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Biomedical subjects

J D Macfarlane

Publications and source records attributed to J D Macfarlane.

48 records · Page 3Linked to original sources

Effect of Methionine Sulfoximine on the Accumulation of Ammonia in C(3) and C(4) Leaves : The Relationship between NH(3) Accumulation and Photorespiratory Activity.

Additions of methionine sulfoximine (MSX), an inhibitor of glutamine synthetase (GS), result in an increase in NH(3) in seedling leaves of C(3) (wheat [Triticum aestivum cv. Kolibri] and barley [Hordeum vulgare var Perth]) and C(4) (corn [Zea mays W6A x W182E] and sorghum [Sorghum Vulgare var MK300]) plants. NH(3) accumulation is higher in C(3) (about 17.8 micromoles per gram fresh weight per hour) than in C(4) (about 4.7 micromoles) leaves. Under ideal conditions, when photosynthesis is not yet inhibited by the accumulation of NH(3), the rate of NH(3) accumulation is about 16% of the apparent rate of photosynthesis. A maximum accumulation of NH(3) was elicited by 2.5 millimolar MSX and was essentially independent of the addition of NO(3) (-) during either the growth or experimental period. When O(2) levels in the air were reduced to 2%, MSX resulted in some accumulation of NH(3) (6.0 micromoles per gram fresh weight per hour). At these levels of NH(3), there was no significant inhibition of rates of CO(2) fixation. There was also a minor, but significant, accumulation of NH(3) in corn roots treated with MSX. Inhibitors of photorespiration (isonicotinic hydrazide, 70 millimolar; 2-pyridylhydroxymethanesulfonic acid, 20 millimolar) or transaminase reactions (aminooxyacetate, 1 millimolar) inhibited the accumulation of NH(3) in both C(3) and C(4) leaves. These results support the hypothesis that GS is important in the assimilation of NH(3) in leaves and that the glycine-serine conversion is a major source of that NH(3).

Journal Article↗

Popliteal cyst mimicking thrombophlebitis as the first indication of knee disease.

Five patients, none of whom were previously known to have knee disease, developed leg swelling which was misdiagnosed as thrombophlebitis. Four were treated with anticoagulants and one developed a large calf hematoma requiring fasciotomy. The primary physicians failed to appreciate evidence of knee disease in these patients, although the rheumatology consultant found knee effusion, and a popliteal cyst was found by arthrography or ultrasonography in every case. The occurrence of popliteal cyst as the first sign of knee disease emphasizes the importance of careful examination of the knee in all patients with a clinical picture of thrombophlebitis.

Adult↗

Pulmonary and pleural lesions in rheumatoid disease.

Lung and pleural involvement in rheumatoid disease is reviewed and discussed. Attention is drawn to the male preponderance, to the frequency with which lung infections occur in rheumatoid patients and to some problems posed in them by infection with mycobacteria. Pleural effusion, pulmonary nodules and fibrosing alveolitis are familiar in association with rheumatoid arthritis. Less familiar associations include upper lobe fibrosis, 'shrinking lung' and mixed pleural and pulmonary involvement. It is suggested that rheumatoid patients display a wider range of intrathoracic disease than seems generally appreciated.

Adrenal Cortex Hormones↗

Gastrointestinal blood loss on phenylbutazone and feprazone.

Feprazone, a new anti-inflammatory drug, is a useful antirheumatic preparation which causes little gastrointestinal upset. This short cross-over study shows no significant gastrointestinal blood loss with either feprazone or phenylbutazone by the red-cell chromium-51 labelling method.

Arthritis↗

Alizarin red S staining of synovial fluid in inflammatory joint disorders.

In 153 patients with mainly inflammatory joint disorders alizarin red S staining was used to detect calcium-containing crystals in synovial fluid (SF). The reproducibility of the results of this staining technique in 207 SF samples proved to be fairly good (65% concordant results after two observations). Electron-microscope studies confirmed the presence of apatite or calcium pyrophosphate dihydrate (CPPD) crystals in 92% of the alizarin red S positive samples, and in 27% of the weakly positive samples. Based on these figures it can be estimated that approximately 16% of SF samples obtained from patients with inflammatory joint disorders contain apatite and/or CPPD crystals. In contrast with other studies, mainly involving patients with degenerative joint disorders, no correlation was found between alizarin red S staining results and either radiological joint destruction (n = 130) or age.

Anthraquinones↗