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Biomedical subjects

I Robertson

Publications and source records attributed to I Robertson.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1991

Assessment and treatment of childhood asthma.

In June 1990 a meeting of Paediatric Respiratory Physicians was held near Adelaide. The guidelines for assessing and treating asthma as prepared by the Thoracic Society of Australia and New Zealand for the management of patients with asthma was considered. Although not explicitly stated, these guidelines were designed for adult asthmatics. There was complete agreement that a companion statement was needed to take into account differences between the management of children and adults. This document fulfils that role. Further recommendations are found in a statement prepared by Australian and New Zealand respiratory paediatricians following a workshop in June 1989. This present statement should be read in association with the previous documents.

Asthma↗
PubMed1990

Systems analysis of cerebrovascular pressure transmission: an observational study in head-injured patients.

In an observational study in head-injured patients, cerebrovascular pressure transmission was investigated using a systems analysis approach whereby the blood pressure (BP) waveform was used as a measure of an input stimulus to the cerebrovascular bed (CVB) and the intracranial pressure (ICP) waveform as the response to that stimulus. The transfer function is a measure of how much pressure is transmitted through the CVB at a given frequency and is calculated using Fourier analysis of the pressure waveforms. The transfer function allows quantification of the pressure transmission performance of the CVB, thus providing a basis for comparison between normal and abnormal function. Fifteen hundred samples of ICP and BP waveforms were collected from 30 head-injured patients via microcomputer. Off-line spectral analysis of the waveform database revealed four main classes of transfer function: those with an overall flat transfer function (curve type 1); those with an elevated low-frequency response (curve type 2); those with an elevated high-frequency response (curve type 3); and those exhibiting both an elevated low- and high-frequency response (curve type 4). Curve types 2 and 4 were most often associated with raised ICP (greater than 20 mm Hg), whereas curve types 1 and 3 were most often affiliated with ICP less than 15 mm Hg. Studies of this type may provide insight into the pathophysiology of the CVB and ultimately aid in the prediction and treatment of raised ICP.

Adolescent↗
PubMed1990

Hyperlipidaemia in general practice: three year follow up of an opportunistic screening project.

As part of the national lipid screening project 927 people with a plasma cholesterol level greater than 6.5 mM were detected by screening 4006 men and women aged 25-59 years. Three years later 801 of the 878 patients eligible for a follow-up study (91%) had been followed up at least once. The median number of follow-up visits was two. The bulk of the workload fell on the nursing staff. The mean decrease in cholesterol level was 8-14% in those receiving dietary advice only, 15-25% in those receiving additional drug treatment and 12% for all patients. A proportion of this decrease must be attributable to regression to the mean, loss to follow up when patients were doing well, and the patients' knowledge of their follow-up date. Data on a group of patients not attending for regular follow up suggest that regression to the mean could account for up to 7% of the cholesterol reduction observed. Screening for hyperlipidaemia in general practice is feasible when the necessary infrastructure is provided, but even with a fairly conservative protocol 3% of those screened received drug treatment.

Adult↗
PubMed1989

Anomalies in the laterality of omissions in unilateral left visual neglect: implications for an attentional theory of neglect.

Patients suffering from unilateral left visual neglect may show problems in deploying attention generally in space, particularly in "controlled processing" type tasks (Schneider and Shiffrin), in addition to showing specifically lateralized attentional difficulties. The prediction is made that cueing to the left should result in a significant increase in right-sided omissions because of this general attentional difficulty. This hypothesis was confirmed, and two patterns of results were observed. One group continued to neglect a left stimulus in the cued condition, in spite of accurately reading a word on the left side, while the other group showed a mainly right-sided omission pattern.

Aged↗
PubMed1987

Multiple melanomas associated with diffuse melanocytic dysplasia.

An uncommon form of presentation of melanocytic dysplasia is described in 15 patients with primary cutaneous melanoma and a high incidence of multiple melanomas. This variation in melanocytic dysplasia appears macroscopically to the pathologist and to the clinician as a diffuse mottling or 'freckling' of the widely excised skin around the melanomas. Most patients also were described clinically as having multiple moles in other sites as well as round the melanoma. Histologically, the abnormally pigmented skin of the wider excisions has the features of melanocytic dysplasia, usually of lentiginous type, and this is seen both in continuity with the melanoma and distant from it including the margins of the wider excisions. These patients seem particularly prone to developing additional primary melanomas and therefore recognition of this form of presentation of melanocytic dysplasia may be important in patient management and prophylactic care of their families.

Adult↗
PubMed1987

Effectiveness of a controlled drinking self-help manual: one-year follow-up results.

Following the description of six-month follow-up results by Heather et al. (1986), this article reports one-year follow-up for a cohort of media-recruited problem drinkers sent either a controlled drinking self-help manual or a general advice and information booklet. Among those remaining in the sample, mean reduction in drinking at six months had been retained at the one-year point. This stability of reduced consumption included respondents showing evidence of late dependence or high consumption at initial assessment. When respondents who had received other forms of treatment had been excluded, the results confirmed the superior effectiveness of the self-help manual in enabling problem drinkers to reduce consumption. Evidence for a superior outcome among respondents interviewed by telephone, rather than contacted solely by post, was again observed. Some limited evidence is presented as to the reliability and validity of self-reports of consumption in the main sample.

Alcohol Drinking↗
PubMed1987

Total body electrolyte composition in patients with heart failure: a comparison with normal subjects and patients with untreated hypertension.

Total body elemental composition was measured in 40 patients with well documented heart failure who were oedema-free on digoxin and diuretics. The results were compared with values for 20 patients with untreated essential hypertension matched for height, weight, age, and sex. Total body potassium alone was also measured in 20 normal subjects also matched for anthropomorphic measurements. Patients with hypertension had a very similar total body potassium content to that of normal subjects, but patients with heart failure had significantly reduced total body potassium. This could not be explained by muscle wasting because total body nitrogen, largely present in muscle tissue, was well maintained. When total body potassium was expressed as a ratio of potassium to nitrogen mass a consistent depletion of potassium was revealed in the group with heart failure. Potassium depletion was poorly related to diuretic dose, severity of heart failure, age, or renal function. Activation of the renin-angiotensin-aldosterone system was, however, related to hypokalaemia and potassium depletion. Such patients also had significantly lower concentrations of serum sodium and blood pressure. Serum potassium was related directly to total body potassium. Despite the absence of clinically apparent oedema total body chlorine was not consistently increased in heart failure, but the calculated extracellular fluid volume remained expanded in the heart failure group. Total body sodium was significantly increased in patients with heart failure, but less than half of this increase could be accounted for by extracellular fluid volume expansion. Potassium depletion in heart failure may account in part for the high frequency of arrhythmias and sudden death in this condition.

Anthropometry↗