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Biomedical subjects

I Robertson

Publications and source records attributed to I Robertson.

At least 55 records · Page 3Linked to original sources
PubMed1998

Sources of error in intra-arterial pressure measurements across a stenosis.

OBJECTIVE: To investigate potential errors associated with different techniques of intra-arterial pressure measurement at angiography. MATERIALS AND METHODS: An experimental model of an arterial stenosis was developed. Experiments were performed to assess the relevance of catheter position, catheter direction and catheter type on the recorded intraluminal pressure. Transstenotic pressure gradients were recorded with and without angiographic catheters crossing the stenosis. RESULTS: At physiological flow rates angiographic catheter type does not influence the recorded pressure. At high flow rates through tight stenoses there is a significant catheter-related difference in recorded pressure adjacent to a stenosis. Downstream pressures may be altered by up to 85 mmHg when standard angiographic catheters are placed across a stenosis. CONCLUSION: The different techniques employed to measure pressure differences across a model stenosis may introduce significant errors up to 85 mmHg. Care must be taken when pressure measurements alone are used to interpret the clinical significance of a stenosis. In low flow conditions there may not be a detectable pressure gradient across a 95% stenosis.

Angiography↗
PubMed1998

Attentional skills following traumatic brain injury in childhood: a componential analysis.

Recent research has documented residual deficits in attention following traumatic brain injury in childhood. The present study aimed to investigate whether such deficits are global, or affect specific components of attention differentially. Four attentional domains were examined using a newly developed test of attention, the Test of Everyday Attention for Children: sustained attention, focussed attention, divided attention, and response inhibition. Eighteen children with a history of traumatic brain injury, aged between 8 and 14 years, and 18 non-injured matched controls participated in the study. Results indicated that attentional skills may be differentially impaired after TBI, with children who have sustained moderate-to-severe TBI exhibiting significant deficits for sustained and divided attention, and response inhibition, but relatively intact focussed attention.

Adolescent↗
PubMed1998

Process modelling and simulation for managing clinical care in the community.

'Care in the Community' is an easy catch phrase but a difficult goal. It is a phrase that addresses a current growth area within health care, and one that comes complete with an impressive array of political, economic and social factors that would seem to support the notion of a continuing trend. Technology, specifically information systems, however, has not been successfully cast in a supporting role. There are many reasons for this lack of success but a major one is the mismatch between the understanding of what is required to support the clinical care processes and the specifications of the current systems supplied. Specifically the interest here is in the use and assessment of two computer science techniques, i.e. process modelling and simulation, as suitable means of capturing and communicating requirements so as to bridge the divided and power differential between users and developers of information systems.

Community Health Nursing↗
PubMed1997

Relationship of serum leptin to total and truncal body fat.

1. In this study we investigated the relationship between serum leptin levels and body fat distribution in a random sample of women of widely ranging age and body mass index. Anthropometry and dual energy X-ray absorptiometry were used to measure body fat and its distribution. 2. Leptin levels (log transformed) were not significantly correlated with age, but were significantly positively correlated (P < 0.001) with most anthropometric measures except waist-to-hip circumference ratio. The strongest correlations were with total grams of body fat and percentage body fat (r = 0.68 and 0.76 respectively, P < 0.001). When corrected for percentage body fat the partial correlation coefficients for all other measures became non-significant. The correlation with truncal body fat fell significantly from 0.66 to -0.05 after correction, but the partial correlation with total body fat remained significant (P < 0.005) when grams of truncal fat were controlled for (r = 0.21). 3. These results indicate that the relationship of serum leptin to percentage body fat is the strongest, and that truncal body fat, although the most metabolically active, does not appear to have an independent association with serum leptin.

Absorptiometry, Photon↗
PubMed1997

Cutaneous manifestations of chronic graft-versus-host disease.

Graft-versus-host disease (GVHD) occurs in a number of clinical settings. It is well recognized after bone marrow transplantation, an increasingly used therapeutic option for haematological disorders. Chronic GVHD, occurring at an interval greater than 100 days post-transplant, has many systemic manifestations, but it is the cutaneous manifestations which are most frequent and often most troubling to the patients. In this review article, the wide spectrum of cutaneous chronic GVHD (including involvement of hair, nails and mucosae), and its complications and associations are discussed. The clinical and histological features and management guidelines are presented to assist the dermatologist with diagnosis and treatment of this condition.

Bone Marrow Transplantation↗
PubMed1997

The case of the disappearing glioma.

A case of glioblastoma multiforme disappearing on CT after a course of dexamethasone is reported. The possibility of mistaking this for lymphoma is discussed. There is no other case similar to this described in the literature.

Antineoplastic Agents, Hormonal↗
PubMed1996

Mango dermatitis: allergic contact dermatitis to Mangifera indica.

Mango Dermatitis' is the common term given to allergic contact dermatitis to the sap or skin of the fruit of Mangifera indica. Four patients presented with urticaria and eczematous rash following exposure to mangoes or the trees. Patch testing with diluted sap, crushed leaf, crushed stem and fruit skin was strongly positive.

Adult↗
PubMed1996

Excess dietary urea intake in ewes and its effect on ovulation rate and embryo development.

The effect of excess dietary urea on ovulation and early embryo development of sheep was studied. Thirty Border Leicester x Scottish Black face ewes randomly assigned to three treatments were given a basal control diet (C) which met energy requirements for body weight maintenance. Other treatments were basal diet plus 24 g of urea/day (low urea, L) or plus 48 g (high urea, H)/day. The reproductive cycles of the ewes were synchronized using a single injection of prostaglandin (PGF2 alpha) and progesterone by an intravaginal controlled internal drug release (CIDR) device for 12 days. Ovulation was induced by the use of pregnant mare serum gonadotrophin (PMSG). Ewes were inseminated approximately 52 hours after CIDR device removal using a laparoscopic technique. Embryos were recovered at Day 4 or Day 11 after insemination from half of the ewes from each treatment group. There were no significant differences in ovulation rates among the three groups. The embryo recovery rates were not affected by day of recovery. At embryo recovery on Day 4, 7/13 in C, 3/6 in L and 0/7 in H embryos were morulae. After 72 hours of in vitro culture 6/10 in C, 2/3 in L and 0/4 in H embryos developed to the blastocyst stage. Pregnancies sustained were C 6/8, L 5/7 and H 1/3 of the autotransfers. Throughout the experiment plasma urea levels were significantly affected by diet (p < 0.01). Plasma ammonia levels in the H group were significantly higher than those in the C and L groups (p < 0.05) for 4 hours after each feed. There was no treatment effect on plasma progesterone concentration. The luteinizing hormone (LH) surge onset time and amplitude were not correlated to ovulation rate and were not affected by treatment. It is concluded that high circulating concentrations of plasma urea and ammonia have an adverse effect on early embryo development. This effect was independent of any alterations in progesterone and LH concentrations.

Ammonia↗
PubMed1995

Pustular vasculitis of the hands.

BACKGROUND: Several patients were observed with a peculiar cutaneous eruption limited to the dorsa of the hands and fingers. Clinically the lesions had some resemblance to those seen in Sweet's syndrome, but biopsy specimens showed severe leukocytoclastic vasculitis. OBJECTIVE: Our purpose was to characterize this eruption clinically and histologically and compare it with previously described diseases. METHODS: Six patients observed since 1977 are described. Skin biopsy specimens were obtained. RESULTS: In six women (age, 41 to 79 years) a symmetric eruption of papules and plaques limited to the dorsa of the radial sides of the hands and first three digits developed. The lesions resembled those of Sweet's syndrome and were associated with fever, sterile culture, blood neutrophil leukocytosis, nonresponse to antibiotic therapy, and rapid response to prednisone. Biopsy specimens showed a severe leukocytoclastic vasculitis. CONCLUSION: These patients appear to have a distinct entity that we have termed pustular vasculitis of the hands.

Adult↗
PubMed1995

Excessive numbers of skin cancers and pre-malignant skin lesions in an Australian heart transplant recipient.

One and a half years after heart transplantation an Australian man developed his first skin cancer. In the period until his death, 7 years after the transplantation, 34 histologically confirmed squamous cell carcinomas developed, 17 intra-epidermal carcinomas, and 9 basal cell carcinomas. Most skin cancers were confined to chronically sun exposed sites. Exposure to sunlight and human papillomavirus are important factors in the development of skin cancer in renal transplant recipients, and further studies are needed to establish the role of these risk factors in cardiac transplant recipients.

Carcinoma in Situ↗
PubMed1995

A review of correspondence to a general dental practice 'helpline'.

The aim of this retrospective study was to examine the correspondence sent to a dental helpline. A general dental practice telephone helpline was established under the auspices of the British Dental Health Foundation (BDHF). The name and contact telephone number were provided via the BDHF or through various media and patient organisations such as the Phobic Society. All the telephone enquirers were encouraged to follow up their telephone call with a written letter. The contents of the 105 letters which were received over a four-year period were collated and categorised. Correspondents fell into two categories: those seeking information about various dental issues and those who described themselves as dental phobics. There were 64 requests for information; of these, 20 were straightforward requests for information booklets, 16 were complaints about denture problems and 10 wanted advice on finding a 'sympathetic' dentist. 'Dental phobics' was how 41 correspondents described themselves. Seven of these 'dental phobics' wrote that they perceived their dental state to have become so poor that they were too embarrassed to attend a dentist. In conclusion, this pilot study highlights the potential value of a helpline in a general dental practice setting and describes the scope of enquiries received. The findings will help general dental practitioners who may wish to use a dental helpline to improve patient access to primary dental care.

Correspondence as Topic↗
PubMed1993

Cerebral aspergilloma in a child with autosomal recessive chronic granulomatous disease.

A 2 year old girl presented with epilepsy 16 months after being diagnosed as having autosomal recessive chronic granulomatous disease. Computed tomography showed a cerebral mass which was surgically removed and proved histologically to be an aspergilloma. This case illustrates the application of molecular diagnostic techniques to the diagnosis of chronic granulomatous disease. The occurrence of, and unusual reaction to, cerebral aspergillus infection indicates the need to consider this possibility in the differential diagnosis of mass lesions in chronic granulomatous disease. Furthermore, it is clear that autosomal recessive chronic granulomatous disease cannot be considered to be a clinically mild form that is exempt from major neurological complications.

Aspergillosis↗
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↗