J. A. McGuigan

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In measurements of the intracellular free calcium concentration ([Ca2+]) using either microelectrodes or fluorescent probes, calibration is normally carried out in EGTA calcium buffer solutions. In the first part of the article the general properties of calcium buffer solutions are discussed, the equations used to calculate the apparent calcium binding(More)
This study examined the association between 17p allelic loss and p53 gene mutation in a series of 16 esophageal adenocarcinomas arising on a background of Barrett's esophagus. Two highly polymorphic dinucleotide repeat polymorphisms mapping to 17p13 were analyzed to assess the frequency of 17p allelic loss in these tumors. Mutations in the p53 gene were(More)
1. The effect of [K]0 on the current-voltage relationship is described. In the negative potential range the curves cross over as [K]0 is increased. At positive potentials the curves re-cross so that in low [K]0 there is more outward current than in high [K]0. 2. Chord conductance has been calculated from the current-voltage relationship and this is taken as(More)
In sheep and calf ventricular bundles, increasing the internal calcium by increasing the frequency of voltage-clamping to plateau range potentials increased the time-independent outward current. This effect was more marked with higher [Ca]o, and was reduced if the Ca current blockers Verapamil or D 600 were used. 2. If the internal Ca was increased by the(More)
This study examined the association between 17p allelic loss, p53 gene mutation, p53 protein expression and DNA aneuploidy in a series of adenocarcinomas arising in the oesophagus and gastric cardia. 17p allelic loss was detected in 79% (15 of 19) of oesophageal and in 83% (29 of 35) of gastric adenocarcinomas. p53 mutations were detected in 70% (14 of 20)(More)
We have considered the manner in which data obtained with ion-selective electrodes should be evaluated. The potential difference recorded by such electrodes, with respect to a stable reference, is converted to a concentration by a non-linear transformation--the Nernst or Nikolsky equation. The mean and standard deviation of such estimations of concentration(More)
To identify chromosomal loci involved in the development of proximal gastric adenocarcinoma, this study delineated the pattern of allelic imbalance in a series of 38 adenocarcinomas arising in the gastric cardia. A total of 137 microsatellite markers covering all autosomal arms, excluding acrocentric arms, were analysed. A mean of 35 out of a total of 39(More)
Intracellular free magnesium ([Mg2+]i) was measured in isolated ferret papillary muscles using ion-selective microelectrodes filled with the new magnesium sensor ETH 5214. This new sensor, unlike its predecessor ETH 1117, does not react to marked changes in K+, Na+ or pH. Reducing Ca2+ from 20 microM to around 10 nM also did not affect the response so these(More)
Primary lymphoma presenting as a solitary lesion of the chest wall is extremely rare, as the majority of chest-wall tumours arise from metastasis. We demonstrate a case report of a 67-year-old male who underwent investigations for a chronic left-sided pleural effusion. A computed tomography scan demonstrated a large chest-wall lesion, without rib(More)
Human Technology is an interdisciplinary, scholarly journal that presents innovative, peer-reviewed articles exploring the issues and challenges surrounding human-technology interaction and the human role in all areas of our ICT-infused societies. Human Technology is published twice a year by the Agora Center, University of Jyväskylä and distributed without(More)