Biomedical subjects
Publications and source records attributed to J Noble.
A patient is presented in whom painful instability persisted more than a year after the resection of 1 1/2 inches of the distal ulna, for a painfully subluxed distal radio-ulnar joint. The palmaris longus tendon was detached distally, passed through a drill hole in the distal radius and then wrapped and stitched, as a sling, around the distal ulna stump. Two years later the patient's symptoms were relieved.
Eighteen patients with ocular manifestations of Graves' disease were treated by plasma exchange. Detailed clinical, ophthalmological and orthoptic assessments were made including computerized axial tomography and A + B scan ultrasound of the orbits. Seventeen different ocular parameters were separately rated for each patient. The changes recorded were small, statistically insignificant, and no patient was cured of ocular disease. There were no significant correlations between the ocular changes recorded and age, sex, duration of ophthalmic symptoms, the presence of thyroid antibodies, the number of exchanges, or the concurrent administration of azathioprine.
The relationship between meniscal tearing and degenerative joint disease was studied by macroscopic examination of 115 knees at necropsy. The incidence of meniscal pathology was 57 per cent. There was no overall difference in the severity and distribution of tibiofemoral degeneration, whether the meniscus was torn or normal. We found little evidence that degenerative meniscal tears cause osteoarthritis or vice versa.
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UNLABELLED: We have determined rates of leakage of radioactivity from a rabbit synovial pouch in vivo for a number of particle systems of varying sizes and differing resistance to degradation. The estimates were made using a gamma scintillation camera and without killing the test animals. The lowest leakage at twenty-four hours was seen with inert carbonized microspheres and the highest rates were seen with surface-labeled particles of biodegradable denatured human serum albumin and with erythrocytes. The carbonized microspheres had no adverse long-term effects on the health of the animals' articular cartilage. CLINICAL RELEVANCE: Results obtained with inert particles indicate that reducing the biodegradability of the particle or increasing its diameter, or both, reduces radioactivity losses from the knee joint. Large (twenty-five-micrometer-diameter) microspheres of human serum albumin incorporating the radioactivity and carbonized microspheres are suggested as potential carriers of isotopes for human radiation synovectomy.
To clarify the pathogenesis of chest pain in patients with cardiomyopathies, we compared coronary blood flow and other indicators of ischemia at rest and during pacing-induced tachycardia in nine patients with cardiomyopathy (four hypertrophic and five congestive) and in five control subjects. Coronary blood flow was reduced at rest and during pacing in cardiomyopathy patients compared with controls. In patients with hypertrophic cardiomyopathy, pacing induced chest pain in all, increased ST-segment depression in three patients and increased coronary venous lactate concentration. With pacing, two of five patients with congestive cardiomyopathy had chest discomfort and three had increased ST-segment depression, but coronary venous lactate concentration did not change significantly. In both groups of cardiomyopathies, the ratio of the systolic and diastolic pressure-time indexes tended to decrease more than in controls during pacing. Thus, myocardial perfusion is decreased in patients with cardiomyopathy, both at rest and during pacing. The changes detected during pacing point to subendocardial ischemia as the likely mechanism for angina in hypertrophic and possibly also in congestive cardiomyopathy.
The in vitro breaking forces of the distal femoral growth plates of young rabbits were measured as a background to the design of a bone lengthening method, using epiphyseal distraction. The mean breaking force in 16 femora was 12.98 +/- 3.48 kg and the mean strain was 0.91 +/- 0.33 mm. The mean stress in 10 femora was 14.51 +/- 3.88 kg/cm2. The procedure was repeated, after applying a 1.0 kg dead weight to 6 femora for 24 hours and the breaking force was then 15.01 +/- 4.70 kg, with a mean strain of 0.85 +/- 0.62 mm. A further 8 rabbits then underwent epiphyseal distraction for 2 days in vivo, with 1 or 2 kg forces delivered to two parallel K wires by a pair of spring devices, whereupon the femora were removed and tested as before. The breaking force on the distracted side was now only 8.91 +/- 3.71 kg, compared with 13.99 +/- 3.40 kg on the control side. Although not fractured, these plates had obviously been weakened. The clinical implication of this is discussed.
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Synovial osteochondromatosis is a rare disease which usually runs a benign course. The knee, hip, elbow and the small joints of the hands and the wrists are the joints most affected, (Chadwick, 1977; Milgram, 1977; Murphy, 1962) and the common complaints are of swelling and stiffness, sometimes associated with locking and pain. We present a case with symptoms and signs of ulnar nerve palsy, due to synovial osteochondromatosis of the elbow.
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Thirty-one tension headache sufferers were assigned to frontalis electromyographic (EMG) biofeedback training, to a highly credible pseudotherapy providing no opportunity to learn control of EMG activity, or to a symptom-monitoring control group. Participants receiving biofeedback showed significant reductions in frontalis EMG within and across treatment sessions and exhibited reduced EMG activity following treatment. Participants receiving pseudotherapy showed no changes in EMG activity. Although biofeedback and pseudotherapy were rated as equally credible treatments, only the headache activity of the biofeedback group was significantly improved following treatment. These results suggest that outcomes obtained with biofeedback do not result merely from exposure to a credible treatment procedure. Evidence suggesting that headache improvements may be mediated by cognitive and behavioral changes and not the learned control of physiological activity is discussed.
Persistent effects of a short course of intra-articular dextran sulphate, dextrans, or chondroitin sulphate were examined in rabbit knees. Only dextran sulphate produced gross arthritis, associated with high synovial acid phosphatase and beta-glucuronidase activities. Synovial degradative capacity in synovium-cartilage cocultures was increased 2-fold by dextran sulphate and 1.5-fold by chondroitin sulphate treatments. Stimulation of cartilage breakdown in vitro paralleled the content of synovial marker enzyme at death of the animal, but the 2 responses could be dissociated.
Of 250 patients scheduled for meniscectomy 50 had symptoms which subsided and operation could be deferred; of the remaining 200 only 73 per cent were found to have a significant tear. It is shown that the risks of removing a normal meniscus far exceed those of leaving a tear in the posterior third. Statistical analysis of clinical features revealed no reliable diagnostic pattern.
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1. The destruction of articular cartilage in human rheumatoid and other arthritides is the result of diverse mechanical, inflammatory and local cellular factors. A tissue-culture model for studying cartilage-synovial interactions that may be involved in the final common pathway of joint destruction is described. 2. Matrix breakdown was studied in vitro by using bovine nasal-cartilage discs cultivated in contact with synovium. Synovia were obtained from human and animal sources. Human tissue came from patients with ;classical' rheumatoid arthritis, and animal tissue from rabbits with antigen-induced arthritis. 3. Cartilage discs increased their proteoglycan content 2-3-fold during 8 days in culture. Proteoglycan was also released into culture medium, approx. 70% arising from cartilage breakdown. 4. Synovial explants from human rheumatoid and rabbit antigen-induced arthritis produced equivalent stimulation of proteoglycan release. After an initial lag phase, the breakdown rate rose abruptly to a maximum, resulting in a 2-fold increase of proteoglycan accumulation in culture medium after 8-10 days. 5. High-molecular-weight products shed into culture media were characterized chromatographically and by differential enzymic digestion. Proteoglycan-chondroitin sulphate accounted for 90% of the released polyanion, and its partial degradation in the presence of synovial explants was consistent with limited proteolytic cleavage. 6. Rheumatoid synovium applied to dead cartilage increased the basal rate of proteoglycan release. Living cartilage was capable of more extensive autolysis, even in the absence of synovium. However, optimal proteoglycan release required the interaction of living synovium with live cartilage. These findings support the view that a significant component of cartilage breakdown may be chondrocyte-mediated.
Plasma levels of digoxin were measured in a patient after massive intoxication. Pharmacokinetic analysis of the data as compared with other cases of digoxin intoxication reveals that in these situations oral administration of cholestyramine may be of benefit to the patient.