Biomedical subjects

F Nyberg

Publications and source records attributed to F Nyberg.

241 records · Page 14Linked to original sources

PubMedDate not supplied

Classification of CSF samples from normal and post-partum psychotic women using chromatographic profiles with bilinear projections: a multivariate approach.

This paper demonstrates how chromatographic profiles of cerebrospinal fluid (CSF) have been subjected to multivariate data analysis to discriminate between CSF samples from women with post-partum psychosis and those from healthy women. Instead of peak-heights or areas, digitally defined chromatographic profiles were examined using principal component analysis (PCA). In accordance with the diagnosis, we have found a complex profile pattern of at least ten composite peaks that discriminates between these groups. Two of these peaks were for the discrimination particularly clearly between the two groups. We speculate that these findings can be useful in the diagnosis of post-partum psychosis, increasing diagnostic precision and having both clinical and prognostic implications.

Chromatography, High Pressure Liquid↗

PubMedDate not supplied

Quantitation and identification of two cholecystokinin peptides, CCK-4 and CCK-8s, in rat brain by HPLC and fast atom bombardment mass spectrometry.

A sensitive HPLC method has been described for quantitation of two cholecystokinin (CCK) peptides in discrete rat brain regions. Separation and quantitation was performed by the reversed-phase HPLC combined with electrochemical detection. Analytical recoveries of the tetrapeptide (CCK-4) and octapeptide-sulphate (CCK-8s) were 96% and 94%, respectively. The between assay coefficient of variation (CV) was less than 3% for both peptides. The within-assay CV was 4% and 6% for CCK-4 and CCK-8s and the detection limit was 2 and 10 pmol/mL, respectively. For identification of structures, the peptides were fractionated by semi-preparative HPLC using a novel SMART system for micropurification. The fractions were analysed by fast atom bombardment mass spectrometry (FAB MS) which confirmed the presence of both CCK-4 and CCK-8s in the rat brain tissue.

Amino Acid Sequence↗

PubMedDate not supplied

Endorphins in human cerebrospinal fluid.

Opiate activity in CSF samples drawn from patients with suspected intracranial hydrodynamic dysfunction has been fractionated on Sephadex G-10 and separated by column electrophoresis in agarose suspension. From the Sephadex G-10 chromatography two receptor active fractions (FI and FII) were recovered. Both FI and FII were further resolved by the electrophoresis. FI separated into at least four components and FII into two components. The study also includes a comparison of the endorphin concentrations in CSF (samples drawn from healthy volunteers) measured by receptorassay with those detected by radioimmunoassay of beta-endorphin, [Met]enkephalin and dynorphin, respectively. The data obtained indicated negligible quantities of the radioimmunoassayable endorphins in the total CSF opiate activity.

Dynorphins↗

PubMedDate not supplied

Calcitonin gene-related peptide is metabolized by an endopeptidase hydrolyzing substance P.

Calcitonin gene-related peptide (CGRP) is cleaved by an endopeptidase, also known to hydrolyze substance P (SP). The enzyme which was isolated from human cerebrospinal fluid, converted rCGRP into two products, clearly separable on HPLC. Amino acid analysis showed cleavage to occur at Leu16-Ser17. The carboxy-terminal fragment, rCGRP-(17-37), was weakly active in inhibiting 125I-rCGRP binding to a rat medulla oblongata membrane preparation, but it showed no binding to spinal cord membranes. The N-terminal fragment, rCGRP-(1-16), had very low or no affinity. Autoradiography with 125I-rCGRP showed distinct labelling of rat dorsal spinal cord, while there was no consistent pattern with 125I-rCGRP-(1-16). In the isolated guinea pig ileum preparation, the two fragments showed no CGRP-like activity. The ability of CGRP to interfere with SP degradation is offered as the explanation why CGRP has been reported to potentiate several biologic actions of SP.

Amino Acid Sequence↗

PubMedDate not supplied

Micropurification and amino acid sequence of beta-casomorphin-8 in milk from a woman with postpartum psychosis.

Milk was obtained from a woman with acute postpartum psychosis and with ongoing lactation. Defatted samples were subjected to micropurification and collected fractions were analyzed by means of their beta-casomorphin-8 immunoreactivity. Immunoreactive material with the same chromatographic properties as synthetic human beta-casomorphin-8 was determined by amino acid sequence analysis to be Tyr-Pro-Phe-Val-Glu-Pro-Ile-Pro. Its molecular mass was determined by fast atom bombardment-mass spectrometry to be 962.3 Da. These determinations, which ultimately identify the immunoreactive material as human beta-casomorphin-8, represent the first structural identification of a beta-casomorphin peptide from a body fluid.

Acute Disease↗

PubMedDate not supplied

Aging effects on growth hormone receptor binding in the brain.

Recent years have seen an increasing interest in research focused on the role that growth hormone (GH) may have in the central nervous system. The psychological improvements seen in adults following GH therapy combined with the observation that the hormone may affect the cerebrospinal fluid levels of several brain transmitters have received a great deal of attention. Studies have also revealed the presence of specific GH receptors in distinct areas of the brain of many mammals. This article will review our recent studies on the aging effects on GH binding in these regions. It also includes some data on the age-related effects on the expression of the GH-receptor messenger ribonucleic acid (mRNA) in certain brain areas.

Aging↗

PubMedDate not supplied

Role of soluble and cell surface molecules in the pathogenesis of autoimmune skin diseases.

The skin is one of the most commonly involved tissue in rheumatic autoimmune diseases. Different mechanisms are thought to be implicated in the pathogenesis of skin lesions. In genetically predisposed individuals, ultraviolet (UV) light can contribute to the induction of skin lesions via an inflammatory process. UV light promotes the release of cytokines by keratinocytes and the induction of adhesion molecules on the surface of epidermal cells initiating a cascade of inflammatory events and recruiting immunoinflammatory cells into the skin. In this review data regarding the expression of TNF-alpha in lesional skin tissue from subacute cutaneous lupus erythematosus patients and the role of interferons in the pathogenesis of skin manifestations of rheumatic autoimmune diseases are reported. In addition, an overview on the expression of cellular adhesion molecules in these diseases is provided.UV light can also induce apoptosis in keratinocytes. During this cell death several enzymes became activated. Among them, desoxyribonuclease (DNase) is an enzyme involved in degrading DNA during apoptosis. Data regarding the activity of DNAse in patients with cutaneous lupus erythematosus as a possible risk factor for the development of systemic disease are here reported.

Apoptosis↗