Amino acid composition of proteins eluted from polyacrylamide gels: background considerations.
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Biomedical subjects
Publications and source records attributed to G C Howard.
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A total of 41 superficial tumours have been treated with radiation alone (21 lesions) or in combination with hyperthermia (20 lesions) in a non-randomized study on 16 patients. A minimum tumour heat dose in excess of 30 min equivalent at 43 degrees C was achieved in 46 of the 80 (57 per cent) hyperthermia treatments. Small lesions received better quality heat treatments and were more likely to achieve a complete response. There is a significant increase in the response of lesions treated with the combined modality compared with radiation alone (P less than 0.01). Similar results were obtained when matched lesions with internal controls were analysed separately. There was an increased incidence of severe skin reactions in the hyperthermia-treated group with the reaction tending to develop more quickly. There were three instances of late fibrosis in the hyperthermia group. There is a significant correlation between the severity of the skin reaction and the average maximum skin heat dose per treatment.
A prospective study was conducted to study the effect of radiotherapy (RT) and regional pelvic hyperthermia (HT) on intestinal permeability in three groups of patients. Fifteen acted as cancer controls, receiving RT away from the peritoneal cavity, 21 patients received radical pelvic or abdominopelvic RT and 13 patients pelvic RT followed by pelvic HT using a BSD 1000 phased array applicator. Small bowel permeability was measured by oral administration of a mixture of [51Cr]EDTA, [14C]mannitol and lactulose before and after a course of treatment. The absorption of each marker was calculated by measuring the urinary excretion over 0-6 and 0-12 hours. The 6 hour collection gave results similar to the 12 hour collection, but had logistical advantages. The EDTA absorption rose and the mannitol absorption fell during a course of treatment, but the best index of permeability change was the EDTA/mannitol ratio (E/M). The E/M ratio rose by a factor of 2.4 (P less than 0.001) and 1.82 (P = 0.05) following RT and RT/HT respectively. There was no significant difference between the RT and RT/HT groups but the thermal dose to the RT/HT group was low (23 min./equiv 43 degrees C over three or four fractions in 4 weeks). There was no correlation between small bowel permeability and bowel frequency. The E/M permeability test is a useful simple functional assay for assessing small bowel damage after RT and RT/HT.