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Biomedical subjects

O Andersen

Publications and source records attributed to O Andersen.

At least 253 records · Page 14Linked to original sources
PubMed1982

Plasma concentrations of the cyclic nucleotides, adenosine 3',5'-monophosphate and guanosine 3'.5'-monophosphate, in healthy adults treated with theophylline.

Plasma concentrations of cyclic adenosine monophosphate and cyclic guanosine monophosphate were measured in 10 health adults before, during and after periods of theophylline administration. Cyclic adenosine monophosphate concentrations did not change significantly, but cyclic guanosine monophosphate concentrations decreased by 29% on average when theophylline was administered. The change in cyclic guanosine monophosphate was not correlated to the plasma concentration of theophylline in the range studied.

Adrenergic beta-Agonists↗
PubMed1981

A complex four-break rearrangement between chromosomes 4 and 13 resulting in a recombinant chromosome 4.

A complex four-break rearrangement between chromosomes 4 and 13 was ascertained in a 10-year-old mentally retarded girl. The rearrangement was inherited from the phenotypically normal mother, who had an inverted insertion of part of the long arm of chromosome 4 into the long arm of 13 and, in addition, a pericentric inversion of the deleted 4. Meiotic crossing-over between the normal and the inverted 4 resulted in a recombinant chromosome 4, which was inherited by the proband, together with the 13/4 insertion. In this way the proband became monosomic for 4q35 leads to qter and trisomic for 4pter leads to 4p15, but she showed only minor physical malformations, as compared with other reports on the trisomy 4p syndrome. The cytogenetic findings are difficult to describe using the ISCN nomenclature.

Chromosome Aberrations↗
PubMed1981

Metal interactions in carcinogenesis: enhancement, inhibition.

Metals constitute a fundamentally important part of the total human environment. Since human exposure often involves complex mixtures of metal compounds and, possibly, organic compounds which may be carcinogenic per se, interactions between these compounds may add significantly to human cancer risk. Our present knowledge about these kinds of interactions is very limited. The best investigated area is benzo(a)pyrene (BP)-metal oxide particle interactions in respiratory carcinogenesis in the hamster. Metal oxide particles were also shown to modify the carcinogenic effect of nitrosamines. Several reports describe experiments in which selenium compounds exerted a generally anticarcinogenic and antimutagenic activity. Inorganic arsenic compounds, which are accepted to be carcinogenic in man, have so far been negative in animal experiments except for one recent suggested report. Several authors have, however, suggested that these compounds may act as cocarcinogens due to their inhibition of DNA repair, although animal experiments to demonstrate a cocarcinogenic effect of arsenic compounds have been negative so far, except for one preliminary report. The concentration of zinc in the diet seemed to influence both transplanted tumor growth and the carcinogenicity of several organic compounds, and the possibility of a correlation between dietary zinc and certain cancer forms in man has been suggested. Protection against development of Leydigiomas usually induced by cadmium injection was afforded by simultaneous injection of zinc salts. Nickel carcinogenesis has been reported to be antagonized by manganese, and synergism between Ni and organic carcinogens, e.g. BP, has been demonstrated. There is no firm evidence that lead may be a cocarcinogen, although some limited experimental evidence is available. Oxidizing agents have been demonstrated to increase, and reducing agents to antagonize, the mutagenic effect of chromium compounds in vitro. The content of carcinogenic and other metals in asbestos has been suggested to modify the carcinogenic properties of asbestos. Since much of the information available at present is suggestive, further research on these interactions as well as other possible interactions in metal carcinogenesis is needed. Studies should be made both in well defined in vitro systems and in relevant animal models.

Animals↗
PubMed1981

Monoamine metabolites in successive samples of spinal fluid. A comparison between healthy volunteers and patients with multiple sclerosis.

Homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and 4-hydroxy-3-methoxyphenylglycol (HMPG) were measured in the cerebrospinal fluid from patients with multiple sclerosis and from healthy volunteers. The fluid was withdrawn with the persons in the lateral recumbent position. In the controls and in 4 of the patients 10 successive samples of 2 ml each were analyzed. In the remaining patients the first 2 ml and last 2 ml of a total 20 ml were analysed. The highest values were obtained in the last portion. Patients with multiple sclerosis had significantly lower levels of 5-HIAA than controls in both the first and last CSF samples. Patients with a progressive course of prominent residual symptoms had a lower concentration of 5-HIAA and HVA than those with a relapsing course and little residual symptoms. The difference was significant for 5-HIAA.

Female↗
PubMed1981

Clinical studies on multiple sclerosis. I. Presentation of an incidence material from Gothenburg.

Probable and possible MS cases with a debut during the years 1950-1964 within the city of Gothenburg were identified (312 cases). This corresponds to an incidence of 5.3 per 100,000. The material was stratified according to diagnostic probability into three categories. For the final analysis cases with the lowest diagnostic probability were omitted (about 9%). The follow-up was completed during 1977, i.e. 13-27 years from onset. A longitudinal analysis of each case was based upon a mixed prospective/retrospective study in which the authors personally examined the majority of the cases during most of the years. The female/male ratio was 1.5-1.6. The mortality rate was higher for males due in part to an earlier progressive development of multiple sclerosis and in part to a higher trend for acquisition of other mortal diseases. Bouts, as the first manifestation of the disease, were more frequent in young ages than in old, and more frequent among females than in males. The averages bout frequency decreased significantly with the duration of the disease as well as with the age of onset. The opposite trend was characteristic for development of a progressive course. Among symptoms at onset, those indicating lesions of long sensory and/or motor tracts (particularly the sensory) dominated. Such initial symptoms were seen in 30-40% of the younger patients and 70% of the older patients. The rest was divided between cases with optic nerve lesions (20-30% among younger, 12-15% among older patients) and brain stem lesions (approx. 25% among younger, 10-19% among older patients). The occurrence of various symptoms during the first two decades of the disease was also analyzed and the pattern of symptoms presented graphically. These results will be treated further in subsequent studies.

Adolescent↗
PubMed1979

Homogeneous enzyme immunoassay of serum digoxin with use of a bichromatic analyzer.

We applied the Enzyme Multiplied Immunoassay Technique (EMIT; Syva Corp., Palo Alto, CA) for determination of serum digoxin to the ABA-100 bichromatic analyzer. Assay conditions were almost exactly as prescribed for the manual procedure, but the ABA-100 offers high automation, smaller reagent volumes, and shorter reaction time. Precision studies gave CV's of less than 10%. Sixty patients' samples, analyzed for digoxin by radioimmunoassay and this enzyme immunoassay, gave a correlation (r) of 0.941. Results obtained with the ABA-100 were apparently slightly higher. One kit provides reagents for 250 assays, as compared to 70 assays with the manual procedure. In an emergency situation a result will be available about 60 min after the patient's sample is received; one operator can analyze about 120 samples in 8 h.

Digoxin↗
PubMed1978

Stability and maturation of E. coli ribosomal RNA.

The kinetics of rRNA maturation were investigated in a rifampicin permeable strain of E. coli during exponential growth in glucose minimal medium. The method used involves isotopic labelling of rRNA, and separation of precursor and mature forms by gel electrophoresis. The maturation of both 16s and 23s rRNA was found to follow first order kinetics. The mean life time of the precursors was found to be about 1.5 min. In glucose minimal medium all pulse label in precursors was recovered in mature rRNA, i.e. nascent rRNA is stable.

Escherichia coli↗
PubMed1978

In vitro induction of uncoiled chromosomes with inhibitors of RNA and protein synthesis.

When inhibitors of cellular DNA, RNA or protein synthesis are added to the growth medium of human lymphoid cells in G2 phase, these agents produce, within narrow ranges of concentrations, G banded or uncoiled chromosomes in the treated metaphase cells. It is suggested that the induced structural alteration is a consequence of an inhibition of the normal chromosome condensation and fusion of bands taking place between prometaphase and metaphase. This inhibition seems to be due to a partial inhibition of G2 phase synthesis of RNA and protein molecules, necessary for normal chromosome condensation in metaphase. It is found that this condensation can be reversed during a resting period after metaphase.

Amanitins↗
PubMed1977

Receptor binding and biological effect of insulin in human adipocytes.

The binding of 125I-labelled insulin to human adipocytes was studied at 37 degrees C. The precipitability of the 125I-labelled insulin preparation (0.03 nmol/l) in trichloroacetic acid and the concentration of biologically active insulin (7.5 nmol/l) remained constant in buffer incubated with human adipocytes (100 microliter cells/ml suspension) for 30--60 minutes at 37 degrees C, whereas more than half of the insulin was inactivated by rat fat cells under the same conditions. A constant level of binding of 125I-labelled insulin (0.03 nmol/l) to human adipocytes was obtained after 45 minutes. The apparent dissociation constant of receptor binding was about 0.2 nmol/l as compared to about 2 nmol/l for rat adipocytes. Conversion of [UP14C]glucose to lipids was stimulated half-maximally by about 0.05 nmol/l of insulin (similar to rat adipocytes). Thus, half-maximal stimulation of human adipocytes was obtained with a recptor occupancy of about 20--30 per cent.

Adipose Tissue↗