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Endogenous opioids serve as modulators of neuroendocrine and immune system processes, the investigation of which calls for high-specificity radioimmunoassays (RIAs). This study focuses on the development and use of a specific radioimmunoassay for the opioid peptide Met5-Enkephalin-Arg6-Phe7 (MEAP), the C-terminus part of proenkephalin A. Antibodies were raised in four rabbits and investigated in terms of titre, avidity and specificity, followed by finding ideal conditions for these antibodies in RIA. MEAP concentrations were determined in crude extracts of rat hypothalamus, dorsal root ganglia, adrenals and ankle using this standardized assay after an oxidizing process. At reverse-phase high-pressure liquid chromatography (HPLC), the position of immunoreactive material from rat hypothalamus eluted as two peaks out of which one was compatible with that of synthetic MEAP. All rabbits exhibited individual differences in relative immune response and time of its onset. The avidity constant was 10 times higher on a molar basis for ab 4108 compared with ab 4182. There was no cross-reactivity for ab 4182 to related peptides, such as enkephalins and dynorphin B, and negligible background values for ab 4108. The relative levels ofimmunoreactive MEAP from the CNS versus peripheral tissues contrasted in accordance with current knowledge. It is suggested that reports with RIA results should include characterization of antibodies, extraction procedures, standard curves and compositions of buffers. Furthermore, the results should preferably be expressed in relation to total protein content. [ABSTRACT FROM AUTHOR]

Investigates the long-term effects of weight change on medication for diabetes and cardiovascular disease in severely obese subjects. Changes in the use and costs of medication in relation to treatment and weight change; Results of the Swedish Obese Subjects (SOS) intervention study.

To examine how soil organisms affect soil organic nitrogen (N) storage and mineralisation, we theoretically derive the soil substrate nitrogen to carbon ratio and total soil N storage for both donor-controlled (DC) and Lotka-Volterra (LV) soil systems with three trophic levels: substrate, microbes and grazers. We show that substrate N:C ratioand soil N storage are functions of the structure of the soil food web, of the properties of the organisms in the soil community, and of the properties of litter input from above ground. The carbon production-to-assimilation efficiency of soil organisms is the most importantproperty determining how the substrate N: C ratio and soil N storageare affected by changes in the soil community. The qualitative effects of grazers depend on whether they have an efficiency larger or smaller than some critical efficiencies. In this paper, we derive these critical efficiencies mathematically. Within the normal range of efficiencies, substrate N:C ratio and soil N storage will usually decrease, and the nitrogen mineralization will increase, with addition of grazers, or as a result of a succession of species from a lower to a higher level of metabolic activity. Numerical analyses show that an increase in soil temperature has a pronounced negative effect on soil N storage through the effects on the metabolic activity of organisms atall trophic levels. N dilution in litter, because of increased CO2 levels in the atmosphere, can lead to a moderate increase in soil N storage. [ABSTRACT FROM AUTHOR]

Presents a correction to the article "Repeated Massage-Like Stimulation Induces Long-Term Effects on Nociception — Contribution of Oxytocinergic Mechanisms," by I. Lund, Y. Ge, L. C. Yu, K. Uvnas-Moberg, J. Wang, C. Yu, M. Kurosawa, G. Agren, A. Rosen, M. Lekman and T. Lundeberg, published in the "European Journal of Neuroscience."