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Biomedical subjects

C R Carter

Publications and source records attributed to C R Carter.

25 records · Page 2Linked to original sources
PubMed1995

Indium-111 leucocyte scintigraphy and ultrasound scanning in the detection of intra-abdominal abscesses in patients without localizing signs.

The clinical records of 45 patients with suspected intra-abdominal sepsis but without localizing abdominal signs were retrospectively reviewed. All had undergone both indium-111 leucocyte scintigraphy and real time ultrasound. Twenty-two of the 45 patients were subsequently shown to have intra-abdominal abscesses. Twenty-one patients were identified correctly by indium-111 scintigraphy (sensitivity 95%) and 10 by ultrasound (US: sensitivity 45%). There were two false positive scintiscans (specificity 91%) but no false positive US scans (specificity 100%). There was no correlation between the peripheral white cell count and the presence of absence of an abscess or the likelihood of obtaining a positive scintiscan result. Because of the excellent specificity ultrasound scanning should remain the initial investigations in this group of critically ill patients with indium-111 scintigraphy being used to clarify the US findings or in US negative patients.

Abdominal Abscess↗
PubMed1994

Endoscopic laser treatment of diffuse gastric antral vascular ectasia.

Eight patients (six women and two men) were found to have iron deficiency anaemia due to diffuse gastric antral vascular ectasia. The mean age of the patients was 74.6 years (range 57-83). All required repeated blood transfusions (mean 18 units/year) before treatment. Five patients were classified as having the 'watermelon stomach' (group A) and three the 'honeycomb stomach' (group B), according to criteria described in previous reports. All were treated using neodymium:YAG laser photocoagulation. Significant endoscopic improvement and reduction in blood requirements were noticed in group A in which only one patient required a transfusion after treatment. Results in group B were disappointing. One patient was operated on and the other two still require blood transfusions. Laser treatment was safe in both groups and no major complications were encountered.

Aged↗
PubMed1994

Classification of impulse radar waveforms using neural networks.

In this paper, it is demonstrated that multilayer neural networks, trained with the backpropagation algorithm and radial basis functions, can classify impulse radar waveforms from three different asphalt-covered bridge decks, each with its own structure. It might be thought that the thickness of asphalt and the depth of concrete over the reinforcing bars would be nearly constant for any one bridge deck; however in practice this is not the case. There are often significant changes in the thickness of the asphalt and the cover over reinforcement. Furthermore, a certain amount of damage to the concrete caused by severe winter climate often produces a random variation in the reflected waveforms obtained from different locations. These factors lead to a significant number of combinations of waveforms that can be obtained from any given structural type of deck. The classification accuracies achieved ranged between 89.9% and 100%. The accuracies achieved after using principal components analysis to reduce the dimensionality of the input data ranged between 95.6% and 100%.

Algorithms↗
PubMed1992

The augmentation of lymphokine-activated killer activity following pulsing of human peripheral blood mononuclear cells with recombinant human interleukin-2.

The short-term exposure of peripheral blood mononuclear cells (PBMC) to recombinant human interleukin-2 (rhIL-2) at 37 degrees C leads to the generation of lymphokine-activated killer (LAK) activity similar in magnitude to that obtained by the exposure of PBMC to rhIL-2 continuously for 3-5 days. In order to investigate whether the required signal for LAK induction occurred during the short exposure to rhIL-2 or at a later point in the induction phase, PBMC were exposed to rhIL-2 for 1 h at 4 degrees C and then exposed to a low-pH wash to remove bound IL-2 from its receptor. PBMC treated in such a way showed increased LAK activity and proliferation compared to cells exposed to rhIL-2 alone. Expression of the p55 (alpha) subunit of the IL-2 receptor was also increased. In order to cause the augmentation, a lowering of the pH below 4.0 was necessary, and exposure of PBMC to low pH alone (in the absence of rhIL-2) failed to cause activation. Another relevant feature was a transient increase in the expression of the p75 subunit of the IL-2 receptor (beta chain) immediately following the exposure to low pH and the release of interferon gamma, tumour necrosis factor alpha and IL-6; activation was blocked by the inclusion of neutralising antisera raised against rhIL-2 and interferon gamma, thus demonstrating that the endogenous release of these cytokines is important for activation.

Cytokines↗