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Biomedical subjects

J Clausen

Publications and source records attributed to J Clausen.

At least 91 records · Page 5Linked to original sources
PubMed1991

Uptake and distribution in rat brain of organic and inorganic selenium.

Polyunsaturated fatty acids (PUFAs) occur in relatively high amounts in phospholipids of the synapses. PUFAs may thus determine the fluidity of the synaptosomal membrane and, hereby, they may regulate the neuronal transmission. It was therefore tempting to suggest a system in the brain, that inhibits autooxidation of PUFAs. In order to trace such a protection system, Wistar rats were equally loaded with 4500 kBq of 75-Se either as selenite or as L-Se-methionine. By means of gradient ultracentrifugation, particulate fractions of the brains were isolated, and the radioactivity as well as the glutathione-transferase and -peroxidase activities were estimated. The distribution of the two selenium components among the particulate fractions was different. Thus, selenite gave higher radioactivity in myelin, then followed by the light synaptosomal and the vesicular fraction. L-Se-methionine was more equally incorporated in all particulate fractions, although highest activity was found in the mitochondrial fraction. Myelin and synaptic vesicles were devoid of transferase activity. On the other hand, the synaptosomal fraction showed highest specific transferase activity. The glutathione peroxidase activity was highest in the myelin fraction, followed by the vesicular and the synaptosomal fractions. The data obtained thus support the idea that the PUFAs of the synaptic compartment are protected against peroxidation, at least in part, by the selenium containing glutathione peroxidase.

Animals↗
PubMed1990

Brainstem auditory-evoked responses with and without sedation in autism and Down's syndrome.

Brainstem auditory-evoked responses (BAER) were obtained from 46 control, 16 Down's syndrome, and 48 autistic male subjects. Six Down's syndrome and 37 autistic subjects were tested with sedation. Sedated and unsedated Down's syndrome subjects displayed shorter absolute and interpeak latencies for early components of the BAER whereas the sedated autistic group showed longer latencies for the middle and late components. The prolongation of latencies in the sedated autistic group was unrelated to age or intellectual level. Although individuals requiring sedation may have a higher probability of neurological impairment, an effect of sedation on the BAER cannot be ruled out.

Adolescent↗
PubMed1990

Are blood pressure levels increasing in Denmark?

The Copenhagen City Heart Study is a prospective cardiovascular population study designed to evaluate the incidence of and risk factors for cardiovascular disease. A random population sample comprising approximately 20,000 individuals was invited to participate. Blood pressure was measured, and information regarding the use of antihypertensive medication was collected in an initial survey during the period 1976-1978 (attendance rate 74%) and from a second survey during the period 1981-1983 (attendance rate 70%). A significant increase in systolic and diastolic blood pressure between survey 1 and survey 2 was found among both men and women greater than 40 years of age and not using antihypertensive medication. The increase in blood pressure in the follow-up survey could not be explained by changes in methods, changes in the prescription of antihypertensive medication, or selection bias. Factors associated with changes in systolic and diastolic blood pressure were examined by multiple linear regression analysis. Both increase in body mass index and increase in alcohol consumption were positively correlated with changes in systolic and diastolic blood pressure, while use of antihypertensive medication, a high value of body mass index at survey 1 and a high level of education were negatively correlated with changes in systolic and diastolic blood pressure. Female sex and advanced age were also negatively correlated with changes in diastolic blood pressure. Consumption of tobacco and alcohol, income and changes in consumption of tobacco were not significantly correlated with changes in systolic and diastolic blood pressure.

Adult↗
PubMed1990

Antibody reactivity against animal retroviruses in multiple sclerosis.

A total of 27 MS patients and 82 controls were studied for presence of antibodies reacting with maedi-visna virus and bovine leukemia virus by means of 2 ELISA techniques. Furthermore, the differentiated antibody response against BLV antigens was evaluated by immunoblotting. People with elevated activities against MVV were detected in the MS group as well as controls. Elevated antibody activity against BLV as determined by biotinylated protein A and peroxidase-labelled streptavidin tended to occur more frequently in MS patients than in controls. No such difference was found, however, when peroxidase-conjugated antibodies against human kappa chain were used for detection of antibodies reacting with BLV. Immunoblotting revealed no difference between the MS and the control group when anti-kappa antibodies were used to detect antibody binding to BLV antigens. The protein A method revealed significantly decreased antibody activity against a BLV antigen with molecular weight of about 29 kD in MS compared with controls, whereas a significant rise in number of MS patients responding to a component of about 53 kD was observed. The differences between the 2 detection systems could be due to unspecific reactions. The present data indicate that MS patients exhibit an inhomogeneous and, in some cases elevated, antibody activity against BLV.

Adult↗
PubMed1989

[Effect of posture on the diuretic treatment of decompensated cirrhosis and heart failure].

The diuretic effect of the supine position was evaluated in six patients with cirrhosis and ascites and six with congestive cardiac failure. All patients received 1 mg bumethanide intravenously and were randomly assigned to either bed rest in the supine position or normal daily activity in the upright position for the next six hours. The diuretic response was similar in patients with heart failure and cirrhosis, and was significantly greater in the supine than in the upright position: mean 1,133 v 626 ml/6 h (p less than 0.01). The natriuresis was similarly greater during recumbency: mean sodium 96 v 45 mmol (mEq)/6 h (p less than 0.01), and the excreted potassium in six hours was similar in both postures. The glomerular filtration rate was 100 and 66 ml/min (p less than 0.01) and the heart rate 76 and 83 beats/min (p less than 0.05) in the supine and upright positions, respectively. Plasma concentrations of noradrenaline, renin, and aldosterone rose significantly during the upright position. The results suggest that the attenuated response to intravenous bumethanide in the upright position and during normal daily activity may be due to the activation of several, homoeostatic mechanisms which may reduce the excretion of water and salt.

Adult↗
PubMed1989

Cross-sectional study of health effects of cryolite production.

A cross-sectional health study of 101 cryolite workers was performed, using spirometry and a questionnaire. Multiple regression analysis revealed a significant correlation between the index of smoking and a decrease in FEV1 (per cent). There was no significant correlation between work-related exposure and lung function. Many cryolite workers described a group of symptoms appearing after 15 to 30 min of heavy dust exposure: nausea, followed by epigastric pain with relief after spontaneous or provoked vomiting. Thirty-four (33.6 per cent) workers complained of nausea, vomiting or diarrhoea in relation to work, compared to 3.8 per cent of 1752 men participating in the Copenhagen Male Study.

Adult↗
PubMed1986

Diuretic treatment in decompensated cirrhosis and congestive heart failure: effect of posture.

The diuretic effect of the supine position was evaluated in six patients with cirrhosis and ascites and six with congestive cardiac failure. After fasting overnight in bed the patients received bumetanide 1 mg intravenously and were then immediately randomly assigned to either bed rest in the supine position or normal daily activity in the upright position for the next six hours. Two days later the procedure was repeated, the patients being assigned to the other posture. The diuretic response was similar in patients with heart failure and cirrhosis, and was significantly greater in the supine than in the upright position: mean 1133 v 626 ml/6 h (p less than 0.01). The natriuresis was similarly larger during recumbency: mean sodium 96 v 45 mmol(mEq)/6h (p less than 0.01), and the excreted potassium in six hours was similar in both postures. The glomerular filtration rate was 100 and 66 ml/min (p less than 0.01) and heart rate 76 and 83 beats/min (p less than 0.01) in the supine and upright positions respectively. Plasma concentrations of noradrenaline, renin, and aldosterone were all raised even when the patient adopted the supine position, and a further significant rise was observed during the upright position. The results suggest that the attenuated response to intravenous bumetanide in the upright position and during normal daily activity may be due to the activation of several homeostatic mechanisms that may reduce the excretion of water and salt.

Adult↗
PubMed1985

Effect of multiple sclerosis alpha 2-macroglobulin on mitogen induction of lymphocyte proliferation.

Electrophoretic studies on microheterogeneity of alpha 2-macroglobulin (alpha 2M) have revealed the presence of an abnormal acidic form of alpha 2M in multiple sclerosis (MS). In the present study we have characterized alpha 2M chemically and compared the inhibitory effect of MS and normal alpha 2M on the mitogen induction of lymphocyte proliferation. The antitrypsin activity and total reducing sugar content of MS alpha 2M were comparable with those of normal alpha 2M. However, the sialic acid content of MS alpha 2M was found to be significantly higher than that of normal alpha 2M. In agreement with previous studies, normal alpha 2M was found to inhibit the mitogen induction of lymphocyte proliferation in more than 90% cell cultures. However, MS alpha 2M was found to inhibit the mitogen-induced lymphocyte proliferation in less than 35 percent cell cultures. The effects of MS or normal alpha 2M on the lymphocyte cultures of either groups were found to be apparently the same. The possible explanations for the loss of the above-mentioned inhibitory effect of MS alpha 2M have been discussed.

Cells, Cultured↗
PubMed1985

Kinetics of inhibition of mitogen-induced proliferation of human lymphocytes by alpha 2-macroglobulin in serum-free medium.

The effect of alpha 2-macroglobulin (alpha 2M) on the ability of human lymphocytes to proliferate in response to stimuli by 3 mitogens, concanavalin A, phytohaemagglutinin and pokeweed mitogen was investigated in in vitro lymphocyte cultures in serum-free medium. The following experiments were performed: 1. lymphocytes were treated with alpha 2M prior to stimulation with the mitogens; 2. alpha 2M and mitogens were added simultaneously to the lymphocyte cultures; and 3. alpha 2M was added to the lymphocyte cultures after they were stimulated with the mitogens. In all cases, alpha 2M was found to inhibit mitogen induced proliferation of the lymphocytes as evaluated by (6-3H)-thymidine uptake of the cells. The mechanisms involved in the inhibition of lymphocyte proliferation by alpha 2M are discussed.

Adult↗
PubMed1985

Characterization of DNA and RNA in circulating immunocomplexes in multiple sclerosis, amyotrophic lateral sclerosis and normal controls.

The total levels of DNA and RNA in serum immunocomplexes from multiple sclerosis (MS) patients and healthy control persons were compared. Furthermore, the levels of single-stranded DNA (ss DNA) and double-stranded DNA (ds DNA) in serum immunocomplexes from MS patients, amyotrophic lateral sclerosis (ALS) patients and controls were studied. The mean values of DNA and RNA were found to be elevated (P less than 0.01) in MS compared to the control means. Furthermore, the RNA/DNA ratio and the ratio ss DNA/ds DNA were decreased in MS. In contrast the ss:ds DNA ratio in ALS was increased. In ALS, however, the sum of ss DNA and ds DNA was lower (P less than 0.05) than the control mean value.

Adult↗
PubMed1985

Membrane-bound 2',3',-cyclic nucleotide 3'-phosphohydrolase activity of lymphocytes, granulocytes and erythrocytes in multiple sclerosis.

A sensitive fluorimetric method was used for the assay of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) activity of lymphocyte, granulocyte and erythrocyte membranes from patients with multiple sclerosis (MS). The data obtained were compared with the corresponding data from normal individuals. CNP activities of granulocyte and erythrocyte membranes of the 2 groups did not differ significantly. However, a 40% decreased membrane CNP activity of MS lymphocytes was found when the data were compared with the normal lymphocytes' activity (P less than 0.0005) by both the non-parametric median test and Student's t-test. A role of CNP in immunoregulation is suggested.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1985

Quantitation of multiple sclerosis specific central nervous system antigens in various regions of MS brains.

We have estimated the levels of partially purified multiple sclerosis (MS) specific glycoproteins (MSG2) in gray matter, white matter, spinal cord and brain stem of MS autopsy brains by an enzyme immunoassay in which antisera to a pooled MSG2 was employed. Similarly, the levels of KG2 (non-MS brain isolate corresponding to MSG2) were assayed in various topographic areas of non-MS autopsy brains. Comparison of data on MS and non-MS groups revealed that the MS specific antigens may be preferentially located in the normal appearing white matter of MS brains. The concentration of MS antigens was found to be highest in the normal appearing white matter of MS brains, followed by periplaque and finally plaque. These results indicate that the MS specific antigens are not the degraded products of MS brains. They further support the view that normal appearing white matter of MS brains should be the target tissue for the isolation of MS specific antigens.

Antigens↗
PubMed1984

Organochlorine compounds in human breast fat from deceased with and without breast cancer and in a biopsy material from newly diagnosed patients undergoing breast surgery.

Epidemiological studies have related the incidence of mammary cancer to the dietary intake of fat and/or meat. Since organochlorine compounds (e.g., polychlorinated biphenyls (PCB) and DDT (and its metabolite DDE] are accumulated in the adipose tissue it was tempting to suggest a relationship between levels of PCB and "DDT" (i.e., DDT + DDE) in breast fat tissue and the occurrence of mammary cancer. To elucidate this theory, the organochlorine levels of 14 breast fat tissue samples from breast cancer patients and similar samples from 18 deceased mammary cancer patients were compared to that of 21 similar samples from noncancer patients and finally to adipose tissue samples from 35 non-cancer autopsy specimens. No significant differences were traced. Thus it seems that the accumulation of PCB and DDT measured in breast fat tissue do not relate to the occurrence of mammary cancer.

Adipose Tissue↗
PubMed1984

Glutathione peroxidase and reductase, glucose-6-phosphate dehydrogenase and catalase activities in multiple sclerosis.

Our previous studies have demonstrated a decreased glutathione feroxidase (GSH-Px) activity of erythrocytes and leucocytes from multiple sclerosis (MS) patients. In the present communication these activities were compared with the activities of associated enzymes (glutathione reductase (GSSG-RD), glucose-6-phosphate dehydrogenase (G-6-PD) and catalase). All enzymic activities were compared between MS patients, other neurologic patients (ON patients) and normal control individuals. Compared to data of ON patients and normal controls, in MS the ratio of GSHPx/GSSGRD in lympho- and granulocytes was significantly decreased (2 alpha less than or equal to 0.05) by 35% and 51%, respectively. The significant correlation between GSSG-RD and the GSH-Px activity (2 alpha less than or equal to 0.05, r = 0.501) found in control lymphocytes was not present in MS lymphocytes. However, the lymphocyte GSH-Px activities of controls as well as of MS correlated with the corresponding serum selenium levels (2 alpha less than or equal to 0.05, r = 0.594 and 2 alpha less than or equal to 0.01, r = 0.967, respectively). The G-6-PD activity was insignificantly increased by 41% in MS lymphocytes compared to normal control. Catalase activity was unchanged in lymphocytes but decreased 50% in MS granulocytes compared to normal control. No significant differences were found between MS and the ON group. The catalase activity of MS erythrocytes was increased by 63% (2 alpha less than or equal to 0.05) in comparison with both the normal control and ON data.

Catalase↗