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Biomedical subjects

B L Diffey

Publications and source records attributed to B L Diffey.

At least 181 records · Page 10Linked to original sources
PubMed1982

A co-operative study on the clinical value of dynamic renal scanning with deconvolution analysis.

An international project was set up to study the clinical usefulness of intrarenal transit times derived from the renogram by deconvolution. A common data sheet, to collect clinical, biochemical, radiological and isotopic information, was completed by the centres. Five hundred and ninety-one patients were studied and the results analysed. The mean transit time (MTT) in normal kidneys was found to be 3.6 +/- 1.1 min. If the MTT is greater than 7.6 min, a kidney is likely to be obstructed. In vesico-ureteric reflux, the transit times are prolonged, but they are normal in infection, hypertension, parenchymal disease and minimally irradiated kidneys. In transplantation, when the kidney is normal, the transit times are shorter than in the natural kidney; in acute rejection, transit time are prolonged.

Adult↗
PubMed1981

A mathematical model of the biologically effective dose of solar UVA received by patients undergoing oral psoralen photochemotherapy for psoriasis.

A theoretical analysis is presented of the biologically effective dose of the solar long wave ultraviolet radiation (UVA) received by patients who are being treated for psoriasis by oral psoralen photochemotherapy. It is shown that patients treated during the summer months in the UK may well receive a UV dose which is comparable with, or even in excess of, the dose of artificial UVA received in the treatment centre and consequently should be advised about limiting their exposure to sunlight on the treatment days. In the winter months in the UK the UVA intensity in sunlight is such that no unduly restrictive precaution need apply. However, at locations between about 40 degrees N and 40 degrees S, the solar UVA intensity in midwinter is still sufficiently high that unnecessary sunlight exposure on treatment days should be avoided.

Humans↗
PubMed1981

Personal solar UV-A doses received by patients undergoing oral psoralen photochemotherapy for psoriasis.

Patients undergoing oral psoralen photochemotherapy (PUVA) for psoriasis receive a known amount of UV-A in the treatment cubicle and an unknown amount of UV-A from sunlight. In order to measure the solar UV-A dose, fifty-six patients received a UV-sensitive film badge to be worn from the time they took their psoralen tablet throughout the course of the day, except during treatment. The UV-A doses measured in this way varied from less than 0.2 J cm-2 to 7 J cm-2, with a median of around 1 J cm-2. These results show that the solar UV-A received by patients who have been photosensitized by 8-MOP may not be insignificant in relation to the treatment dose.

Film Dosimetry↗
PubMed1981

Eye protection in psoralen photochemotherapy.

The optical performance of some commercially-available tined lenses is discussed. There is a wide variation in the UV absorbing power of sunglasses although adequate protection against solar UV-A can be achieved with some, but not all, polarizing material. The darkness of a tint is not an indication of its likely performance within the ultraviolet bands and it is possible that lenses could be produced that lacked any significant tint yet absorbed strongly throughout the UV region.

Eye↗
PubMed1980

Chemotherapy in pancreatic cancer: results of a controlled, prospective, randomised, multicentre trial.

Forty patients with inoperable pancreatic cancer were included in a prospective, randomised, controlled trial of multiple chemotherapy. The survival of 19 untreated control patients was compared with that of 21 patients who received an initiation course of intravenous fluorouracil, cyclophosphamide, methotrexate, and vincristine given over five days followed by intravenous fluorouracil and mitomycin given over three or five days at six-week intervals thereafter. Median survival in treated patients was 44 weeks, which was significantly longer than the nine weeks seen in controls. In patients without metastases median survival was 48 weeks in the treated group and 12 weeks in controls. In patients with metastases it was 30 weeks in treated patients and seven weeks in controls. The treatment was well tolerated and seemed to confer a significant prolongation of survival, comparing favourably with previous reports of chemotherapy with or without radiotherapy. If the results are confirmed this regimen may be useful in district general hospital practice.

Adult↗
PubMed1980

A comment on the routine testing of sunglasses in photochemotherapy.

An estimate of the UV transmission of sunglasses is often made in Dermatology Departments by employing the irradiation source used for PUVA therapy and a UV-A meter. The object of making these measurements is to assess the UV opacity of the glasses in natural sunlight. The present communication examines the adequacy of this simple experimental technique and concludes that, in general, the results obtained are unlikely to lead to a misleading impression.

Eyeglasses↗
PubMed1980

A survey of the ultraviolet radiation emissions of photochemotherapy units.

Measurements have been made of the spectral emission and irradiance from whole body ultraviolet irradiation units used in the treatment of psoriasis by photochemotherapy (PUVA). A total of ten units were studied, located at nine different treatment centres in England. The results showed that within the limits of experimental accuracy there was no significant difference in the profile of all spectra measured, although the measured value of irradiance compared with each centre's own UV-A meter showed wide discrepancies. There is poor documentation provided by manufacturers of UV-A meters on the meaning of the scale reading in mWcm-2, and it would seem expedient that some agreed calibration procedure for these instruments is forthcoming.

England↗
PubMed1979

Measurement of colloid clearance rate as an adjunct to static liver imaging.

A technique for the measurement of the rate of uptake of 99mTc labelled sulphur colloid in the liver using a gamma camera and computer is described. The mathematical model showing the factors affecting the rate of uptake, and the results of the measurements in a series of normals and patients with a variety of liver diseases are presented. The range in cirrhosis was found to be significantly lower than normal and the range in acute liver injury significantly higher. The technique can easily be incorporated into a standard colloid liver imaging procedure and is considered to be a valuable adjunct to diagnosis using the static images.

Colloids↗
PubMed1979

Solar dosimetry of the face: the relationship of natural ultraviolet radiation exposure to basal cell carcinoma localisation.

Measurements have been made of the distribution of natural ultraviolet radiation (UVR) at 41 sites on the face of a large fibreglass model of a head. The dosemeter used was the polymer film polysulphone. The results have been correlated with published values of the distribution of basal cell carcinomas on the face. Although the comparison has highlighted the problems of trying to relate frequency of skin tumour occurrence to sunlight exposure, the present results are compatible with the hypotheses that human skin cancer incidence increases with environmental UVR exposure, and that sunlight is not the only factor in the aetiology of basal cell carcinomas of the face.

Basal Cell Carcinoma↗
PubMed1979

Chemotherapy in advanced gastric cancer: a controlled, prospective, randomised multi-centre study.

Seventy-six patients with advanced gastric adenocarcinoma were studied in a prospecitive, randmoised, controlled trial using vincristine, methotrexate, cyclophosphamide, and 5-fluorouracil in an initiation course and mitomycin-C with 5-fluorouracil as maintenance therapy. Thirty-seven patients were inoperable and 39 had the primary tumour resected with histological evidence of residual disease. Survival in the inoperable group was short and showed no significant difference between treated and control patients. The median survival times for treated and control groups were 9.5 and 9.0 weeks respectively. In the resected patients there was no difference in ultimate overall survival between the groups but up to 20 weeks there was a suggestion that the probability of survival in treated patients was higher (P = 0.06). The patients were well-matched and it is concluded that chemotherapy has had an early effect but that a further trial with more detailed stratification, particularly of staging and histological grade, is needed. No patient received treatment for longer than two years and unacceptable toxicity occurred in only two patients. Nausea occurred more frequently in the treated group but was short-lived and clinically manageable.

Adenocarcinoma↗