Biomedical subjects

T M Maguire

Publications and source records attributed to T M Maguire.

7 recordsLinked to original sources

PubMed1997

Plasma sialyltransferase levels in psychiatric disorders as a possible indicator of HPA axis function.

A dysfunction in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis, possibly attributed to a change in glucocorticoid receptor (GR) functionality, has been implicated in depression. We have measured both lymphocyte GR receptor binding parameters and plasma sialyltransferase activity, as a biochemical marker of GR function, in two groups of patients suffering from depression or schizophrenia and in a group of age- and sex-matched controls. While there was a significant increase in plasma cortisol levels in the depressed group, there were no changes in the lymphocyte GR binding parameters (K(m) and Bmax). There was, however, a significant decrease in the plasma sialyltransferase: cortisol ratio in the depressed group suggesting an inability of the raised cortisol levels to induce enzyme expression and this ratio may provide a useful biochemical marker of cortisol receptor function. Although there was an increase in the plasma activity of the alpha 2,6 sialyltransferase isozyme in the schizophrenic group, no other changes were determined. Therefore, while the total plasma sialyltransferase:cortisol ratio reflects HPA axis function, alterations in specific isozyme activity may also be associated with other CNS disease states.

Binding Sites↗

PubMed1997

Assay of E-cadherin by ELISA in human breast cancers.

E-cadherin is a membrane-bound adhesion glycoprotein. Loss of E-cadherin has been correlated with invasion and metastasis in model systems. Using a new ELISA, we found higher levels of E-cadherin in fibroadenomas than in primary breast cancers. Levels in primary cancers showed no significant relationship with either tumour size, nodal status or oestrogen receptor levels. Patients with breast cancers containing low levels of the adhesion protein had a significantly shorter disease-free interval than patients with high levels (P = 0.041). The prognostic value of E-cadherin, for disease-free interval, was also found in node-negative patients as well as in patients presenting with small tumors (< or = 2 cm). In conclusion, loss of E-cadherin expression in human breast cancers is associated with increased metastatic potential as has previously been found in model systems. Loss of E-cadherin is thus likely to contribute to breast cancer progression.

Biomarkers, Tumor↗

PubMed1996

Evidence for a correlation between ambient cholesterol levels and soluble plasma sialyltransferase enzyme activity.

While soluble forms of the sialyltransferase (sialyl-T) enzyme have been detected in significant quantities in serum, the exact source(s) of the enzyme, or the factors controlling its secretion are poorly understood. In this study, we have examined the relationship between ambient plasma cholesterol concentrations and sialyl-T-activities and also levels of constituent plasma sialoglycoproteins (SGP). There was an inverse relationship between levels of the alpha 2, 6 sialyl-T enzyme and both total plasma cholesterol and HDL, although no such relationship was observed for the alpha 2,3 enzyme. While there was no correlation between total cholesterol and the levels of plasma SGPs, there was an inverse relationship between the HDL component and alpha 2,3 SGPs.

Cholesterol↗

PubMed1985

Massive gastrointestinal hemorrhage cecal ulcers and salmonella colitis.

A 65-year-old man presented with massive lower gastrointestinal tract hemorrhage. Minimal changes were noted on sigmoidoscopy, no bleeding lesions were identified on arteriography or red blood cell scan, and barium enema examination demonstrated only diverticular disease and minimal cecal deformity, interpreted as secondary to a recent appendectomy. Colonoscopy demonstrated multiple deep cecal ulcers. These were presumed to be due to an infectious etiology, since the stools were culture-positive for Salmonella typhimurium. The hemorrhage stopped within 24 hours of treatment with Ampicillin, Flagyl, and Gentamicin. The patient has remained well over a 12-month follow-up period. Repeat colonoscopy demonstrated healing of the cecal ulcers and there was also clearing of the Salmonella from the stools. This case report serves to remind us of the different methods used to diagnose lower gastrointestinal tract hemorrhage, and the importance of considering infectious causes of colitis.

Aged↗

PubMed1970

In prison.

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England↗

PubMedDate not supplied

A decrease in serum sialyltransferase levels in Alzheimer's disease.

A reliable antemortem serum marker for Alzheimer's disease (AD) would be of great importance for the early detection and subsequent therapeutic management of the disease. We have noted a significant decrease in serum levels of the soluble form of the sialyltransferase enzyme in a group of AD patients when compared with both age-matched elderly (over 60 years) and young (under 60 years) controls. In a population of Down's syndrome patients, who develop AD pathology with increasing age, there was an age-related decrease in serum sialyltransferase activity in patients from 20 to 60 years to approach enzyme levels similar to those observed in the AD group. This significant decrease in serum sialyltransferase levels observed may both prove a useful peripheral early biochemical marker of neurodegeneration and provide an indication of the underlying cellular events that occur during the process of nerve cell death in AD.

Adult↗

PubMedDate not supplied

A decrease in neural sialyltransferase activity in Alzheimer's disease.

The activities of both a particulate and soluble form of the sialyltransferase enzyme have been examined in post-mortem brain samples from Alzheimer's disease patients and age-matched controls. There was a considerable decrease in the activity of both the soluble and membrane-bound forms of the enzyme in the frontal and temporal cortical lobes, although no change was observed in the hippocampus. There was, however, no change in activity of the Golgi marker enzyme thiamine pyrophosphatase. Therefore, it is suggested that the decrease in sialyltransferase enzyme activity may be a specific biochemical event associated with the AD-like neurodegeneration.

Aged↗