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Biomedical subjects

A Atkinson

Publications and source records attributed to A Atkinson.

At least 73 records · Page 4Linked to original sources

[A method of closing fistulae from drainage blebs to the out-side after glaucoma operations (author's transl)].

A method for closing fistulae in drainage blebs after anti-glaucoma surgical procedures is described. Its aim is to line internally and support the wall of the bleb, including the fistula, with subconjunctival tissue. The decisive factor in achieving this is the firm anchoring of the subconjunctival tissue pulled down between the corneo-scleral opening and the thin conjunctival tissue layer.

Conjunctiva↗

[Preventive surgery in the treatment of severely injured eyes: late results, complications, postoperative care (author's transl)].

Definitive reconstruction of the eye is the main objective of surgery in severe trauma. Therefore the damaged lens and vitreous have to be primarily removed in combined injuries to the anterior and posterior segments. 81 cases, treated according to this, have been followed-up from 6 months to 6.2 years. 43 have a VA of 0.1 or better, 18 at least a useful visual field. Main causes of blindness in 20 eyes are retinal detachment in 10, hemosiderosis in 4, phthisis in 3 eyes. 8 of the eyes lost through retinal detachment had a massive intraocular hemorrhage during the post-traumatic period. This hemorrhage is discussed as a main factor in development of retinal detachment with a poor prognosis. In 9 other cases of severely injured eyes with a massive posttraumatic intraocular hemorrhage the blood was removed from the vitreous cavity by intraocular irrigations with Ringer's solution. In 4 of these cases visual function could be retained.

Adult↗

Affinity chromatography on immobilised nucleotides. Some applications to the purification of thermophilic dehydrogenases and kinases.

The effect of pH and temperature on the capacity and binding of Bacillus stearothermophilus, alcohol dehydrogenase and phosphofructokinase to N6-(6-aminohexyl)-5'-AMP-Sepharose has been examined. Specific elution from the substituted AMP-Sepharose was examined using a variety of cofactors, fragments of cofactors and substrates. A purification scheme for each enzyme on the substituted AMP-Sepharose using nucleotides and gradients of pH and salt is presented. Interestingly, elevated temperature increased the affinity of both enzymes for N6-(6-aminohexyl)-5'-AMP-Sepharose, however, the Michaelis constant for nucleotide determined at various temperatures remained constant. The effect of pH and salt concentration on the binding of B. stearothermophilus glyceraldehyde-3-phosphate dehydrogenase to 6-aminohexanoyl-NAD+-Sepharose was also examined; raising the pH above 7.5 lowers the capacity of the matrix and the effect of a range of ammonium sulphate concentrations on the adsorption of the enzyme was examined. A specific purification of glyceraldehyde-3-phosphate dehydrogenase from partially purified extracts of this organism was achieved.

Adenosine Monophosphate↗

Whole cell biosensors--electrochemical and optical approaches to ecotoxicity testing.

Two different approaches to the interrogation of prokaryotic and eukaryotic cells have been explored, with the objective of developing biosensor based rapid ecotoxicity test protocols for use in a wide range of applications. Prokaryotic cells and some eukaryotic cell types lend themselves to interrogation by mediated amperometry, a technique that allows metabolic activity of the cell to be monitored by accessing cellular redox events with a chemical mediator. Reduction of the mediator by the cell is followed by re-oxidation at an electrode surface poised at a fixed potential. The resulting current flow is proportional to the metabolic status of the cell. A commercial ecotoxicity test, CellSense, employing such whole cell biosensors has now been developed. An alternative approach to interrogation of vertebrate cells has been the use of luminescent reporter genes to determine changes in the metabolic status of the cells following environmental challenge. Several clones have been established of epithelial cells from the bluegill sunfish (BF-2), transfected with the pCIneoLuc plasmid, that express luciferase constitutively. Protocols using these transformed cells are being developed to provide an alternative to the standard neutral red retention test.

Animals↗