Biomedical subjects
B A Roberts
Publications and source records attributed to B A Roberts.
Wellness approached from a different perspective: staff wellness promotes patient wellness.
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Reflection mode diffraction tomography.
A reconstruction algorithm is presented which possesses a simple scanning geometry and promises higher resolution than conventional transmission mode diffraction tomography algorithms. This broad-band reflection mode algorithm inherently lacks a certain amount of low frequency information but an estimate of the information is recovered by spectral extrapolation. The resolution of the algorithm will be shown to be limited by the bandwidth and physical size of the single plane wave transducer, as well as the Born approximation.
The failure of trichothecene mycotoxins and whole cultures of Fusarium tricinctum to cause experimental haemorrhagic syndromes in calves and pigs.
Piglets and calves were dosed orally with pure diacetoxyscirpenol (DAS) and T-2 toxin, crude extracts of Fusarium tricinctum containing T-2 toxin, and whole cultures of F tricinctum containing T-2 toxin at a constant daily rate of 0.1 mg toxin per kg body-weight (piglets) or 0.2 mg toxin per kg body-weight (calves). The treatment continued for periods of seven to 78 days but it failed to induce clinical haemorrhagic syndromes. Increasing the dose of F tricinctum culture five-fold for eight days following 78 days at the lower dose was equally ineffective. The lack of an effect by daily intakes of toxin that could have been ingested with naturally contaminated feedstuffs suggests that DAS, T-2 toxin and other metabolites of F tricinctum probably have little or no part to play in the aetiology of feed associated haemorrhagic disease.
The occurrence of soil-borne tremorgenic fungi in England and Wales.
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The 'carry-over' of aflatoxin, ochratoxin and zearalenone from naturally contaminated feed to tissues, urine and milk of dairy cows.
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Preoperative basal chemotherapy in the management of cancer of the stomach: a preliminary report.
Nine patients with advanced gastric carcinoma have been treated with a programme of chemotherapy as the first stage of management with the objective of reducing tumour extent and viability in preparation for subsequent surgery where feasible. In eight patients the chemotherapy was given by intraarterial infusion into the coeliac axis, and the remaining patient was given intravenous chemotherapy. Most patients gained symptomatic improvement, including pain relief, and in seven patients tumour regression was achieved. In six patients tumour regression was followed by gastrectomy. Residual tumour was found in five of these six patients, and was not found in one.
Tremorgenic toxins produced by soil fungi.
Penitrem A or an unknown tremorgenic toxin, "X," was produced by 10 of 60 fungal isolates obtained from a pasture involved in an outbreak in cattle and sheep resembling migram and ryegrass staggers. Tremorgenic properties of extracts containing penitrem A or toxin X were confirmed by bioassay.
Mycotoxins in animal feedstuffs: sensitive thin layer chromatographic detection of aflatoxin, ochratoxin A, sterigmatocystin, zearalenone, and T-2 toxin.
Improvements have been made to a previously described multi-mycotoxin method that involved a membrane cleanup step. Using 2-dimensional thin layer chromatography and appropriate solvent systems, aflatoxin B1 can be detected in mixed feedstuffs and various ingredients at levels ranging from 0.1 to 0.3 microgram/kg. Corresponding detection limits for ochratoxin A and sterigmatocystin are 5 to 20 microgram/kg and for T-2 toxin and zearalenone 20 to 200 microgram/kg.
Isolation of potentially tremorgenic fungi from pasture associated with a condition resembling ryegrass staggers.
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The estimation of aflatoxin M1 in milk using a two-dimensional thin-layer chromatographic method suitable for survey work.
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T-2 toxin and haemorrhagic syndromes of cattle.
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Aflatoxin, ochratoxin, and zearalenone in animal feedstuffs: some clinical and experimental observations.
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Metabolism of ochratoxins A and B in the pig during early pregnancy and the accumulation in body tissues of ochratoxin A only.
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Diazoxide-induced renin release in diagnosis of remediable renovascular hypertension.
In hypertensive patients with unilateral renal artery stenosis, intravenous diazoide increased renal vein renin activity more on the involved side than on the contralateral side, whereas, in a group with predominantly unilateral renal parenchymal disease, the increase in renal vein was similar for both kidneys. In patients with bilateral renal artery stenosis, the use of diazoxide was helpful in lateralizing the dominant ischaemic lesion. Diazoide administration appears to be a safe, rapid and convenient method of increasing the sensitivity of the renal vein renin test used in predicting the outcome of surgical treatment of renovascular hypertension. Bilateral renal vein renin determination of established value in the diagnosis of functional renal ischaemia. 1-4 However, in the use of this procedure to predict the efficacy of corrective surgery, false positive and false negative results still occur. Thus, various manoeuvres which stimulate renin release have been employed to improve the sensitivity of the test. 5-7 We report a new application the practical approach to of this procedure in the diagnosis of renal hypertension, which both basal and stimulated levels of renal venous renin activitity can be measured during a brief period of bilateral renal vein catherization.
Automation in cervical cancer screening. Part 1: fixed cell scanning systems.
Cytology automation is highly desirable if a mass cancer screening system is to be effective, and has been the subject of widespread research and development effort. Several experimental systems have been developed based on fixed cell scanning or flow techniques, but clinical trials have produced disappointing results. The major problem with these early systems has been that of false positive "abnormal cell" signals caused by cell overlaps and artifacts. Most current research is devoted to the development of better techniques for cell presentation, to the improvement of pattern recognition techniques, and to the exploitation of novel cell parameters in flow systems.
Automation in cervical cancer screening--part 2: flow systems and other techniques.
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Investigation of suspected cases of mycotoxicosis in farm animals in Britain.
Mycotoxins were detected in 13 out of 131 feed samples examined over two years. Screening of feeds associated with cases of suspected mycotoxicosis occurring in farm animals over a further 12 month period showed that most incidents occurred during the winter and involved mainly cattle and pigs fed concentrates. A haemorrhagic syndrome in cattle and abortions in sows were most frequently connected with mouldy food. One or more known toxins (the aflatoxins, ochratoxin A, sterigmatocystin and zearalenone) were detected in three out of 65 cases and a wide variety of fungi were isolated. Toxicity to experimental animals was demonstrated in four out of 22 samples.