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Biomedical subjects

I Robertson

Publications and source records attributed to I Robertson.

At least 19 recordsLinked to original sources
PubMed1992

Early rightwards orienting of attention on simple reaction time performance in patients with left-sided neglect.

A specific disruption in the ability to automatically disengage attention from its previous focus has been hypothesized to account for the extinction phenomenon often observed in the unilateral spatial neglect syndrome. Recent literature, however, also brings out the role played in neglect by an imbalance in the attentional orienting systems, resulting in an early shift of attention towards the side of space ipsilateral to the brain lesion. In the present study we hypothesized that this attentional bias in orienting of attention might be demonstrated in a paradigm of simple reaction time to lateralized visual stimuli by contrasting the presence vs the absence on the computer screen of the square boxes used to facilitate position expectancy. A main prediction was made that patients with neglect would show a significant increase in reaction time to contralateral visual stimuli in the presence of bilateral reference boxes as compared to conditions in which no boxes were displayed. The right-sided box was in fact expected to exert an early attraction on the patient's attention, thus modifying the pattern of reaction times to the proper targets. This prediction was confirmed in right brain-damaged patients with moderate to severe neglect.

Adult↗
PubMed1992

Attentional load and visual neglect.

Ten subjects suffering from left unilateral neglect carried out a letter cancellation task under normal conditions, while counting forward, and when generating random numbers, respectively. The index of neglect increased with each of these conditions, though only the normal-random difference was statistically significant. In a second study, four left unilateral neglect subjects and four right brain-damaged controls carried out a simple reaction time task, with stimuli appearing randomly to the left and right, with and without the simultaneous performance of a secondary task (counting backward in threes from 100). The discrepancy between left versus right latencies increased significantly in the secondary task condition for two patients in the neglect group but not for the other two. None of the control group showed this effect. Theoretical implications of these findings for understanding neglect are discussed.

Aged↗
PubMed1992

Motivational effect of cholesterol measurement in general practice health checks.

A randomized trial was conducted in five general practices in and around Aylesbury, Buckinghamshire to assess the motivational effect of cholesterol measurement on compliance with advice to reduce dietary fat intake and to stop smoking. The advice was given by practice nurses during health checks for cardiovascular risk factors. A total of 578 patients were recruited to the study and randomized into two groups. Both groups were given the same advice and were followed up after a median of three months, but the intervention group was also given immediate feedback on their cholesterol concentration. Follow up was completed for 88.2% of subjects, and those who were not followed up were assumed not to have changed their behaviour. The mean fall in total cholesterol at follow up was 0.11 mmol l-1 (95% confidence interval 0.03 to 0.18) in the intervention group who were told their cholesterol result and 0.02 mmol l-1 (95% CI -0.06 to 0.10) in the control group who were not. The proportion of smokers who were not smoking at follow up was 10.7% and 10.1% in the two groups, respectively. Patients in the intervention group with an initial total cholesterol level of 6.50 mmol l-1 or greater showed a mean fall of 6.2% in cholesterol level whereas those with an initial cholesterol level of less than 5.20 mmol l-1 experienced a mean increase of 3.6%, but as differences of this magnitude were also seen in the control group they probably reflect regression to the mean rather than an effect of knowledge of cholesterol level.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude to Health↗
PubMed1991

Probable congenital esophageal stenosis in a thoroughbred foal.

Esophageal stenosis was diagnosed in a 7-day-old Thoroughbred foal referred for evaluation of bilateral milky nasal discharge. Double-contrast radiography revealed concentric narrowing of the esophagus at the level of the fifth rib, overlying the base of the heart. Lateral displacement of the esophagus was not apparent. X-ray computed tomography of the cranial portion of the thorax confirmed normal cardiac and great vessel anatomy, ruling out vascular ring anomaly. A nasogastric tube was placed, extending past the stenosis and into the stomach, and the foal was fed mares' milk via this tube. On day 14, the foal was allowed to nurse the mare hourly and was made to stand, with the cranial half of its body elevated for 5 minutes after each feeding. On day 19, the foal was allowed to nurse ad libitum and eat hay and grain with the mare. Signs of regurgitation and aspiration were not apparent. On day 29, the foal was discharged to the owner.

Animals↗
PubMed1991

Body concentration of caesium-137 in patients from Western Isles of Scotland.

OBJECTIVES: To compare caesium-137 concentrations in patients from the Western Isles Health Board, Glasgow area, and other parts of the Scottish mainland, and to investigate the source of 137Cs in patients from the Western Isles. DESIGN: Study of hypertensive patients having electrolyte concentrations measured, including 137Cs. Interview by questionnaire of island subjects about intake of foods likely to contain radiocaesium and the source of these foods. Measurement of 137Cs and 134Cs in food, urine, and vegetation. SETTING: Scottish mainland and Western Isles, 1979-86. All measurements before Chernobyl nuclear accident. PATIENTS: 413 consecutive patients referred to the blood pressure unit for investigation of hypertension. 60 from the Western Isles, including 44 from North Uist; 32 from North Uist participated in the dietary analysis. MAIN OUTCOME MEASURES: Concentration of radiocaesium in the body, urine, food, and vegetation. Islanders' consumption of local produce. RESULTS: Patients from the Western Isles had five times higher body concentrations of 137Cs (median 2.54 (interquartile range 1.25-3.73)) Bq/gK) than did patients from around Glasgow (0.47 (0.26-0.66) Bq/gK) and other parts of the Scottish mainland (0.42 (0.24-0.71) Bq/gK). Islanders often consumed local milk and mutton, but ate local fish rarely. 137Cs and 134Cs were present in coastal (21.6 Bq/kg 137Cs, 0.25 Bq/kg 134Cs) and moorland (135.9, 0.65 Bq/kg) grasses and in islanders' urine (2.01, 0.013 Bq/l). Lower concentrations (0.336, 0.004 Bq/l), were found in the urine of Glasgow controls (p less than 0.001 for both isotopes). CONCLUSIONS: Islanders have excess body 137Cs concentrations, most of which probably comes from local milk and lamb. The radioactivity is not above the recommended safety limit. The presence of 134Cs suggests that nuclear reprocessing is the source of some of the radiocaesium.

Adolescent↗
PubMed1991

Use of left vs right hand in responding to lateralized stimuli in unilateral neglect.

Previous research suggests that contralesional limb activation may reduce the degree of visual neglect shown by hemi-inattentive subjects. The present study examines whether minimal assisted-left-limb activation (pressing a response key with the hemiplegic hand, aided by the ipsilesional hand) resulted in lowered response latencies on the neglected side in a group of six patients showing unilateral left visual neglect. The study was carried out using a simple computerized test of speed of detection of lateralized stimuli, with responses being made on a key located at the body midline. In five of the subjects, there was no evidence of relatively faster response times to contralesional stimuli when the contralesional limb was involved in the responses. In one of these five subjects, there was no hemiplegia, and hence full use of the contralesional limb. Only in one subject did an interaction appear between the side of presentation of the stimuli and limb used. In this case, a small but significant tendency appeared for the subject to make relatively faster responses to left-sided stimuli when using the left hand to make responses.

Aged↗
PubMed1991

Transfacial access for neurosurgical procedures: an extended role for the maxillofacial surgeon. I. The upper cervical spine and clivus.

A variety of osteoplastic flaps have been devised for transoral or extraoral access to the base of skull and the upper anterior cervical spine. Part I of this two-part review will describe access to the clivus and upper anterior cervical spine. Part II will describe access to the middle cranial fossa, the infratemporal fossa and the pterygoid (retromaxillary) "space".

Bone Diseases↗
PubMed1991

Transfacial access for neurosurgical procedures: an extended role for the maxillofacial surgeon. II. Middle cranial fossa, infratemporal fossa and pterygoid space.

A variety of osteoplastic flaps have been devised for transoral or extraoral access to the base of skull and the upper anterior cervical spine. Part I of this two-part review describes access to the clivus and upper anterior cervical spine. Part II will describe access to the middle cranial fossa, the infratemporal fossa and the pterygoid (retromaxillary) "space".

Bone Diseases↗
PubMed1979

Visual loss caused by corneal crystals in myeloma: rapid improvement and plasma exchange and chemotherapy.

Recognition of needle-like crystals in the cornea of a patient with deteriorating visual acuity initiated laboratory studies which demonstrated underlying multiple myeloma. Crystal deposition in the cornea occurs only rarely in multiple myeloma, and evidently reflects an unusual tendency for certain paraproteins to form numerous small aggregates which are deposited particularly within, and between, corneal epithelial cells. Treatment with chemotherapy, plus repeated plasma exchange with a normal plasma protein product resulted in significant depletion of crystals, and improvement in visual acuity over a period of three weeks. Accelerated clearance of paraprotein by plasmapheresis appeared to contribute materially to the rapidity of recovery, since recovery was considerably faster than in reported cases where treatment was with chemotherapy alone.

Aged↗
PubMed1978

Magnesium metabolism in patients with coronary heart disease.

1. The oral absorption of magnesium, its myocardial uptake and exchangeable magnesium have been studied in patients with coronary heart disease and controls using the radioactive isotope magnesium-28. 2. No significant difference in oral absorption or myocardial uptake was found between patients and controls. 3. The exchangeable magnesium per kg body weight was significantly lower in the patients than in the controls.

Adult↗
PubMed1976

Follow-up of five severely deprived and malnourished siblings, after their placement in foster care.

Five siblings, neglected and malnourished to the extent that they had become nutritional dwarfs, were placed in foster care. Their weights and heights were recorded at the time of placement, and at intervals for the following 6 years. In all cases there was an initial spurt in weight, which lasted for 1 to 2 years. Thereafer, the gains in weight and height continued on lines parallel with, but below the centile lines, except in the cases of the 2 youngest children, both of whom achieved the 3rd centile for weight and approached it for height. The eldest sibling was the most severely dwarfed.

Body Height↗
PubMed1976

Study of a proposed international standard for blood coagulation factor IX.

An International Collaborative Study was organized to establish a standard for factor IX. Two freeze-dried concentrate preparations, C1 and C2, and one freeze-dried plasma P were compared with each other, with fresh normal plasmas and with local standards in 13 laboratories. One of the concentrate preparations (C1) contained heparin and this gave rise to non-parallel assays in laboratories testing concentrate C1 in dilutions containing more than 0.05 i.u. of heparin per ml. Assays of factor IX showed good precision for both plasma and concentrate in all laboratories; no systematic effect of method, operator or day of assay was detected. The plasma preparation P and the concentrate preparation C2 were compared with 59 individual fresh normal plasma samples, and a mean potency ratio of 0.78 (95% confidence limits 0.73-0.84) for plasma and 5.62(95% confidence limits 5.13-6.16) for the concentrate C2 obtained. Only 21 estimates of concentrate C1 in terms of fresh plasma were obtained giving a mean potency ratio of 3.85 (95% confidence limits 1.87-7.92). The estimated loss of potency for freeze-dried plasma stored at -20 degrees C is approximately 0.4% per year. The concentrate C2 is apparently more stable and only very small losses occurred even at higher storage temperatures. All participants agreed that the preparation C2 would be suitable to serve as an International Standard for factor IX; they also agreed that the figure assigned for the unitage should be based on the number of ml of 'average fresh normal plasma' estimated to contain the factor IX activity of one ampoule of the preparation. It is proposed to recommend to the World Health Organization that the preparation of factor IX concentrate C2, in ampoules coded 72/32, be considered for establishment as the International Standard for factor IX, and that the international unit for factor IX be assigned on the basis of 5.62 units per ampoule of this preparation.

Blood Preservation↗