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Biomedical subjects

J C Buckland-Wright

Publications and source records attributed to J C Buckland-Wright.

At least 55 records · Page 3Linked to original sources
PubMed1991

Osteophytes in the osteoarthritic hand: their incidence, size, distribution, and progression.

Quantitative microfocal radiographic assessment of osteophytes in osteoarthritic hands showed that their number and area were greatest at joint margins, in the dominant hand, in the second and third compared with fourth and fifth phalanges, in the third phalanx, and in the second distal interphalangeal joint respectively. These sites correspond with those for the largest forces exerted in the hand: the dominant side, the finger tripod used in the precision grip, power grip, and pulp-pinch respectively. The greater osteophytosis on the trapezium of the nondominant first carpometacarpal joint was probably related to forces exerted during power grip. Osteophytes increased significantly in number and area during the 18 month study period.

Arthrography↗
PubMed1990

Quantitative microfocal radiographic assessment of progression in osteoarthritis of the hand.

We studied 32 patients with osteoarthritis who had 5x macroradiographs taken of their wrists and hands at 6-month intervals over an 18-month period. The higher magnification and resolution of microfocal radiography permitted the quantitative detection of progressive changes in 4 different features: subchondral sclerosis, the number and size of osteophytes, juxtaarticular radiolucencies, and joint space narrowing. Compared with normal control subjects, subchondral cortical thickness was greater in all patients at entry and showed a variable degree of change over the study period. Osteophytes and juxtaarticular radiolucencies were present in all patients at study entry; by the end of the study, osteophytes had increased in number and area, and juxtaarticular radiolucencies had increased in area, but not in number. At entry, 44% of the patients had joint space narrowing significantly greater than that in the control subjects; by 18 months, this proportion increased to 65%. No correlation was found between subchondral sclerosis, osteophytes, juxtaarticular radiolucencies, and joint space narrowing. We conclude that in osteoarthritis of the hand, the bony changes have progressed significantly before the occurrence of radiographically evident joint space narrowing indicative of cartilage thinning.

Aged↗
PubMed1990

Quantitative microfocal radiography of children with renal osteodystrophy; comparison with laboratory and histological findings.

High definition microfocal radiography permitted the quantitative assessment of the radiographic features of renal osteodystrophy in the phalanges of 11 children in stable chronic renal failure, treated with phosphate binders for 1 year. The most consistent feature was subperiosteal cortical resorption, expressed as a ratio total length of resorbed subperiosteal bone/total length subperiosteal bone x 100. It was found that the extent of resorbed bone was significantly greater in the middle phalanx and on the ulnar surface of the phalanges. The radiological findings over the duration of the disease were compared with laboratory assessments and bone histomorphometry. The extent of the percentage of subperiosteal resorption at base line and its change during the study period correlated significantly with the level of serum parathyroid hormone levels and its change over the same period. No other significant correlations were found between radiographic features and laboratory assessments or with bone histomorphometry.

Adolescent↗
PubMed1989

A neurogenic mechanism for symmetrical arthritis.

Human synovium is richly innervated by autonomic and sensory nerve fibres, many of which contain neuropeptides. The hypothesis is that, in addition to a sensory role, some of these fibres modulate the response of the synovial membrane to a variety of noxious stimuli by releasing these peptides. Synovial damage results in acute inflammation in the damaged joint and a neurogenically mediated infiltrate of inflammatory cells in the contralateral joint. These cells might protect the contralateral synovium from injury similar to that in the damaged joint. An increased response would lead to synovitis and symmetrical disease.

Arthritis↗
PubMed1989

Erosion number and area progression in the wrists and hands of rheumatoid patients: a quantitative microfocal radiographic study.

Microfocal radiography has been used to evaluate the relation between erosion number and erosion area in the hands and wrists of 51 patients with early to moderately advanced rheumatoid arthritis. The hands of these patients showed different patterns of erosion progression, in terms of the relation between changes in number and area, and included those showing a decrease in one or both of the erosion parameters. The mean number of erosions in the group increased between the first and second visits. By the third visit (a mean of 48 months from the onset of symptoms) the mean number of erosions in the wrist and hand of the group had approached a constant value of 75 erosions. Over the same period the mean erosion area of the group continued to increase. Measurement of changes in erosion area is a more sensitive indicator of erosion progression than erosion number, both within the group and in individual patients.

Arthritis, Rheumatoid↗
PubMed1989

A new high-definition microfocal X-ray unit.

A new microfocal unit is described with an operating range up to 170 kVp (limited to 125 kVp for medical use), 0-1 mA and a maximum output of 75-80 W. The unit comprises a lanthanum hexaboride (LaB6) cathode, a single electromagnetic lens and a stationary oil-cooled multifaced tungsten target. The estimated source size ranges from 6 to 20 microns between 14 and 77 W. The tube's output is x 3 to x 3.5 greater than that of a conventional X-ray unit. The use of fast rare-earth film-screen systems permits exposures of most views of the patient within 1 s. The spatial resolution within these film-screen systems is 40-30 microns diameter at magnifications of x 5-10. The tube is fixed so as to project a horizontal beam and the patient table is designed to position the patient close to the source (20-30 cm) with the film placed at a focus-film distance of 1-3 m. Stereopair macroradiographs permit greater accuracy in the identification and location of radiographic features. The large magnification and resolution of macroradiographs allow direct and accurate measurement of radiographic features.

Equipment Design↗
PubMed1989

Clinical applications of high-definition microfocal radiography.

Recent advances in technology have lead to the development of a high-definition microfocal X-ray unit allowing macroradiographic examination of different parts of the body at x 5 to x 10 magnification and with a high spatial resolution. Its applications in the study of a number of arthritides, metabolic and some other bone diseases are described in terms of early detection of diagnostic features. Emphasis is placed on the advantages of direct accurate measurement of these features, providing a precise evaluation of disease progression and response to therapy.

Arthritis, Rheumatoid↗
PubMed1987

Incidence and size of erosions in the wrist and hand of rheumatoid patients: a quantitative microfocal radiographic study.

Quantitative macroradiographic examination of a group of early to moderately advanced rheumatoid patients showed the wrist and hand to have an average of 75 (SD 26) erosions out of 142 possible sites. Joint involvement was greatest in the wrist followed by the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints respectively. In the wrist erosion distribution was concentrated in the radiocarpal and medial carpometacarpal complex, in the hand it tended to be located at the second and third MCP and third PIP joints. No difference was observed in erosion number and area between the right and left extremities. The distribution of the lesions is discussed in relation to the intra-articular pressures on normal hand function. The similarity of erosion development, across the joints at the different regions of the hand, suggests the presence of factors other than mechanical pressure. In general, erosions were widespread, and the largest erosions occurred in the larger bones of the wrist and hand.

Adult↗
PubMed1986

Quantitative microfocal radiography accurately detects joint changes in rheumatoid arthritis.

Microfocal radiography, producing x5 magnified images of the wrist and hands with a high spacial resolution (25 microns) in the film, permitted direct measurement of erosion area and joint space width in patients with rheumatoid arthritis. The magnitude of errors relating to direct measurement, repositioning the wrist and hand on successive x ray visits, repeated identification of erosions and their area calculation were assessed. The coefficients of variation for length and area measurements were 3.7% and 13% respectively, while the change in joint space width and erosion area in five patients over 18 months had average coefficients of variation of 12.7% and 42.0% respectively. The combined errors correspond approximately to the fifth percentile level for the total changes in size of these x ray features. The remaining alterations were due to the disease, which was markedly greater that that attributable to errors of measurement.

Arthritis, Rheumatoid↗
PubMed1984

Microfocal radiographic examination of erosions in the wrist and hand of patients with rheumatoid arthritis.

The microfocal x-ray unit, a new type of x-ray machine characterised by an extremely small x-ray source, enables great detail to be recorded in the projection radiographs owing to the high object magnification and resolution obtained with this system. Microfocal radiographic examinations were carried out on the wrists and hands of 26 patients with early or moderately advanced rheumatoid arthritis. The macroradiographs confirmed the presence or absence of erosions in patients with early disease activity who otherwise had no detectable lesions visible in standard radiographs. The site of onset, development, and distribution of erosions are described. Their approximate order of appearance is listed. The first to appear occurred in the medial carpal bones, second and third metacarpophalangeal joints and third and fourth proximal interphalangeal joints. In origin they were subperiosteal either immediately adjacent to the insertion of an interosseous ligament or at the transitional zone of the articular cartilage. Erosions in the subchondral bone appeared subsequently and were either indirect (subperiosteal) or direct (subchondral) in origin. Cyst formation was frequently associated with the enlargement of an erosion which it often replaced.

Adolescent↗
PubMed1984

Combined treatment of post-menopausal osteoporosis: effect on muscle function and a new radiological method for assessing trabecular bone.

Ten women presenting with at least two osteoporotic vertebral crush fractures were treated with alfacalcidol (one-alpha-hydroxycholecalciferol), calcium lactogluconate, oestrogen and progestagen for 6 months. Significant improvements in the patient's assessment of pain, grip strength, walking and stair climbing times were found. These suggest that a sub-clinical myopathy may be a feature of osteoporosis. The role of combination treatment is discussed in depth. Radiographs of the thoracic and lumbar spines revealed no further deterioration and there was no significant reduction in standing height. Microfocal radiographs of the hand showed no change in metacarpal cortical bone width. This novel technique allowed a qualitative assessment of trabecular bone in the distal metacarpal but no consistent effect of treatment was observed.

Aged↗
PubMed1983

X-ray assessment of activity in rheumatoid disease.

This review paper examines the limitations of X-ray techniques, and describes the results of the different methods of assessing disease progression including joint involvement in relation to the duration of the disease, and the different methods for scoring joint destruction. The application of the new X-ray technique of microfocal radiography, which produces radiographs of high magnification (x5-x10) and resolution (2 x 10(-5)m object diameter), is described. The techniques, developed by the author, provide the most accurate method of qualitative and quantitative assessment of disease progression in the wrist and hands of rheumatoid patients.

Arthritis, Rheumatoid↗
PubMed1983

Advances in the radiological assessment of rheumatoid arthritis.

Standard radiographic assessment of changes in rheumatoid joints is limited by factors within the radiographic process, i.e. the performance of the X-ray equipment, recording medium and X-ray assessment. The development of microfocal X-ray units overcomes many of the limitations of conventional radiology. The radiographs of high magnification and resolution produced by this system permit early diagnosis and direct quantitative evaluation of disease progress, providing a more effective assessment in therapeutic trials. Advances in other imaging techniques such as computed tomography (CT), nuclear magnetic resonance (NMR) and emission tomography are evaluated in terms of their potential value in assessing disease activity.

Arthritis, Rheumatoid↗
PubMed1981

Microfocal radiography in the quantitative assessment of experimentally induced inflammatory arthritis in guinea-pigs.

Microfocal projection radiography was used to examine a new model of experimentally induced inflammatory arthritis, developed at Roche Projects Ltd. The high resolution and magnification of the stereoprojection radiographs provided a non-destructive and three-dimensional assessment of the changes in the arthritic knee joints and enabled direct measurements to be made from the radiographs. During the time course study it was possible to quantify the increase in the size of the suprapatella bursa in the early stages of the inflammatory process, the onset and development of erosions in the articular bones and both juxta-articular and systemic osteoporosis. The results of the quantitative radiographic study when compared with standard arthritis assay techniques of knee diameter and flexion showed maximum damage when the latter were near normal. Histology confirmed the radiographic results, although, alone it did not contribute substantially to the assessment of the changes occurring in the diseased joints. The measurements from the projection radiographs showed that the destruction of the articular bone progressed rapidly subsequent to subperiosteal erosions and consequent invasion of pannus into the epiphyses. The rate and degree to which articular bone was destroyed was independent of the extent to which juxta-articular and systemic osteoporosis had developed. Microfocal projection radiography has considerable advantages over any other method in quantifying the changes in arthritic joints for evaluating the pathogenesis of the arthritis and in screening different compounds.

Animals↗
PubMed1980

An investigation of the effect of anti-inflammatory and anti-rheumatoid drugs in cell-mediated immune arthritis in guinea-pigs by microfocal radiography.

Guinea-pigs were sensitized by intra-articular injection of M. tuberculosis (2.0 mg) into one knee joint and arthritis induced in the opposite knee 21 days later by intra-articular injection of antigen (0.2 mg). The time course off the arthritic changes was followed for 25 days by assessment of knee swelling and hind-limb flexion. Twenty-eight days after challenge the experiment was terminated and radiographic changes evaluated by means of a microfocal X-ray unit. The effect of treatment with the anti-rheumatic drugs, D-penicillamine (100 mg/kg by mouth), dexamethasone (0.1 mg/kg i.p.), aspirin (100 mg/kg by mouth), chloroquine phosphate (30 mg/kg by mouth) and sodium aurothiomalate (2 mg/kg i.m.) given daily from 10 days after sensitization until 28 days after challenge was assessed. Changes in joint swelling and hind-limb flexion were maximal 1-3 days after challenge. None of the drug treatments influenced these parameters. Microfocal radiography showed marked changes in arthritis animals of all X-ray parameters measured. It was possible readily to identify joint erosion, trabecular loss and associated osteoporosis, the latter occurring proximal to and relatively remote from the affected joint. None of the treatments prevented the radiographic changes but exacerbation of trabecular number in the area of the epiphysis was seen with aspirin and D-penicillamine and of trabecular density further up the shaft of the femur was seen with D-penicillamine. The changes with D-penicillamine may reflect the potentiation of cell-mediated hypersensitivity with this drug reported by other workers. It was concluded that the model is not suitable for the detection of clinically active anti-rheumatic drugs but that microfocal radiography provides a sensitive index for the assessment of joint damage in small animals.

Animals↗
PubMed1980

Stereo-projection radiography in the study of the structural organisation of cat skull bones.

The relatively low resolution in the radiographs produced by clinical X-ray machines has led to the rejection, by a number of investigators, of this machine as a method of examining the detailed structural organisation of bone. In the recently developed microfocal X-ray unit a fine beam of electrons is focussed onto the side of a water cooled target. Stereo-projection radiographs of specimens can be produced at magnifications of x 1-100 and a theoretical resolution to the diamter of the X-ray source (5-10 micrometer). The application of stereo-projection radiography to the study of cat skulls revealed details of structure not readily visible with conventional X-ray techniques. Using three different methods, the shadow images of trabeculae and vascular canals seen in the radiographs were closely correlated with the structures observed in the coronal sections and dissected regions of the cat skulls. The smallest structures recorded from the radiographs had a diameter of 60 micrometer. The effect of the depth of bone and of overlapping trabeculae and large vascular canals on the number of osseous structures recorded in the radiographs of five cat skulls was assessed. The results showed that 50% of the trabeculae and large vascular canals were no longer visible at a bone depth of 4 and 1x5 mm respectively and when superimposed by twelve and two structures respectively.

Animals↗