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Biomedical subjects

L B Andersen

Publications and source records attributed to L B Andersen.

At least 37 records · Page 2Linked to original sources
PubMed2001

Sulfur amino acid deficiency depresses brain glutathione concentration.

Dietary sulfur amino acid content is a major determinant of glutathione concentration in some tissues. We examined whether brain glutathione (GSH), a key component of antioxidant defense important for minimizing ischemic injury, was also responsive to short-term sulfur amino acid deficiency. Female Long-Evans adult rats were fed a sulfur-deficient L-amino acid defined diet for five days; the control diet was supplemented with L-cystine and L-methionine (n = 6). Sulfur amino acid deficiency was confirmed by a reduction in liver cysteine and GSH concentrations, marked decreases in food intake, and weight loss. GSH concentration analyzed by reverse-phase high performance liquid chromatography was significantly depressed in the neocortex and thalamus of deficient rats. Brain cysteine was not decreased in a parallel manner. Classical glutathione peroxidase activity was increased in the liver and brain of sulfur amino acid deficient rats. This suggests an upregulation of antioxidant defense but these findings may be complicated by alterations in tissue composition. The depletion of brain GSH by a reduced supply of dietary precursors may be important during brain ischemia when the rate of GSH utilization and the need for synthesis are increased.

Amino Acids, Sulfur↗
PubMed2000

All-cause mortality associated with physical activity during leisure time, work, sports, and cycling to work.

BACKGROUND: Physical activity is associated with low mortality in men, but little is known about the association in women, different age groups, and everyday activity. OBJECTIVE: To evaluate the relationship between levels of physical activity during work, leisure time, cycling to work, and sports participation and all-cause mortality. DESIGN: Prospective study to assess different types of physical activity associated with risk of mortality during follow-up after the subsequent examination. Mean follow-up from examination was 14.5 years. SETTING: Copenhagen University Hospital, Copenhagen, Denmark. PARTICIPANTS: Participants were 13,375 women and 17,265 men, 20 to 93 years of age, who were randomly selected. Physical activity was assessed by self-report, and health status, including blood pressure, total cholesterol level, triglyceride levels, body mass index, smoking, and educational level, was evaluated. MAIN OUTCOME MEASURE: All-cause mortality. RESULTS: A total of 2,881 women and 5,668 men died. Compared with the sedentary, age- and sex-adjusted mortality rates in leisure time physical activity groups 2 to 4 were 0.68 (95% confidence interval, 0.64-0.71), 0.61 (95% confidence interval, 0.57-0.66), and 0.53 (95% confidence interval, 0.41-0.68), respectively, with no difference between sexes and age groups. Within the moderately and highly active persons, sports participants experienced only half the mortality of nonparticipants. Bicycling to work decreased risk of mortality in approximately 40% after multivariate adjustment, including leisure time physical activity. CONCLUSIONS: Leisure time physical activity was inversely associated with all-cause mortality in both men and women in all age groups. Benefit was found from moderate leisure time physical activity, with further benefit from sports activity and bicycling as transportation.

Adult↗
PubMed2000

[Physical activity--what minimal level is sufficient seen from health perspective?].

Physical inactivity represents an important risk factor for development of cardiovascular and metabolic disease and is tightly coupled to a reduced energy expenditure both at work and during leisure activities. Although comprehensive physical training is known to influence oxygen uptake capacity, muscle strength and metabolic factors, also increased weekly energy expenditure achieved through activities with moderate intensity will influence risk factors such as hypertension, insulin resistance, oxidative metabolism in skeletal muscle and a low HDL/total cholesterol ratio beneficially and improve metabolic fitness. To achieve this, all adults should aim at a total of 30 min of moderate physical activity daily, preferentially through activities that can be a natural part of daily living (walking, cycling or gardening). This recommendation can also be achieved through accumulation of several minor activity periods of 5-10 min each. Further increase in amount or intensity of physical activity above the minimal recommendations improves the morbidity preventive effect further, although several risk factors show a curvelinear and levelling-off pattern of their dosis-response curve between training and risk factors.

Adolescent↗
PubMed2000

Repression of myosin isoforms in developing and denervated skeletal muscle fibers originates near motor endplates.

During development of chicken pectoralis muscle, a neonatal myosin heavy-chain isoform is supplanted progressively by an adult isoform. This expression is under neuronal control. In this study we test the hypothesis that developmental myosin transformations are initiated near the motor endplate of each muscle fiber, thereafter progressing toward the fiber ends. By using immunocytochemical methods, pectoralis muscle from chickens aged 1-115 days after hatching were labeled by antibody against neonatal isoform. Ellipse minor axis and mean optical density of labeled and/or unlabeled fiber profiles from each bird were measured by computer image analysis. Acetylcholinesterase (AChE) activity was demonstrated histochemically. Using serial cross sections, we show that smaller fiber profiles are the tapered ends of larger fiber profiles. The largest fiber profiles (central regions of the fibers) were the first to lose their neonatal myosin during development. Motor endplates were localized by AChE activity to the central regions of the fibers. The pectoralis of mature chickens was denervated for 3, 7, 15, or 21 days. After 2 weeks' denervation, neonatal myosin is first reexpressed in the fiber ends. Dev Dyn 2000;217:50-61.

Animals↗
PubMed2000

Effects of body-mind training and relaxation stretching on persons with chronic toxic encephalopathy.

The purpose of this project was to investigate the psychological and physical effects of training of body awareness and slow stretching on persons with chronic toxic encephalopathy (CTE). In the present study, a method of self-regulation, a body-mind training, is presented. The body-mind training used was a guided relaxation technique combined with meditative stretching. The techniques are introduced and the psychological and physiological effects of the training is presented. Eight subjects with CTE, 48.5 years, were trained for 8 weeks. Outcome measures were percentage alpha brain waves (alpha%), electromyography (EMG) on the frontalis muscle, state-trait anxiety (STAI), creativity (RAT), and mood measured as anxiousness, humour and mental fatigue. The mean alpha% increased 52% during the training period (P < 0.01), and the EMG decreased 31% (P < 0.001. State anxiety decreased 22% during the training period (P < 0.01), but no changes were observed in trait anxiety and in the creativity score. The level of anxiousness and fatigue before a training session decreased during the training period. In conclusion, the body-mind training resulted in an improved ability for physical and mental relaxation as indicated from the lower EMG, the higher alpha% and the decrease in state anxiety.

Alpha Rhythm↗
PubMed2000

Effectiveness of counselling over 1 year on changes in lifestyle and coronary heart disease risk factors.

Many have studied the effects of different lifestyles on disease, mortality or risk factors for a disease, but little is known about how behaviour is changed in the population. We studied the need for counselling and its effect on willingness and ability to change lifestyle, and subsequent changes in CHD risk factors. All 152 male employees in a computer company, 25-45 years of age, were invited to participate. Subjects were randomized into an intervention group (I-group) and a control group. The I-group was divided into subgroups based on baseline behaviour and risk factor status. Changes were evaluated after 1 year. After an initial health examination, participants from the I-group were counselled at baseline and after 5 months. Eighty-five (56%) males participated. Twenty-nine were assigned to a control group and 56 to an intervention group (I-group) (dropout = 8). An exercise group (E-group) was advised to exercise aerobically three times/week, a diet group to reduce the intake of saturated fat and increase fish products, and smokers to quit smoking. Forty subjects were recommended one or more behavioural changes and eight had no need. Thirty-four were willing to make behavioural changes. Compared to the control group, the fitness level increased (P < 0.01) and body weight decreased in the I-group (P < 0.05). It may be concluded that individual counselling promotes regular exercise with subsequent improvements in CHD risk factors. The diet- and smoking counselling models were less successful in terms of adherence.

Adult↗
PubMed1999

Constitutive expression of GAP-43 correlates with rapid, but not slow regrowth of injured dorsal root axons in the adult rat.

It has been postulated that the neuronal growth-associated protein GAP-43 plays an essential role in axon elongation. Although termination of developmental axon growth is generally accompanied by a decline in expression of GAP-43, a subpopulation of dorsal root ganglion (DRG) neurons retains constitutive expression of GAP-43 throughout adulthood. Peripheral nerve regeneration occurring subsequent to injury of the peripheral axon branches of adult DRG neurons is accompanied by renewed elevation of GAP-43 expression. Lesions of DRG central axon branches in the dorsal roots are also followed by some regenerative growth, but little or no increase in GAP-43 expression above the constitutive level is observed. To determine whether dorsal root axon regeneration occurs only from neurons which constitutively express GAP-43, we have used retrograde fluorescent labeling to identify those DRG neurons which extend axons beyond a crush lesion of the dorsal root. Only GAP-43 immunoreactive neurons supported axon regrowth of 7 mm or greater within the first week. At later times, axon regrowth is seen to occur from neurons both with and without GAP-43 immunoreactivity. We conclude that regeneration of injured axons within the dorsal root is not absolutely dependent on the presence of GAP-43, but that expression of GAP-43 is correlated with a capacity for rapid growth.

Amidines↗
PubMed1998

A comparison of mortality rates in three prospective studies from Copenhagen with mortality rates in the central part of the city, and the entire country. Copenhagen Center for Prospective Population Studies.

Valid generalizations of results from population-based epidemiological surveys requires knowledge about how representative the sample is. The Copenhagen Center for Prospective Population Studies have assessed mortality on the basis of pooled data from three research programmes in the region of Copenhagen. In two of the studies, subjects were randomly selected, using the Danish Central Population Registry, within certain age groups and area-restricted sectors of the Greater Copenhagen. In the third study, men employed in 14 companies participated. Participation rates were between 78% and 87% in the three programmes. Standardized mortality rates (SMR) were calculated in relation to mortality rates in the municipality of Copenhagen and in the whole country in three age groups and the two genders. SMR values in the whole sample including non-participants were similar to rates for Copenhagen in the Copenhagen City Heart Study, whereas mortality rates in the Glostrup Population Studies were similar to rates for the whole country. The mortality rates among participants were lower than in the whole sample, and differences existed in relation to region and selection criteria of the cohorts. The Copenhagen Male Study, where only employed men were included, showed the lowest mortality rates, and higher rates were found in the study from the central part of the City (the Copenhagen City Heart Study) compared to the study from the suburbs (the Glostrup Population Studies). The difference between mortality rates in the cohorts and in Copenhagen City decreased with increasing age. The SMR converged towards 1.00 with increasing observation time. In conclusion, high participation rates were found in all three studies, resulting in SMR values for participants only slightly lower than in the source population in the two randomly selected samples, but 30% lower values in the sample of employed men. As mortality rates in the total samples including non-participants were markedly higher than among the participants, generalizations of results for participants to the whole population should be made with caution, especially during the first years of observation.

Adult↗
PubMed1996

[Changes in physical activity are not reflected in physical fitness of older teenagers. A 2-year follow-up study].

The study describes changes over two years in different physical fitness measures and the relationship between these changes and changes in physical activity. Maximal aerobic work capacity (watt(max)), functional strength, muscle endurance, agility and flexibility were measured in 259 randomly selected high school boys and girls 16.5 years of age and followed-up two years later, while they still attended school. Most physical fitness measures increased over time in boys, and in girls an increase was found in arm extensor strength and trunk extensor endurance, but watt(max) per kg body mass decreased. Changes in physical performance between 16 and 18 years of age seem to be very similar in different countries, despite differences in physical activity patterns and absolute level of performance. No change was found in time spent participating in physical activity or sports activity in either gender, but fewer girls participated in leisure-time sports at the second test (p < 0.001). Change in physical activity or sports activity did not relate to change in physical fitness level. The relationships between level of sports participation (competition, for health or none) and physical fitness measures at baseline and at the second test were weak or non-significant. Three explanations for the weak relationship between physical activity and fitness are suggested: a) part of the variability in fitness is explained by genetics, b) growth and hormonal changes, especially in boys, override the stimulus of training, and c) the physical fitness level in adolescents is so high that only physical activity at high relative intensity is supposed to have an effect on the fitness level.

Adolescent↗
PubMed1996

Lineage-specific CaN19 expression in human skin: lack of expression in normal melanocytes.

Although expression of CaN19 is reduced in cell lines derived from tumors of diverse origin, its expression in their normal counterparts has not been studied in detail. We find that CaN19 mRNA is expressed at very low to undetectable levels in normal melanocytes as well as malignant melanoma cell lines, confirming that CaN19 expression in normal cells is lineage-dependent.

Cells, Cultured↗
PubMed1996

Tracking of risk factors for coronary heart disease from adolescence to young adulthood with special emphasis on physical activity and fitness. A longitudinal study.

Physical activity (PA), fitness and selected coronary heart disease (CHD) risk factors were studied in 2 Danish adolescent cohorts; changes in PA and fitness from the age of 16-18 years were measured in a subgroup of high school children; changes in lifestyle, fitness level and coronary heart disease risk factors were measured from late adolescence to young adult hood in a random sample of subjects attending school at baseline. Risk factors and physical fitness tracked from adolescence to young adulthood. The proportion of subjects in the upper quintile of risk still being in the upper quintile 8 years later was 2-3 times the expected in most risk factors. No relationship was found between physical activity and coronary heart disease risk factors in the adolescent population, and only a weak, but highly significant, relationship was found between VO2max and blood pressure in the large cohort of 17 year olds. These weak relationships could result from a relatively high fitness level and a small variation in fitness level in the young Danish population. Because of a great statistical power in the group of subjects at the same age from population 2, it was possible to analyze the relationship between blood pressure and fitness further. Lower blood pressure was found with higher fitness level, but only VO2max, and not physical activity, related to blood pressure, and the relationship became weaker with higher fitness level. In the adult male population, the variations in both VO2max and risk factors were much larger and a great number of the men had become sedentary. Inactive lifestyle was associated with low educational level, and the decrease in fitness and increase in coronary heart disease risk factor levels were more distinct in the former trade and vocational students than in the 'gymnasium' students. In the 17-year-old cohort, lower blood pressure was found with higher VO2max until a level of 53 and 45 ml.min-1.kg-1 in boys and girls, respectively, but above these levels no relationship was found between VO2max and blood pressure.

Adolescent↗
PubMed1995

A maximal cycle exercise protocol to predict maximal oxygen uptake.

Maximal oxygen uptake (VO2max) was predicted from maximal power output (MPO) in a progressive cycle ergometer test. The subjects were 232 men and 303 women 15-28 years of age. The relationship between VO2max and MPO was: VO2max (1.min-1) = 0.16 + (0.0117 x MPO) (w). A correlation coefficient of r = 0.88 was found between MPO and VO2max. Test-retest reliability was evaluated by two procedures. Standard deviations of test-retest differences in MPO and VO2max using the same standardized procedure in 35 subjects, were 10% and 8%, respectively, and Pearson correlations between test and retest values were 0.95 and 0.96, respectively. When MPO of tests conducted at the schools was compared to a standardized test performed by a physiologist in 267 subjects, test-retest Pearson correlation was 0.82. A prediction model only including MPO and explaining 80% of the variability in VO2max, is suggested for use in healthy adolescents and young adults.

Adolescent↗
PubMed1995

Physical activity and physical fitness as protection against premature disease or death.

It is known from prospective studies that the incidence of coronary heart disease (CHD) is lower in the physically active compared with the sedentary part of the population, and the rate of CHD is lower with higher fitness level. In studies where both physical activity (PA) and fitness are assessed, only fitness, and not PA, appear to be an independent predictor of mortality from CHD. It is unclear whether other fitness components than maximal oxygen uptake (Vo2max) have a beneficial effect on the rate of CHD. Further, it seems likely that there is an upper threshold of fitness (Vo2max) above which no further improvement in risk factors for CHD is found. However, most middle-aged people have fitness levels below this threshold. There is no doubt that the middle-aged sedentary person benefits from physical activity regardless of type and intensity, and it may be easier to motivate a sedentary person to carry out moderate physical activity. However, it is likely that the best effect is achieved by performing physical activity of a type and intensity sufficient to improve the fitness level. Still, recommendations of type, frequency, duration and intensity are matters of debate.

Coronary Disease↗
PubMed1995

Coronary heart disease risk factors, physical activity, and fitness in young Danes.

In a random sample of young Danish adults (86 men and 115 women, 23-27 yr of age) maximal oxygen uptake (VO2max), physical activity (PA), blood pressure, blood lipids, body fat content, and smoking habits were studied. Cholesterol, triglyceride and body fat related negatively to VO2max. The ratio HDL/total cholesterol was positively related to VO2max (r = 0.3, P < 0.001), but no relationship was observed for HDL cholesterol. No association was found between PA and any of the risk factors. The relationships between different measures of PA and directly measured VO2max was around r = 0.3. No relationship existed between heart rate recorded during submaximal testing and PA (r = 0.0), which indicates that the method of assessing VO2max is important in demonstrating relationships to PA and risk factors. In conclusion, a favorable coronary heart disease risk profile was related to a higher VO2max, but not to time spent on physical activity. This suggests that in this age group intensity must be high enough to have an effect on VO2max before a preventive effect is present.

Adult↗
PubMed1994

[Viral encephalitis after tick bite].

TBE is caused by a Flavivirus and is endemic in certain areas of Central and Eastern Europe, such as Austria, the south of Germany, Hungary, Czechoslovakia, Poland, the former Yugoslavia and SNG and certain areas of Sweden and Finland. Recent developments in the Eastern European countries have made them popular with Danish travellers, who are thus exposed to infection. Until now TBE has been a very rare disease in Denmark. The clinical course is biphasic being preceded by an incubation period of ten days. After the initial phase with uncharacteristic symptoms, a period af about five days follows where the patient has no symptoms. About one-third of the patients develop meningo-encephalitis where paresis can be seen. The course of the disease is often prolonged. The prognosis is good in terms of full recovery and low mortality. The diagnosis is made serologically with haemagglutination-inhibition test or ELISA-technique. Differential diagnosis includes other causes of viral encephalitis and Lyme disease with neurological manifestations, when there is a history of tick-bites. Vaccination provides good protection and is recommended for certain travellers with trips of some duration in endemic areas.

Denmark↗
PubMed1994

[HIV-positive drug addicts treated at the Copenhagen City Drug Dependency Clinic 1986-1992].

The Copenhagen City Drug Dependency Clinic at the former Rudolph Bergh's Hospital was established in 1986 as part of the measures taken by the municipality of Copenhagen to control the spread of HIV/AIDS among the intravenous drug addicts in the City of Copenhagen. The aim was to attract those HIV-positive drug addicts who were in no formal treatment for their drug addiction at other treatment centres and to retain them in treatment for a longer period acknowledging the fact that no causal cure exists for either the drug addiction or for AIDS. The goal of the treatment was to reduce HIV-risk behaviour i.e. sharing needles and syringes and unprotected sex with multiple partners and to reduce the adverse medical and social consequences of continued drug abuse. The treatment was supported by methadone treatment. During the five year period of 1986-92 a total of 196 HIV-positive drug addicts were referred to the clinic. A little more than half of those referred for the first through the third time and five out of six referred for the fourth time were admitted to treatment at the clinic. Half of the 126 first-time treated patients were retained in treatment for up to one year, while the rest were retained in treatment from one to five years. The mean time spent in treatment at the clinic was shorter for the relatively few patients who were admitted for the second time than for those admitted for the first time. At the end of the study 39 patients (20%) had died, most of them for non-AIDS related reasons.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗