased understanding of the influence of certain amino acid residues on the partitioning. The salt K2SO4 was used to reduce the charge dependent salt effects on partitioning and to evaluate the contribution to the partition coefficient from the hydrophobic-hydrophilic properties of the amino acid residues. The effect of Trp on peptide partitioning was independent of the difference in primary structure for (Trp)n, (Trp-Pro)n, (Ala-Trp-Trp-Pro)n and was only determined by the number of Trp. The effect of the charged residues, Arg and Asp, was dependent on the surrounding residues, i.e. if they were situated next to Trp or not. The partitioning behaviour observed for the peptides was qualitatively and in some cases also quantitatively the same as for the fusion proteins. The effect of the salts sodium perchlorate and triethylammonium phosphate on the partitioning was also studied. The salt effects observed for the peptides were qualitatively similar to the effects observed for the fusion proteins.

Amino Acid Sequence↗