Biomedical subjects
Publications and source records attributed to L A Williams.
Technetium labelled, negatively charged, unilamellar liposomes were given by intravenous injection to patients with rheumatoid arthritis and the joints scanned 20-22 hours later. Positive scintigraphy was obtained in all six patients with active disease, and, with the exception of the small interphalangeal joints, all clinically involved joints could be visualised.
Of 693 elderly patients admitted with suspected hip fractures, 43 had normal radiographs and were investigated by isotope bone scan. The 30 patients (70%) with normal scans were mobilised and none developed a fracture. All 13 of the patients with specific bone scan abnormalities were subsequently proved to have fractures, five of which became displaced. Clearly conventional radiography does not exclude fracture of the femoral neck in elderly patients; bone scanning is advisable in doubtful cases.
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The incidence of lameness in cows recorded by five veterinary practices over one year and one practice over four years was plotted with rainfall and potential soil moisture deficit. Correlation coefficients calculated between lameness, rainfall and potential soil moisture deficit over two-week periods showed the incidence of lameness in summer to be significantly related to the potential soil moisture deficit in the same two-week period and rainfall in the previous two-week period. Differences in patterns of lameness incidence among practices and years were also partly explained by differences in rainfall and potential soil moisture deficit; however, these effects were small compared with those of other factors that affect lameness incidence such as herd size, age and stage of lactation.
Guidelines for the initial management of head injuries were formulated by neurosurgeons and a multidisciplinary group of clinicians and administrators attending a seminar convened by the UK Department of Health and Social Security (DHSS). Analysis of data collected previously by the Royal College of Radiologists in nine accident and emergency units in the UK shows that admitting practice varied between centres and was very different from that recommended subsequently in the guidelines. Only 49 per cent (range 22 to 71 per cent) of patients who had skull X-rays and possessed symptoms and signs warranting admission were admitted to hospital and 14 per cent (range 1 to 20 per cent) of those without appropriate symptoms and signs were admitted. Rates of admission for patients with a history of unconsciousness, which according to the guidelines is not a criterion for admission, were up to ten-fold higher than for comparable patients with no such history. Implementation of the guidelines could have a substantial effect on clinical practice and could reduce admissions of patients who had skull X-rays by up to 46 per cent.
Lameness in herds during one year was commonest in the first month of lactation (15 per cent of all cases). Leg lesions were particularly common at this time (24 per cent of all cases of leg lesions) but white line abscess and sole ulcer were more common a month later. Foul-in-the-foot was one of the two most common lesions at all stages of pregnancy and lactation, and white line abscess the most common (20 per cent of all lesions) in late lactation. Both sole ulcer and underrun heel had lower incidence in the second half of the year than the first. White line abscess was particularly common in March and November although there were significant interactions between month and veterinary practice; foul-in-the-foot was most common in October. Susceptibility to lameness increased with age; 10-year-old cows were over four times more likely to develop lameness than three-year-old cows. This was due particularly to increased incidence with age of white line abscess and sole ulcer and, to a lesser extent, underrun heel. In contrast, foul-in-the-foot and leg lesions showed little change with age. Whereas these lesions accounted for 68 per cent of the total in cows up to two years old, they accounted for only 15 per cent of all lesions in cows over 10 years old. White line abscess was slightly commoner in cows with large heart girths.
A novel halophenol-enhanced luminol-peroxide luminescent detection method for horseradish peroxidase has been tested in an enzyme immunoassay for IgE. The luminescent enzyme immunoassay was reproducible (within-batch CV, 3.9-13.2%) and values obtained on serum samples showed good agreement with those obtained by colorimetric enzyme immunoassay. The major advantages of the luminescent detection method are that it is rapid, 30 s compared with 30 min for the colorimetric assay using o-phenylenediamine, and the luminescent signal is intense and stable for several minutes.
A lens protein with a molecular mass near 46 000 daltons has been purified from the turtle lens. It is a monomeric protein which differs from other lens crystallins in its antigenicity, near-UV circular dichroism spectrum and amino acid composition. Like delta-crystallin, it has appreciable secondary structure (52% alpha-helix). This lens protein has been named tau-crystallin. tau-Crystallin cross-reacts with the novel 48 000 dalton protein identified recently in lenses of the sea lamprey. Although distinct, the possibility that tau-crystallin shares an ancestral relationship with delta-crystallin is discussed.
A total of 275 liver biopsies were performed on dairy cows in 6 Friesian and one Guernsey herd during the first 2 weeks after calving. Liver samples were processed by 2 independent histological procedures: (a) formalin-fixed frozen sections were stained with oil-red O (ORO), or (b) samples fixed in glutaraldehyde-osmium tetroxide were embedded in plastic and sections stained with toluidine blue (TOLB). The sections were then subjected to stereological point-counting procedures to assess the quantities of stainable fat present within the liver cells. Estimates of liver cell fat by the 2 techniques were highly correlated, although those obtained by the TOLB method were consistently lower than those obtained by the ORO method. The analytical sampling error was slightly lower in the TOLB method. The simpler ORO method should prove an acceptable alternative in the routine histology laboratory to the tedious and technically demanding TOLB method.
Marine sediments were assayed for their concentration of Vibrio spp. and Aeromonas hydrophila over 1 year. A temporal variation was observed in which A. hydrophila, and to a lesser degree V. fluvialis, were found in the winter months, V. parahaemolyticus and V. vulnificus predominated in the spring and summer, with non-O-1 V. cholerae and V. alginolyticus detected in the late summer and fall. These organisms were found in greatest numbers in the top 5 cm of sediment, but were detectable down to 15 cm. Epidemiological data revealed a predominance of non-O-1 V. cholerae infections at the time the organisms were observed to flourish in the sediments.
Forty patients with Crohn's disease were divided into undernourished (18) and well nourished (22) groups depending on whether their midarm circumference was below or above 90% of the ideal standard. Plasma 25-(OH)D3 and the dihydroxylated metabolites, 24,25-(OH)2D3 and 1,25-(OH)2D3 were measured in the summer. Results were related to clinical and biochemical parameters and also compared with results from patients with ulcerative colitis and healthy subjects who served as controls. Plasma 25-(OH)D3 was reduced in the undernourished Crohn's group compared with the well nourished Crohn's group, who did not differ from the controls. Over 50% of the undernourished Crohn's group had evidence of secondary hyperparathyroidism and raised alkaline phosphatase concentrations, although concentrations of 1,25-(OH)2D3 were normal. The low 25-(OH)D3 concentrations related to disease activity. It is suggested that undernourished Crohn's patients who have high levels of disease activity are at risk of vitamin D deficiency, and attempts should be made to improve their vitamin D nutrition.
Negatively charged phospholipid liposomes were labelled with technetium 99m and used as a radioisotopic tracer to detect focal inflammatory lesions in deep-seated sepsis and rheumatoid arthritis. Patients received an intravenous injection of the radiolabelled liposome preparation and were submitted to scintigraphy on the following day. Both the human volunteer and patients showed uptake in liver and spleen but no radioactivity was observed associated with the intestines. Radioactive uptake was visualised in infected prosthetic joints, tubo-ovarian abscess and osteomyelitis. In a patient with active rheumatoid arthritis radioactive uptake was confined to clinically affected joints. The preliminary findings suggest potential for technetium labelled liposomes as a diagnostic tracer.
We have studied the natural history of spontaneous dislocation of the hip in cerebral palsy, with particular reference to the pattern of neurological involvement. In patients with bilateral hemiplegia and severe involvement of the upper limbs the incidence of dislocation was very high (59%), while in those with diplegia and little involvement of the upper limbs, only 6.5% were affected. There was no evidence of dysplasia or instability of the hip in any of the patients with unilateral hemiplegia. A strong correlation was found between the stability of the hip and the patients' ability to walk. These findings have a bearing on clinical surveillance and also on the indications for prophylactic surgery.
Guidelines formulated by the Royal College of Radiologists' Working Party on the Effective Use of Diagnostic Radiology were introduced into an accident-and-emergency department to determine their effect on the use of skull radiographs in patients with head injuries and on the number of admissions for observation. After approval by senior staff and substitution of the routine casualty record with a head-injury casualty card, the guidelines were distributed throughout the department, and seminars on the suggested use of skull radiographs were held for junior medical staff. The proportion of new accident-and-emergency attenders having skull radiographs fell by 51%. The average number of skull examinations carried out in the department decreased from 373 to 189 per month, but there was no increase in the number of patients with head injuries admitted for observation.
During a review of 74 patients with cerebral palsy, a notch on the supero-lateral aspect of the femoral head was demonstrated in 17. It is postulated that this is due to moulding in response to the tendency of the femur to migrate upwards and outwards. Its presence is a good prognostic sign that such a hip is unlikely to dislocate.
The relationship between liver fat content and haematology was investigated in 369 cows from eight herds sampled in the second week after calving. High levels of fat in the liver were associated with a depression in total white cell count and in neutrophils, eosinophils and lymphocytes. There was no correlation between liver fat content and the percentage of E rosetting lymphocytes, packed cell volume or haemoglobin concentration. The changes in peripheral white cell counts may be related to the increased incidence of post parturient disease in cows with fatty liver.
The incidence of lameness in herds visited by veterinary practitioners in winter (0.87 cases per 100 cows per month) was greater than in summer (0.71 cases per 100 cows per month). The relative proportions of leg lesions and underrun heel were higher, and those of foul-in-the-foot, interdigital hyperplasia and foreign body in the sole were lower in winter than in summer. In winter, leg lesions and aseptic laminitis were most common in cows housed in cowsheds, white line abscess in cows in strawyards and sole ulcer in cows in either cowsheds or cubicles with concrete yards. The overall incidence of lesions was lower in strawyard accommodation (0.71 cases per 100 cows per month) than in cubicles with yards (0.93 cases per 100 cows per month). Veterinary practitioners saw proportionally fewer cases of foul-in-the-foot but proportionally more cases of sole ulcer in larger than in smaller herds. The animal incidence of lameness ranged from 1.7 to 11.4 per cent among practices; in 20 practices which recorded a total of at least 100 lesions in both summer and winter there was a large variation in the proportions observed of each lesion. A principal component analysis contrasted those practices which tended to see mainly cases of white line abscess, white line separation, foul-in-the-foot and leg lesions with those which saw mainly cases of underrun heel, interdigital hyperplasia, punctured sole with pus and sole ulcer. Twenty-nine per cent of cases of underrun heel and 22 per cent of cases of both deep sepsis and interdigital hyperplasia occurred in conjunction with another lesion.
Sixty patients with symptomatic coronary artery disease undergoing coronary artery bypass graft operation were prospectively randomized into one of six equal groups based on the intraoperative method of left ventricular venting and venous drainage. Group 1 had bicaval venous drainage without snaring and left ventricular venting through the superior pulmonary vein; Group 2, two-stage venous drainage and venting as in Group 1; Group 3, bicaval venous drainage without snaring and no left ventricular vent; Group 4, two-stage venous drainage and no left ventricular vent; Group 5, bicaval venous drainage without snaring and with ascending aortic venting through a catheter; and Group 6, two-stage venous drainage and venting as in Group 5. Left ventricular performance was determined by radionuclide ventriculography from which global ejection fraction and regional wall motion were determined. Cardiac output was obtained by the thermodilution technique. Myocardial temperature was assessed by a needle thermistor during aortic cross-clamping. Serial electrocardiograms and levels of myocardial-specific isoenzymes (serum CPK-MB) were also analyzed. Each of the techniques tested was equally effective as determined by an analysis of intraoperative myocardial cooling and postoperative hemodynamic profiles, radionuclide ventriculography, and ECG or enzymatic evidence of myocardial damage. However, we maintain that this conclusion is valid only if adequate ventricular decompression is provided intraoperatively.