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Biomedical subjects

C M Driscoll

Publications and source records attributed to C M Driscoll.

8 recordsLinked to original sources
PubMed2001

Role of stress responses in human cell survival following exposure to ultraviolet C radiation.

PURPOSE: To investigate in human skin and other cells the role of tyrosine kinase and protein kinase-C (PKC) in eliciting cell-signalling responses to UV radiation (UVR) that affect the survival of irradiated cells. MATERIALS AND METHODS: The survival of HeLa S3 cells, NCTC 2544 human keratinocytes and A431 human epidermal carcinoma cells was measured following incubation with various tyrosine kinase or PKC inhibitors and exposure to UVC (254nm) radiation. In addition, Western blotting measured PKC isozyme expression in human keratinocytes following UVC exposure. RESULTS: It was confirmed that inhibition of tyrosine kinase activation reduces the survival of UV-irradiated HeLa S3 cells. However, no effect was seen on the survival of either NCTC 2544 human keratinocytes or A431 human epidermal carcinoma cells. In contrast, specific inhibition of PKC reduced the survival of UV-irradiated keratinocytes but had no effect on HeLa cells. Comparison of the effects of different inhibitors in keratinocytes suggested that this effect was mediated mostly through PKCmu and PKClambda/iota. In addition, keratinocyte exposure to UVC induced large and temporally distinct increases in PKCmu and PKClambda/iota. CONCLUSIONS: The survival of NCTC 2544 keratinocytes, but not HeLa S3 cells, following UVC exposure is mediated by signalling through PKC, mostly PKCmu and PKClambda/iota. Further study is required to confirm these results in normal human keratinocytes.

Carcinoma, Squamous Cell↗
PubMed1997

An improved process for the production of sterile modified haemoglobin solutions.

The process for manufacturing bulk quantities of sterile solutions of human haemoglobin (Hb) cross-linked between the alpha chains (alphaalphaHb) with bis(3,5-dibomosalicyl) fumarate (DBBF) was modified to: (1) improve product purity; (2) increase product yield; (3) eliminate non-United States Pharmacopoeia materials; (4) reduce reagent costs; and (5) reduce production time. These process modifications were the result of increased scientific understanding of the Hb cross-linking chemistry and were in the form of engineering and procedure controls that reflect current good manufacturing practices (cGMP). Purity, as reflected in the fractional yield of the desired alphaalphaHb product, has increased from 60% to 90+% of total Hb, and uncross-linked Hb was virtually eliminated. Impurities such as pyrogens, methaemoglobin, phospholipid, and free iron were reduced. The net yield of alphaalphaHb was increased from 33% to 58% of starting Hb content. Production time, the use of overtime, the consumption of expensive reagents and filters, and losses because of contamination have all been reduced. As a result, cost per gram of alphaalphaHb produced has decreased 60%. With this improved process, efficient production of very pure alphaalphaHb is possible.

Chemistry, Pharmaceutical↗
PubMed1988

A method for determining simultaneously the dose and the elapsed time since irradiation using TLDs.

Information about the time that has elapsed since an external radiation exposure is useful in order to determine the time of occurrence of an abnormal exposure in personal and accidental dosimetry is presented. This information can be obtained from certain irradiated thermoluminescent dosimeters. A computational method based on decay rates of thermoluminescence glow peaks has been used to estimate a range of suitable values of trap lifetimes of low temperature glow peaks. This provides a basis for the selection of an appropriate thermoluminescent material to assess not only the absorbed dose from a radiation exposure, but also the elapsed time. Experimental studies have been used to obtain additional information on decay rates as a function of energy, temperature and absorbed dose.

Accidents↗
PubMed1985

Surveys of natural radiation exposure in UK dwellings with passive and active measurement techniques.

A representative sample of over 2,000 UK dwellings was monitored for a year using thermoluminescent and etchable plastic dosemeters to measure gamma-ray dose rates and radon concentrations. The survey was carried out by post. Each householder completed a questionnaire on the type of dwelling and its characteristics. These data will be used in the assessment of the factors affecting indoor exposure. The mean gamma-ray dose rates were 0.062 and 0.057 microGy h-1 in air and the mean radon concentrations were 25 and 18 Bq m-3 for living areas and bedrooms respectively. Other results of the preliminary data analysis are given. More detailed surveys were conducted in areas where the local geology indicated that elevated exposures to natural radiation might occur. Over 800 dwellings were visited and measurements made of several parameters. The mean gamma-ray dose rates varied from 0.05 to 0.10 microGy h-1 in air. The mean radon concentrations varied from 14 Bq m-3 to 520 Bq m-3. Other findings related to equilibrium factors and regional differences are discussed.

Environmental Exposure↗
PubMed1982

The suitability of different preparations of thermoluminescent lithium borate for medical dosimetry.

The thermoluminescence properties of three different preparations of lithium borate have been studied with specific reference to their use in medical dosimetry. The properties of lithium borate powder doped with copper make it more attractive for low dose measurements than the more conventional phosphor doped with manganese. However, the energy response of the copper-doped material was not quite so suitable as that of the manganese-doped material for measuring doses to tissue at photon energies below 100 keV. It also exhibited appreciable light induced fading.

Borates↗