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Biomedical subjects

Øivind Larsen

Publications and source records attributed to Øivind Larsen.

12 recordsLinked to original sources
PubMed2005

[Is there a Norwegian medical identity?].

Norwegian medicine is interwoven with the country's history, social structure, and its organization of health services. Health services in Norway are based on an ideology of equality and solidarity in which decentralization and strong primary care are crucial elements. The aim is treatment at the lowest effective level of care, irrespective of patients' financial or social status. Health services have high political priority and people expect a great deal of them. The medical profession in Norway has a double loyalty: to the individual patient and to society at large. The gate keeper-role, which has been most prominent among general practitioners, reflects economic responsibility as well as some hesitation in the use of extensive diagnostic and therapeutic procedures. Norwegian medicine has never been particularly eager on interventions. This could be explained both by strong governmental control and a traditional Norwegian moderation. The medical profession is less homogenous than before, but still has a strong community of communication. The concept of health among Norwegians is pragmatic and holistic. The relationship between health and nature is strong and in line with people's conception of nature in general. Social developments such as individualization, internationalization and economic ways of thinking together with increasing specialization and market adjustment in the health services make for rapid changes in Norwegian medicine. It is more and more difficult to define national features, but those existing are well worth defending.

Attitude to Health↗
PubMed2005

[Medical publishing in Norway 1905-2005].

The nation-building process in Norway took mainly place before the Norwegian-Swedish union came to a close in 1905. This was not a dramatic change, though the end of the union did bring a lift to Norwegian national consciousness. In 1905 there were three general medical journals in Norway and approximately 1200 doctors. German was the most important language of international science, but most scientific publishing was done in Norwegian. After the Second World War, English became the dominating language of scientific communication. Twentieth-century medicine and medical publishing was an era of specialisation and internationalisation. Norwegian medicine has to a large extent been internationalised through Nordic cooperation, with the Nordic specialist journals being of particular importance. With increasing professionalism in research, international English-language journals have become the major channels of communication, though several Norwegian-language journals (on paper or on the internet) have been established and are of crucial importance to a national identity within medical specialties. In 2005 there is only one general medical journal in Norwegian, in a country with approximately 20,000 doctors. A national identity related to medical publishing is not given much attention, though national medicine is still closely tied in with national culture. Good clinical practice should be based on a firm knowledge of local society and local tradition. This is a challenge in contemporary medical publishing.

History, 20th Century↗
PubMed2005

Characterization of a prokaryotic haemerythrin from the methanotrophic bacterium Methylococcus capsulatus (Bath).

For a long time, the haemerythrin family of proteins was considered to be restricted to only a few phyla of marine invertebrates. When analysing differential protein expression in the methane-oxidizing bacterium, Methylococcus capsulatus (Bath), grown at a high and low copper-to-biomass ratio, respectively, we identified a putative prokaryotic haemerythrin expressed in high-copper cultures. Haemerythrins are recognized by a conserved sequence motif that provides five histidines and two carboxylate ligands which coordinate two iron atoms. The diiron site is located in a hydrophobic pocket and is capable of binding O(2). We cloned the M. capsulatus haemerythrin gene and expressed it in Escherichia coli as a fusion protein with NusA. The haemerythrin protein was purified to homogeneity cleaved from its fusion partner. Recombinant M. capsulatus haemerythrin (McHr) was found to fold into a stable protein. Sequence similarity analysis identified all the candidate residues involved in the binding of diiron (His22, His58, Glu62, His77, His81, His117, Asp122) and the amino acids forming the hydrophobic pocket in which O(2) may bind (Ile25, Phe59, Trp113, Leu114, Ile118). We were also able to model a three-dimensional structure of McHr maintaining the correct positioning of these residues. Furthermore, UV/vis spectrophotometric analysis demonstrated the presence of conjugated diiron atoms in McHr. A comprehensive genomic database search revealed 21 different prokaryotes containing the haemerythrin signature (PROSITE 00550), indicating that these putative haemerythrins may be a conserved prokaryotic subfamily.

Amino Acid Sequence↗
PubMed2004

Genomic insights into methanotrophy: the complete genome sequence of Methylococcus capsulatus (Bath).

Methanotrophs are ubiquitous bacteria that can use the greenhouse gas methane as a sole carbon and energy source for growth, thus playing major roles in global carbon cycles, and in particular, substantially reducing emissions of biologically generated methane to the atmosphere. Despite their importance, and in contrast to organisms that play roles in other major parts of the carbon cycle such as photosynthesis, no genome-level studies have been published on the biology of methanotrophs. We report the first complete genome sequence to our knowledge from an obligate methanotroph, Methylococcus capsulatus (Bath), obtained by the shotgun sequencing approach. Analysis revealed a 3.3-Mb genome highly specialized for a methanotrophic lifestyle, including redundant pathways predicted to be involved in methanotrophy and duplicated genes for essential enzymes such as the methane monooxygenases. We used phylogenomic analysis, gene order information, and comparative analysis with the partially sequenced methylotroph Methylobacterium extorquens to detect genes of unknown function likely to be involved in methanotrophy and methylotrophy. Genome analysis suggests the ability of M. capsulatus to scavenge copper (including a previously unreported nonribosomal peptide synthetase) and to use copper in regulation of methanotrophy, but the exact regulatory mechanisms remain unclear. One of the most surprising outcomes of the project is evidence suggesting the existence of previously unsuspected metabolic flexibility in M. capsulatus, including an ability to grow on sugars, oxidize chemolithotrophic hydrogen and sulfur, and live under reduced oxygen tension, all of which have implications for methanotroph ecology. The availability of the complete genome of M. capsulatus (Bath) deepens our understanding of methanotroph biology and its relationship to global carbon cycles. We have gained evidence for greater metabolic flexibility than was previously known, and for genetic components that may have biotechnological potential.

Bacterial Proteins↗
PubMed2003

The surface-associated and secreted MopE protein of Methylococcus capsulatus (Bath) responds to changes in the concentration of copper in the growth medium.

Expression of surface-associated and secreted protein MopE of the methanotrophic bacterium Methylococcus capsulatus (Bath) in response to the concentration of copper ions in the growth medium was investigated. The level of protein associated with the cells and secreted to the medium changed when the copper concentration in the medium varied and was highest in cells exposed to copper stress.

Bacterial Outer Membrane Proteins↗