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Biomedical subjects

A Atkinson

Publications and source records attributed to A Atkinson.

At least 55 records · Page 3Linked to original sources
PubMed1988

QALYS and long-term care for elderly people in the UK: scales for assessment of quality of life.

QALYs have developed in the UK as a tool for comparing the outcome of health care procedures in a single index over time. This tool can then be used, along with information on costs of procedures, in decision-making about health service resource allocation. It is shown that the attributes of disability and distress, on which QALYs are presently based in the UK, are insensitive to changes in the health status of elderly people in long-term care when compared to other measures of quality of life which are frequently used in studies of older people. Thus, if the use of QALYs increases, they should be based on attributes appropriate to the groups studied, otherwise certain groups may be discriminated against in health service resource allocation owing to the use of an insensitive measure of outcome.

Aged↗
PubMed1985

The production and properties of a tissue plasminogen activator from normal epithelial cells grown in microcarrier culture.

A plasminogen activator with different biochemical and physical properties to the one obtained from Bowes melanoma cells has been isolated from a normal epithelial cell line derived from guinea-pig keratocytes (GPK). Cell growth and enzyme production is carried out in microcarrier cultures using up to 15 g Cytodex 3 per litre. Cells are maintained in optimum conditions by the use of a closed perfusion loop and the system has been scaled up to 20 litres. Initially enzyme production was in serum-free medium following a growth phase in serum supplemented medium. However, the discovery that the cells produce the enzyme mainly during the replicative phase has led to investigating the use of serum-substitutes and growth factors on cell growth and enzyme production. The aim is to harvest the enzyme after the growth phase which precludes the use of high (greater than 1%) serum concentrations. The biochemical and biophysical properties of the enzyme are described.

Animals↗
PubMed1983

The role of calcium in the mechanical behaviour of bone.

Plugs of fresh post mortem human patellar subchondral bone were soaked for three weeks in an organic solvent (ethanol) which contained a chelating agent (EDTA). This technique selectively removes the calcified inorganic component without disrupting the structure of the remaining bone matrix. These plugs, together with untreated plugs as controls, were treated in unconfined compression at a fixed strain rate and allowed to relax to evaluate the contribution made by the calcium component to the physical and time-dependent properties of subchondral bone.

Adolescent↗
PubMed1980

Phenotypic and genotypic characterization of some thermophilic species of Bacillus.

Some thermophilic species of Bacillus were characterized using biochemical tests, antibiotic sensitivity, bacteriocin and bacteriophage sensitivity, esterase patterns, DNA hybridization and % G+C content. The three caldo-active strains of bacilli isolated by Heinen (1971) were compared with strains of B. stearothermophilus. Eight of the strains examined showed characteristics which enabled them to be placed in the three main taxonomic groups suggested by Walker & Wolf (1971). Two strains showed characteristics of both groups 1 and 3. Examination of genotype data showed taxonomic groupings which differed from those based on phenotypic characterization.

Anti-Bacterial Agents↗
PubMed1980

Isolation and characterization of a mutant of Escherichia coli K12 synthesizing DNA polymerase I and endonuclease I constitutively.

A mutant of Escherichia coli K12, highly resistant to ultraviolet radiation, has been isolated. Preliminary tests show that this mutant is also resistant to mitomycin C, nalidixic acid, fluorouracil and thymineless death. The mutant strain apparently repairs its damaged DNA more efficiently than wild-type E. coli K12 strains and, to do so, constitutively produces 35 times more DNA polymerase I and 12 times more endonuclease I than the wild-type strain.

DNA Polymerase I↗
PubMed1978

Vitreous morphology after perforating injury treated by primary vitrectomy.

Perforating eye injuries result in patterns of damage which vary greatly in extent and severity. In undertaking reconstruction of the injured eye the ophthalmologist requires instruments and materials designed for handling each type of traumatized tissue. Problems associated with injury to the vitreous are logically dealt with by purpose-built vitrectomy instruments with the object of attaining a satisfactory and safe vitreous configuration in a visually useful eye.

Eye Injuries↗
PubMed1977

Primary vitrectomy as a preventive surgical procedure in the treatment of severely injured eyes.

The results of treating 72 severely injured eyes by primary vitrectomy combined with anterior and posterior segment reconstruction are presented. This approach aims at improving the visual prognosis by allowing fundus examination and immediate retinal surgery where indicated, and by preventing the more severe complications associated with vitreous and anterior segment disorganisation. The prospects for improved visual results and the problems encountered, particularly secondary haemorrhage, are discussed.

Adolescent↗
PubMed1977

Results of primary vitrectomy in severe perforating ocular injuries.

Vitrectomy in the initial treatment of perforating injuries is indicated when lens damage involves the posterior capsule, when anterior segment disruption involves vitreous, with extensive vitreous haemorrhage and overt or suspected retinal damage, in removal of a non-magnetic intraocular foreign body and in perforating injury with endophthalmitis. The visual results in 72 eyes followed for up to 6 years are: blind or enucleated 19 (26%), acuity less than 0.1 in 14 (19%), 0.1-0.4 in 18 (25%) and 0.5 or better in 21 (30%). Retinal detachment occurred in 27 eyes with successful reattachment in 18 (66%).

Eye Diseases↗
PubMed1976

[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↗
PubMed1976

[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↗
PubMed1975

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↗