Biomedical subjects

K Darton

Publications and source records attributed to K Darton.

5 recordsLinked to original sources

PubMed1995

Arthritis in scleroderma.

Thirty-four patients (24 females and 10 males) selected from 300 consecutive patients with established systemic sclerosis (SSc), with a current or past history of articular symptoms, were clinically documented and further studied using thermography and bone scan to define the pattern of arthritis. Clinical evidence of synovitis was observed in 30 (88%) and joint inflammation was detected in 31 (91%) by the above-mentioned imaging techniques. A distinctive subset of 10 patients with deforming arthritis was characterized in which seven (70%) patients fulfilled criteria for both rheumatoid arthritis and SSC; three of these satisfied the criteria for diagnosis of CREST, but none met the criteria of mixed connective tissue disease. These patients, as a group, when compared with the rest showed limited skin involvement (skin score of 19 +/- 11 vs 33 +/- 14; P < 0.05) and were positive for rheumatoid factor (80 vs 13%; P < 0.05) and anticentromere antibodies (37 vs 4%; P < 0.05).

Adult↗

PubMed1991

Pyroelectric vidicon thermography and cold challenge quantify the severity of Raynaud's phenomenon.

Thermographic images of the hands of patients with primary and secondary Raynaud's phenomenon and of a group of normal subjects, recorded before and after cold provocation using a pyroelectric vidicon thermal imaging system, showed differences in thermal distribution patterns that were characteristic of primary Raynaud's phenomenon (RP), scleroderma (RS) and normal, and were exaggerated by cold provocation. The responses to cold challenge, assessed by computing the mean temperature of the hand as it recovered from cold challenge and plotting these values against time to produce a rewarming curve, were also characteristic of the patient and the normal groups, and gave an indication of the severity of circulatory impairment. Methods are described for the simple numerical characterization of these parameters.

Adolescent↗

PubMed1990

A pyroelectric thermal imaging system for use in medical diagnosis.

The value of infra-red thermography in a number of pathologies, notably rheumatology and vascular diseases, is becoming well established. However, the high cost of thermal scanners and the associated image processing computers has been a limitation to the widespread availability of this technique to the clinical community. This paper describes a relatively inexpensive thermographic system based on a pyroelectric vidicon scanner and a microcomputer. Software has been written with particular reference to the use of thermography in rheumatoid arthritis and vasospastic conditions such as Raynaud's phenomenon.

Arthritis, Rheumatoid↗

PubMed1990

The use of infra-red thermography in a rheumatology unit.

Infra-red thermography is a technique that is under-used in rheumatology; one reason is the supposed necessity for a temperature-controlled room in which to conduct tests. The results of a series of cold challenges to the hand, repeated on a normal subject in a temperature-controlled room and in other parts of a rheumatology ward, show very good reproducibility outside the temperature-controlled room, provided that the immediate environment is draught-free.

Humans↗

PubMed1985

Long-latency spinal reflexes in humans.

Stretching human muscles with a mechanical device gave rise to multiple peaks in the rectified and averaged electromyogram. In the first dorsal interosseous the latency of the first peak (M1) was 32.4 +/- 2.4 ms (SD) and the latency of the second peak (M2) was 55.1 +/- 11.3 ms, in both cases measured from the time of the stimulus to the take-off point of the peak. Often a third peak (M3) was seen, having a considerably longer latency. The origin of peak M1 was considered to be in the stretch reflex arc because of its latency and its invariable association with muscle movement. Peak M2 was due to stimulation of afferent terminals in the skin and/or subcutaneous tissues by the mechanical device producing the muscle stretch. The conduction velocity of the pathway involved in the generation of the M1 component is the same as that for M2. This implies that central processing in the spinal cord delays the M2 response. The M2 mechanism does not involve a transcortical (long-loop) pathway because in foot muscles the M1-M2 delay remains the same as is found for hand muscles, although M1 latency is prolonged (to 39.4 +/- 6.2 ms for extensor digitorum longus). This indicates that there is not time for M2 impulses to traverse a pathway any longer than that passing to and from the spinal cord.

Afferent Pathways↗