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Biomedical subjects

D B Archer

Publications and source records attributed to D B Archer.

At least 181 records · Page 10Linked to original sources
PubMed1982

The traumatized eye.

Injuries to the eye, both contusional and perforating, have a considerable visual morbidity not the least of which is a cosmetically unacceptable eye. Meticulous primary surgical repair and judicious secondary reconstruction of the eye may not only preserve visual functions but substantially improve the patient's appearance. Most cosmetic problems follow perforating eye injuries and include corneal leucomata, iris and pupillary abnormalities, cataract, phthisis bulbi and enucleation. Oculo-motor abnormalities, particularly divergent squint, are common where substantial loss of vision has occurred in one or both eyes. In the series reported 215 eyes were enucleated secondary to ocular trauma over a 10 year period (2,162 injured eyes), the vast majority following perforating injury. The risk of sympathetic ophthalmia was the reason for enucleation in 50.7 per cent of cases although sympathetic ophthalmia was identified in only two instances. Cosmetic defects secondary to contusional injuries are uncommon and mostly due to iris abnormalities and cataract.

Adult↗
PubMed1981

Treatment of neovascularization secondary to branch retinal vein obstruction.

Fifty patients who developed preretinal or papillary neovascularization following tributary vein occlusion were treated by laser photocoagulation. Areas of non-perfused retina within the distribution of the obstructed vein were identified by fluorescein angiography and ablated using moderately intense laser photocoagulation burns. In forty-six patients there was satisfactory atrophy of both preretinal and papillary neovascularization without further complication or vitreous haemorrhage. Four patients who responded poorly to laser photocoagulation did so either because areas of ischaemic retina were inadequately treated or because they were unamenable to laser photocoagulation e.g., sited in the parafoveal region. Ablation of ischaemic perimacular retina together with associated intraretinal microvascular abnormalities aided the resolution of macular oedema in 19 patients. No post-operative complications could be attributed to laser photocoagulation excepting the development of fine perimacular retinal folds in one patient.

Constriction, Pathologic↗
PubMed1981

H.L.A. antigens in proliferative diabetic retinopathy.

One hundred and four patients with diabetes mellitus present for at least 15 years were tissue typed for HLA antigens AI and B8. Fifty six patients had severe proliferative retinopathy and 48 patients no retinopathy. The results were compared with a group of 200 normal blood donors. There was no significant difference in frequency of AI and B8 between the two groups od diabetic patients. The HLA pattern A-I B+8 was more frequently present among the group of patients with proliferative retinopathy.

Adolescent↗
PubMed1981

Electron microscopic features of experimental choroidal neovascularization.

We produced choroidal neovascularization in the rhesus monkey by diminishing the blood supply to the inner retina and producing defects in Bruch's membrane by photocoagulation. The neovascular fronds which developed either infiltrated the subretinal space or proliferated through necrotic and gliotic retina into the vitreous cavity. Sequential electron microscopic sections of neovascular fronds in the subretinal space demonstrated that the advancing capillary sprouts were composed of primitive endothelial tubes surrounded by pericytes and enmeshed in a loose basement-membrane-like substance. More mature capillaris and displayed endothelial fenestrations and endothelial-pericyte membranous contacts. Large neovascular fronds developed major feeding vessels that closely resembled normal small choroidal arteries and veins. Retinal pigment epithelial cells in various guises were in constant association with proliferating neovascular networks.

Animals↗
PubMed1981

Morphologic fluorescein angiographic, and light microscopic features of experimental choroidal neovascularization.

We induced choroidal neovascularization in the rhesus monkey by impoverishing the blood supply to the inner retina and producing defects in Bruch's membrane by photocoagulation. Fourteen of 46 eyes undergoing photocoagulation developed neovascular fronds which were identified and categorized by histopathologic examination and fluorescein angiography. All new vessels gained access to the retina through defects in Bruch's membrane at the site of photocoagulation marks. In eight eyes the new vessels remained localized to the immediate vicinity of photocoagulation marks. In four eyes neovascular fronds infiltrated the subretinal space for distances up to 6 disk diameters from the point of entry into the retina. In the two eyes choroidovitreal neovascular complexes developed but rapidly regressed shortly after gaining the vitreous cavity. Fluorescein angiography demonstrated that all neovascular fronds were grossly incompetent to dye but that formed feeding channels had some degree of integrity. Light microscopic studies showed the proliferating networks to be composed of capillaries with well-formed basement membranes and more mature vessels with the basic structure of choroidal arteries and veins.

Animals↗
PubMed1980

Purification and preliminary characterization of Spiroplasma fibrils.

Fibrils 3.5 nm in diameter were released from the honeybee spiroplasma (BC3) by treatment with detergents and then purified by isopycnic centrifugation. Purified fibrils were flexuous, of indeterminate length, and had an axial repeat of 8.5 nm. The fibrils were associated in pairs, but in 1 M salt formed aggregates with a marked striated appearance. Pronase completely degraded the fibrils, but trypsin had little effect. The fibrils were composed of a single protein of molecular weight 55,000 which represented about 1% of the total cell protein. A protein of molecular weight 26,000 appeared to be associated with the fibrils. The significance of this in relation to membrane attachment and the possible role of fibrils in maintenance of cell shape and in motility are discussed.

Bacterial Proteins↗
PubMed1980

Loss of contrast sensitivity following contusional eye injury.

Contrast sensitivity was evaluated in 95 patients who regained a visual acuity of 6/6 following a contusional injury of one eye. The injuries occurred 2 to 12 years prior to examination. A book of printed sinusoidal grating patterns of varying contrasts and spatial frequencies was used, and 15 patients were found to have a significant difference in contrast sensitivity between injured and uninjured eye. Eight patients had abnormalities of the media or fundus, and in 2 patients amblyopia was probably a factor. Five patients had a defect in contrast sensitivity in their injured eye, although no structural abnormalities could be detected on full clinical examination. Alterations in contrast sensitivity appeared to be a sensitive indicator of functional abnormality in eyes which appeared normal on ophthalmoscopy and other clinical investigations.

Adolescent↗
PubMed1980

A 10-year survey of eye injuries in Northern Ireland, 1967-76.

Ocular injuries of sufficient severity to necessitate admission to the Eye and Ear Clinic, Royal Victoria Hospital, Belfast, were sustained by 1707 male patients and 325 female patients. Blunt injury occurred in 1063 eyes (49.2%), perforating injury in 1037 (48%), and intraocular or intraorbital foreign bodies in 181 eyes (8.4%). More than three-quarters of the patients (77.4%) were less than 36 years of age and 84% of all injuries occurred in males. Normal visual acuity (6/6 or better) was regained by 41.2% of the patients in whom the final visual outcome was known. The benefit of wearing seat belts in road vehicles and protective goggles in industry and sport should receive more publicity on radio and television and via poster campaigns. Compulsory fitting of laminated windscreens in all road vehicles is recommended. The vulnerability of children to ocular injury should be highlighted through the mass media, schools, and health centres.

Adolescent↗
PubMed1980

Morbidity and mortality in patients with diabetic retinopathy.

Most studies indicate that diabetics have both a higher mortality rate and a higher morbidity rate secondary to generalized vascular occlusive disease than non-diabetic patients of corresponding age and sex. There is also some evidence that diabetics with proliferative retinopathy are more at risk than diabetics without retinopathy. This study was undertaken to determine and compare the morbidity and mortality rates in diabetics with: (a) No retinopathy, (b) Background retinopathy, (c) Proliferative retinopathy. The records and fundus photographs of 800 diabetics were reviewed and the data statistically analysed according to age, sex, presence and type of retinopathy, morbidity, and mortality. The mortality rates were also compared with the normal population life study data.

Adolescent↗
PubMed1979

Immunoprecipitation of Triton X-100-solubilized Mycoplasma mycoides proteins.

Mycoplasma mycoides subsp. mycoides (PG1 and strain Y) proteins were solubilized in Triton X-100, and the antigenic proteins were precipitated from this complex mixture by addition of antiserum and then separated by two-dimensional gel electrophoresis. Of the 300 proteins solubilized, about 10 were precipitated. Proteins of PG1, a slow-growing, small colony (SC) strain, were precipitated by antiserum to PG1 and by antiserum to strain Y, a fast-growing, large colony (LC) strain. Similarly, strain Y proteins were precipitated by antiserum to PG1 and by antiserum to strain Y. The few proteins precipitated in this way gave similar patterns after two-dimensional gel electrophoresis indicating that many of the dominant protein antigens of PG1 and strain Y are shared. Antiserum to Mycoplasma mycoides subsp. capri (PG3) also precipitated some proteins of strain Y. Antiserum to Mycoplasma gallisepticum gave no reaction with any M. mycoides antigens. It was concluded that, in addition to the polysaccharide antigens, there are proteins in M. mycoides that are antigenic and that some of these are found in both the SC and LC strains of subsp. mycoides and also in subsp. capri.

Antigens, Bacterial↗
PubMed1979

Atropine versus glycopyrrolate. A study of intraocular pressure and pupil size in man.

Following control observations of intraocular pressure and pupil size, in doses suitable for pre-anaesthetic medication, glycopyrrolate (0.004 mg/kg) and atropine (0.01 mg/kg) were given intramuscularly to healthy volunteers in a randomised, cross-over fashion. No significant change in either intraocular pressure or pupil size was noted 45 min after drug administration.

Adult↗