Search PubMed⌕ Search

Biomedical subjects

R Wilson

Publications and source records attributed to R Wilson.

At least 415 records · Page 23Linked to original sources
PubMed1993

Childbirth in the north. A qualitative study in the Moose Factory zone.

Cree women from the Moose Factory zone were asked about their views on evacuation for childbirth. Significant concerns cited were separation from children, loneliness, boredom, and the hospital accommodations. Shopping, the medical staff and equipment, and the opportunity to visit relatives were considered positive factors. Suggested improvements were to bring along family members, to provide alternative accommodation, and to have activities to occupy the time.

Adult↗
PubMed1992

Studies of oxidative stress in cellular systems. The interaction of monocytes and erythrocytes.

1H spin echo NMR spectroscopy is used to follow the interaction of intact and viable erythrocytes and monocytes obtained from different sources in mixed cultures. After a lag time (270 min) erythrocyte glutathione is observed to become more oxidised. This result is believed to occur as a consequence of monocyte activation generating hydrogen peroxide or hypochlorous acid, which is targeted at the erythrocyte. The red cell in turn employs its sulphydryl system as an anti-oxidant defence.

Erythrocytes↗
PubMed1992

Secondary structures of a new class of lipid body proteins from oilseeds.

The three main isoforms of the 19-kDa lipid body proteins (oleosin) have been purified to homogeneity from embryos of rapeseed. The secondary structures of these proteins as derived from circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy were compared with the secondary structures predicted from the primary sequences. The salient feature of the primary sequence of all oleosins is its division into three defined structural domains: a central hydrophobic domain flanked on either side by relatively hydrophilic domains, respectively. Using a variety of predictive methods based on primary amino acid sequence data, the oleosins exhibited a high probability of beta-strand structure in the 70-residue central hydrophobic domain, with relatively little alpha-helical content. Secondary structure data derived from CD and FTIR were consistent with the predictions from primary sequence, showing that the oleosins contained about 45% beta-strand and 13% alpha-helical structure. Under high salt conditions, a 40-kDa polypeptide was obtained from purified preparations of the 19-kDa oleosins. The 40-kDa polypeptide has a very similar secondary structure, as analyzed by CD and FTIR, to that of the 19-kDa oleosins. This polypeptide is therefore probably a dimer of the 19-kDa oleosins that is formed in high salt environments. A model of the general structure of oleosins is proposed whereby the central hydrophobic domain of the protein with a predominantly beta-strand structure is embedded into the non-aqueous phase of lipid-bodies. This hydrophobic region is flanked by putative alpha-helical structures in the polar N- and C-terminal domains which are probably oriented at the lipid-water interface.

Amino Acid Sequence↗
PubMed1992

The C. elegans genome sequencing project: a beginning.

The long-term goal of this project is the elucidation of the complete sequence of the Caenorhabditis elegans genome. During the first year methods have been developed and a strategy implemented that is amenable to large-scale sequencing. The three cosmids sequenced in this initial phase are surprisingly rich in genes, many of which have mammalian homologues.

Animals↗
PubMed1992

Immunological changes in normal pregnancy.

During pregnancy the mother must tolerate intra-uterine allogenic fetal tissue. Failure of this tolerance may cause spontaneous abortion. The immunological changes occurring in normal pregnancy are poorly understood. The aim of this study was to investigate the immunological changes occurring in pregnancy. Thirty women in the first trimester; 10 in the second and 10 in the third trimester of pregnancy were studied and compared to age matched non-pregnant controls. In normal pregnancy there was an increase in the total white cell count with no change in the lymphocyte count. There was a fall in total T cell numbers and activated T cell numbers, with no change in helper/inducer or suppressor/cytotoxic T cell numbers. [3H]Thymidine uptake in response to three different mitogens was increased. This implies an increase in potential for the cells to respond to mitogens. There was no change in interleukin-2 receptor levels, suggesting that despite this increased potential there was no general activation of the immune system. A rise in IgM and IgG was found after mitogen stimulation of peripheral blood lymphocytes, suggesting an increase in potential antibody production. These results demonstrate that lymphocytes from pregnant women have an increased potential rather than an increased activity.

Female↗
PubMed1992

Making real neural nets: design criteria.

Neural nets may be assembled with living nerve cells in vitro to test theories about neural processing and the ways in which patterns develop in the nervous system, and to test ideas about plasticity and learning in processing systems. This may benefit the design of computer systems and prosthetic devices. Extracting information from such nets can be achieved by means of intracellular and extracellular electrodes and fluorescent dyes. Patterning of cells may be achieved using microfabrication techniques, and extracellular electrodes can be combined within the patterned substrate.

Humans↗
PubMed1992

Dendritic processing: using microstructures to solve a hitherto intractable neurobiological problem.

In vivo, intracellular recordings of mammalian brain stem motoneurones, followed by peroxidase staining and tridimensional reconstruction, suggest that the shape of the dendritic tree plays an important role in the processing of neural information. To test this hypothesis attempts were made to guide, in culture, the growth of neuritic branches of neurones dissociated from the hypoglossal nucleus of rat brain stem. This was performed using topographical and adhesive microstructures which were designed to control the shape of the neuritic tree. Guidance of the neuritic processes can be observed with small grooves engraved on quartz and plastic substrates, and simple shapes with few processes and bifurcations on each neurite could be obtained using adhesive microstructures. These procedures, which allow the shape of a neurone to be controlled, are very promising in the study, by means of classical electrophysiological methods as well as optical recordings, of the involvement of dendritic architecture in the processing of neural information.

Animals↗
PubMed1992

Effects of exogenous monounsaturated fatty acids on fatty acid metabolism in cultured skin fibroblasts from adrenoleukodystrophy patients.

The conversion of [1-14C]16:0 to very-long-chain saturated fatty acids (VLCSFA) was greater in fibroblasts from adrenoleukodystrophy (ALD) patients than fibroblasts from normal subjects. Added 23:1(n-9) decreased the formation of VLCSFA from [1-14C]16:0 in ALD fibroblasts to the value found in normal fibroblasts. Chain-elongation as well as extensive chain-shortening of added 20:1(n-9), 22:1(n-9), 23:1(n-9) and 24:1(n-9) occurred in both normal and ALD fibroblasts, with chain-shortening being less in ALD than in normal fibroblasts. Added 18:1(n-9) together with 22:1(n-9) reduced the levels of both VLCSFA and total n-6 and n-3 polyunsaturated fatty acids (PUFA) in normal and ALD fibroblasts. The levels of total (n-6) and (n-3) PUFA but not the levels of VLCSFA were readily restored by culturing the cells in the presence of 18:1(n-9), 22:1(n-9), 18:2(n-6) and 18:3(n-3). The results are consistent with added monounsaturated fatty acids reducing levels of VLCSFA in ALD fibroblasts by depressing their biosynthesis from 16:0. They also support the use of oils rich in long chain monoenes as a dietary therapy for ALD patients but caution that the PUFA status of ALD patients should be monitored with a view to dietary supplementation, if necessary, with PUFA.

Adrenoleukodystrophy↗
PubMed1992

Utility of immunohistochemistry in distinguishing ovarian sertoli-stromal cell tumors from carcinosarcomas.

Poorly differentiated Sertoli-stromal cell tumors and carcinosarcomas of the ovary both show biphasic epithelial and stromal patterns and may both show heterologous stromal elements, presenting a difficult diagnosis. We studied the immunohistochemical profile of Sertoli cell differentiation in human testes and applied these findings to the ovarian tumors. Eleven Sertoli-stromal cell tumors, six carcinosarcomas of the ovary, and 11 testes (six fetal, one infant, and four adult) were studied using antibodies to cytokeratin AE1:AE3 (AE1:3), cytokeratin CAM 5.2 (CAM), epithelial membrane antigen (EMA), vimentin, desmin, muscle-specific actin (MSA), S-100 protein (S-100), CA 19-9, CA 125, carcinoembryonic antigen monoclonal (CEA-M), carcinoembryonic antigen polyclonal (CEA-P), and placental alkaline phosphatase (PLAP). In the fetal testes, immature gonadal stroma and sex cord areas stained with vimentin (six of six cases), AE1:3 (five of six cases), and CAM (six of six cases). Sertoli cells in immature gonadal stroma areas, sex cords, and seminiferous tubules of normal fetal, infant, or adult testes never showed immunoreactivity for EMA, S-100, CA 19-9, CA 125, CEA-M, CEA-P, or PLAP. All Sertoli-stromal cell tumors stained with AE1:3 and CAM in areas of Sertoli cell differentiation (11 of 11 cases) but did not stain with EMA, PLAP, CEA-P, CEA-M, CA 19-9, CA 125, or S-100 (none of 11 cases). Carcinosarcomas expressed AE1:3 and CAM in all epithelial areas (six of six cases) and most stromal areas (five of six cases). Carcinomatous areas of carcinosarcoma also showed immunoreactivity for EMA (six of six cases), CA 125 (two of six cases), PLAP (two of six cases), CEA-P (two of six cases), and CEA-M (one of six cases), while stromal areas of carcinosarcoma expressed EMA (four of six cases) and S-100 (four of six cases). Heterologous stromal elements were present in three of 11 Sertoli-stromal cell tumors (two showed skeletal muscle and one showed both skeletal muscle and cartilage differentiation) and in four of six carcinosarcomas (one skeletal muscle, one cartilage, and two cartilage and skeletal muscle). All skeletal muscle heterologous elements expressed desmin, vimentin, and MSA. The heterologous cartilage in carcinosarcoma stained with S-100 (three of three), while the one case of heterologous cartilage in Sertoli-stromal cell tumor did not. These results suggest that ovarian Sertoli-stromal cell tumor can be distinguished from carcinosarcoma by the absence of staining for EMA, PLAP, CEA, CA 125, or CA 19-9 in epithelial areas of Sertoli-stromal cell tumor.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

Spectrophotometric enzyme-amplified immunoassay for thyroid stimulating hormone.

Thyroid stimulating hormone (TSH) regulates the function of the thyroid gland. Its determination at low concentrations in serum is useful in the diagnosis of hyperthyroidism. In this paper, it is detected using a spectrophotometric enzyme-amplified immunoassay. The reporter enzyme is alkaline phosphatase and its substrate is flavin adenine dinucleotide phosphate (FADP). Reaction with alkaline phosphatase converts FADP into flavin adenine dinucleotide (FAD), which, unlike FADP, re-activates apo-D-amino acid oxidase (apo-AOD). Re-activation of apo-AOD allows the product of the reporter enzyme to be amplified. The lower limit of detection for TSH by this method is 0.06 microU cm-3. This compares with 0.54 microU cm-3 for an identical assay in which p-nitrophenyl phosphate was the substrate for alkaline phosphatase. Contaminating alkaline phosphatase was removed from the reagents by affinity chromatography.

Alkaline Phosphatase↗