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Biomedical subjects

K Hansen

Publications and source records attributed to K Hansen.

At least 253 records · Page 14Linked to original sources
PubMed1985

Comparison of an enzyme-linked immunosorbent assay using crude S. haematobium soluble egg antigen with a radioimmunoassay using purified S. mansoni egg antigen for the serodiagnosis of schistosomiasis haematobium.

An enzyme-linked immunosorbent assay (ELISA) using crude Schistosoma haematobium soluble egg antigen (ShSEA) was compared with a radioimmunoassay (RIA) employing purified heterologous species S. mansoni egg antigen (MSA1) for the serodiagnosis of schistosomiasis haematobium in a group of 45 Nigerian school children living in an area endemic for S. haematobium. Both assay systems appeared applicable. The ELISA proved to be more sensitive detecting 100% of the 27 parasitologically positive individuals while the RIA defined 89% of this group. Neither test had false-positive results for the 10 non-endemic area parasitologically negative controls, although the ELISA demonstrated that 56% of the 18 endemic area parasitologically negative controls had anti-ShSEA antibodies. The RIA indicated that 44% of this group had anti-MSA1 antibodies. These latter findings were interpreted as related to the hyperendemicity of schistosomiasis haematobium for the study area.

Adolescent↗
PubMed1984

The nasion-sella reference line in cephalometry: a methodologic study.

This investigation was undertaken to examine the effects of the registration error of the nasion-sella reference line (NSL) upon the values of angular and linear head film measurements. A comparison was made between two methods of constructing the NSL: (1) using the anatomically defined landmarks nasion and sella (L method) and (2) using the stable skull structures in the anterior cranial base (S method). Double registrations of sixteen pairs of lateral head films, from before and after 3 years of activator treatment, were performed by two observers. The results of the investigation revealed the following: (1) The registration error of the NSL affected angular and linear head film measures to a considerable degree. (2) The registration error was larger for the S method than for the L method. (3) The two observers differed in locating the NSL. The interobserver difference was especially apparent for the S method. The clinician should be aware of the NSL-registration error in the analysis of both single and serial radiographs. A misjudgment of the position of the reference line may result in diagnostic misinterpretations, thus affecting treatment planning or leading to false conclusions when the outcome of a particular treatment procedure is evaluated. In longitudinal studies covering a short period of growth, the L method would be the method of choice.

Adolescent↗
PubMed1984

Bone lesions in early syphilis detected by bone scintigraphy.

We report a case of early syphilis with multiple bone lesions which all resolved after treatment with penicillin. We discuss why bone lesions may be more prevalent than generally believed and why 99m-Tc-MDP-bone scintigraphy is more sensitive than radiography in detecting syphilitic periostitis.

Adult↗
PubMed1984

Toxicity and transformation potency of nickel compounds in BHK cells in vitro.

An in vitro bioassay utilizing BHK-21 cells in culture was used to determine the relative transformation potency of nickel metal and a number of nickel compounds. These included as relatively insoluble particulates a known carcinogen, nickel subsulfide (Ni3S2) and several oxides either of commercial interest or found in the working environment in the metal industry [e.g., nickel oxide (NiO)], and a soluble salt, nickel acetate [Ni(CH3COO)2]. Although a wide range of transformation potency was found as a function of the dose of nickel per area of culture, all substances produced the same number of transformed colonies at the same degree of toxicity (e.g., 50% survival). Toxicity may arise from nickel originating in membrane-bound or phagocytized particles, or nickel available from solution. If toxicity is a direct measure of net available nickel, then apparently nickel or nickel ion per se is the ultimate transforming agent, independent of source or uptake mechanism.

Acetates↗
PubMed1983

Effects of bromide on behaviour of mice.

Groups of mice, housed individually in standard cages placed in a frame especially designed for the recording of locomotive behaviour, were fed diets containing sodium bromide at a level of 0, 400, 1200, 3600 or 10,800 ppm for 36 days. A fully automated system was used to record and process measurements of the nocturnal motility of the mice, together with three other variables (evasion time, spontaneous treadmill performance and body weight), for a total of 128 days before, during and after administration of the test diets. The data obtained, analysed statistically by univariate and multivariate analysis of variance, indicated that for sodium bromide, the 'effect limit' based on behavioural variables and body weight lay for mice between 400 and 1200 ppm in the diet. The fact that the overall effect of the 10,800 ppm dietary level was not completely reversible seemed to be largely attributable to the effect of this level of sodium bromide administration on body weight.

Animals↗
PubMed1983

Formaldehyde and hexamethylenetetramine in Styles' cell transformation assay.

A dose-dependent increase in the transformation rate in Styles' cell transformation assay using BHK-21/cl.13 cells was observed after exposure to formaldehyde and hexamethylenetetramine. The toxic and transforming effect was equal after exposure to 20 micrograms/ml of formaldehyde or 1000 micrograms/ml of hexamethylenetetramine which is slowly hydrolysed in aqueous solution to form ammonia and formaldehyde.

Animals↗
PubMed1983

Multiple mononeuritis and radiculitis with erythema, pain, elevated CSF protein and pleocytosis (Bannwarth's syndrome).

Four patients with Bannwarth's syndrome were examined. One to three weeks weeks after the appearance of a large erythematous skin lesion they developed pain of variable localisation. Four days to four weeks later uni- or bilateral facial palsies and other nerve lesions developed. CSF showed elevated protein and mononuclear pleocytosis. There was a defect of the blood-brain barrier and increased intrathecal production of IgG. Facial nerve latencies were increased 4 to 7 times in three cases and normal in one case examined 15 months after onset. Conduction velocity along other nerves was normal apart from slight slowing in one diabetic patient. Recovery was incomplete in three patients 8 to 15 months after onset of disease and complete in one patient after 15 months.

Adult↗
PubMed1983

In vitro toxicity and transformation potency of nickel compounds.

An in vitro bioassay utilizing BHK-21 cells in culture is used to determine the relative transformation potential of a number of nickel compounds including, as relatively insoluble particulates a known carcinogen (Ni3S2) and several oxides either of commercial interest or found in the working environment in the metal industry (e.g., NiO), and a soluble salt [Ni(CH3COO)2]. Although a wide range of transformation potency is found as a function of the dose of Ni per area of culture, all substances produce the same number of transformed colonies at the same degree of toxicity (e.g., 50% survival). If toxicity is a direct measure of intracellular concentration, then apparently nickel per se is the ultimate transforming agent independent of source or uptake mechanism.

Animals↗
PubMed1982

Use of the Limulus test to determine the hygienic status of milk products as characterized by levels of gram-negative bacterial lipopolysaccharide present.

The Limulus test was used to investigate the occurrence of Gram-negative bacterial lipopolysaccharide (LPS) in milk and dairy products. This test specifically detects the extremely heat-resistant LPS, and so determines the total accumulated quantity of LPS in a product whether it has been heat-treated or not. A positive correlation between number of psychrotrophic bacteria and amount of LPS in fresh farm milk was found (r = 0.63). Fresh farm milk and freshly produced market milk contained on average less than 1 ng LPS/ml. The Limulus test is considered highly suitable for use in the dairy industry, being a method which will characterize quickly and specifically the hygienic level of a product by the extent of the cumulative contamination by Gram-negative bacteria.

Animals↗
PubMed1980

Single-pore sensilla of damselfly-larvae: representatives of phylogenetically old contact chemoreceptors?

The four single-pore sensilla on the maxillary palp of Agrion and Ischnura possess two bipolar sensory cells for A-sensilla and five for B-sensilla. Distally, their dendrites are enclosed by a dendritic sheath and a pore tube. The dendritic tips have access to the outside via the opening of the pore tube. The inner dendritic segments join the receptor cell bodies laterally. The receptor cells of each sensillum are enveloped by three sheath cells and three receptor lymph cavities. Receptor lymph cavity 1 and 3 are connected with the outside by the pore tube and a minute canal system in the cuticle, respectively. All three sheath cells show microvilluslike processes of the apical membrane. Moreover, all sheath cells contain two centrioles in tandem arrangement. The structure of the single-pore sensilla is compared with that of similar sensilla of other arthropods. Functional and phylogenetic aspects are discussed.

Animals↗
PubMed1980

Mutual pro-drugs of beta-lactam antibiotics and beta-lactamase inhibitors.

The principle of combining a beta-lactam antibiotic with a beta-lactamase inhibitor in a single molecule functioning as pro-drug for the two active components is illustrated by the linked esters 3 and 4 in which ampicillin and mecillinam, respectively, are combined with the beta-lactamase inhibitor penicillanic acid sulfone. It is shown that in man these esters are excellently absorbed from the gastro-intestinal tract and after absorption hydrolyzed with simultaneous liberation of the active components. As a result high blood and tissue levels of antibiotic and beta-lactamase inhibitor in a balanced ratio are attained. The advantages of "mutual pro-drugs" over simple combinations are discussed.

Anti-Bacterial Agents↗