Biomedical subjects

K M Cecil

Publications and source records attributed to K M Cecil.

22 records · Page 2Linked to original sources

PubMed1998

Proton magnetic resonance spectroscopy for detection of axonal injury in the splenium of the corpus callosum of brain-injured patients.

OBJECT: This study was conducted to determine whether proton magnetic resonance spectroscopy (MRS) is a sensitive method for detecting diffuse axonal injury, which is a primary sequela of traumatic brain injury (TBI). Diffuse axonal injury is characterized by selective damage to white matter tracts that is caused in part by the severe inertial strain created by rotational acceleration and deceleration, which is often associated with motor vehicle accidents. This axonal injury is typically difficult to detect by using conventional imaging techniques because it is microscopic in nature. The splenium was selected because it is a site vulnerable to shearing forces that produce diffuse axonal injury. METHODS: The authors used proton MRS to evaluate the splenium, the posterior commissure of the corpus callosum, in normal control volunteers and in patients with TBI. Proton MRS provided an index of neuronal and axonal viability by measuring levels of N-acetyl aspartate (NAA). CONCLUSIONS: A majority of mildly brain injured patients, as well as those more severely injured, showed diminished NAA/creatine (Cr) levels in the splenium compared with normal control volunteers. The patients displaying lowered NAA/Cr in the splenium were also likely to exhibit lowered NAA/Cr in lobar white matter. Also, the levels of NAA/Cr in the splenium of normal volunteers were higher compared with those found in lobar white matter. Decreases in NAA/Cr levels in the splenium may be a marker for diffuse injury. A proton MRS examination may be particularly useful in evaluating mildly injured patients with unexplained neurological and cognitive deficits. It is concluded that MRS is a sensitive tool in detecting axonal injury.

Acceleration↗

PubMed1998

Proton MR spectroscopy in inflammatory and infectious brain disorders.

This article reviews the proton MR spectroscopy literature regarding brain infarction and inflammatory diseases. We examine the salient findings reported for bacterial abscesses, intracranial tuberculomas, Creutzfeldt-Jakob disease, herpes simplex encephalitis and HIV. These processes demonstrate specific metabolic profiles which may be useful in differential diagnosis. The results reported in the literature support the view that MR spectroscopy can be employed in longitudinal studies to monitor the response to therapy and therefore may lead to individual optimized treatment effectiveness.

AIDS Dementia Complex↗

PubMedDate not supplied

Structure/activity relationships affecting the ability of monoanionic 3-hydroxyprid-4-ones to mobilize iron.

Current attempts to remove iron from individuals suffering from iron overload have encountered difficulty due to the toxicity of the administered chelating agent. In a search for iron chelators of potentially reduced toxicity, nine monoanionic compounds have been examined. To determine the chemical features which govern their ability to induce the excretion of iron, the compounds were administered to female Sprague-Dawley rats. All carboxylate derivatives were tested for biliary excretion following iv injection, as well as for urinary excretion following iv or po injection. Sulfonate derivatives were tested for biliary and urinary excretion as well, but only one representative compound was tested po. The biological activity of the new pyridinones was compared to that of 1,2-dimethyl-3-hydroxypyrid-4-one, L1, which served as the standard. While none of the chelators was able to surpass L1 in both urinary and biliary iron excretion, all of the chelators at least equaled L1 in one of these two areas following iv administration. Two derivatives surpassed the standard in mobilizing iron into the bile, and all others were statistically equivalent. In terms of urinary excretion, two compounds were equivalent to L1 after iv administration, although none of the compounds equaled L1 when administered orally. The structure of (1,4-dihydro-3-hydroxy-2-methyl-4-oxo-1- pyridyl)methanecarboxylic acid was determined by X-ray diffraction, as this compound showed higher activity than previously reported by other investigators. We speculate that these chelators utilize organ-specific, monoanionic transport systems in the liver and kidneys to mobilize iron and that their toxicity may be substantially less than that of their neutral analogs.

Animals↗

PubMedDate not supplied

Discrepancy between neuroimaging findings and clinical phenotype in Alexander disease.

We present a case of infantile-onset Alexander disease (AD) with a novel glial fibrillary acidic protein mutation but without clinical evidence of neurologic deterioration. Brain MRI studies showed typical AD findings and increasing size of frontal cavitations. Serial proton MR spectroscopy demonstrated high levels of myo-inositol and lactic acid and decreasing levels of N-acetylaspartate. The degree of demyelination and the timing of the axonal degeneration may determine phenotypic severity of the disease. Conventional neuroimaging techniques cannot always predict the outcome.

Alexander Disease↗