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Biomedical subjects

A H Roberts

Publications and source records attributed to A H Roberts.

At least 19 recordsLinked to original sources
PubMed2001

Fluoride accumulation in pasture forages and soils following long-term applications of phosphorus fertilisers.

Ingestion of soils with high fluoride (F) concentration may cause chronic fluorosis in grazing animals. Analysis of New Zealand pasture soils with long-term phosphorus (P) fertilisation histories showed that total surface soil (0-75 mm depth) F concentration increased up to 217-454 mg kg-1 with P fertiliser application. One-third to two-thirds of F applied in fertilisers resides in the top 75 mm soil depth. Pasture forage accumulation of F was low, and therefore, F intake by grazing animals through pasture consumption is expected to be much lower than F intake by soil ingestion. Ten annual applications of single superphosphate (30 and 60 kg P ha-1 year-1) to a Pallic Soil (Aeric Fragiaqualf) significantly increased total F and labile F (0.01 M CaCl2 extract) concentrations to 200 and 120 mm depths, respectively, of the 300 mm depth investigated. The mobility of F in the soil profile was similar to two other elements, P and cadmium derived from the fertiliser.

Agriculture↗
PubMed2001

Burn depth and its histological measurement.

This paper describes a new technique for burn depth measurement, based on the histological assessment of dermal microvascular occlusion in burn biopsies. The technique was validated in a preliminary study of acute progressive microvascular damage in five adults with partial thickness burns. Burn depth was calculated at three time points post burn from the mean histological measurement of the most superficial patent and the deepest blocked vessels in five separate sections from each biopsy. The results were expressed as a percentage of the total dermal thickness and correlated well with the laser Doppler measurement of dermal blood flow and clinical estimation of burn depth. The reproducibility of the technique was tested by the repeated blind analysis of five randomly chosen biopsies on a separate occasion. Altman-Bland plot analysis demonstrated a median variation of 0.1% (95% confidence interval -1 to 2%). A second independent observer (MPHT), who carried out a blind analysis of the same randomly chosen biopsies, tested the precision of the technique. The median variation was 2% (95% confidence interval -5 to 8.5%).

Adult↗
PubMed2001

The influence of body mass index on burn surface area estimated from the area of the hand.

It is well recognised that initial estimates of the area involved in a burn injury by inexperienced clinicians are frequently excessive. In Britain the palmar surface area of the hand is taught to approximate 1% of the total body surface area (TBSA), but no allowance is made for variations in individual body weight. This study aimed to evaluate the relationship between hand surface area (HSA) and body mass index (BMI) using healthy volunteers. We found that mean HSA diminished significantly as BMI increased in both sexes (P<0.001). This effect was, however, more pronounced in women, particularly those with a BMI greater than 31 kg/m(2) in whom the HSA represented only 0.64%. Awareness of the potential for over-estimation of burn surface area using this method alone may improve the accuracy of burn area estimation and consequent need for commencing resuscitation.

Adult↗
PubMed2001

Dermal cellular inflammation in burns. an insight into the function of dermal microvascular anatomy.

The damage caused by thermal trauma is augmented by the subsequent inflammatory response in a similar fashion to reperfusion injury. Animal studies have demonstrated a significant role for neutrophils in this delayed damage, but little is known about the numbers of neutrophils or other leucocytes that enter human skin following burns. We have longitudinally examined profiles of leucocyte migration into five cases of human partial thickness burns in relation to continued dermal microvascular destruction during the acute post-burn period. All burn wounds had a rapid influx of neutrophils that was followed by a delayed influx of macrophages. Compared to the controls, the two superficial burns also had rapid and sustained influx of CD4 and CD8 lymphocytes via patent post capillary venules in the dermal superficial vascular plexus, whilst in the three deeper burns, in which this superficial vascular plexus was occluded, the number of lymphocytes decreased. These results suggest that the patterns of leucocyte extravasation were dependent on the initial level of vascular occlusion, indicating that the dermal microvascular anatomy plays a pivotal role in determining the composition of the extravascular inflammatory cell infiltrates. The potential importance of this finding is highlighted by the differences in wound behaviour associated with the different leucocyte profiles.

Adult↗
PubMed2000

Burns sustained by hot bath and shower water.

An 8-year retrospective review of patients admitted to Stoke Mandeville Hospital (Aylesbury, UK) because of burns sustained by hot bath and shower water was undertaken. Fifty-seven patients of all ages were identified and stratified into paediatric (< 16 years) and adult groups. Nine patients died. The main characteristics of the burns, causes and outcomes of treatment were analysed for each group. Children were predominantly under three years of age (83%), sustaining most frequently only superficial burns (41%) with areas of less than 10% total body surface area (72%). Parents' supervision was inadequate in 85% of cases. Eighty-three percent of the adults were over the age of 60. Two thirds had some form of psycho-motor disorder that predisposed to an accident which should have been anticipated. In comparison to children, adults suffered more extensive and deeper burns that resulted in a mortality of 44% (8/18). In both groups, the lower parts of the body were most frequently involved. The observed decline in the number of admissions for the period of investigation is encouraging. It supports an ultimate need for further development and actual implementation of preventative measures for hot water burns in the homes of people who are at greatest risk.

Accidents, Home↗
PubMed2000

Frostbite: pathogenesis and treatment.

Frostbite, once almost exclusively a military problem, is becoming more prevalent among the general population and should now be considered to be within the scope of the civilian physician's practice. Studies into the epidemiology of civilian frostbite have identified several risk factors that may aid the clinician in the diagnosis and management of cold injuries. Research into the pathophysiology has revealed marked similarities in inflammatory processes to those seen in thermal burns and ischemia/reperfusion injury. Evidence of the role of thromboxanes and prostaglandins has resulted in more active approaches to the medical treatment of frostbite wounds. Although the surgical management of frostbite involves delayed debridement 1 to 3 months after demarcation, recent improvements in radiologic assessment of tissue viability have led to the possibility of earlier surgical intervention. In addition, several adjunctive therapies, including vasodilators, thrombolysis, hyperbaric oxygen, and sympathectomy, are discussed.

Clinical Protocols↗
PubMed1998

Pleomorphic lipoma of the parotid gland.

Lipomata are rare tumours of the parotid gland. The pleomorphic lipoma represents an unusual histological variant of the benign lipoma. We report a case of a pleomorphic lipoma arising in the parotid gland. Only one case of a similar nature has previously been recorded. This tumour is benign, was fully excised and recurrence is not expected.

Aged↗
PubMed1998

Spontaneous rupture of extensor pollicis longus tendon in a kick boxer.

A 23 year old male kick boxer presented with a 24 hour history of pain and being unable to extend the interphalangeal joint of the left thumb. There was no history of trauma or any other risk factor for spontaneous rupture of the extensor pollicis longus tendon. On the previous day, he had been doing reverse press ups on the dorsum of his hands with his wrists hyperflexed as part of his training for kick boxing. At operation the extensor pollicis longus tendon was found to be divided at the level of the dorsal tubercle of the radius and was not directly repairable. The treatment was an extensor indicis proprius transfer. We suggest that the cause of the tendon rupture was direct pressure on the dorsal tubercle of the radius sustained while performing reverse press ups.

Adult↗
PubMed1997

The palmaris longus tendon. Another variation in its anatomy.

The palmaris longus is one of the most variable muscles of the human body. An understanding of its variations is useful as it is often used as a tendon graft and for tendon transfer. We report another interesting variation in its anatomy.

Arthritis, Rheumatoid↗
PubMed1997

Grip and pinch strength variations in different types of workers.

We measured grip and pinch strengths in non-manual, light manual and heavy manual workers using a Jamar dynamometer and a pinch measuring device. Heavy manual workers had the strongest grips with the least difference between sides. Office workers had the weakest grips and the greatest difference between sides. Light manual workers were between these two groups. Consequently, the occupation of the patient must be taken into account when using grip and pinch strength measurements to assess the need for rehabilitation and in medicolegal reports.

Adult↗
PubMed1996

The treatment of hand injuries.

A major hand injury can completely change a person's life. The consequences of the injury can be reduced by proper assessment, appropriate treatment and careful follow-up. Whenever experienced help is available then it should always be sought. This article describes the management of hand injuries. In Papua New Guinea the worst disasters occur when injuries are missed on initial assessment and the patient is not referred to a surgeon. Another common cause of poor outcome is failure to splint the hand in the correct position.

Bandages↗
PubMed1995

Motor vehicle-related burns: a review of 107 cases.

Motor vehicles are a major cause of morbidity and mortality. Burn injuries sustained from motor vehicles form a small but important subgroup. The authors have reviewed the case notes of 107 patients with motor vehicle-related burns over a 13-year period. The age ranged from 18 months to 65 years and the male to female ratio was 4:1. The mechanisms of injury were variable, although four major categories could be identified. These accounted for 83 per cent of the cases. Car fires following road traffic accidents was the largest group accounting for 48.5 per cent of cases. The remaining three groups were: motorcycle-related burns following road traffic accidents (6.5 per cent of cases), garage fire-related burns (15 per cent of cases) and car radiator-related burns (13 per cent of cases). Garage fire-related burns had the highest mortality of the four groups (25 per cent). This study demonstrated that garage fire burns are an important subgroup of motor vehicle-related burns.

Accidents↗
PubMed1994

Volitional vasomotor lability and vasomotor control.

This experiment tested the hypothesis that skin temperature variability during instructions to attempt skin temperature self-control without feedback (volitional vasomotor lability) predicts the acquisition of vasomotor control through biofeedback training. Skin temperature was recorded from the hands of 232 volunteers during a screening session. Twenty-three labile and 17 stabile subjects were chosen to participate in a 16-session training program under double blind conditions. Visual and auditory feedback were used to train subjects to produce temperature differences between the two hands in a specified direction. Comparisons between the labile and stabile groups revealed statistically significant differences in the predicted direction on measures of performance and learning. These findings provide preliminary support for the hypothesized positive relationship between volitional temperature variability and voluntary vasomotor control. Fruitful directions for future research are suggested.

Adult↗