Biomedical subjects
Publications and source records attributed to J Williamson.
A patient is presented with ischemic heart disease and mitral regurgitation; the patient's pulmonary artery wedge "V" waves and left ventricular end diastolic pressure decreased during exercise. Possible explanations for this unusual hemodynamic response are discussed.
In 1977 a scheme of attachment to acute medical wards of consultants in geriatric medicine and associated junior medical staff was instituted in a large Edinburgh teaching hospital. The effect on admissions of patients aged 65 and over was examined for comparable periods before and during this arrangement. Mean and median stays were reduced for both sexes but more noticeably for women. The mean stay for all women aged over 65 was reduced from 25 to 16 days and for women aged over 85 from 50 to 19 days. The proportion staying under two weeks was significantly increased in both sexes, and the proportion discharged home also increased, correspondingly fewer patients being transferred to convalescent wards. These changes were not accompanied by increased transfers to the geriatric department, and probably the skills and extra resources available to the geriatric service were the factors mainly responsible for the changes in performance.
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The medical and nursing needs of elderly patients admitted to acute medical wards were examined. About one third of these patients received only care which could have been delivered at home.
A technique using pendulum-arc rotation is presented for electron-beam treatment of generalized superficial malignancies. The technique consists of six arcing fields symmetrically dispersed around the body surface for circumferential coverage. The arc angle is selected to scan the height of the body fully. Beam uniformity within 10% over a height of 180 cm is achieved at a treatment distance of 385 cm. Randophantom dosimetry, using an 8 MeV electron beam degraded by 3/8 in. Plexiglas, indicates a surface dose uniformity within +/- 7% over most of the body surface. Underdosages occur at regions obstructed by adjacent body parts.
The recommendation of the 1978 report of the Institute of Medicine, Washington, D.C., states that there should not be "a formal practice specialty in geriatrics." The United Kingdom has a comprehensive geriatric service based on a separate specialty of geriatric medicine. This speciality was developed before the National Health Service in 1948. The future of geriatric medicine is not clearly defined. It should continue, I believe, as a separate speciality but with deliberate policies to bring it back into "mainstream medicine." This will involve closer integration with family practice, internal medicine, and psychiatry. While I realize that the operation of the geriatric service in Edinburgh, where I work, could not simply be transplanted into an American setting, the principles of geriatric care ought to be applied within a specialist service if the increasing problems of the aging in American society are to be adequately met.
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Commercial ophthalmic chloramphenicol solutions and ointments were applied to human eyes, and the concentrations of chloramphenicol in aqueous humor and tear samples were analyzed using gas-liquid chromatography. Within several minutes after a single application of 0.5% chloramphenicol solution, the tear concentrations of the drug had fallen below 1 mg/liter, the minimal bacteriostatic concentration for many ocular pathogens. Repeated drops of 0.5% chloramphenicol solutions during several hours were required to produce an aqueous humor concentration of 1 mg/liter. A single application of 1% chloramphenicol ointment gave prolonged drug concentrations in the tears and aqueous humor, falling to 1 mg/liter in two to four hours. The repeated use of chloramphenicol solution or ointment was well tolerated by the patients. We conclude that the penetration of chloramphenicol in the anterior segment of the eye is best carried out by the repeated application of chloramphenicol ointment.
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A microtest has been devised for the rapid preliminary assay in vitro of the effect of over 100 drugs and inhibitors on African trypanosomes (Trypanosoma brucei and T. rhodesiense). Parasite motility and infectivity for mice are indexes, respectively, of respiration and glycolysis and of cell division; trypanocidal titers based on these indexes can show primary metabolic areas of drug attack. Various specific inhibitors have also been tested to detect metabolic sites which might be therapeutically vulnerable. RNA synthesis inhibitors are highly active (adenine nucleosides, daunorubicin, doxorubicin, chromomycin, actinomycin D, mitomycin C); the activity of the nucleoside cordycepin was increased in vitro and in vivo by an adenosine deaminase inhibitor. In view of the polyanionic nature of the trypanocide suramin, a series of polyanions was tested; several showed activity but only poly-d-glutamic acid was active in vivo. Among various miscellaneous inhibitors, quercetin, disulfiram, and the Ca-complexing agents arsenazo I and III showed marked activity, the latter exclusively on the arsenical-resistant T. brucei. The implications of these results for combination chemotherapy and depot prophylaxis (with polyanions) are indicated.
Forty-nine biopsies of bulbar conjunctiva from patients with no apparent conjunctival disease were studied by light and transmission electron microscopy. No significant morphological changes were recorded in those specimens from patients less than 79 years old. However, in the older age group the epithelium showed irregularities in thickness, a reduction in the goblet cell population, and in 25% the presence of 'hyaline bodies'. The epithelial irregularities consisted of mild superficial stratification, which was observed also in a few of the specimens from the younger age groups. The goblet cells appeared morphologically normal in all age groups. The significance of the hyaline bodies and their possible relationship to goblet cells is discussed.
A clinicopathological correlation was performed on 24 patients suffering from keratoconjunctivitis sicca (KCS). Examination of conjunctival biopsies by light and transmission electron microscopy revealed stratification of the conjunctival epithelium with separation of the superficial cell layers, and this was directly proportional to the clinical severity of the disease. Counts of goblet cells were found to be inversely proportional to the degree of stratification. The goblet cells were morphologically identical to, but significantly fewer in number than, those found in normal conjunctival tissue. A reduction in epithelial cell stratification and separation and an increase in goblet cell density were closely related to nasolacrimal duct occlusion--an operation performed only in the severe examples of KCS in this series. The possible causes of 'mucous' plaques and 'filaments' are discussed in relation to these phenomena. Moreover, there is a dramatic reduction and deformation in the microplicae on the surface of the conjunctival epithelium. The significance of this was considered in relation to tear film stability.
Central-axis depth-dose data for 4-MV x rays, including tissue-maximum ratios, were measured for wedge fields. Comparison with corresponding open-field data revealed differences in magnitude which increased with depth, field size, and wedge thickness. However, phantom scatter correction factors for the wedge fields differed less than 1% from corresponding open-field factors. The differences in central-axis per cent depth doses between the two types of fields indicate beam hardening by the wedge filter. This study also implies that the derivation of tissue-maximum ratios from central-axis per cent depth is as valid for wedge as for open fields.
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