Biomedical subjects

F Simpkins

Publications and source records attributed to F Simpkins.

5 recordsLinked to original sources

PubMed2005

Proteomic analysis for the early detection and rational treatment of cancer--realistic hope?

Proteomics is an emerging field in medical science focused on the library of proteins specific to a given biosystem, the proteome, and understanding relationships therein. This field incorporates technologies that can be applied to serum and tissue in order to extract important biological information to aid clinicians and scientists in understanding the dynamic biology of their system of interest, such as a patient with cancer. These tools include laser capture microdissection, tissue lysate arrays and mass spectrometry approaches. These new technologies are more potent coupled with advanced bioinformatics analysis. They are used to characterize the content of, and changes in, the proteome induced by physiological changes, benign and pathologic. The application of these tools has assisted in the discovery of new biomarkers and may lead to new diagnostic tests and improvements in therapeutics. These tools additionally can provide a molecular characterization of cancers, which may allow for individualized molecular therapy. Understanding the basic concepts and tools used will illustrate how best to apply these technologies for patient benefit for the early detection of cancer and improved patient care.

Breast Neoplasms↗

PubMed1996

Studies of working memory using 18FDG-positron emission tomography in normal controls and subjects with epilepsy.

We have studied three groups of subjects with a working memory paradigm, using 18FDG-PET. Controls show the greatest increase on uptake in dorsolateral prefrontal cortex, basal forebrain and angular gyrus. A group of subjects with focal frontal epilepsy did not show increases compared to a control task of attention. Primary generalized epilepsy subjects show the greatest changes in angular gyrus, dorsal temporal, medial frontal and parietal regions. Factor and regression analyses extend these observations and show reliance of both patient groups on the medial and inferior temporal lobe. We propose that the normal network of working memory is disrupted by these two forms of epilepsy and different networks are accessed. Declarative memory may be used as a compensatory system, which results in decreased performance.

Adult↗

PubMed1996

Primary or working memory in frontal lobe epilepsy: An 18FDG-PET study of dysfunctional zones.

INTRODUCTION: We previously demonstrated that patients with frontal lobe epilepsy show deficits on a visual working memory paradigm and that this paradigm produces increased 18FDG uptake in the dorsolateral prefrontal cortex (DPFC), premotor cortex, angular and supramarginal gyri, basal forebrain, and ventral frontal poles of normal subjects when compared with a control task. We hypothesized that subjects with frontal lobe epilepsy would have impaired frontal activation during this task. METHODS: One resting and two activated images were obtained with 18FDG-PET in 15 subjects and 14 controls. One was a delayed (DMS) and one an immediate (IMS) match to sample paradigm. Discriminant and factor analyses were used to analyze the data, supplemented by selected t tests. RESULTS: No differences in glucose uptake were found between the DMS and IMS in the epilepsy subjects, in distinct contrast to controls. A comparison between controls and epilepsy subjects showed differences both ipsilateral and contralateral to the epileptic focus in the frontal regions involved in the task, with small changes in nonfrontal, task-related regions as well. The task itself brought out or highly exaggerated differences seen at rest. There was weak evidence that other frontal and temporal regions were attempting to compensate for the DPFC deficit. CONCLUSION: A unilateral epileptic focus is capable of suppressing function along a large task-related circuit ipsilateral and contralateral to the focus. Peripheral cortical regions compensate poorly for the area of dysfunction.

Adult↗

PubMed1996

Visual working memory in primary generalized epilepsy: an 18FDG-PET study.

It is generally believed that patients with primary generalized epilepsy have normal cognition and neuroimaging studies. We have previously shown that patients with juvenile myoclonic epilepsy (JME) have impaired visual working memory. In this study we examined relative regional changes in 18FDG uptake during a visual working memory paradigm in patients with JME. At rest, there were regional decreases in relative glucose uptake compared to controls. Unlike control subjects, increased activity in the dorsolateral prefrontal cortex was not found during the working memory task. Other regions with increased uptake in controls, such as premotor cortex and basal frontal cortex, also showed no increases, whereas medical temporal structures appeared to play a role in JME but not in control subjects' task performance. The data suggest that JME, a type of primary generalized epilepsy, may suffer from cortical disorganization that affects both the epileptogenic potential and frontal lobe cognitive functioning.

Adult↗

PubMed1995

Improved sensitivity of 18FDG-positron emission tomography scans in frontal and "frontal plus" epilepsy.

We evaluated three techniques of analyzing 18FDG-positron emission tomography-(PET) scans in 23 cases of presumed frontal lobe epilepsy (FLE): routine visual or "qualitative linear," "qualitative normalized," and quantitative normalized approaches. Patients were then classified as having pure frontal, probable frontal, frontoparietal and frontotemporal epilepsy based on prolonged surface EEG monitoring with video, magnetic resonance imaging (MRI), chronic intracranial recording (CIR), and results of surgical excision. Overall sensitivity and accuracy of the scans was 52 and 48%for qualitative linear analysis, which was equivalent to that of MRI, and 69 and 43% for qualitative normalized analysis. Quantitative normalized analysis had 96% sensitivity and 74 - 78% accuracy and also detected 9 of 11 (81%) abnormalities in nonlesional cases, improving routine sensitivity from 1 of 11 (9%). We conclude that qualitative linear (routine) analysis is inadequate for diagnosis of FLE lobe or "frontal-plus" epilepsies and does not add to the MRI scan. Because qualitative normalized images improve on routine analysis only slightly, quantitative techniques should be applied for preoperaive evaluations.

Adult↗