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T Carroll

Publications and source records attributed to T Carroll.

16 recordsLinked to original sources
PubMed1999

Meningiomas, dicentric chromosomes, gliomas, and telomerase activity.

Lack of telomere maintenance during cell replication leads to telomere erosion and loss of function. This can result in telomere associations which probably cause the dicentric chromosomes seen in some tumour cells. One mechanism of telomere maintenance in dividing cells is the action of telomerase, a ribonucleoprotein enzyme that adds TTAGGG repeats onto telomeres and compensates for their shortening during cell division. Over 90 per cent of extracranial malignant neoplasms have been found to have telomerase activity. This study sought to determine if there was a relationship between absence of telomerase activity and presence of dicentric chromosomes in meningiomas and to what extent the other main group of central nervous system tumours, the gliomas, expressed telomerase activity. Telomerase activity was measured on 25 meningiomas and 29 gliomas. Four of the meningiomas were atypical variants and 11 were positive for dicentric chromosomes. Twenty-five of 29 gliomas were glioblastoma multiforme tumours. Measures were taken to ensure absence of false positives due to primer-dimer interaction and false negatives due to protein degradation or the presence of Taq polymerase inhibitors. All 25 meningiomas and the four low-grade gliomas (WHO grade II) were telomerase activity-negative. Seven (28 per cent) of the 25 glioblastoma multiforme tumours showed telomerase activity. The absence of telomerase activity in meningiomas and the high frequency of telomere associations support the hypothesis that these tumours are benign, transformed but pre-crisis. The relatively low frequency of telomerase activity in the malignant glioblastoma multiforme suggests that most of these tumours may have other mechanisms of telomere maintenance and that the potentially therapeutic telomerase inhibitors will not be of great value in the future management of the majority of patients suffering from these tumours.

Brain Neoplasms↗
PubMed1999

Closing the gap.

Explore the source record for details and available documents.

Decision Trees↗
PubMed1998

Novel technetium-99m-labeled platelet GPIIb/IIIa receptor antagonists as potential imaging agents for venous and arterial thrombosis.

OBJECTIVES: Either venous or arterial thrombosis is a potentially life-threatening event and existing diagnostic modalities are inadequate to diagnose and to determine the morphology of the evolving thrombus. Thus development of a noninvasive imaging agent that can detect clot location remains a critical and unmet need in nuclear diagnostic medicine. The present study was undertaken to determine the potential of platelet GPIIb/IIIa receptors compared with direct thrombin inhibitors, in the detection of venous and arterial clots. METHODS: Initially, the validity of exploiting the degree and extent of specific uptake and retention of a potent GPIIb/IIIa receptor antagonist in venous and in arterial thrombus was confirmed in vitro in artificially created arterial- or venous-type clots, using the radiolabeled antagonist, 3H-DMP728. This was followed by comparing the in-vivo clot/blood distribution of various technetium-99m (99mTc)-labeled, DMP728-derived, GPIIb/IIIa receptor antagonists and of thrombin inhibitors, over time, in mixed arterial/venous or venous clots in arteriovenous shunt and in venous clot models in dogs. In addition, we performed noninvasive single-photon emission tomographic imaging of the venous clot in a deep vein thrombosis model in dogs. RESULTS: Our data confirmed that potency for the platelet GPIIb/IIIa receptors was maintained after radiolabeling of the parent active GPIIb/IIIa receptor antagonists. DMP728 demonstrated a relatively greater affinity for activated than for unactivated human platelets, which might be essential for attaining an optimal thrombus/blood (target/background) distribution ratio and the optimal detection of small clots (i.e. greater sensitivity). CONCLUSIONS: These data suggest a potential utility of 99mTc-GPIIb/IIIa receptor antagonists, but not of direct thrombin inhibitors, in the diagnosis of venous clots in deep vein thrombosis, pulmonary embolism and arterial thromboembolic disorders including stroke and coronary and peripheral artery thrombotic disorders.

Analysis of Variance↗
PubMed1997

A strategy for empowerment: the role of midwives in computer systems implementation.

The procurement and implementation of patient administration systems has been done on numerous occasions in the past. The Rotunda project however encompassed major bespoke clinical developments which were going to impact upon large clusters of midwives, and medical staff to a lesser extent. A broad based four level structured methodology was used to implement the project which is significantly ahead of schedule. This methodology together with its strengths and weaknesses is comprehensively discussed. The empowerment of midwives, their roles in systems analysis and design, software testing and organisational re-engineering is described. The importance of undertaking comprehensive computer training is highlighted and a compact 10 h information technology course coupled with ongoing educational and related activities which could be adopted by any organisation is documented. The seven deadly sins of project management are mapped out. An update on benefits realisation is provided. Gender issues are also discussed.

Computer Systems↗
PubMed1995

The Dandy-Walker syndrome--a 10-year experience of its management and outcome.

Hydroephalus of childhood may be associated with intracranial haemorrhage, infection, aqueductal stenosis, Arnold-Chiari malformation (spina bifida), tumours or more uncommonly with the Dandy-Walker syndrome (DWS). We present our experience with the management of this condition over a 10-year period. Twelve children with a definite diagnosis of DWS are reviewed with regard to the age at diagnosis, investigations, treatment, associated problems and overall outcome. Two patients died; there was a high incidence of mental retardation (65%) and associated problems. All but one child had ventriculo-peritoneal shunting and two had cysto-peritoneal shunts in addition to their V-P shunts. There were no familial cases; one child had a chromosomal abnormality. Although the long-term outcome is dismal in most cases, about 35% of the children have a reasonable outcome and hence the condition warrants energetic treatment.

Child↗
PubMed1994

A comparison of conventional and matched filtering techniques for rapid eye movement detection of the newborn.

This paper compares an extended conventional filter technique for automated detection and analysis of rapid eye movements (REM) in neonates, using amplitude, synchrony, velocity, and coherence threshold criteria, with a matched filtering technique using the morphology of the REM waveform. Analyses of both simulated and real data were carried out. Automated REM tabulations are compared with visual scoring by a trained observer. Both preterm and fullterm neonates were used to test these methods. Both the advantages and disadvantages of these two techniques are discussed as compared with conventional methods which use only amplitude and synchrony threshold criteria. The major advantage of the extended conventional over the conventional method, as well as the matched filtering over the extended conventional technique, is the increased REM detection rate for ten minute intervals of artifact-free sleep. More accurate methods of automated REM detection that can be applied over extended monitoring periods are still needed.

Computer Simulation↗
PubMed1990

Differences between multisite postmortem ethanol concentrations as related to agonal events.

In a study of postmortem ethanol concentrations, blood was withdrawn from the right atrium, ascending aorta, and inferior vena cava. These samples, vitreous humor, and gastric fluid were analyzed in 307 autopsies, where a minimum blood ethanol concentration of 0.05% weight/volume (w/v) was present. Premortem, agonal, and postmortem events were reviewed in an attempt to account for differences in blood ethanol concentrations between sites. The agonal aspiration of vomitus having at least 0.80% w/v ethanol appears to be associated with an increase in aortic ethanol concentrations. We conclude that valid interpretation of postmortem ethanol concentrations must take into consideration the possible entry of ethanol into the pulmonary venous circulation via the respiratory system.

Adult↗
PubMed1990

Drug and AIDS education for Australian youth. The Get Real project.

It illustrates an approach to "at risk" youth which implicates the age group in planning and application, in an area where they are involved. It is a communication and health initiative which has achieved a good measure of success in Australia with the rock'n roll music sub culture. It reaches out not only in the drugs area but also in the area of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Subarachnoid hemorrhage due to late recurrence of a previously unruptured aneurysm after complete endovascular occlusion.

We present a case of subarachnoid hemorrhage attributed to rupture of an aneurysm 18 months after endovascular occlusion. The aneurysm was diagnosed after the patient had a seizure; however, there was no evidence of subarachnoid hemorrhage. Angiography at 6 months revealed a totally occluded aneurysm. This case illustrates that the long-term results of endovascular occlusion remain uncertain.

Aneurysm, Ruptured↗