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Biomedical subjects

I Engström

Publications and source records attributed to I Engström.

At least 19 recordsLinked to original sources
PubMed2003

Higher drive for thinness in adolescent males with insulin-dependent diabetes mellitus compared with healthy controls.

UNLABELLED: Eating behaviour in adolescent males with insulin-dependent diabetes mellitus (IDDM) living in central Sweden was compared with that of healthy age-matched male controls using the Eating Disorder Inventory for Children and an interview. The patients were heavier than controls (p = 0.004) and had higher Drive for Thinness scores (p = 0.002). None was diagnosed as having a current eating disorder. CONCLUSION: The results of the study may indicate an increased risk of future eating disorders in males with IDDM.

Adolescent↗
PubMed2003

Psychosocial functioning in a group of Swedish adults with Asperger syndrome or high-functioning autism.

This study reports on psychosocial functioning in Swedish adults with Asperger syndrome (AS) or high-functioning autism (HFA). A systematically selected sample of patients and relatives was interviewed concerning their psychosocial situation. The majority was living independently. All persons but one were unemployed. None was married and none had children. Only a few had some kind of partner. Most persons needed a high level of public and/or private support. The overall adjustment was rated good in 12 percent, fair in 75 percent and poor in 12 percent. Adult persons with AS/HFA have extensive need for support from their families and/or society. This information is important in order to provide adequate interventions that are in accordance with the expressed needs of the individuals themselves.

Activities of Daily Living↗
PubMed2002

Estimation of the population "at risk" for eating disorders in a non-clinical Swedish sample: a repeated measure study.

OBJECTIVE: To estimate the late-adolescent population "at risk" for eating disorders (EDs), establish its stability over time using repeated measures, and analyse its social and demographic background factors. METHOD: The Eating Disorder Inventory (EDI) and a number of related questions were administered to students in their last year of high school in five Swedish towns in 1993 (n=3855) and 1998 (n=2925). RESULTS: It was found that 6% of girls were "at risk" for eating disorders with no increase over time. There was an association between this risk and certain socio-demographic factors (living alone, moving away from home early, excessive physical training and experiences of bullying). No differences were found between cities of different size. CONCLUSION: A considerable proportion of girls in late adolescence are preoccupied with weight and dieting, and may be considered "at risk" for developing a clinical eating disorder. This proportion seems to be fairly stable over time.

Adolescent↗
PubMed2001

Increased erythrocyte content of Ca2+ in patients with Tarui's disease.

OBJECTIVES: To establish by flow cytometry and fluorophores an increased calcium ion load in erythrocytes of four patients with Tarui's disease. DESIGN: Calcium ion levels were determined in erythrocytes of patients and controls under normal and energy-deprived conditions. Adenylates were measured to assess energy status of incubated erythrocytes. SETTING: The experiments were carried out at the Department of Clinical Chemistry of the University Hospital of Uppsala, Sweden. SUBJECTS: Four family members with Tarui's disease participated in the study. The proband (patient 1) was a 39-year-old male; patients (male, aged 46 years) 2 and 3 (female, 30 years) were his two siblings. Patient 4 (male, 16 years) was the son of patient 2. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Calcium ion homeostasis was measured under basic conditions and under energy-deprived conditions and related to cellular adenylate content. RESULTS: All patients showed enhanced erythrocyte calcium ion loading compared to controls under energy-deprived conditions. Under normal conditions, however, three out of the four patients showed an increased erythrocyte calcium ion level compared to controls. CONCLUSIONS: We conclude that erythrocytes from patients with Tarui's disease have an increased Ca2+ permeability, initiating compensatory mechanisms involving increased Ca2+ pump activity and increased glycolytic flux, which are not always sufficient to keep erythrocyte calcium ion concentration within physiological range.

Adenosine Monophosphate↗
PubMed2001

Familial phosphofructokinase deficiency is associated with a disturbed calcium homeostasis in erythrocytes.

OBJECTIVES: To critically evaluate whether an altered calcium homeostasis in erythrocytes could be contributing to the symptomatology of the Tarui's disease, which is an inherited phosphofructokinase (PFK) deficiency of the muscle isoenzyme. PFK is a tetrameric enzyme with three different isoenzymes, muscle (M), liver (L), and platelet (P). Erythrocytes contain a 50 : 50 hybrid of M and L type. The deficiency of the muscle isoenzyme displays a symptomatology which is mainly characterized by myopathy, and a compensated haemolytic anaemia. DESIGN: Erythrocyte deformability was assessed before and after autoincubation. Energy related metabolites and energy charge was determined in erythrocytes under various experimental conditions. SETTING: The clinical part of the study was performed at the Departments of Cardiology and Clinical Chemistry, Umeå University Hospital, and the experimental investigation was carried out at the Department of Clinical Chemistry of the University Hospital of Uppsala, Sweden. SUBJECTS: Four family members with Tarui's disease participated in the study: the proband (patient 1), a 39-year-old male and two siblings, patient 2 (male, aged 46 years) and patient 3 (female, 30 years). Patient 4 (male, 16 years) was the son of the patient 2. Five healthy persons served as controls (controls 1-5). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Cell-physiological variables were determined after autoincubation of erythrocytes (i.e. incubation in their own plasma at 37 degrees C) and after incubation in a composite buffered medium. RESULTS: Erythrocyte deformability as assessed by the erythrocyte fluidity was substantially decreased in patients compared to the moderate decrease in the control after 24 h of autoincubation, in presence of endogenous Ca2+ (heparin plasma). Moreover, autoincubation of erythrocytes shows that the patient's erythrocytes, although being moderately deficient in PFK activity, exhibit a normal (or slightly increased) lactate production compared to controls. Despite this, we show an increased ATP turnover with an Ca2+-induced AMP deaminase (and 5'-nucleotidase) activation leading to an increase in hypoxanthine content in patients' erythrocytes of about 100% after 24 h of autoincubation in heparin plasma, when compared to controls. A loss of volume in patient's erythrocytes after 24 h of autoincubation (in presence of Ca2+), as revealed by a diminished MCV, was consistent with an increased metabolic pool of intracellular calcium ions with a selective loss of K+ due to the activation of the K+ channel by intracellular Ca2+ (Gardos-effect). CONCLUSION: We conclude that the different calcium ion-induced effects on energy metabolism, structure and function of patients' erythrocytes are due to an augmented membrane leakage of Ca2+ and therefore an accumulated intracellular Ca2+ pool. This will result in an increased energy demand by the Ca2+-stimulated ATPase (calcium pump) to compensate for the dissipated Ca2+ gradient across the plasma membrane. The concomitant haemolysis may be explained by a diminished erythrocyte deformability due to Ca2+ overload.

Adolescent↗
PubMed2000

Sixteen years age limit for learner drivers in Sweden--an evaluation of safety effects.

Through a reform implemented in Sweden, September 1993, the age limit for practising car driving was lowered from 17 1/2 to 16 years while the licensing age remained 18. The purpose of lowering the age limit was to give the learner drivers an opportunity to acquire more experience as drivers before being allowed to drive on their own. The primary aim of this study was to evaluate the effect of the reform in terms of accident involvement and data were therefore obtained from the national register of police reported accidents. The results show that after the reform there was a general reduction in the accident risk (accidents per 10 million km) of novice drivers with approximately 15%. Additional analyses show that the reduction of accident risk in the group who utilised the new age limit was approximately 40%, whereas those who did not utilise the prolonged training period did not benefit at all. Between 45 and 50% of the age population were found to utilise the reform. The accident reduction does not seem to be just an initial first year effect since the results were similar over 3 years of novice drivers during their first 2 years with a licence. These results suggest that the reform has been beneficial for the safety of novice drivers in Sweden. The results also suggest a potential for additional safety improvements if more young learner drivers can be brought to utilise the low age limit.

Accidents, Traffic↗
PubMed1999

Mental health and psychosocial characteristics in adolescent obesity: a population-based case-control study.

In this population-based study we compared self-esteem, social background, social and academic competence, behavioural problems and lifestyle in 58 obese adolescents (BMI > or =99.6th percentile or > or =30 kg/m2), aged 14-18 y, with 58 sex- and age-matched controls of normal weight. The instruments used were: I Think I Am, Youth Self Report and a lifestyle questionnaire. The obese group was on average, 40 kg heavier than the controls. The obese individuals rated themselves significantly lower in physical characteristics, but in all other aspects of self-esteem, mental health and social and academic competence there were no differences between the two groups. There were significant socioeconomic differences, with more obese adolescents living with only one parent and with the mothers in the obese group having, in general, lower education than those in the control group. This study confirms previous observations that obesity is associated with special socioeconomic conditions in youth, but that obese adolescents do not differ from their normal-weight peers in other aspects of mental health.

Adolescent↗
PubMed1999

Eating disorders in adolescent girls with insulin-dependent diabetes mellitus: a population-based case-control study.

In this study the prevalence of eating disorders in a population-based cohort of 89 female patients with type 1 diabetes, 14-18 y of age, was compared with that in age-matched healthy controls. Of all diabetic girls in the study area, 92% participated in the study. The majority were treated with multiple insulin injections and the mean HbA1c of the participants was 8.4%. On average, diabetic girls were 6.8 kg heavier than the controls. A two-stage design was used. The first consisted of a validated self-report questionnaire, the Eating Disorder Inventory (EDI). Girls who had high scores were then interviewed about eating habits and mental health using a semistructured interview, the BAB-T (Assessment of Anorexia-Bulimia - Teenager version). No cases of anorexia or bulimia nervosa were found, but 15 diabetic patients (16.9%) compared with 2 control girls (2.2%), p<0.01, had disturbed eating behaviour according to the questionnaire. In 6 of these 15 diabetic girls an eating disorder was confirmed at the interview, mainly binge eating and self-induced vomiting. None of the control girls showed an eating disorder. Overweight diabetic girls scored higher on EDI than non-overweight diabetic girls (chi2 = 4.9; p = 0.038). No relationships were found between EDI scores and metabolic control (HbA1c), dose of insulin, frequency of hypoglycaemia or diabetic ketoacidosis.

Adolescent↗
PubMed1996

Influence of breathing pattern on transcutaneous oxygen and carbon dioxide tension during histamine provocation in children with bronchial asthma.

The influence of the breathing pattern on transcutaneous blood gases was evaluated in 18 boys and 8 girls 7-18 years of age, with bronchial asthma, during bronchial provocation with histamine-HCl. Transcutaneous oxygen tension (tcPO2), carbon dioxide tension (tcPCO2) and the breathing pattern assessed by the transthoracic impedance technique were continuously monitored during the provocation. At reaction, when the fall in the forced expiratory volume in 1 s (FEV1) was 20% or more, the tcPO2 fell by 15% or more below the baseline in 22/26 and by 20% or more in 14/26 children. In some children, a marked fall in the tcPO2 was already noted after the saline inhalation and the first histamine dose steps without simultaneous changes in the FEV1. This early fall in the tcPO2 correlated to changes in the breathing pattern and was interpreted as a sign of compensatory hypoventilation secondary to the hyperventilation observed during the inhalations. We conclude that transcutaneous oxygen tension can be used as an indicator of a bronchial reaction during bronchial provocation tests in children only if one takes account of the fact that the breathing pattern during the inhalation of the challenge compound per se has an effect on the oxygen tension.

Administration, Inhalation↗
PubMed1996

Activation of AMP deaminase in human erythrocytes by calcium ions.

We examined 5'-AMP aminohydrolase (AMP deaminase, EC 3.5.4.6. AMPD) together with metabolite changes in intact red blood cells from normal human adults under different incubation conditions. Moderate changes occurred in erythrocyte adenylates upon incubation for 1 h at 37 degrees C in the absence of glucose and the concentration of IMP was negligible. Calcium in the incubation medium, at concentrations up to 1.50 mmol l-1 did not influence the nucleotide pattern. Inclusion of the ionophore A 23187 in the incubation medium resulted in a sharp decrease of ATP content at 60 min and increases in AMP and ADP concentrations. A maximally low level of ATP was observed at 60 min of incubation in the presence of both the ionophore and 0.25 mmol l-1 of external calcium. With increasing concentrations of calcium up to 1.50 mmol l-1 in the presence of the ionophore, a significant rise occurred in both IMP and ATP concentrations, whether glucose was present or not, and significant correlations existed between the concentrations of calcium and IMP. The presence of the ionophore together with glucose but without extra calcium in the incubation medium produced the highest concentrations of lactate, indicative of an enhanced glycolytic flux under these conditions. The stimulatory effect of intracellular calcium ions on AMPD activity is discussed.

AMP Deaminase↗
PubMed1995

Alzheimer amyloid beta-peptides exhibit ionophore-like properties in human erythrocytes.

There is growing evidence that the amyloid beta-peptide (beta 1-40) is involved in the aetiology of Alzheimer's disease also implicating an altered calcium homeostasis of affected cells. Beta 1-40 has been proposed to form calcium channels in synthetic bilayer membranes [1]. We wanted to investigate in the present study whether beta 1-40 (or fragments thereof) could act as ionophores in a biological membrane like the one in human erythrocytes. Incubation of the cells for 2 h and 4 h at 37 degrees C together with 6 mumol L-1 of beta 1-40 or of fragments beta 1-28 and beta 25-35, resulted in a significantly decreased energy charge qualitatively similar to the one obtained by a known calcium ionophore (A 23187, 0.05 mumol L-1). Moreover, beta 1-40 and its two fragments induced a significant alteration of 45Ca permeability in human red blood cells of the same type as the one achieved by the calcium ionophore. The ionophoric action of beta 1-40 and its two fragments may lead to an increase of the intracellular calcium ion concentration, in turn resulting in enhanced Ca(2+)-ATPase activity and a decrease in energy charge. This may be valid also for neuronal plasma membranes and could, therefore, be a possible aetiological mechanism in Alzheimer's disease.

Adenosine Diphosphate↗
PubMed1993

Dissipation of the calcium gradient in human erythrocytes results in increased heat production.

Heat production rates were measured by a microcalorimetric method in suspended human erythrocytes in the absence and presence of different concentrations of the divalent cationophore A23187. Determinations were carried out during 60 min under static conditions on erythrocytes incubated in various isotonic media at 37 degrees C, pH 7.35. In incubations containing the ionophore, time-power curves showed an early peak followed by a descending slope levelling off at a steady state after 30-60 min. In contrast, the controls lacked the early peak, showing hyperbolic ascending curve profiles before reaching steady state. The appearance of the early peak in the presence of ionophore was dependent upon the composition of the medium, both Mg2+ ions and glucose being decisive. Likewise, dose-response relationships concerning heat production at 60 min depended on the composition of the media. In a basic incubation medium lacking Mg2+ and glucose, no effect was seen on heat production by the ionophore (1-3 mumol/l). Rather modest effects were obtained by the ionophore at 2 and 3 mumol/l when Mg2+ was present. A clear-cut dose-response relationship was observed in a Mg2+ and glucose enriched medium for the ionophore from 1-3 mumol/l. The significant increase in heat production observed at 60 min with 2 mumol/l of A23187 in the Mg2+ and glucose enriched medium was abolished by 1 mmol/l EGTA. Calmidazolium, a calmodulin antagonist, could only marginally reduce the ionophoric effect on heat production. It was concluded that the appearance of the early peak was not the result of an increase in glycolytic rate but rather a consequence of the ionophoric action on the Ca2+ gradient.

Adenosine Triphosphate↗
PubMed1993

Respiratory resistance and transcutaneous PO2 during histamine provocation in children with bronchial asthma.

Bronchial reactivity was assessed in 66 children with bronchial asthma (aged 8-15 years) by provocation with histamine-HCl during a symptom-free period. A significant bronchial reaction to histamine was defined as a 50% increase in the resistance of the respiratory system (Rrs) determined by the forced oscillation technique. The provocative dose causing a 50% increase in the Rrs (PD50Rrs) was interpolated from the log dose-response curve. The mean PD50Rrs was significantly lower in children with asthma (0.22 mg/mL) compared with a group of healthy children in the same age range (1.55 mg/mL) (P < 0.001). In children with clinically severe asthma, the mean PD50Rrs was lower (0.13 mg/mL) than in children with mild asthma (0.34 mg/mL) (P < 0.001). Transcutaneous PO2 (PtcO2) was monitored in 25 of the children with asthma. In this group the proportion of mild and severe asthma, the baseline lung function variables, and the PD50Rrs were not significantly different from those of the whole group of children. During the reaction, the PtcO2 fell on average by 29% of the baseline value (P < 0.001); in 88% of the children, the fall in PtcO2 was 20% or more of the baseline value. We conclude that histamine provocation tests using the forced oscillation technique and transcutaneous PO2 to assess a bronchial reaction have a good discriminatory capacity for different degrees of clinical severity of asthma in children.

Adolescent↗
PubMed1993

Ionophore A23187 reduces energy charge by enhanced ion pumping in suspended human erythrocytes.

Washed human erythrocytes were basically incubated in phosphate-buffered saline at 37 degrees C with different concentrations (1-5 mumol l-1) of the divalent cationophore A23187. This ionophore induced a decrease by about 75% of ATP content and energy charge (EC) and a concomitant increase in ADP and AMP contents in a dose-dependent fashion such that an inverse ATP/ADP relationship developed. EGTA at 1 mumol l-1 annihilated the effect of A23187 on energy status. When glucose was added to the basic incubation medium A23187 inclusion resulted in an elevated lactate production concomitantly with a partial restoration of EC. Introduction of Mg2+ to basic incubation medium containing glucose and the ionophore resulted in a sharp increase in lactate production with an energy state that was maintained at a control level. It is concluded that the low EC of erythrocytes obtained by this ionophore is the result of runaway ATPases dissociated from glycolysis. Since human erythrocytes are devoid of organelles other than the plasma membrane it is concluded that the ionophoric effect is exerted in the plasma membrane.

Adenosine Diphosphate↗
PubMed1993

Effects of the ionophore gramicidin D on energy metabolism in human erythrocytes.

Washed human erythrocytes were incubated in phosphate-buffered saline at 37 degrees C with different concentrations (2-80 mg l-1) of the monovalent cationophore gramicidin D. The ionophore induced a decrease of ATP content and energy charge (EC) and a concomitant increase in ADP and AMP contents. At a concentration of 10 mg l-1 of the ionophore the reduction of EC and ATP concentration was about 50%. Increasing the concentration of the ionophore resulted in a substantial haemolysis with no further effect on the nucleotide levels. Lowering the concentration of the ionophore to 5 mg l-1 (to avoid haemolysis) lead to a similar effect on the energy status. Ouabain at 0.5 mmol l-1 in incubation medium distinctly blunted the ionophoric effect on EC and adenine nucleotides. Addition of glucose on the contrary reversed these effects by about 80%. Hence, the glucose-induced increase in glycolytic flux as evidenced by an increase in lactate production was not sufficient to restore energy state.

Adenosine Diphosphate↗
PubMed1992

Transcutaneous blood gas monitoring during salbutamol inhalations in young children with acute asthmatic symptoms.

The effect of salbutamol inhalations on transcutaneous blood gases was investigated in 23 children (aged 11 months-2.5 years) with asthmatic symptoms. After one salbutamol inhalation there was a mean increase in transcutaneous PO2 (tcPO2) of 0.5 kPa (P less than 0.01); after a second dose given 30 minutes later, the mean increase was 1.2 kPa (P less than 0.001). The increase in tcPO2 after only one dose of salbutamol was significantly correlated to age (P less than 0.01). No such correlation was observed after a second dose. The overall increase in tcPO2 after two salbutamol inhalations showed a negative correlation to the duration of the current symptomatic period (P less than 0.05). We conclude that salbutamol inhalations have beneficial effects in young children with acute asthmatic symptoms, even below the age of 18 months, provided that an adequate dose reaches the lung and preferably at an early stage of obstruction.

Acute Disease↗
PubMed1992

Mental health and psychological functioning in children and adolescents with inflammatory bowel disease: a comparison with children having other chronic illnesses and with healthy children.

Psychiatric disorders and behaviour problems were found to be commoner in children and adolescents with inflammatory bowel disease (IBD) than in matched comparison groups with tension headache and diabetes as well as in healthy children. Depression, anxiety and low self-esteem were common. Many children denied their problems. This may be due to the type of illness, its social consequences and the embarrassment experienced by the children. Discrepancies were found between the children's and their mothers' replies. These results are discussed in terms of their implication for paediatric practice.

Adolescent↗